最新刊期
卷 57 ， 期 3 ， 2025
- “在数字业务领域，专家构建了分布式无证书身份认证技术体系，为国家数字经济安全发展提供保障。”摘要：SignificanceDue to the continuous evolution and deepening of the Internet of everything, the scale of digital businesses such as the industrial Internet, energy Internet, and vehicular Internet continues to expand, as various software and hardware devices and systems become increasingly intelligent and complex. Traditional centralized identity authentication methods face increasingly prominent performance and security threats, while there remains a significant lack of technologies and platforms suitable for certificate-less distributed network identity authentication. In this context, this research focuses on the key technologies of certificate-less distributed network identity authentication to address issues such as secure and efficient key system management, hardware-accelerated authentication for massive access, and parallel optimization of smart contract execution, effectively responding to the severe challenges in network identity authentication. The research outcomes hold considerable importance and value for scientific research, technological development, and industrial promotion and application in the field of network identity authentication within certificate-less distributed environments. They not only improve the security and efficiency of digital identities but also provide robust support for the high-quality and secure development of the national digital economy, underpinning major strategic implementations in cyberspace security and governance. Future reliance on a comprehensive platform for large-scale IoT identity authentication based on domestic chips, targeting enterprises and institutions across industries, enables the promotion and application of platform products and distributed identity authentication services, directly and indirectly supporting annual transaction volumes of tens of billions in various internet businesses.ProgressThis research adopted a comprehensive technical route of authentication architecture design, efficient key management, access process acceleration, parallel execution of smart contracts, and demonstration application, and systematically studied the key technologies of certificate-less distributed network identity authentication. The study focused on three fundamental scientific challenges in certificate-less distributed network identity authentication: secure and efficient key system management, hardware-accelerated authentication for large-scale access, and parallel optimization of smart contract execution. It explored five key research directions: high-performance certificate-less network identity authentication technologies and architectures, certificate-less distributed key management, hardware-enhanced high-parallel distributed terminal access, multi-level parallelized smart contract virtual machines, and large-scale distributed IoT identity authentication applications and validation. The study aimed to achieve breakthroughs in ten critical technologies, including high-performance distributed identity marking and consensus mechanisms, certificate-less identity authentication protocol families and network architectures, smart contract-based automated certificate-less key management, attack-resistant distributed key generation, distribution, and revocation, intrinsically secure high-performance hardware layer construction, integrated hardware acceleration for secure cross-domain access of heterogeneous terminals, smart contract parallel co-processing architectures, optimized scheduling for smart contract virtual machines, lightweight certificate-less public key identification frameworks, and IoT identity management based on national cryptographic standards. In addition, the research developed five core systems and tools: a comprehensive digital identity management system, a full-lifecycle key management system, a hardware-enhanced high-performance concurrent terminal access system, a smart contract co-processor system based on domestic chips, and a large-scale distributed digital identity system evaluation and testing tool. Targeting network identity authentication scenarios in certificate-less distributed environments for industrial applications such as the energy IoT and vehicular IoT, the study aimed to establish a large-scale distributed IoT identity authentication platform that integrated national cryptographic standards and IoT identity authentication mechanisms to ensure trusted device identities, secure access, and robust security management. The project made significant progress across five key research areas. In high-performance certificate-less network identity authentication technology and architecture, a distributed certificate-less authentication framework, a lightweight attack-resistant consensus mechanism, and a cross-domain hierarchical authentication model were designed. In certificate-less distributed key management, smart contract-based key management schemes and multi-party attack-resistant key agreement protocols were developed, achieving breakthroughs in distributed key generation and anonymous secure data transmission. In hardware-enhanced high-parallel distributed terminal access, optimized acceleration schemes for IoT nodes and secure integration of heterogeneous terminals were designed, achieving authentication hash computing speeds of up to 200 Gbit/s and IoT authentication traffic handling of up to 100 Gbit/s. In multi-level parallel smart contract virtual machines, a co-processing architecture was developed, overcoming challenges in vector instruction set design and memory management, which led to the implementation of a smart contract co-processor on domestic chips. Lastly, in large-scale distributed IoT identity authentication applications and validation, a lightweight public key identification model based on national cryptographic standards was designed, achieving breakthroughs in GBA protocol integration and AI-driven certificate-less authentication, with evaluation tools developed to simulate IoT networks with at least 300 nodes.Conclusions and ProspectsThis research aims to address challenges such as the design of authentication architectures, efficient key management, acceleration of access processes, and parallel execution of contracts, ensuring functionalities such as data allocation on demand and anonymous identity verification, while guaranteeing user privacy, security, and supporting dynamic collaborative computing for massive terminals. This project provides theoretical models and technical methods for digital identity authentication that are suitable for large-scale IoT identity authentication by constructing a high-performance hardware layer and developing multi-level smart contract virtual machines. The research introduces four key innovations: a distributed certificate-less identity authentication framework, a resilient and attack-resistant distributed key management system, hardware-enhanced integrated acceleration for large-scale heterogeneous terminal authentication, and a multi-level parallel smart contract virtual machine co-processing technology optimized for domestic hardware acceleration. The research not only helps mitigate risks associated with centralized management but also supports the development of the national digital economy, serving identity authentication needs in various sectors such as industry, energy, and vehicular networks, promoting the construction of a community of shared future in cyberspace.关键词：cyberspace security;blockchain;certificate-less;key management;hardware enhancement;parallel processing;identity authentication329|215|0更新时间：2026-01-24
FOCUS ON STATE KEY RESEARCH DEVELOPMENT PROGRAM OF CHINA
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Research on Traction Speed Regulation and Braking Device of Pipeline Intelligent Plugging Robot AI导读
“在油气管道抢修领域，专家设计了管道智能封堵机器人牵引调速与制动装置，实现了快速封堵破损段并有效减速。通过流场特性分析和原理实验，确定了最优结构参数，验证了装置的调速可靠性。”摘要：ObjectiveWith increasing pipeline mileage and service time, more pipelines are being damaged due to environmental corrosion and human factors. This damage results in interruptions in transport and leakage of oil and gas, which in turn causes economic losses, environmental pollution, ecological damage, and other safety issues. To quickly address pipeline breakage during oil and gas transportation and to plug pipelines without halting transmission, pipeline intelligent plugging robots must be capable of rapidly and accurately reaching the damaged section and achieving maximum deceleration.MethodsTo this end, a DC cut-off valve-type traction speed regulation and braking device for a pipeline intelligent plugging robot is designed. Based on the in-pipe motion model of the robot and analysis of the speed regulation mechanism, a motion mechanism model incorporating the traction speed regulation and braking device is established. Its motion influencing factors are analyzed to determine key parameters affecting speed control characteristics. Using finite element numerical simulation, the speed valve’s flow field characteristics are analyzed, examining how the valve seat’s axial length, drain length, and internal diameter affect pressure drop. The influence of each parameter on flow and pressure drop is determined to optimize the design. Simulations of the crude oil pipeline plugging robot's motion mechanism are carried out under actual working conditions to identify performance-related factors. Proportional scaling test devices are fabricated for crude oil and refined oil pipeline conditions. Using a power torque system to supply liquid, throttling pressure drop experiments are conducted. Pressure values at varying valve openings are measured to verify the structural design’s reliability and effectiveness.Results and DiscussionsThe results show that the traction speed control and braking device’s performance is strongly affected by the structure and shape of the speed control valve. Six different axial elongation values for the valve seat—0.10D, 0.15D, 0.20D, 0.25D, 0.30D, and 0.35D (D is the inner diameter of the pipe)—significantly influence pressure drop. As the elongation increases, pressure loss decreases. Likewise, five drain hole lengths—0.80Z, 0.75Z, 0.70Z, 0.65Z, and 0.60Z (Z is the speed control valve axial length)—exert a significant effect on pressure drop across the device. Longer drain holes lead to lower pressure differentials. In contrast, five inner diameters of the valve seat—Φ169.7 mm, Φ179.7 mm, Φ189.7 mm, Φ199.7 mm, and Φ209.7 mm—have a relatively minor effect on pressure drop. After comprehensive analysis, the optimal structural parameters are determined: an axial elongation of 96.7 mm, an inner diameter of 169.7 mm, and a drain hole length of 92.8 mm. This combination yields a pressure loss of 0.139 MPa. As the valve opening decreases, the flow rate and velocity at the device outlet increase. Turbulence intensity also rises, peaking at an opening of 0.4, where high-speed water jets strike the pipeline's inner wall, effectively removing debris and preventing downstream clogging. This also reduces drag on the robot. Conversely, at full opening (1.0), the pressure differential is minimal, enabling the maximum deceleration effect. The study confirms that the designed device enables the robot to achieve efficient pipeline flushing, maintain effective speed regulation, and attain maximum deceleration, thereby fulfilling the plugging task.ConclusionsThis study provides a theoretical foundation for the structural design and parameter selection of intelligent pipeline plugging robots. It also offers valuable data and design guidance for fluid-driven pipeline robots equipped with bypass rotary valves.关键词：pipeline intelligent plugging robot;traction speed regulation and braking device;speed regulation characteristics;speed control valves352|263|0更新时间：2026-01-24 - “最新研究提出了一种基于MIC-NNG-LSTM的动态预测方法，有效预测高盐有机废液焚烧过程中SCR脱硝塔入口NOx浓度，为降低NOx排放量提供新思路。”摘要：ObjectiveThis study proposes a dynamic prediction method based on MIC‒NNG‒LSTM that addresses the typical delay, nonlinearity, and dynamic characteristics present in the incineration and flue gas treatment of high-concentration saline organic waste liquids. The method predicts the NOx concentration at the inlet of the selective catalytic reduction (SCR) denitration tower and solves the problem of the denitration system’s inability to adjust the ammonia injection amount in a timely manner when operating conditions change.MethodsFirstly, given the complex operation of the waste liquids incineration process, which involved strong coupling and high correlation among operating parameters, the prediction method examined in this study was based on the traditional Long Short‒Term Memory (LSTM) neural network as the foundational model. This model captured the temporal dependency in the input data and memorized and utilized information over extended periods, ensuring the dynamic temporal relationship between auxiliary variables and target variables throughout the modeling process. Secondly, variables that affected the NOx concentration at the inlet of the Selective Catalytic Reduction (SCR) system, such as furnace temperature, air supply, and natural gas flow rate, exhibited nonlinearity and time lag. The Maximal Information Coefficient (MIC), being relatively insensitive to time lags, automatically identified the optimal delay time between variables in time series. Accordingly, this study adopted the MIC method to determine the delay time of relevant auxiliary variables, comprehensively capturing the dynamic relationships among variables. The variables affecting the NOx concentration at the SCR inlet belonged to high-dimensional multi-feature variable data that contained a substantial amount of redundant information. This study applied MIC to reflect the importance of each input variable relative to the target variable, improved the Non-negative Garrote (NNG) algorithm capable of shrinking variable coefficients, and designed the MIC‒NNG algorithm to reduce the input node count of the LSTM network, eliminating redundant variables and achieving adaptive selection of auxiliary variables. Finally, the set of auxiliary variables, including delay time, was used as the input variable set for the LSTM network to establish a dynamic prediction model for the NOx concentration at the SCR inlet. Experimental comparisons were conducted with three other methods for predicting NOx concentration at the SCR inlet: LSTM, MIC‒LSTM, and NNG‒LSTM.Results and DiscussionsOnce the experimental results were analyzed and compared, the basic LSTM prediction model, which did not consider the time lag between input variables and the impact of redundant variables, exhibited significant fluctuations in its prediction fitting curve. When the NOx concentration underwent drastic fluctuations, the prediction results displayed lags, indicating lower prediction accuracy. The MIC‒LSTM model, which applied the MIC algorithm to screen out nine relevant variables and estimate their delay times, achieved a better fit to the actual NOx concentration values compared to the LSTM model, with reduced prediction lags. This confirmed that considering the delay time of auxiliary variables captured the fluctuation characteristics of NOx concentration more effectively, and selecting highly correlated auxiliary variables contributed to improving prediction accuracy. The NNG‒LSTM model, which incorporated the NNG algorithm, reduced the number of auxiliary variables participating in the prediction from 19 to 13, though this was still four more variables than those selected by MIC. This indicated that neglecting the importance of auxiliary variables relative to the target variable increased the number of weakly correlated variables included in the prediction. Although the NNG‒LSTM model demonstrated better prediction fitting ability than the MIC‒LSTM model, its failure to consider the time delay of auxiliary variables on SCR inlet NOx concentration resulted in prediction lags, demonstrating that considering the time delay of auxiliary variables affected prediction accuracy. The proposed MIC‒NNG‒LSTM model, which integrated the improved NNG algorithm, reduced the number of auxiliary variables participating in the prediction to 7, with more accurately selected relevant variables compared to the NNG‒LSTM model. This led to a fitting curve that closely matched the actual values, with improved prediction lags. The combination of MIC’s time delay estimation and MIC‒NNG’s variable selection allowed the prediction model to achieve higher accuracy and lower complexity. The prediction error distributions revealed that the LSTM model’s errors were relatively dispersed, while the MIC‒LSTM model’s errors were more concentrated. The NNG‒LSTM model’s error distribution was narrower than those of the LSTM and MIC‒LSTM models, and the MIC‒NNG‒LSTM model’s error distribution was the most concentrated. The standard deviations of the four models were 4.007 0, 2.679 3, 1.826 8, and 0.812 5, respectively, with the MIC‒NNG‒LSTM model showing the smallest standard deviation, further confirming its superior prediction capability. The performance indicators RMSE for the LSTM, MIC‒LSTM, NNG‒LSTM, and MIC‒NNG‒LSTM models were 3.552 2, 2.492 1, 1.875 6, and 1.567 4 mg/Nm3, respectively. The MAPE values were 0.007 9%, 0.004 7%, 0.004 2%, and 0.003 4%, and the A·R2(adjusted R-squared) values were 74%, 86%, 88%, and 93%, respectively. The MIC‒NNG‒LSTM model demonstrated the best performance among the four models in all indicators, confirming that it accounted for the impact of time delay on prediction results and eliminated redundant variables, achieving optimal prediction performance. This further highlighted the accuracy and effectiveness of the MIC‒NNG‒LSTM prediction model.ConclusionsThe results indicate that considering the delay time of input variables ensures the dynamic performance of the LSTM network while accurately expressing the nonlinear relationship between SCR inlet NOx concentration and related auxiliary variables. The MIC‒NNG algorithm more accurately selects input variables than the NNG algorithm, shortening model prediction time and improving both prediction accuracy and generalization ability. The dynamic prediction model based on the MIC‒NNG algorithm and LSTM neural network comprehensively considers the delay characteristics of variables and the dynamic time-series relationships between parameters in the incineration process of organic waste liquid, which provides a new approach for reducing NOx emissions.关键词：organic waste liquid;dynamic prediction;variable selection;LSTM;MIC‒NNG algorithm205|291|0更新时间：2026-01-24
- “在风力发电功率预测领域，专家提出了基于白鲸优化算法优化变分模态分解和时序卷积网络双向门控循环单元联合预测模型，显著提高了预测精度。”摘要：ObjectiveUnder the guidance of the “dual carbon” target, wind power, as a critical component of clean energy, plays a crucial role in its efficient utilization. Short-term wind power forecasting helps improve grid stability, optimize wind farm power generation plans, and reduce operating costs, enhancing the economic benefits of wind power and supporting the goals of low-carbon development. In addition, the prediction results provide valuable reference information for wind farms, assist the dispatching department in adjusting the generation plan in advance, reduce the impact of wind power grid connection on the grid, and ensure the safe operation of the power system. Given the instability and high volatility of wind power generation, this study proposes a short-term wind power prediction method based on BWO‒VMD and TCN‒BiGRU to improve the accuracy of wind power prediction and better support the energy transition under the “dual carbon” strategy.MethodsA short-term wind power generation prediction model based on the beluga whale optimization (BWO) algorithm, variational mode de-composition (VMD), temporal convolutional network (TCN), and bidirectional gated recurrent unit (BiGRU) was carefully proposed to improve the prediction accuracy of wind power generation, particularly considering its inherent instability and high volatility. Firstly, considering the comprehensive and complex impact of various meteorological factors on wind power generation, the random forest (RF) method was employed. This involves a comprehensive process of carefully determining the importance of various meteorological factor characteristics, systematically and accurately ranking them, and then extracting the truly optimal features that have a significant impact on subsequent predictions. Secondly, VMD is effectively utilized to decompose raw power data, which is originally in a non-stationary sequence, into relatively stationary sub-sequences. However, due to its complexity, it is difficult to manually determine the two parameters. Therefore, the BWO algorithm began optimizing these parameters of VMD. On this basis, a comprehensive index combining sample entropy and VMD decomposition to reconstruct the errors of each order component is used as a fitness function. Through this method, a thorough search was conducted to identify the optima parameter combination. Then, the optimized VMD (OVMD) is utilized to decompose non-stationary power signals. Then, the decomposed sta-tionary subsequence is combined with carefully extracted optimal features and input into the TCN‒BiGRU combination model for prediction. This combination model aims to use the advantages of TCN and BiGRU to process data and make more accurate predictions. Finally, the pre-dicted values of each subsequence are sequentially stacked to obtain the result, which is expected to provide reliable predictions for wind power generation.Results and DiscussionsThe RF algorithm is strategically employed to screen meteorological features and systematically rank their importance, enabling the accurate selection of features that significantly impact wind power forecasting. The experimental results indicate that wind speeds at vertical heights of 10, 30, and 50 m from the ground play an important role in influencing the accuracy of wind prediction. VMD is adopted to address the non-stationarity of wind power generation; however, manually determining its two parameters has proven to be challenging. Therefore, the BWO is proposed to optimize these parameters, with sample entropy and error reconstruction serving as key fitness function indicators. Compared to other optimization algorithms such as genetic algorithm (GA) and whale optimization algorithm (WOA), the BWO algorithm demonstrates significant per-formance, with faster running speed, stronger stability, and greater robustness. Then, the optimized VMD is utilized to decompose the non-stationary power signal, resulting in higher-quality subsequences and ultimately improving prediction accuracy. The dataset is carefully divided into a training set, a validation set, and a testing set to verify the accuracy of the model. This study selects a single model to compare the BiGRU network model and the OVMD‒TCN‒BiGRU combination model proposed in this study with other combination models for experimental a-nalysis. Through the graph, error evaluation indicators, and time indicators, the experimental results show that although the time of the proposed model is not optimal, its error evaluation indicator value is the smallest, highlighting its advantages. In addition, experiments are conducted not only on the main dataset but also extended to January and August data, which represent seasonal differences, for generalization to verify the re-liability and broad applicability of the model. The verification results indicate that the constructed model effectively handles various datasets and complex time series features, with strong robustness and generality, and can run stably and efficiently in various practical scenarios.ConclusionsThe decomposition of raw wind power data is primarily examined using the OVMD algorithm in this study. The meteorological factors selected by combining the decomposed sub-components with RF features are input into the TCN‒BiGRU model for prediction. Their respective advantages are integrated to enhance the accuracy and stability of the prediction. The experimental results indicated that applying this series of methods improves the prediction accuracy. Its capacity to manage complex time series data is demonstrated, and the advancement and innovation of algorithms and models are supported. New directions for technological progress and practical application in the field of wind power prediction are established.关键词：short-term wind power prediction;variational mode decomposition;random forest;temporal convolutional network;bidirectional gate recurrent unit;beluga whale optimization205|670|0更新时间：2026-01-24
INTELLIGENCE INTERDISCIPLINARY SCIENCE AND ENGINEERING
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Frictional Characteristics and Mechanical Model of PTFE Against Stainless Steel Under Low Loads AI导读
“在建筑隔震领域，专家通过实验和模型验证，揭示了PTFE-不锈钢摩擦副在低载荷下的摩擦特性，为滑移隔震支座动力响应分析提供新方法。”摘要：ObjectivePolytetrafluoroethylene (PTFE) is a highly effective solid lubricating material that has been widely applied in engineering, particularly in sliding isolation bearings. Its friction pair with stainless steel effectively controls the upward transmission of seismic energy and reduces the seismic response of the superstructure through frictional energy dissipation. However, existing research and experiments have primarily concentrated on the friction characteristics under heavy load conditions, with limited understanding of the friction behavior under low load conditions. With growing awareness of preventive protection, seismic isolation technology has been increasingly employed to safeguard various free-standing objects, including cultural relics and precision instruments, which are typically small in volume and light in weight. Given the close relationship between friction characteristics and contact surface pressure, it is of practical significance to investigate the friction characteristics of PTFE and stainless steel under low load conditions. This research contributes to enhancing the accuracy of isolation effect predictions and optimizing the design of seismic isolators.MethodsThe specimens of PTFE and 304 stainless steel were prepared to ensure a smooth surface and accurate size, and a test device was designed and constructed. When measuring the static friction coefficient, the relative moving speed of the specimen was set at 1.5 mm/s. A series of vertical loads were applied to the specimen, and the corresponding static friction force was recorded. The relationship between the static friction coefficient and the pressure was then obtained. A simple harmonic wave was employed as the displacement excitation, with an amplitude of 6 cm and a frequency of 0.4 Hz, to measure the dynamic friction coefficient. The relationships between friction and displacement were recorded under different vertical load conditions. The variation of the dynamic friction coefficient with velocity and pressure was analyzed. Based on the test results, a mechanical model describing the friction and velocity of PTFE and 304 stainless steel friction pairs was established. The established friction model was compared to the classical Coulomb friction model. The accuracy and differences between the two models in predicting friction behavior were evaluated by comparing the test results with the numerical analysis results.Results and DiscussionsThe static and dynamic friction coefficients are correlated with the vertical load. When the pressure is between 0 and 0.5 MPa, the static friction coefficient exhibits a pronounced decline with increasing pressure. When the pressure is between 0.5 and 1.2 MPa, the rate of decline of the static friction coefficient slows down and stabilizes at 0.045. Regarding the dynamic friction coefficient, when the pressure is between 0 and 2 MPa, there is a trend of initial decrease followed by a subsequent increase. However, the growth rate continues to slow down. In addition, under the same pressure, the dynamic friction coefficient increases with increasing velocity and tends to stabilize after the velocity reaches a certain threshold. The upper limit values under different pressures are close to 0.202. In the multiple vibration response tests, the coincidence degree of the acceleration time-history curves is better than that of the relative displacement. Regarding the acceleration response, the time-history curves exhibit consistent trends and minimal differences in the extreme values, and the coincidence degree between the curves is exceptionally high. For the displacement response, the repeatability of test results is relatively poor, with differences in the displacement values of each curve at a specific time. However, the overall shape or trend of the curves remains relatively consistent, with local segments exhibiting considerable similarity. As the number of tests increases, the coincidence degree of the displacement response curve also increases. The theoretical analysis results based on the novel model are in good agreement with the experimental results. When the Coulomb model is used, if the friction coefficient is relatively low, the isolation efficiency and displacement response of friction slip will be overestimated. In contrast, if the coefficient is higher, these results will be underestimated.ConclusionsThe static and dynamic friction coefficients of the PTFE‒stainless steel friction pair are found to be significantly influenced by pressure under low-load conditions. Based on the test results concerning the relationship between friction coefficient and sliding velocity, the proposed exponential function model proves to be more suitable for simulating the friction behavior under low loads and for accurately evaluating the isolation effect of sliding isolation bearings. This holds substantial importance for the development and enhancement of sliding isolation bearings designed for free-standing objects.关键词：polytetrafluoroethylene (PTFE);stainless steel;sliding isolation;mechanical model;low loads;friction coefficient549|1018|0更新时间：2026-01-24 - “在减震结构地震响应分析领域，研究者基于等效线性方法，提出了全时程迭代分析方法，有效提高了计算精度和效率。”摘要：ObjectiveTwo typical approaches for assessing the seismic response of a structure equipped with viscous dampers are direct integration methods and equivalent linear methods. Although direct integration methods provide precise results, their extensive computational cost and susceptibility to numerical instability stemming from the integration step hinder their practical use in most engineering applications. The equivalent linearization method provides a more tractable alternative by linearizing the system and incorporating stiffness and damping proportional to the response level. However, the equivalent linearization method is based on a single-degree-of-freedom structure, and the seismic response of the structure is assumed to be a sine function. For this reason, practical engineering applications of the equivalent linear method can also introduce errors. Therefore, proposing a simple yet highly precise analysis method to calculate the seismic response of a structure equipped with viscous dampers is of great significance.MethodThis study introduces an alternative method for seismic response analysis of structures incorporating viscous dampers. Based on the equivalent linear method, the Maxwell model is used as the assumed restoring force model to account for dampers. The analysis is based on an inter-history iteration approach to simulate the response over time. In this approach, an extra equivalent linear damper replaces all dampers on each floor, and its supplementary equivalent damping coefficient is computed and updated based on the velocity response of the structure during an earthquake. Then, the velocity response of the structure is recalculated using the updated additional equivalent damping coefficient. This iterative process continues until the additional equivalent damping coefficient meets the specified criteria. The increasing adoption of finite element analysis (FEA) platforms in civil engineering enables high-precision simulation of structural dynamic behaviors through advanced numerical modeling techniques. Among the various finite element software options, ABAQUS stands out for providing several user-subroutine interfaces. These interfaces empower users to expand the functionality of the main program by writing specific function codes designed to their requirements. It becomes practical and meaningful to develop a seismic response analysis method by integrating the concept and approach of inter-history iteration and using the capabilities of ABAQUS software. This method aims to avoid complicated calculations and achieve rapid convergence, which is of great significance to the seismic design of structures equipped with viscous dampers in practical engineering.Result and DiscussionThis study introduces the Maxwell viscous damper model at the beginning. After the brief introduction, the inter-history iteration method, grounded in the equivalent linear method, is presented. This method is used for the seismic response analysis of structures equipped with viscous dampers. ABAQUS is utilized to model and analyze a seven-story frame structure. Simultaneously, the seven-story frame structure is also modeled in MATLAB, which calculates the structural response using the direct integration method. The outcomes obtained through the direct integration method in MATLAB are used as the standard of comparison to the modeling and analysis in ABAQUS. The error of the first five modes is small, with the error of the first and second modes being less than 0.1%, demonstrating that the two modeling approaches are very close. The comparison and error of the first five modes in the two software verify the correctness of the model in ABAQUS. Python is further utilized to perform the secondary development of ABAQUS to realize the automatic iteration of the inter-history iteration method, thus obtaining a method that efficiently calculates the additional equivalent damping coefficient. Finally, a comparative analysis is conducted between the results obtained from the automated inter-history iteration method developed in ABAQUS and those from the direct integration method. The results demonstrated that, in the case of a seven-story frame structure, the inter-history iteration method exhibits strong convergence. In addition, it aligns well with the top displacement response curve calculated using the direct integration method. The error in the results meets engineering accuracy requirements, confirming that the automatic inter-history iteration calculation method provides high calculation accuracy and reliability while enhancing analysis efficiency. The error rate between the two calculation methods remains within 5%, indicating high accuracy. Simultaneously, compared to the direct integration method, the inter-history iterative method produces a smaller calculation result. This discrepancy arises because, in the calculation formula of the additional equivalent damping coefficient, the hysteresis curve corresponding to a larger response amplitude is fuller, while the curve for a smaller response amplitude is flatter. Therefore, the calculated additional equivalent damping coefficient is larger, leading to a smaller result in the inter-history iteration method. The automatic inter-history iteration calculation method, developed through the secondary development of ABAQUS, reduces manual data processing complexity and minimizes operational errors, significantly simplifying the calculation process of the inter-history iterative method. Based on the analysis above, the inter-history iterative method demonstrates the potential for broader application in engineering practice.ConclusionThe inter-history iterative method presented in this study provides several advantages: 1) Utilization of ABAQUS. The seismic response analysis of damped structures is performed using ABAQUS, eliminating the need for a complex numerical integration method. 2) Efficiency of the iterative process. Unlike the extensive computational steps required by the numerical integration method, the inter-history iterative method achieves strong convergence with only a few iterations. 3) Nonlinear problem avoidance. The model employs an equivalent linear damper, allowing for the avoidance of nonlinear challenges.关键词：seismic response;linearization;damping;ABAQUS;secondary development686|878|0更新时间：2026-01-24
SEISMIC ISOLATION AND ENERGY DISSIPATION FOR ENGINEERING STRUCTURES
- “在建筑领域，可再生能源的间歇性问题得到有效解决，氢能利用系统成为低碳建筑的新途径。专家综述了氢能应用于建筑的背景、形式和问题，为氢能在中国建筑领域的推广提供参考。”摘要：The application of renewable energy in the building sector can greatly reduce carbon emissions. However, due to the intermittent nature of renewable energy supply, it cannot meet the energy demands of buildings at all times. In recent years, extensive research has been conducted on the application of hydrogen energy in buildings, both domestically and internationally. Firstly, the various stages of hydrogen energy—from production to application in buildings—were reviewed. Current mainstream methods of hydrogen production, storage, transportation, and utilization in buildings, as well as future development trends, were summarized. The results show that hydrogen production via electrolysis of water using renewable energy is still in its early stages and accounts for only a small share of total hydrogen production. However, with further reductions in the cost of wind and solar power generation, and improvements in long-distance hydrogen storage and transportation, this method may become a primary means of hydrogen production in the future. Proton exchange membrane electrolyzers show good potential for absorbing fluctuating wind and photovoltaic power. Liquid hydrogen transport by vehicles and ships, pure hydrogen pipelines, and natural gas pipelines blended with hydrogen are likely to be the main forms of hydrogen transport moving forward. Currently, hydrogen is used in buildings in several ways: blending with natural gas, using pure hydrogen, converting hydrogen to methane, and applying hydrogen fuel cell cogeneration systems. Secondly, the specific forms of building hydrogen utilization systems were categorized, including combinations of photovoltaic hydrogen storage with solar thermal systems, ground source heat pumps, hydrogen fuel vehicles, batteries, and fossil fuel systems. The structure and operational strategies of these systems were outlined. Practical cases of hydrogen application in buildings—spanning residential buildings, office buildings, building clusters, and communities—were collected and described, along with typical examples highlighting the modes and key parameters of hydrogen utilization. The cost conditions related to photovoltaic hydrogen production, hydrogen storage and transport, and hydrogen fuel cells were also detailed. The results indicate that although photovoltaic hydrogen production is still more expensive than hydrogen production from coke oven gas, it shows competitiveness compared to other methods such as natural gas reforming, methanol-based production, and ammonia decomposition. From a carbon emission perspective, photovoltaic hydrogen production holds significant advantages over coke oven gas methods in the long term. At present, most hydrogen-related equipment in China relies on imports. High costs, particularly for hydrogen fuel cells, remain a key obstacle to the broader promotion of hydrogen energy. Finally, the application of hydrogen energy in buildings in China was discussed, and future development directions were summarized, including how to match building load characteristics in various scenarios with different energy storage systems; evaluating the comprehensive performance of hydrogen energy systems in buildings; and achieving breakthroughs in key technologies such as renewable hydrogen production, fuel cells, and combined heat and power generation to reduce the cost of hydrogen utilization. These research findings can serve as a reference for promoting and applying hydrogen energy in Chinese buildings.关键词：carbon neutrality;low-carbon building;renewable energy resources;hydrogen storage;green hydrogen661|796|0更新时间：2026-01-24
- 摘要：ObjectiveIn the process of architectural renovation or expansion, structural design is a crucial aspect of building design. After the initial completion of the scheme design, architects often need to consider the compatibility between the architecture and its structure. Therefore, early intervention and immediate response in the structural scheme design are urgently needed. In this paper, addressing the preliminary design phase of architecture and focusing on situations where parts of the structure have already been determined, we propose a framework for the overall layout of the structural plan based on a Generative Adversarial Network (GAN), termed PF‒structGAN. This framework facilitates the design of the structural framework under the dual constraints of both architectural forms and predetermined structural elements. The core of this method involves constructing a model for the overall layout of the structural plan, which includes three main stages: constructing datasets, training and evaluating the model, and applying the model.MethodsIn the dataset construction stage, due to the limited number of data samples, and to reduce model training parameters, refine sample features, and improve training outcomes, this paper proposes three information representation methods for architecture, beams, and columns. It utilizes RGB color channels to store information separately: architectural space information is stored in the blue channel (B), beam information in the green channel (G), and column information in the red channel (R), thereby avoiding feature overlap in overlapping regions. The architectural information representation method is used to express architectural features strongly correlated with structural features. The beam information representation method is designed to express beam cross-sectional features in planar graphics. The column information representation method is designed to express column cross-sectional features in planar graphics. These three methods establish correlations between architectural and structural features. To integrate architectural and structural features, the feature maps are superimposed. The architectural feature map, partial beam feature map, and partial column feature map are superimposed to obtain the architectural and partial structural feature map. The beam and column feature maps are superimposed to obtain the structural feature map. The architectural and partial structural feature map, along with the structural feature map, constitute a pair of feature superposition maps. To address the problem that column features occupy too few pixels in the image, and to help the model learn these features more effectively, the paired feature superposition maps are cropped into four parts to increase the column feature ratio. Further augmentation of the original dataset is achieved by rotating it at 0°, 90°, 180°, and 270°, resulting in an expanded dataset. In the model training phase, the architectural and partial structural feature maps are used as constraint conditions, and the real structural feature maps are used as labels. The generator produces structural feature maps under the given constraints. The discriminator determines whether the generated image is real or synthetic. Through adversarial training, the generator and discriminator iteratively improve until reaching a Nash equilibrium. In the model evaluation phase, to assess the model’s design capability more reasonably, in addition to using the intersection over union (IoU) metric, this paper proposes the original column ratio index (γy), the irrationality index (γS), and the comprehensive index (γall) based on practical experience and frame structure design rules. These indicators comprehensively evaluate the model’s capability to produce an overall frame structure layout. γy evaluates the retention of frame columns generated by the model at their original input positions—the higher the ratio, the better the design compliance. γS evaluates the distribution of columns across different building components and spaces—the lower the index, the more reasonable the arrangement. γall integrates the above indicators—the higher the value, the more reasonable the structural layout. The best-performing model is determined based on these four indicators. Once the PF‒structGAN model is trained, the architectural and partial structure feature maps are input into the optimal model to generate a frame structure layout.Results and DiscussionsA total of 5 120 dataset pairs were created for training the generative model—4 320 for training and 800 for testing. The training set was input into the pix2pixHD framework, and training was stopped once adversarial training reached a Nash equilibrium. Model performance was evaluated using the four indicators. The IoU curve showed a general upward trend as training epochs increased. After the first epoch, γy remained at 1. γS generally trended downward. γall peaked at epoch 26; therefore, the model from the 26th epoch was selected as the best layout model. To verify the model’s structural design capability, an instance analysis was conducted using a teaching building project. The IoU between the model’s design and the engineer’s design was 0.56, indicating high similarity. γy was 1, showing full retention of original column positions. γS was 1.78, indicating a reasonable arrangement of columns. γall reached 0.88, suggesting that the generated structural layout was sound. The model’s generated frame columns met functional requirements, were well-placed, and had appropriate size and density. The layout of columns and beams closely resembled the engineer’s design.ConclusionsThis method enables intelligent and rapid generation of structural designs that comply with regulatory standards and follow conventional design practices. It offers reference solutions for architects during the structural design process.关键词：frame structure;generate adversarial network;intelligent generative design454|481|0更新时间：2026-01-24
GREEN BUILDING AND SMART CONSTRUCTION
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Macroscopic Dynamic Characteristics and Microscopic Simulation of Round Gravel Under Cyclic Loading AI导读
“最新研究揭示地铁循环荷载下地基圆砾动力特性演化规律，为地铁安全运营提供参考。”摘要：A series of saturated undrained dynamic triaxial tests are conducted using the DYNTTS large-scale triaxial cyclic test system, and a discrete element (DEM) undrained dynamic triaxial model is established based on indoor experiments to explore the evolution of macroscopic dynamic properties and the internal microstructural dynamic response of round gravel under subway cyclic loading. The macroscopic dynamic characteristics of the round gravel and the internal microscopic parameter response law under different relative densities, confining pressures, and dynamic stress amplitudes are analyzed. The results show that when the confining pressure is small (σ3=100 kPa) and the relative density is low (Dr=0.3), the accumulated plastic strain of the round gravel is too large (greater than 0.61%), posing a severe safety hazard for train operation. When the confining pressure is higher (σ3=200, 300 kPa), the cumulative plastic strain is smaller (less than 0.14%), indicating relatively safe train operation. The greater the relative density and confining pressure, the lower the cumulative plastic strain of the specimen, the higher the resilient modulus, and the lower the energy consumption inside the specimen. Therefore, extrusion measures such as high-pressure grouting are considered to improve the relative compactness of the soil to reduce the settlement of the subway foundation. During the cyclic loading process, both the coordination number and anisotropy change periodically. The direction of change in coordination number is opposite to that of cyclic loading, while the direction of change in anisotropy aligns with cyclic loading. With the increase in relative density and confining pressure, the coordination number becomes larger and the anisotropy becomes weaker. With the increase in dynamic stress amplitude, the coordination number decreases and the anisotropy increases. The strong contact is mainly controlled by the axial stresses, which play a significant role in bearing capacity. The research results provide a reference for the design and safe operation of subway lines on round gravel foundations.关键词：cyclic loading;round gravel;dynamic characteristics;discrete element225|284|0更新时间：2026-01-24 - “在土质边坡稳定性监测领域，专家利用有源波导系统和声发射技术，研究土体剪切条件下AE信号特征演化规律，为土质边坡滑动预测预警提供理论依据。”摘要：ObjectiveMonitoring internal shear processes and assessing potential risk perception in landslides is crucial for maintaining the stability of earthy slopes. This research uses an active waveguide system and acoustic emission (AE) technology to examine the evolution of AE signal characteristics under different shear conditions. The primary objectives are to 1) characterize the behavior of AE signals, including ring count, energy, and b‒value, during the soil shear process, 2) analyze the influence of water content and loading rate on AE signal evolution, as these factors significantly affect soil stability, 3) establish a theoretical framework for selecting characteristic indicators that enhance the predictive capabilities of AE technology in monitoring soil slope stability, 4) support the development of more effective monitoring and early warning systems for soil slope sliding, improving the safety and management of infrastructure and human settlements in landslide-prone areas.MethodsThrough a systematic experimental approach, the study aimed to uncover the multifactorial dynamics of AE signals during soil shear, providing valuable insights for the application of AE technology in geotechnical engineering and slope stability assessments. The research methodology was designed to systematically investigate the AE characteristics of soil under shear conditions using an active waveguide system. The approach encompassed several key stages, beginning with the selection and preparation of the soil material. Chengdu clay, representative of high-water-content soils, was chosen for its prevalent geotechnical properties, including high water content and a complex pore structure. The clay was meticulously compacted within a specially designed shear box, ensuring a controlled environment for the experiments. An active waveguide rod was integrated into the setup to enhance the sensitivity of AE signal detection and reduce signal attenuation, a common challenge in granular media. The waveguide rod was positioned within a granular material bed, facilitating the transmission of AE signals from the shear zone to the sensors. The experimental design involved varying two critical parameters: the loading rate and the water content of the soil. Three distinct loading rates (5, 10, and 20 mm/min) and five different water content levels were selected, resulting in a comprehensive matrix of 15 test conditions. Each test was conducted under displacement control, with a predetermined shear displacement of 50 mm, beyond which the test was halted to analyze the accumulated AE data. The AE signals were captured using a DS5‒16 b‒type data acquisition system with a sampling frequency of 3 MHz and a frequency response range of 100 to 400 kHz. The system recorded the AE events, including the ring count, energy, and b‒value, which were essential parameters for analyzing the soil's shear behavior. The data collected were then subjected to statistical and cluster analyses to identify the underlying patterns and correlations between the AE parameters and the experimental conditions. This comprehensive methodology established a robust understanding of the AE signal evolution during soil shear, providing insights into the multifactorial processes involved and contributing to the development of predictive models for soil slope stability.Results and DiscussionsThe research yielded substantial insights into the behavior of AE signals during the shear testing of soil, underpinned by the analysis of three pivotal AE parameters, ring count, energy, and b‒value, each responding distinctly to variations in shear displacement and soil water content. Ring count findings: The research identified that the ring count escalates swiftly with an increase in shear displacement, with drier soils demonstrating heightened AE signal activity. This indicates that soil moisture plays a critical role in the generation of AE signals. The ring count's exponential decline with increasing water content highlights the need to consider soil consistency in AE monitoring systems. Energy observations: The study demonstrated that AE energy, representing the aggregate energy emitted during soil shearing, exhibits a gradual increase with shear displacement. Soils with reduced water content were observed to release higher energy, likely due to greater frictional resistance in less hydrated conditions. In addition, the energy output was shown to escalate with faster loading rates, indicating the importance of the rate of stress application in energy release. b‒value insights: The b‒value, a measure of AE event magnitude distribution, displayed a trend of decreasing initially with shear displacement and then leveling off. This trend implies that as soil approaches failure, there is a rise in the proportion of high-magnitude AE events. The b‒value is negatively correlated with water content, with higher water content of soil showing larger b‒values, potentially attributable to the water's lubricating effect, which can decrease frictional energy dissipation. Multifactorial Analysis: Cluster analysis clarified the multifactorial nature of AE signal characteristics influenced by shear rate and water content. The analysis showed distinct patterns between different water content groups, with lower water content correlating with lower b‒values and higher ring counts. In addition, a positive correlation was observed between energy and ring count, with both parameters increasing with water content. The impact of the loading rate on result distribution was also noted, with higher shear rates leading to more pronounced class separation.ConclusionsThis study concludes that AE signal characteristics are sensitive indicators of soil behavior during shear, demonstrating significant potential to enhance the predictive capabilities of AE technology in soil slope stability monitoring. The findings highlight the necessity of a detailed understanding of the interaction between AE parameters and soil properties, which is essential for developing accurate monitoring systems. It highlights the value of employing a multi-parameter analysis in AE-based monitoring to achieve a more comprehensive evaluation of soil slope conditions. The study advances the development of early warning systems capable of detecting the onset of slope instability with increased precision by integrating insights from ring count, energy, and b‒value analyses. These conclusions affirm the effectiveness of AE technology in geotechnical engineering, particularly for predicting and alerting against soil slope failure. The results provide a theoretical foundation for applying AE in monitoring, providing a basis for future research and practical applications in soil mechanics and slope stability management.关键词：soil shear;loading rate;moisture content;acoustic emission;characteristic parameters288|571|0更新时间：2026-01-24
- “在地震边坡安全评价领域，专家采用随机场方法和概率分析，系统研究了水平和竖向地震力对无限长边坡可靠度的影响，为地震边坡稳定性评价提供了新思路。”摘要：ObjectiveEvaluating seismic slope stability is a critical research topic in the field of geotechnical engineering. Natural soils exhibit spatial variability, with properties varying from point to point. This characteristic significantly affects slope stability, necessitating a statistical approach to its investigation. The infinite slope model evaluates the stability of long slopes running down a hillside and analyzes the mechanics of shallow landslides. This study focuses on the reliability of infinite undrained slopes and cohesive-frictional soil slopes subjected to seismic loadings using the random field method.MethodsThe random field method was adopted to investigate the effects of horizontal and vertical seismic loadings on the reliability of infinite slopes. The deterministic method was also employed to verify the results obtained by the random field method. For deterministic stability analyses of infinite undrained slopes with linearly increasing strength, the infinite slope equation was utilized to evaluate the factor of safety FS and derive the analytical formula for the critical slope angle βmin, which leads to the minimum factor of safety FS. An algorithm generating 1D non-stationary random fields of undrained strength was applied to assess the probability of slope failure pf and determine the critical slope angle βmin, which corresponds to the maximum probability of slope failure pf. For deterministic analyses of infinite cohesive-frictional soil slope stability, the infinite slope equation was employed to analyze the factor of safety FS, with the critical slope angle min obtained by calculating the factor of safety FS at intervals of 0.01. The random field method was then applied to compute the probability of slope failure pf and determine the critical slope angle βmin.Results and DiscussionsFor the infinite undrained slopes subjected to horizontal and vertical seismic loadings, the results showed that as the slope angle β increases, the factor of safety FS initially decreases and then increases, indicating the existence of a critical slope angle βmin. As the value of λ (ratio of the vertical seismic coefficient kv to the horizontal seismic coefficient kh) increases, the critical slope angle min gradually rises, and the effect of the vertical seismic loading on the critical slope angle βmin becomes more significant as the horizontal seismic coefficient kh increases. The results also indicated that as the value of λ increases, the probability of slope failure pf increases significantly, highlighting that the effect of the vertical seismic loading on the reliability of infinite undrained slopes cannot be ignored.In addition, the probability of slope failure pf decreases as the nondimensional spatial correlation length
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Calculation Method and Characteristics of Periodic Pile Arrangement Based on Artificial Spring Model AI导读
“周期性排桩减振体系研究取得进展，专家建立了人工弹簧模型，为隔振减振领域提供解决方案。”摘要：As a new type of vibration reduction system, periodic row piles achieve vibration suppression and even isolation, which is of great significance in the field of vibration isolation and damping. Periodic row piles in soil exhibit an attenuation domain, which has a significant isolation effect on vibrations within this domain. This study introduces an artificial spring model based on periodic theory and the energy principle to simulate the boundary of periodic elements and the closely connected interface between piles and soil. The boundary constraints are transformed into the elastic potential energy of the spring, overcoming the difficulty of constructing displacement shape functions that satisfy boundary conditions using traditional energy methods. When calculating the attenuation domain by scanning the wave number, only the stiffness matrix corresponding to the elastic potential energy of the periodic boundary contains the wave number term. In contrast, the mass matrix and other stiffness matrices do not include this term, eliminating the need for repeated calculations and significantly reducing the computational workload. The convergence analysis of the number of terms in the shape function and the stiffness of the artificial spring, compared to the finite element method, demonstrates that the proposed method not only provides high accuracy but also improves computational efficiency. When comparing different forms of hexagonal row piles and square row piles with the same filling rate, the attenuation domain width of hexagonal row piles is larger than that of square row piles. When comparing different pile types, such as pipe piles and solid piles, with the same filling rate, the attenuation domain width of pipe piles is also larger than that of solid piles. In addition, analyzing the influence of filled soil on the attenuation domain indicates that the width of the attenuation domain increases with the density of the filled soil, and first increases and then decreases with the increase of the elastic modulus of the filled soil. The maximum width of the attenuation domain is obtained when E=16 MPa.关键词：geotechnical engineering;vibration reduction;periodic pile arrangement;attenuation domain;energy method;artificial spring224|590|0更新时间：2026-01-24 - “在混凝土损伤分析领域，张-侯损伤计算模型揭示了不同强度混凝土的损伤演化规律，为混凝土裂缝模拟提供理论依据。”摘要：The study of concrete crack propagation is always challenging. A Zhang‒Hou damage calculation model is developed based on the theoretical framework of the concrete damaged plasticity (CDP) model and incorporates Sidoroff's damage theory to analyze the inherent patterns between crack coalescence and damage evolution in concrete of different strengths. This model quantitatively describes the uniaxial compressive and tensile damage behavior of concrete, enabling an in-depth investigation of crack propagation and damage evolution in concrete. The study finds that the damage evolution patterns under uniaxial compression and tension are generally consistent across concretes of different strengths. A critical damage crossover point is identified, where the damage values for compression and tension are 0.57 and 0.62, respectively. This crossover point marks a transition from rapid to slow damage evolution. The damage evolution patterns before and after this point remain consistent across different strengths: before the crossover, higher-strength concrete exhibits lower damage, while after the crossover, the trend reverses. Based on these findings and the implications of the catastrophe criterion, the identified damage crossover point is proposed as a critical criterion for the crack coalescence of concrete, and the corresponding damage values are interpreted as a damage threshold that characterizes the crack coalescence in concrete. In addition, a validated finite element model of reinforced concrete (RC) is utilized to comprehensively analyze its damage state and crack coalescence regions under various loading displacements, confirming the validity of the proposed damage threshold. The findings provide a theoretical basis for concrete damage analysis and crack simulation within the framework of continuum mechanics.关键词：Zhang‒Hou damage calculation model;compression damage;tensile damage;crack coalescence;damage threshold422|629|0更新时间：2026-01-24
- “在桩基加固领域，专家研发了桩侧挤密注浆模型装置，揭示了注浆提升承载力的作用机理，为在役桩基桩侧注浆加固提供指导。”摘要：ObjectiveBridges play a vital role in the development of transportation infrastructure. The pile foundation is the main load-bearing structure of a bridge and plays a vital role in ensuring its structural safety. As the economy and society continue to advance, many highways experience severe traffic congestion and frequent safety accidents due to a significant increase in traffic volume and limited traffic capacity, necessitating the implementation of expansion projects. However, numerous existing bridge pile foundations fail to meet the load-bearing requirements of these expansion projects. Grouting technology, recognized for its efficiency, cost-effectiveness, and convenience, is widely applied to enhance the load-bearing capacity of pile foundations. Despite its extensive application, the mechanism by which grouting reinforces in-service pile foundations remains unclear, and quantitatively evaluating the grouting effect proves challenging. The design of grouting parameters along the pile side and the evaluation of the reinforcement effect on pile foundations remain key research difficulties. Therefore, it is of substantial scientific and engineering value to systematically and comprehensively investigate the reinforcement mechanism of grouting in existing bridge pile foundations.MethodsFocusing on the reinforcement project of friction piles on silty clay-fine sand formations, this study employed model experiments, finite element simulations, and field tests to clarify the mechanisms by which lateral densification grouting enhanced the load-bearing capacity of existing friction piles. It proposed design methods for lateral grouting parameters and conducted load-bearing capacity analysis for silty clay-fine sand formations, achieving reinforcement through grouting in pile foundations within such formations.Results and DiscussionsThe main research contents and achievements were as follows: a lateral densification grouting model device was developed, assuming the grouting reinforcement body to be cylindrical along the pile's length, using the lateral expansion of cylindrical airbags to simulate the lateral densification grouting reinforcement method. The study investigated the effects of grouting pressure and the distance between grouting holes and the pile's side on the effectiveness of grouting reinforcement. Based on the ultimate bearing capacity and lateral friction resistance of the pile foundation, a design method for grouting parameters in silty clay-fine sand composite formations was proposed. For every 0.25 MPa increase in grouting pressure, the ultimate bearing capacity of the pile foundation increased by approximately 20% to 40%. Compared to unreinforced pile foundations, when the grouting pressure reached 1.25 MPa, the maximum increase in the pile foundation's bearing capacity was 167.27%. The relative position of the grouting holes to the pile significantly affects the pile foundation's bearing capacity. For every 5 cm increase in the distance between the grouting hole and the pile's side, the decrease in bearing capacity was 12% to 25%. The distance between the grouting hole and the pile's side must be less than 15 cm to ensure the effectiveness of pile foundation grouting reinforcement. Based on the theory of physical similarity, an index-based load transfer model for pile side loads in silty clay and fine sand formations was established using simulated test data from indoor lateral densification grouting experiments. A load transfer index model for the pile-soil contact surface was developed using FORTRAN language and embedded into ABAQUS to conduct numerical calculations of lateral grouting on an engineering scale in existing pile foundations. The reliability of the model was verified by comparing the numerical simulation results with the measured values of pile bearing capacity in the field. The measured ultimate bearing capacity of the pile foundation on-site was 6 000 N, while the numerical simulation produced a value of 5 850 N, demonstrating good agreement in settlement under ultimate loads. Therefore, this load transfer model accurately predicted the effectiveness of lateral grouting reinforcement in existing pile foundations. The study also analyzed the effects of reinforcement position and length on lateral friction resistance and pile bearing capacity.ConclusionsWhen the length of the reinforced segment is 4 m, the optimal reinforcement effect is achieved when the reinforcement is positioned at a depth ranging from 40% to 90% of the pile length, resulting in a 10.7% to 13.7% increase in bearing capacity. When the reinforcement length exceeds 16 m (approximately 70% of the pile length), it significantly improves the ultimate lateral friction resistance in the lower part of the pile, leading to a noticeable reduction in settlement under the same load level.关键词：Friction pile;Compaction grouting;Load transfer model;numerical simulation;bearing capacity121|267|0更新时间：2026-01-24
- “在建筑结构领域，专家提出采用双相型不锈钢管超高性能混凝土柱代替普通碳钢管混凝土柱，通过轴心受压试验验证了其优越的耐腐蚀、承载力和延性性能，为结构安全提供新方案。”摘要：ObjectiveConventional carbon steel tube-concrete columns (CFST) often exhibit compromised structural performance in corrosive environments, resulting in reduced load-bearing capacity and ductility. This study addresses these limitations by developing ultra-high-performance concrete (UHPC) -filled duplex stainless steel tube (UFSST) columns, which significantly enhance corrosion resistance, load capacity, and deformation behavior.MethodsTwelve rectangular short-column specimens were subjected to axial compression tests to evaluate the performance of UFSST columns. Experimental parameters included three UHPC strength grades (89~164 MPa) and three duplex stainless steel tube thicknesses, with yield strengths ranging from 307 to 807 MPa. Failure modes, load-displacement (N‒Δ) curves, and steel tube strain behavior were examined to assess: 1) axial compressive capacity; 2) interaction effects between duplex stainless steel and UHPC, and 3) the evolution of confinement mechanisms. Results were benchmarked against five international design codes (BS EN 1994‒1‒1, ANSI/AISC 360‒16, ACI 318, T/CECS 952—2021, and CECS 159—2004) through a comparative analysis of the ratio of the test value to the calculated value (Ntest/Ncal).Results and DiscussionsRectangular UFSST stub columns demonstrated good deformation capabilities under axial compression loads, with failure modes categorized into two types based on the ξ coefficient index: primarily waist drumming buckling failure for ξ=2.52 and shear failure for ξ
- “最新研究揭示了混凝土“T”形叠合梁耐火极限的影响因素，并提出了精确计算方法，为叠合梁耐火性能设计提供理论依据。”摘要：ObjectiveThis study develops a new method to investigate the fire resistance limit of T-shaped precast reinforced concrete stacked beams under fire conditions to understand the unique performance differences of T-shaped precast reinforced concrete stacked beams under fire conditions and to examine the damage development process and fire resistance limit.MethodsThis study designed eight test beams with detailed arrangements of dimensions, reinforcement, and temperature measurement points. The test beams were divided into two groups based on specific conditions. The specimen numbering rules and the mechanical properties of the reinforcement are provided. Pre-fire pre-compression was conducted by applying a constant jack load of 38.47 and 57.70 kN at three equal points on the top of the laminated beams using a hydraulic jack. The fire test was performed once the cracks had fully developed. The crack width was measured using the Concordia Crack Width Gauge. The furnace heating curve from the ISO 834 standard heating curve was applied to simulate a realistic fire scenario. The vertical displacement of the specimen and the relative slip of the laminated surface were measured. A finite element model considering the effect of cracks was developed using ABAQUS finite element analysis software. The simulation was conducted using sequential thermal coupling, and temperature rise curves were plotted using the measured furnace temperature data. The complex contact between cast-in-place and precast slabs and precast beams in stacked beams under fire conditions was accurately simulated using the Coulomb-cohesion hybrid model. A calculation method for determining the fire resistance limit of stacked beams was proposed based on the experimental and simulation results. The relationship equation between the fire resistance limit and each parameter was established using SPSS regression software, and the experimental, simulated, and formula-based values were compared to verify the accuracy of the equations.Results and DiscussionsThe following observations were made by comparing the temperature, crack characteristics, and deflection-time development curves of the experimental and simulated values: 1) The error in temperature comparison between the experimental and simulated values was within 6%. After 60 min, the simulated values were slightly lower than the experimental values. 2) The simulated crack development depth was slightly smaller than the actual crack depth; however, the development trend remained consistent. During the first 60 min of ignition, the deflection growth curves were nearly identical. After 60 min, the simulated values were lower than the experimental values, with the error maintained within 10%. 3) The simulated fire resistance limits of all specimens were compared to the test values, and the errors remained within 8%.The accuracy of the formulas fitted using SPSS software was above 0.985, with the errors among the experimental, simulated, and formula-derived values remaining within 11%. The results indicated that the temperature distribution calculated by numerical simulation accurately reflects the actual temperature distribution of the cross-section. In addition, the simulated crack development curves and deflection-time development curves exhibit similar trends to those observed in the actual tests, verifying the accuracy of the finite element simulation and ensuring the reliability of the research findings. Based on these results, subsequent parametric analyses can be conducted.ConclusionsThe load-holding level is one of the critical factors influencing the fire resistance limit of stacked beams and a higher load-holding level results in a lower fire resistance limit. The influence of stacking parameters on the fire resistance limit is relatively minor but still warrants consideration. The span-height ratio also exerts a specific impact on the fire resistance limit of stacked beams, with the fire resistance limit tending to decrease as the span-height ratio increases. An increase in the thickness of the concrete protective layer leads to a linear improvement in the fire resistance limit of the stacked beams. A comparison between simulation and experimental results indicates that the fire resistance performance of stacked beams can be more accurately modeled using the Coulomb-cohesion hybrid model. The proposed method for calculating the fire resistance limit demonstrates high accuracy, with the error between the calculated value and the test value ranging from approximately 3% to 11%. This provides a reliable theoretical foundation for the subsequent design of the fire resistance performance of stacked beams, as well as an effective guideline and reference for damage assessment, reinforcement, and repair of T-shape precast assembled concrete stacked beams after fire exposure. This study holds substantial significance for enhancing the fire resistance and safety of stacked beams and provides a valuable reference for academic research and engineering applications in related fields.关键词：prefabricated concrete composite beam;fire;crack;temperature field;fire resistance limit192|351|0更新时间：2026-01-24
- “在桥梁工程领域，专家探究了斜拉桥混合塔结合段受力特点，为桥梁设计提供新思路。”摘要：This study considers the joint segment of the hybrid tower of Qiyun Bridge in Fu'an City as the research object to explore the mechanical characteristics of the hybrid tower joint segment of a cable-stayed bridge under eccentric load. It clarifies the mechanical performance and force transmission mechanism of the joint segment under eccentric load and the reasonable range of parameters affecting the force transmission efficiency using test and numerical analysis. The results indicated that the high safety coefficient, reliable working performance, and low stress level are the main characteristics of the bearing capacity of the hybrid tower joint segment with the rear bearing plate. The stress performance of the joint segment under the action of vertical eccentric load conforms to the force characteristics of eccentric compression components, and the strain is symmetrically distributed in the section. The bearing plate and the shear connector play a vital role in the load transfer, as demonstrated by the strain change of the steel plate (shell) near the bearing plate, and the shear force borne by the shear key near the bearing plate is greater than that of the stud shear key. In addition, the vertical load is effectively transmitted in the joint segment. The transfer efficiency of the load in the joint segment is greatly affected by the thickness of the bearing plate and the shear stiffness of the shear connector. The transfer efficiency increases initially and then tends to stabilize with the increase in the thickness of the bearing plate or the shear stiffness of the shear connector. When the shear key stiffness increases to more than 10 times the original design shear stiffness or the thickness of the bearing plate exceeds 16 mm, the load transfer efficiency remains basically unchanged. In addition, there is an apparent transmission length within the joint segment, which is about 3 m. Beyond this length, the bearing ratio of the steel shell and the filled concrete is basically close to the section stiffness ratio of the joint segment. The steel shell and the concrete, respectively, bear about 50% of the vertical load after the force transfer. The research results provide guidance and reference for the design of similar projects.关键词：hybrid tower of cable-stayed bridge;joint segment;force performance;load transfer mechanism;model test;FE analysis215|441|0更新时间：2026-01-24
CIVIL ENGINEERING
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Study on Hydrodynamic Characteristics of Continuous Distribution Vegetation Patches Based on LES AI导读
“在河湖水位变化影响下，连续分布植物斑块周围水动力特性研究取得进展，为河湖生态修复提供参考。”摘要：There are numerous continuous plant patches in rivers and lakes, and the distance between these patches and the riverbank changes with water level fluctuations, affecting the flow field structure. This study uses the Hydro 3D open-source code and LES technology based on the Immersed Boundary method to construct a mathematical model of circular rigid emergent vegetation patches to clarify the hydrodynamic characteristics of continuous plant patches under varying water levels. The accuracy of the mathematical model is verified using experimental data, and three-dimensional hydrodynamic characteristics are then analyzed. The results show that a “sheltering effect” exists between continuous plant patches, a “low-speed zone” appears behind the patch, and lateral outflow is generated when water flows toward both sides. Individual plants within the patch do not exhibit significant group effects. High turbulence energy occurs on both sides of the patch due to shear, and the presence of downstream patches disrupts the vortex structure behind the upstream patches. When the solid volume fraction Φ inside a patch is 0.17, the downstream flow forms a vortex structure, which facilitates nutrient enrichment downstream of the patch. The distance (S) between the plant patch and the wall significantly affects the flow field structure around the patch. As S decreases, the flow velocity near the bank decreases, weakening the erosion of the riverbank by the water flow, and the strength and integrity of the vortex structure around and within the continuous plant patches gradually decrease. When Φ decreases from 0.17 to 0.05, the sheltering effect of the upstream patch weakens, and a vortex “blank zone” with a length of approximately 1D appears behind the patch, preventing the formation of a stable vortex structure at the patch scale; only a small amount of vortex exists at the plant scale. The research results provide a reference for clarifying the hydrodynamic characteristics around plant patches during water level fluctuations in rivers and lakes.关键词：vegetation patch;large eddy simulation;hydraulic performance;turbulent kinetic energy;vortex structure143|165|0更新时间：2026-01-24 - “轴向中空壁管结构创新研究取得进展，分析了不同孔形对管道性能的影响，为中空结构壁管设计提供技术支撑。”摘要：Axial hollow-wall pipe has many advantages, such as material saving, lightweight and easy construction, and low cost. Innovating its structure enhances these advantages. Based on external pressure, internal pressure, impact resistance, and buried ground model test and simulation analysis, the basic mechanical properties of arch-hole axial hollow-wall PVC pipe are analyzed. Then, through finite element analysis, a comparative study is conducted on structural wall pipes with different hole shapes and solid-wall pipes, and the influence mechanism of structural wall hole shapes is examined. Finally, the influence of pipe wall layout on pipeline stiffness and strength performance is assessed. The results show that with increasing deformation, the ratio of the external pressure-bearing capacity of solid-wall pipe to structural wall pipe increases gradually, indicating that the stiffness of the structural wall pipe deteriorates rapidly. The mechanical properties under external pressure, internal pressure, impact resistance, and buried ground conditions all demonstrate that the hole shape effect follows the order: circular hole > arch hole > rectangular hole. The cross-sectional moment of inertia of the hollow-wall pipe with circular holes is relatively large, and its deformation resistance is the highest among hollow-wall pipes. The deviation of the hole center toward the inner wall improves the ring stiffness. Due to the specific stress form of axial hollow-wall pipes, the arc length of the hole angle in the circular hole hollow-wall pipe increases the effective wall thickness and reduces stress concentration, resulting in relatively lower stress under load. The circular hole structure should be preferred for axial hollow-wall structures, and selecting the number of holes and eccentricity of hole centers based on different dominant working conditions can further enhance structural performance. This study provides technical support for the structural design of hollow structural wall pipes, uses the advantages of structural wall pipes, and expands the variety of drainage pipes.关键词：axial hollow-wall pipe;PVC;mechanical properties;pipe wall layout;structure optimization115|160|0更新时间：2026-01-24
- “在长江流域泥沙冲淤特性研究领域，专家基于Delft3D模型，模拟采砂活动对沙市河段泥沙冲淤的影响，为长江流域河床调整研究提供新思路。”摘要：ObjectiveThe joint operation of cascade reservoirs with the Three Gorges Project as the core has changed the water and sediment conditions downstream of the dam, causing long-term and long-distance erosion and sedimentation adjustments, especially significant adjustments to the sandy riverbed near the dam section. The rapid economic development of the Yangtze River region has strengthened the demand for river sand resources in the Yangtze River Basin. Due to the dramatic sand mining activities in the downstream of the Three Gorges Dam, serious changes in the river bed level occurred, as well as beach adjustment became more complex. Since the Three Gorges Reservoir impoundment operation, the Sanday River section downstream of the Three Gorges Dam has generally shown a scouring trend, with significant changes in the pattern of beach troughs and continental shoals, and the main stream of the branch channel oscillating more, in the process of a strong adjustment of riverbed. To explore the impact of sand mining on the sediment transport process in the sandy river section, this study selected the Shashi River section as an example and constructed a two-dimensional (2D) water and sediment transport numerical model based on Delft3D.MethodsThe model adopts an orthogonal adherent curve grid, the number of grids is 156×27, the grid length in the river direction is 60~100 m, the grid length in the river width direction is 20~40 m, and the grid is interpolated by using the measured topographic data of August 2018, and the inlet and outlet boundary conditions are based on the observed flow discharge and sediment concentration data of Shashi Hydrological Station from 2019 to 2021. The median sediment size is 250 µm, the initial river bed active layer thickness is 10 m, and the sediment module uses a non-equilibrium sediment transport mode with a calculation time step of 24 s. Verification of the variations in water level and sedimentation was carried out, the maximum water level difference between calculated and measured data is 0.08 m, and the water level simulation accuracy value of RMSE is 0.92, and the simulated scouring and sedimentation pattern was similar to the pattern for the measured distribution, the maximum scour depth in the main channel is about 6 m, and the amplitude of scour and deposition is 3~5 m, the measured scouring volume of the river section is 35.13 million m3 while the simulated volume of 39.45 million m3 with the relative error of 12%. The simulated river bed level changes of typical cross-sections agree well with the measured topographic change trend except for some areas disturbed by the human activities. The simulation results indicate that the developed 2D numerical model has the capable of investigating the influence of sand mining on the river pattern changes in the Shashi River Section. Next, the generalized sand mining pits were set in the Shashi River section based on the investigation of the sand mining activities, and simulated and analyzed the changes in erosion-deposition pattern and sediment concentration distribution with and without sand mining.Results and DiscussionsThe analysis results indicate that small-scale river sand mining has a relatively tiny effect on the sediment transport process in the Shashi River section. The influence range of sediment concentration is within 1 km upstream and downstream of the sand mining pit, and the variation in the sediment concentration during the dry season is 0.004~0.006 kg/m3. During the flood season, a significant change occurs primarily in the area of sand mining pits, with the maximum variation being 0.016 kg/m3. However, the erosion and deposition characteristics of the river section remain unchanged, with the main erosion and deposition distribution being comparable under both sand mining and non-sand mining conditions. The sand mining pit has a slight effect on the sediment scouring and siltation pattern in the upstream and downstream of the pit within a range of about 1 km, and the changes in the river bed level were -0.1~0.1 m. The sediment behavior triggered by the increase of near-bottom flow velocity in the upstream of the sandpit resulted in a tiny increase in erosion. Nevertheless, the Shashi River section under sand mining conditions has witnessed a 2.25 million m3 reduction in erosion amount compared to the condition without sand mining. The amount of erosion and sedimentation in the Shashi River section varies by 6% with and without sand mining. The self-recovery capabilities of the sand excavation pits are closely related to the local incoming water and sediment discharge. Both 2019 and 2021 were normal hydrological years with sediment discharges of approximately 18.8 million tons, whereas 2020 was a year of high water and sediment discharge, resulting in a sediment discharge of 58.7 million tons. The averaged annual deposition rate of the borrow pits is 10%~25%, with a deposition depth of 0.9~1.3 meters and a recovery period of about 4~10 years. However, in abnormal hydrological years (such as high water and sediment discharge), the recovery deposition volume increased to 600 thousand m3, the maximum sedimentation depth reached 7 m, and the mean annual sedimentation rate can attain to 50%. In years of high water and sediment discharge, the recovery period of sand pits is shortened.ConclusionsThis paper explores the impact of small-scale sand mining activities on the erosion and deposition characteristics in the typically sandy river section downstream of the Three Gorge Dam, utilizing the developed two-dimensional (2D) water and sediment transport numerical model. The conclusions of this study provide more accurate and reliable foundational conditions for studying sediment issues in the downstream of the Three Gorges Dam, conducting numerical simulations, creating physical models, and offer substantial support for the scientific management of sand mining in the planning stages along the Yangtze River Basin.关键词：Shashi River section;sand mining;erosion and sedimentation;recovery capacity of sand pits;downstream of the Three Gorges Dam163|512|0更新时间：2026-01-24
HYDRAULIC ENGINEERING
- “在图像压缩感知领域，RND-Net通过零值域分解和深度学习，显著提升了图像重建质量和速度。”摘要：Image compressive sensing (ICS) reconstructs high-quality images from low-sampling observations. Applying deep learning to ICS significantly improves image reconstruction quality. However, deep learning-based ICS methods suffer from poor model interpretability and blind structural design, which degrade reconstruction performance. Therefore, a Range-Null Space Decomposition(RND)-based Deep Image Compressive Sensing Network is proposed, referred to as RND‒Net. This method sparsely senses image feature information through global convolutional sampling. Learning signal-related sampling matrices enables the sampling values to contain richer image features. Compared to common block-wise sampling methods, the global-level sampling approach remarkably reduces block artifacts. In addition, based on the mathematical representation of RND, the sampling and reconstruction processes are transformed into an end-to-end deep learning model. With the deep neural network fitting linear or nonlinear operations involved, model reasoning time is reduced, and image reconstruction ability is improved compared to traditional algorithms. This method, which effectively integrates mathematical prior knowledge into data-driven approaches, is called a collaborative driving method. It fully utilizes mathematical prior knowledge, strengthens model interpretability, simplifies model structure design, and uses the autonomous optimization capabilities of data-driven methods represented by deep learning. Compared to other deep compressive sensing methods, it more easily reaches the global optimal solution. Experiments on multiple test sets demonstrate that RND‒Net significantly improves image reconstruction quality and reduces the time required to reconstruct a single image compared to state-of-the-art algorithms. When the sampling rate is 0.1, and the test set is BSDS68, the average PSNR of RND‒Net is about 1.02 dB higher than that of AutoBCS. On Set14, the average PSNR and SSIM gains of RND‒Net over hybrid-driven GPX‒ADMM‒Net are 1.15 dB and 0.051 8, respectively. In addition, RND‒Net is about 0.104 9 s faster than GPX‒ADMM‒Net when reconstructing a single image.关键词：image compressive sensing;deep learning;image reconstruction;range-null space decomposition;driving collaboratively314|919|0更新时间：2026-01-24
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Flight Conflict Resolution Method Based on Hybrid Differential Evolution and Rat Swarm Optimizer 增强出版 AI导读
“最新研究提出混合差分进化鼠群优化算法，有效解决多航空器飞行冲突解脱问题，提高空中交通流量和飞行安全。”摘要：ObjectiveWith the steady improvement of China's economy, the civil aviation transportation industry continues to recover, and the increasing demand for travel results in a rapid increase in air traffic flow. However, given the limitation of airspace resources, the increase in the number of aircraft inevitably raises the risk of flight conflicts. Therefore, research on flight conflict resolution becomes crucial, and an efficient and reliable conflict resolution method remains essential to address this issue. Two main shortcomings exist in current research on conflict resolution methods: 1) The commonly used conflict resolution methods exhibit low solution accuracy and slow convergence speed, which limit their applicability across different conflict scenarios. 2) The resolution strategies are overly singular, with most studies focusing solely on heading adjustment without sufficient consideration of composite adjustment strategies that integrate heading and speed. Differential Evolution (DE), a population-based global stochastic search algorithm, possesses a simple structure, strong global optimization performance, robust adaptability, and good scalability, making it a feasible solution for global optimization problems such as flight conflict resolution. However, DE exhibits slow search speed, low convergence accuracy, and a tendency to fall into local optima in multi-aircraft conflict resolution problems, which restricts its practicality. Rat Swarm Optimizer (RSO), a novel heuristic algorithm that simulates rat behaviors of chasing and fighting prey, features a simple structure, few regulation parameters, and fast convergence speed and can effectively compensate for DE's limitations. Based on this, the present study combines the advantages of DE and RSO to propose a hybrid algorithm (HDERSO) and applies it to the problem of flight conflict resolution.MethodsHDERSO incorporates the search mechanism of RSO into DE and utilizes a selection probability to adaptively control the generation strategies for offspring individuals at different evolutionary stages. This approach provides directional guidance for the evolution process and avoids blind or ineffective searching. In the early evolutionary stage, the algorithm emphasizes the global exploration capability of DE to search the solution space thoroughly, discover promising regions, and reduce the risk of premature convergence. In the middle and later stages, HDERSO uses the local exploitation ability of RSO to accelerate optimization and enhance convergence accuracy. In addition, control parameters such as the scaling factor and crossover probability influence the quality of DE's offspring individuals. Typically, these parameters require appropriate adjustments during population evolution. Accordingly, HDERSO applies the control parameters to each individual and adaptively generates them by tracking the states of the population and individuals in real-time, improving optimization performance and algorithm applicability.Results and DiscussionsThe performance of HDERSO is evaluated using the IEEE CEC2017 test set comprising 29 functions with diverse features (2 unimodal functions, seven multimodal functions, 10 hybrid functions, and 10 composition functions). The mean and standard deviation of the optimal solutions obtained by HDERSO and the comparative algorithms are statistically analyzed using Wilcoxon and Friedman tests at the 5% significance level. The experimental results demonstrate that the proposed HDERSO achieves higher solution quality and faster convergence speed. Aircraft involved in flight conflict require feasible resolution trajectories based on conflict resolution methods combined with specific strategies, which lead to certain positional offsets from the planned trajectories. Larger positional offsets result in greater flight delays and increased fuel consumption. A flight conflict resolution model based on minimizing the trajectory offset is constructed, and resolution strategies involving heading adjustment, speed adjustment, and composite adjustment are designed. In addition, three typical flight scenarios with varying conflict characteristics (same-direction intersection, vertical intersection, and opposing head-to-head) are developed, and the proposed HDERSO is used in conflict resolution experiments. The results show that HDERSO resolves conflicts using all three strategies in the same-direction intersection scenario. However, in opposing head-to-head scenarios, HDERSO fails to resolve conflicts using speed adjustment alone but successfully resolves them using heading adjustment and composite adjustment. HDERSO effectively resolves conflicts among multiple aircraft by applying different resolution strategies while maintaining the minimum flight safety interval. The results show that the proposed algorithm produces significantly smaller trajectory offsets and target fitness values across various conflict scenarios compared to other algorithms. The evolution curves further confirm that HDERSO is more competitive in convergence speed and solution accuracy, achieving higher accuracy within 250 generations. In addition, the prioritization of the three conflict resolution strategies (heading adjustment, speed adjustment, and composite adjustment) is analyzed based on scenario applicability, solution quality, and operational complexity. The results indicate that in terms of scenario applicability, composite adjustment and heading adjustment outperform speed adjustment; in terms of solution quality, speed adjustment is superior, followed by composite adjustment and heading adjustment; in terms of operational complexity, the strategies are prioritized as heading adjustment, speed adjustment, and composite adjustment.ConclusionsAccordingly, the proposed HDERSO is an effective and feasible conflict resolution method that plans optimal resolution trajectories for different flight scenarios, reducing fuel consumption and minimizing flight costs. The outcomes of this study provide a valuable reference for air traffic control departments in implementing flight conflict resolution measures.关键词：flight conflict resolution;differential evolution;rat swarm optimizer;conflict resolution strategy264|463|0更新时间：2026-01-24 - “在无人机航拍图像小目标检测领域，专家提出了基于YOLOv7-tiny带ConvMixer检测头的算法，有效提升了检测精度和速度，为解决误检和漏检问题提供解决方案。”摘要：ObjectiveUAVs provide advantages such as easy control, low cost, and good performance, and efficiently perform tasks in diverse sites and complex environments. UAV aerial image target detection is widely applied in practical scenarios, including urban transportation, military reconnaissance, and smart agriculture. This study proposes a small target detection algorithm for UAV aerial images using a ConvMixer detection head based on the improved YOLOv7-tiny to address the problems of missed detection and false detection caused by significant variations in target scale, densely distributed small-sized targets and complex backgrounds in UAV aerial images.MethodsFirst, the activation function LeakyReLU is replaced with SiLU to compensate for the limited nonlinear expression of LeakyReLU and to enhance convergence speed and model generalization during training. Second, to strengthen the feature extraction capability for multi-scale targets and improve the detection of small targets, a small-target detection layer is designed, leading to a tiny-target detection head that increases the model receptive field and better addresses the scale variance problem caused by drastic target size changes. In addition, the ConvMixer layer is integrated into the prediction head; the depthwise and pointwise convolutions in ConvMixer capture the spatial and channel relationships in the feature information, improving the processing capability for small targets. Finally, the coupled detection head of YOLOv7-tiny is replaced with a more efficient decoupled head, which separates feature channels for localization and classification tasks and enhances both classification and localization accuracy. Regarding experiments, ablation experiments are designed from two directions to comprehensively verify the effectiveness of each improvement. Comparative experiments are also conducted to assess and analyze the detection performance of the improved algorithm against other algorithms.Results and DiscussionsThis study mainly addresses the following aspects: 1) The network structure of the improved algorithm is proposed, and the principles and components of each improvement are introduced. Based on the YOLOv7-tiny network, the LeakyReLU activation function in the convolution block CBL is replaced by the SiLU activation function. A small target detection layer is introduced at the neck of the network, and a prediction head is incorporated. Several ConvMixer layers are also integrated into the end of the backbone network and the detection head. Finally, the efficient decoupled head structure is adopted for target prediction. All these enhancements to the baseline form the improved YOLOv7-tiny algorithm network structure. 2) Ablation experiments are designed to verify the effectiveness of each modification. This includes, firstly, adding a single improved module to the original YOLOv7-tiny algorithm to observe its impact and, secondly, removing individual modules from the final improved YOLOv7-tiny-SFCE model to evaluate their effect. Ten sets of ablation experiments are conducted under identical conditions. Results indicate that introducing the efficient decoupled head leads to the most significant accuracy improvement, increasing mAP by 1.1%. Removing the fourth small target detection head results in the most obvious performance degradation, reducing detection accuracy by 2.4%. 3) Comparative experiments are conducted to verify the comprehensive performance of the improved algorithm. More than ten recently proposed advanced algorithms are selected for comparison in terms of AP and mAP values across ten target categories. Results show that the proposed algorithm achieves the highest mAP value of 40.9% and performs best in detecting the categories pedestrian, people, car, and motor. Among these, the pedestrian, people, and motor categories show especially strong detection performance. 4) The detection performance of the improved algorithm is verified in real-world scenarios through comparative analysis. Detection results are demonstrated in various conditions, including sparse and dense distributions and day and night scenarios. Five images featuring dense targets, minimal targets, dark scenes, occluded targets, and complex backgrounds are randomly selected from the Visdrone2021 test challenge set to evaluate detection performance in UAV aerial images. Comparative visual detection results with the baseline YOLOv7-tiny show that the proposed algorithm significantly improves the identification of multi-scale small targets and reduces both missed and false detections.ConclusionsThis study mainly addresses and improves the issues of missed and false detections caused by large-scale variations, dense small target distributions, and complex backgrounds in UAV aerial images. Key contributions include enhancing the model’s feature extraction capabilities, providing more accurate localization and classification, and improving small target detection. However, limitations remain: 1) Some missed detections still occur for small targets with minimal pixel information and insufficient features to distinguish them from the background. 2) A balance between detection accuracy and real-time performance has not yet been achieved. The model’s parameter count and computational complexity require reduction. Future research will focus on further improving the detection of very small targets and optimizing the model for lightweight applications.关键词：UAV aerial images;small target detection;SiLU;ConvMixer;efficient decoupled head809|691|0更新时间：2026-01-24
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Handwritten Words Image Character Extraction Adaptive Algorithm Based on the Multi-branch Structure AI导读
“在飞机地面维护工卡识别领域，专家提出了多分支卷积与特征融合提取结构，显著提升了识别精度和速度，为特定领域应用提供了有效解决方案。”摘要：ObjectiveThe aircraft ground maintenance job card is the essential reference for maintenance operations and records. It requires handwritten image identification and digital storage. Due to the limitations of maintenance rules or manuals in civil aviation, a mixture of Chinese and English words often forms complex sentences on the same job card, which creates difficulties in word character extraction and reduces recognition precision. This study applies a new method of multi-branch convolution, the Re-parameterized and Multi-branch Convolution Algorithm (RMCA), to enhance the recognition of complex structures and similar words, improving mean average precision (MAP) and identification efficiency. This study addresses several problems in handwritten word identification. First, the number of layers in the deep convolution network affects the results of characteristic extraction. Second, features extracted from different layers represent varying dimensions in the feature matrix. Third, Chinese words demonstrate varying levels of complexity.MethodsThe identification precision index is defined as the mean average precision of Top1 and Top5, and the identification efficiency index is expressed as memory access cost (MAC) to evaluate the proposed model. However, calculating MAC during the model training process presents challenges. Therefore, MAC is replaced with the number of processed image pieces per second. The improved RMCA algorithm utilizes the strengths of deep convolution to extract image characteristics related to boundaries and fine details. Deep convolution layers are known for learning features at different abstraction levels, while lower layers capture more localized details. In addition, the dimension of the convolutional kernel influences the receptive field and local features within a certain layer. The core of the handwritten word identification model lies in the added convolutional channels and layers, along with an adaptive identification algorithm designed for identical and similar words in handwritten images. Higher identification precision and efficiency serve as reference indices for evaluating the model. The improved RMCA algorithm applies four branches in the initial layers, which differs from the original re-parameterized structure. The kernel sizes in the four branches are set to 11 and 77, equivalent to a variable dimension kernel of 77. The following of a fully connected layer can cause the loss of boundary or specific layer features, making it challenging to meet identification requirements for words with complex or simple structures. Hence, the improved RMCA algorithm utilizes spatial features. The fully connected layer is replaced with fully convolutional layers, and the spatial features from the fourth layer are passed to the classifier. This design enables the improved model to adapt automatically to various word structure complexities. The improved model comprises four functional components. The innovation of this study lies in several aspects. First, the enhanced re-parameterized structure across multiple stages and branches achieves an effect equivalent to variable convolution. Second, the refined classifier with fully convolutional layers combines features from specific intermediate layers with the output layer, resulting in improved precision for complex and similar words. The feature extraction performance is enhanced. Compared to feature outputs from the fourth and fifth layers of traditional models, the conclusion is confirmed. The simple Chinese word characteristics in the fourth layer are more abundant than in the fifth, whereas complex handwritten Chinese words contain similarly detailed features across both layers.Results and DiscussionsThe training image datasets for the experiment consist of two groups. Group 1 includes the HWDB1.0‒1.1, comprising 3 755 classes of Chinese words, totaling 2.68 million images. The test dataset is the ICDAR‒2013, containing 224 thousand Chinese word images. Group 2 extends Group 1 by incorporating English uppercase and lowercase letters (52 classes) and digits from 0 to 9 (10 classes). The test dataset expands the ICDAR‒2013 with additional images of English letters and digits. The experimental results presented in this study demonstrate improvements in evaluation indices compared to other models, including the pre-improvement model. The experiments are divided into two categories: ablation and comparative. The results of the ablation experiment indicate that the Top1 and Top5 precision indices improved to 97.50% and 99.79%, respectively. Specifically, altering the 77 kernel in the first layer increases precision by 0.3%, while modifying the classifier results in a 0.6% gain. Group 2 achieves a Top1 recognition accuracy of 97.23%. The results of the comparative experiment, based on ten traditional models, showed that the proposed model occupies 69.1 MB of storage, slightly more than the 48.34 MB of the lightweight MobileNetV2. However, the model achieves superior precision (97.50%) and identification speed (1 410 cards per second). Compared to the original Rep‒VGG and ResNet50, the improved model increases precision by 6.90% and 8.43%, respectively. Identification speed improves by 8.8% and 17.2%, respectively.ConclusionsThese results confirm that the proposed method enhances word recognition precision and efficiency. Experiments involving similar word identification yield consistent findings. In the long term, the improved model proves applicable in the field of aircraft maintenance job cards and other specialized areas requiring handwritten word identification.关键词：offline handwritten chinese character recognition;fully convolutional network;re-parameterized structure;spatial feature fusion;re-parameterized multi-branch convolutional algorithm173|230|0更新时间：2026-01-24 - “在航空复合材料部件成型固化领域，专家建立了分布式超声波探测2维气体温度场方法，为准确测量大型空间构件成型气体温度场提供解决方案。”摘要：ObjectiveThis study applies several temperature sensors in current autoclave systems to control the forming temperature of composite components. This point-measurement method presents challenges in capturing the spatial temperature field. In addition, this contact-based temperature measurement approach directly influences the temperature distribution at the interface between the mold and the components. These limitations significantly affect the quality of component formation. Accurately capturing the gas temperature field during the forming of large-scale spatial components remains a critical challenge in the curing process of aerospace composite material parts. This study investigates a method for distributed ultrasonic detection of the two-dimensional gas temperature field.MethodsThis study first employed numerical simulation software to analyze the ultrasonic propagation characteristics in an autoclave under steady-state temperature field conditions from the perspective of thermo-acoustic coupling. The analysis was then extended to ultrasonic propagation characteristics under varying temperature fields. Based on these analyses, a distributed ultrasonic gas temperature measurement model was established using time-of-flight characteristics. In addressing issues associated with inverse problems, such as the limitations of least squares and algebraic iterative methods, where the number of discrete points cannot exceed the number of propagation paths and the temperature resolution is low, a two-dimensional temperature field reconstruction algorithm based on logarithmic-quadratic (LQ) functions and singular value decomposition (SVD) was developed for autoclave conditions. The core idea of this algorithm was to fit the distribution of the reciprocal of sound speed using a linear combination of LQ functions to establish an inversion model. SVD was then employed to address the ill-posedness in the inversion process, which enabled the model to be solved. The accuracy of the LQ‒SVD algorithm was analyzed by evaluating the maximum absolute error, mean error, and root mean square error between the reconstructed temperature field and the original temperature field, and the results were compared to those of three other common algorithms. In accounting for practical errors, white noise was added to the theoretical actual values to simulate system errors, and the noise resistance of the algorithm was tested based on this. A distributed ultrasonic temperature measurement system was finally set up in the autoclave for experimental validation. Several thermocouples were utilized to measure the actual temperature field, and the reconstruction error between the experimental system's reconstructed values and the actual values was analyzed to verify the effectiveness of the proposed method.Results and DiscussionsIn addition to the primary longitudinal wave pulses in the propagation of ultrasound within the gas space of an autoclave, multiple reflection waves and wave interferences were present, resulting in complex propagation behaviors. Due to varying temperature distributions, the propagation time of ultrasound along its path differed. This study examined the “time-of-flight characteristics” at the microsecond level, which were influenced by factors such as medium properties, temperature fields, and the propagation distance of ultrasound. The LQ‒SVD algorithm demonstrated the following reconstruction metrics for different types of temperature fields: for a single-peak symmetric temperature field, the maximum absolute error, mean error, and root mean square error were 0.812 3 K, 0.161 1 K, and 0.057 4%, respectively; for a single-peak biased temperature field, these metrics were 0.043 1 K, 0.008 7 K, and 0.002 6%; for a double-peak biased temperature field, they were 9.982 9 K, 0.828 3 K, and 0.317 5%; for a triple-peak biased temperature field, they were 16.301 7 K, 2.125 0 K, and 0.651 6%; and for a quadruple-peak biased temperature field, they were 95.163 8 K, 11.184 3 K, and 3.878 4%. Based on root mean square error, the temperature field reconstruction errors for the Multi-Quadratic (MQ), Markov radial basis function (MK), and Gaussian function-based (GS) algorithms for single-peak symmetric temperature fields were 0.058 3%, 1.249 0%, and 0.529 1%, respectively; for single-peak biased temperature fields, these errors were 0.203 0%, 0.501 7%, and 0.049 4%; for double-peak biased temperature fields, they were 0.588 7%, 1.220 8%, and 1.800 2%; for triple-peak biased temperature fields, they were 1.238 7%, 1.801 7%, and 3.696 5%; and for the quadruple-peak biased temperature fields, they were 3.884 3%, 3.964 4%, and 10.735 7%. These results indicated that regardless of the temperature field model, the LQ‒SVD algorithm consistently achieved the best reconstruction performance. In the noise resistance test of the LQ‒SVD algorithm, with a noise standard deviation of 0.5 us, the three reconstruction metrics for single-peak symmetric temperature fields were 22.409 0 K, 3.965 9 K, and 1.338 6%; for single-peak biased temperature fields, they were 21.174 7 K, 3.507 9 K, and 1.090 3%; for double-peak biased temperature fields, they were 20.757 7 K, 3.417 6 K, and 1.051 0%; for triple-peak biased temperature fields, they were 25.588 9 K, 4.663 4 K, and 1.383 5%; and for quadruple-peak biased temperature fields, they were 85.480 4 K, 11.704 6 K, and 3.9158%. With a noise standard deviation of 1 us, these metrics for single-peak symmetric temperature fields were 36.578 1 K, 5.779 2 K, and 1.956 3%; for single-peak biased temperature fields, they were 46.651 1 K, 7.260 9 K, and 2.581 6%; for double-peak biased temperature fields, they were 67.944 5 K, 8.371 8 K, and 2.647 0%; for triple-peak biased temperature fields, they were 59.341 8 K, 7.221 1 K, and 2.333 9%; and for quadruple-peak biased temperature fields, they were 90.738 4 K, 14.397 9 K, and 4.435 0%. In the on-site experimental validation within the autoclave, the average relative error between reconstructed temperatures and thermocouple measurements was 4.48%, which indicated the effective performance of the distributed ultrasound temperature measurement system in temperature field reconstruction.ConclusionsThe results demonstrate that the method established in this study for distributed ultrasound detection of two-dimensional gas temperature fields precisely describes the propagation characteristics of ultrasound under thermal/acoustic coupling effects within the autoclave. This method accurately reconstructs the temperature field distribution in the autoclave space. Its effectiveness significantly alleviates the current limitation of relying solely on a few sensor points for temperature measurement in autoclaves. It preliminarily fulfills the requirement for accurate measurement of the temperature field of forming gas in significant spatial components during the molding and curing of aerospace composite material parts, providing robust support for enhancing the quality of component formation in the future.关键词：ultrasonic gas temperature measurement;distributed;temperature field reconstruction;thermoacoustic coupling;Radial basis function155|176|0更新时间：2026-01-24
COMPUTER SCIENCE AND TECHNOLOGY
- “在激光选区熔化技术领域，专家建立了Ti6Al4V粉体3维瞬态热流场数值模型，揭示了成型件冶金缺陷的形成机理与抑制方法，为优化加工参数提供指导作用。”摘要：This study investigates the formation mechanisms and suppression strategies for common metallurgical defects—including balling, porosity, powder adhesion, and spatter—in Ti6Al4V alloys fabricated by selective laser melting (SLM). A comprehensive numerical framework linking process parameters, molten pool dynamics, and defect evolution is developed to optimize linear and volumetric energy densities. This research further proposes actionable guidelines aimed at achieving high-quality manufacturing outcomes in SLM processes. A three-dimensional transient thermal-fluid flow model for SLM-processed Ti6Al4V powder was established to elucidate molten pool dynamics under controlled processing conditions. Utilizing dimensionless numbers to quantify dynamic behaviors, the simulations were optimized to accurately capture molten pool evolution. Defect formation mechanisms, particularly for balling and porosity, were thoroughly examined through integrated numerical modeling and experimental validation, emphasizing the critical impact of linear and volumetric energy densities. The analysis revealed that thermal convection predominantly governs heat transfer within the molten pool, driven primarily by evaporation recoil pressure, surface tension, and Marangoni shear stress. A reduction in energy density adversely affects molten pool fluidity, promoting porosity formation as molten metal solidifies into spherical shapes driven by surface tension. This resultant porosity significantly deteriorates the mechanical properties of fabricated parts, underscoring the necessity for meticulous control over energy density. Optimizing key processing parameters, such as laser power, scanning speed, and scanning spacing, enables the formation of high-quality components. The proposed “process parameters‒molten pool characteristics‒forming quality” analytical framework provides robust guidance for parameter optimization. Application of this framework effectively mitigates metallurgical defects, thereby enhancing the density and mechanical performance of parts manufactured through SLM.关键词：selective laser melting;molten pool;Ti6Al4V;Processing defects;process parameters658|492|0更新时间：2026-01-24
- “在机器人打磨领域，专家提出了一种非线性自抗扰控制算法，有效提高了机构恒力控制性能，为打磨作业质量与效率提升提供了解决方案。”摘要：ObjectiveIn robotic polishing operations, an end-effector polishing mechanism is typically used to achieve constant force control. Therefore, the performance of this control directly affects the quality and efficiency of the polishing process. Among various end-effector mechanisms, the pneumatic type is widely adopted due to its lightweight structure, low cost, robustness, and ease of maintenance. This paper focuses on achieving constant force control in a pneumatic end-effector compliant mechanism.MethodsAchieving constant force control in this mechanism is challenging due to nonlinear factors within the pneumatic system (such as gas compression, proportional valve dead zones, and cylinder friction) and the effects of posture changes on output force. A novel control algorithm is proposed, integrating five components: nonlinear active disturbance rejection control, gravity compensation, dead zone compensation, LuGre friction model compensation, and data filtering.Nonlinear active disturbance rejection control: A tracking differentiator preprocesses the input signal to reduce overshoot, yielding a tracking signal and its derivative. An extended state observer estimates total system disturbance in real time. A nonlinear state error feedback law performs error correction and compensates for the observed disturbance. Gravity compensation: A gravity compensation strategy is developed based on the relationship between gravitational force on the mechanism and its output force at different polishing angles. Dead zone compensation: Minimum and maximum working voltages of the proportional valve are experimentally determined. These voltages are used to design mid-position compensation, reducing the dead zone’s impact on control performance. LuGre friction model compensation: Friction data is collected under varying cylinder speeds. LuGre model parameters are fitted, and a compensation strategy is developed to offset frictional disturbances during piston movement.Data filtering: A first-order low-pass filter is integrated into the controller to reduce high-frequency noise in the force sensor readings and enhance control accuracy.The control algorithm is implemented on an STM32F103 microcontroller operating at 50 Hz. Supporting circuits for the pneumatic actuator are designed, and a test bench is constructed to simulate robot polishing conditions. To mimic posture changes during polishing, the platform angle is manually adjusted using a screw. In addition, to simulate the position errors that may occur during the robot’s motion trajectory planning, a stepper motor with a ball screw is used to control the movement of the connection end of the pneumatic end-effector compliant polishing mechanism closer to or further away from the polishing surface. A variety of working condition simulation experiments were conducted, including:1) constant force loading experiments and sinusoidal force loading experiments with the pneumatic end-effector compliant mechanism in a vertically downward position; 2) variable-angle constant force loading experiments involving changes in the polishing posture of the pneumatic end-effector compliant mechanism; 3) external disturbance loading experiments involving vertical movement of the connecting section of the pneumatic end-effector compliant mechanism.Results and DiscussionsUnder a set force of 50 N, the designed controller exhibited an average error of 0.21 N and a standard deviation of 0.18 N. This performance is better than that of PID control, which had an average error of 0.27 N and a standard deviation of 0.21 N. In two sinusoidal force tracking experiments with periods of 8 s and 4 s, the results showed that for the 8 s period, the designed controller’s tracking performance was comparable to PID control, but with smaller tracking error at extreme points. For the 4 s period, the PID-controlled tracking curve exhibited distortion, whereas the designed controller showed some lag but remained closer to the desired values. Under a 50 N loading with polishing angles varying from 0° to 75°, the controller with gravity compensation had a maximum error of 1.44 N. In contrast, the controller without gravity compensation showed a significant decline in end-effector output force as the polishing angle increased, with a maximum error of 8.82 N. Under the same loading with disturbances present, the designed controller achieved a maximum error of 7.24 N, compared to 11.79 N with conventional disturbance rejection control and 14.77 N with PID control. These results indicate that the designed controller performs better in the presence of disturbances.ConclusionsThe experimental results demonstrate that the proposed control algorithm offers superior robustness, tracking performance, and disturbance rejection compared to traditional PID control. In addition, it effectively compensates for changes in polishing angle, thereby improving the constant force control performance of the pneumatic end-effector actuator.关键词：force control;pneumatic system;LuGre friction model compensation;gravity compensation;active disturbance rejection control543|574|0更新时间：2026-01-24
- “在实时磁共振引导的高精度脑深部刺激手术机器人领域，研究了超声电机与本体材料的MRI兼容性，为优化设计提供依据，为其他MRI环境下机电产品提供参考。”摘要：ObjectiveDeep brain stimulation (DBS) surgery, a typical treatment targeting sub-millimeter anatomical points, requires highly precise surgical assistance devices and related technologies for electrode implantation. Magnetic Resonance Imaging (MRI) technology, known for its non-invasiveness, high spatial resolution, and good soft tissue contrast, is extensively used in pre-operative diagnosis, surgical planning, and postoperative follow-up of DBS. The integration of robotic assistance systems with MRI in DBS surgeries is a growing trend. However, since most existing robots are incompatible with MRI, their use in assisting DBS surgeries necessitates moving patients between the MRI scanning room and the operating room. This process is time-consuming and laborious and introduces issues such as contamination of the surgical area, surgery interruption, and re-registration of positioning. Developing a novel MRI-compatible surgical robot system for precise electrode implantation in DBS surgeries is of significant clinical importance and promising application prospects. This research primarily focuses on the ultrasonic motors and materials used in constructing the robot body, evaluating their compatibility in an MRI environment through theoretical analysis and experimental validation. The evaluation includes assessing their interference with MRI scanning to prevent potential safety and imaging issues. The goal is to provide substantial support for developing and applying DBS surgical robot systems by investigating and verifying these critical factors. In addition, these findings are intended to serve as a reference for future research and technological enhancements.MethodsIt is essential to ensure that the selected devices remain unaffected by the MRI environment and operate normally. This can be assessed by comparing their performance in both MRI and standard environments. In addition, the operation of these devices should not significantly impact the imaging quality, particularly concerning clinical quality metrics. Therefore, evaluating the effect of these devices on MRI image quality is necessary. MRI image quality can be assessed through control experiments using a standard object (typically a copper sulfate water phantom) with and without external device interference. Generally, MRI image quality is subjectively evaluated by visually identifying noise and assessing image quality. For DBS surgery, where precision and safety are paramount, any significant artifacts or noise can indicate MRI incompatibility. Another method involves quantitatively and objectively evaluating the signal-to-noise ratio (SNR) in the MRI image's area of interest. This study employs the American College of Radiology's single-image SNR measurement method and related formula for SNR value assessment and analysis. The experimental testing system involves placing the water phantom and the fixed platform on flexible washers. Copper bolts can be employed to secure the motor to the fixed platform for alignment with the curved surface of the water phantom cushion, or the motor can be directly mounted on the cushion with tape. Primarily, cross-sectional MRI imaging of a water phantom is utilized to evaluate image quality, with sagittal imaging being auxiliary observation. The devices undergoing MRI compatibility testing included the ultrasonic motor and the materials used in the robot.Results and DiscussionsExperiments were conducted in 3.0 and 1.5 T MRI environments. At Zhejiang University's 3.0 T MRI lab, magnetic components such as controllers and drivers were placed in the control room, connected to the motor located in the scanner bore parallelly via shielded lines and waveguides. During tests, the MRI scanner remained on continuously. The MRI imaging results showed that the 30 motors inside the MRI caused visible imaging artifacts, making them unsuitable for precision DBS surgery. In contrast, the 60 motors, whether parallel or perpendicular, minimally affected MRI imaging with acceptable SNR reductions. The motor speed curve in the experiment demonstrated that closed-loop control of both motors maintained consistent performance in MRI and non-magnetic environments. Tests on selected robot materials exhibited good compatibility, although metallic contact led to artifacts, indicating that metals should avoid direct contact with the imaging area. At 1.5 T in Xingaoyi Lab., all devices, including magnetic components, were placed inside the scanner room, powered by lead-acid batteries, and connected using an RS485 bus through waveguides. The MRI imaging results indicated external noise introduction by cables and artifact interference from running motors. However, powered but not running motors and devices only slightly affected the SNR. Eliminating controller exposure further reduced the SNR impact.ConclusionsExperimental results indicate alternating motor operation and MRI imaging for robotic-assisted DBS surgery. The MRI scanner remains on during surgery but does not scan or image while the robot (motor) moves. Similarly, the robot (motor) stays powered but stationary during MRI scans. The robot (motor) operates within the MRI scanner's uniform field, allowing timely adjustments to ensure precision and safety. Although full synchronization of MRI imaging and robot movement is not feasible, operating only 60 motors in a 3.0 T environment can allow complete synchronization between MRI scanning and motor operation. This approach meets real-time requirements and expected surgical outcomes, exceeding the performance of most robots that are not operable in MRI chambers. Analytical improvements are proposed for the future design of the robot's control system: 1) Adjusting the drive signals of the 60 and 30 motors to reduce MRI imaging interference due to different compatibilities and sensitive frequencies. 2) Shielding exposed controllers during 1.5 T experiments to reduce electromagnetic leakage and improve image quality. 3) Replacing external communication cables with fiber optics to control indoor devices from outside, effectively blocking external electromagnetic interference. The innovation of this study lies in the detailed experimental analysis of ultrasonic motors and robot materials under MRI conditions, proposing intermittent operation with MRI imaging and providing robust support for DBS surgery robots. Although previous studies used MRI-compatible ultrasonic motors, most did not operate within MRI chambers, limiting their compatibility for DBS surgery. This study provides specific SNR data and improvement methods based on experimental and theoretical analysis. The use of domestically produced ultrasonic motors achieved closed-loop control and compatibility in 3.0 and 1.5 T MRI environments, demonstrating their suitability in strong magnetic fields. This research contributes to the further design and manufacturing of MRI-compatible DBS robotic systems. Future work involves testing the complete robot system's MRI compatibility and developing a high-precision DBS surgery robot with real-time MRI guidance.关键词：deep brain stimulation;surgical robot;MRI compatible505|564|0更新时间：2026-01-24
MECHANICAL ENGINEERING
- “在去除染料废水中刚果红领域，研究人员制备了一种复合材料吸附剂，具有良好的吸附性能和重复利用性，为染料废水处理提供新方案。”摘要：ObjectiveThe discharge of various organic pollutants has caused significant water pollution issues over the past decades. Congo red, a widely used and highly hazardous dye, presents challenges in degradation and treatment. Therefore, it is imperative to explore the development of an efficient, non-polluting, and convenient post-treatment adsorbent for Congo red in wastewater.MethodsA composite adsorbent was created using Nicandra physalodes (L.) Gaertn, polyacrylamide (PAM), and expanded graphite to adsorb Congo red from dye wastewater. The solubility of Nicandra physalodes (L.) Gaertn seeds enabled the extraction of surface gums through a conventional distilled water extraction method. The resulting Nicandra physalodes (L.) Gaertn seed gum (NPG) was prepared using freeze-drying and vacuum-drying. Expanded graphite was modified through the neutralization reaction of strongly acidic ferric chloride hexahydrate and sodium hydroxide. Simultaneously, ethylene glycol was used as a co-solvent and catalyst in the reaction, yielding modified graphite with magnetic properties. The synthesis, which involved the dissolution and compounding of NPG, PAM, and modified graphite, was followed by injection into a configured calcium chloride solution and freeze-drying to produce the composite adsorbent. Characterization was conducted using scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and zeta potential analysis, and the adsorption mechanism was examined.Results and DiscussionsStatic adsorption experiments were conducted to investigate the influence of solution pH, adsorbent dosage, adsorption time, temperature, and initial concentration on the adsorption performance for Congo red. The equilibrium concentration, adsorption capacity, and removal rate were determined through transmittance detection. Isothermal analysis employed the Langmuir and Freundlich models; kinetic analysis involved pseudo-first-order, pseudo-second-order, and intraparticle diffusion models; and thermodynamic analysis calculated parameters to understand the adsorption behaviors and mechanisms of the composite adsorbent on Congo red. Corresponding experiments were performed to assess the reusability of the composite adsorbent. Material characterization indicated that NPG had a relatively dense and smooth surface, with a three-dimensional spatial mesh gel structure formed in Ca2+ ion solution. The incorporation of modified graphite resulted in a composite adsorbent with a rough and porous surface, folds, a long strip-like structure, and grooves, providing numerous active sites for Congo red adsorption. The zeta potential of the composites was positive under acidic conditions (pH < 7) and negative under alkaline conditions (pH > 7). The results of the static adsorption experiments demonstrated the commendable adsorption capacity of the composites for Congo red (CR). pH was identified as the primary factor influencing the composites' performance in CR adsorption. The composite's effectiveness in adsorbing CR is improved in acidic and neutral solutions but decreases under alkaline conditions. At pH 7, the equilibrium adsorption capacity of CR peaked at 89.6%, while a significant decline was observed as the pH increased from 7 to 10, reducing the removal rate from 89.6% to 3.6%. In dosage experiments, with an initial solution concentration of 80 mg/L, increasing the composite dosage from 6 to 18 mg enhances the CR removal rate from 76.5% to 86.6%. The time experiment identified two distinct stages in the adsorption process when the initial solution concentration was 100 mg/L and the composite dosage was 100 mg. From the start to 286 minutes, the adsorption capacity reached 138.52 mg/g, and after 826 minutes, it plateaued at an equilibrium adsorption capacity of 168.96 mg/g. In temperature and concentration experiments, within the range of 303 to 323 K, the adsorption performance of the composites on CR declines with increasing temperature, while the equilibrium adsorption capacity increases with the initial concentration. The fitting results of the adsorption kinetic models indicated that the pseudo-first-order model best represents the adsorption process. Adsorption isotherm fitting results showed better alignment with the Freundlich isotherm model, suggesting that CR adsorption by composites occurs on non-uniform surfaces through multilayer adsorption driven primarily by electrostatic interactions and hydrogen bonding. Thermodynamic analysis confirmed that CR adsorption by composites is a spontaneous exothermic process. In reusability experiments, the equilibrium adsorption capacity and CR removal rate of the composites showed a modest decline of 16.32% and 13.7%, respectively, after five adsorption-desorption cycles, remaining at a high level. This demonstrates the good reusability of the prepared composite adsorbents.ConclusionsThe developed composite adsorbent in this study exhibits robust adsorption performance for CR. Its simple fabrication process, environmentally friendly and readily available raw materials, and the feasibility of solid-liquid separation via magnetism support its potential application in CR removal from dye wastewater, providing valuable insights for the selection and preparation of adsorbents.关键词：Nicandra Physalodes (L.) Gaertn;polyacrylamide;modified graphite;adsorption performance;Congo red116|98|0更新时间：2026-01-24
- “在新材料矫直领域，专家推导了3种材料模型的曲率-弯矩关系，构建了多辊矫直求解模型，并验证了理论模型的准确性，为矫直设备设计和工艺制定提供理论支持。”摘要：ObjectiveWith the development of new materials, increasing complexity in material properties has made it more difficult to define accurate straightening processes. The discrepancy between the assumptions of traditional ideal material models and actual material behavior has made accurate modeling a core issue in straightening process calculations. To more precisely describe the elastic-plastic behavior of different materials, a multi-roll straightening process model was established based on the curvature integral method, and the effects of bilinear and power hardening coefficients on the process were analyzed. The goal is to support the development of straightening techniques for new materials and provide a theoretical basis for intelligent straightening and optimal design of straightening machines.MethodsThree material models—ideal elastic-plastic, bilinear hardening, and power hardening—were selected, and the curvature-moment (M‒K) relationships for these materials during bending were derived. Using these relationships and curvature integration, a mathematical model for the multi-roll straightening process was developed. A least squares algorithm was employed to solve the nonlinear equations iteratively, enabling accurate straightening calculations. To evaluate the applicability of different material models, five straightening schemes were designed, corresponding to plasticity rates of 33.4%, 50.0%, 66.7%, 75.0%, and 80.0%. The influence of various hardening coefficients on curvature and plasticity during straightening was investigated. High-strength steel Q690 was used for experimental validation, with all three material models being imported into the multi-roll straightening model. The results were compared with both experimental data and finite element simulations to assess model accuracy.Results and DiscussionsResidual curvature was calculated under five straightening schemes and for hardening coefficients (0.1, 0.2, 0.3, 0.4, 0.5). The results show that as the bilinear and power hardening coefficients increase, the residual curvature error relative to the ideal elastic-plastic model also increases. Specifically, for bilinear hardening, the residual curvature errors were 0.253, 0.506, 0.759, 1.013, and 1.266; for power hardening, they were 0.145, 0.308, 0.489, 0.692, and 0.919. The bilinear model shows a linear increase in error, while the power model displays a nonlinear pattern. The magnitude of the hardening coefficient affects only the degree of curvature error, not the underlying behavior or material applicability. When the coefficient is fixed at 0.1, curvature changes across the five straightening schemes were analyzed. The results show that with increasing reduction, the error between hardened and ideal models increases. Particularly in schemes four and five, commonly used in practice, the residual curvature error for the ideal model is 6.06%, whereas for the power model it is 13.57%. As both the strengthening coefficient and reduction increase, differences in plasticity between hardened and ideal models become more pronounced. For example, with a coefficient of 0.5, the plasticity deviation is 14.26% for the bilinear model and 12.61% for the power model. If the target plasticity is 80% based on the ideal model, the actual plasticity of the hardened model is closer to 70%, potentially leading to insufficient bending and reduced product quality. In terms of straightening force, the ideal model yields a unidirectional force of 434.4 kN, the bilinear model 512.7 kN, and the power model 478.3 kN. The experimental result is 462.2 kN, and the theoretical value for the power model is 483.7 kN. The 4.65% error for the power model highlights the importance of selecting an accurate material model.ConclusionsThe study shows that as the bilinear and power hardening coefficients
MATERILAL SCIENCE & ENGINEERING
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