最新刊期
卷 43 ， 期 Z1 ， 2011
- 摘要：Abstract:Slope with broken line slip surface is a common type of landslide, the dynamic response under action of earthquake is very complex. In order to study the dynamic response of slope with broken line slip surface under the action of earthquake, applying time history analysis method, we established the numerical model with ANSYS finite element software. We first analyzed mechanical properties under static behavior, then inputted seismic waves to model, and analyzed the dynamic response under dynamic loading. We got that: stress-transfer occurred in the slope under earthquake action; rock bed dislocation occurred on both sides of the joint, since the existence of lock-fixed section，the dislocation of lower part was larger than upper part. The studied slope as a latecomer-landslide, although earthquake action didn’t damage the slope, the cumulative effect of the earthquake reduced the stability of slope.关键词：slope;broken line slip surface;earthquake;dynamic response;numerical simulation
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发布时间：2023-11-14 - 摘要：Abstract:This paper introduces a intelligent benefit evaluation system of hydropower station energy saving dispatching based on the calculation method established by the executive board of clean development mechanism. The system design, structure, function and method are elaborated. The system based on three-layer B/S Structure is developed by Visual Studio.NET 2008, Web Services and Oracle Database. The system which has the advantages of high automatization could be visited and managed by Internet, and is friend-user interface. The software which integrates data reading, intelligent calculation and management function has been applied in many cascaded hydropower stations and the results are satisfactory.关键词：hydropower station;energy saving dispatching;benefit evaluation;intelligent system
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发布时间：2023-11-14 - 摘要：Abstract:Numerical simulation and experimental tests were conducted to study a new type of stilling basin–deflecting stilling basin (DSB). The simulation by using a 3D RNG k－ε turbulence model showed a good agreement with the test data in flow pattern, free surface elevation, velocity and pressure distributions. Results of calculation and experiment revealed the difference of DSB from a conventional stilling basin (CSB). With the turbulence increased and the velocity on the slab reduced, the hydraulic performances and energy dissipation efficiency of DSB were significantly improved over the conventional design.关键词：deflecting stilling basin;hydraulic performances;numerical simulation;turbulence;Energy dissipation
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发布时间：2023-11-14 - 摘要：Abstract:Drinking water source protection is core of the environmental protection .The paper originally discusses overall water source drinking water quality assessment based on the study of relation among precipitation - surface water - ground water and fuzzy quality synthetic evaluation of groundwater water quality .The paper also originally study fuzzy quality synthetic evaluation from of the angle of the environmental monitoring appraisal standard and quality control request . Criterion of validity and standard of practical application's mentality of fuzzy comprehensive assessment is firstly discussed in china. The thinking ,strategy and the means of improving validity and practical application's mentality is discussed: the appraisal goal's pragmaticality, the appraisal basis's validity, the appraisal data's authenticity, appraises link's integrity, the appraisal detail clarity, the appraisal process transparency, appraisal step rigorous the nature, the assessment method rationality, the appraisal operation standards, measure results expression intuitive, the appraisal function multiple and so on. The means and measures of improving appraisal practical application ：① hydrology geology indication ,②Sample and data explanation,③ the background value ( the initial value) to calculation,④Carries on the single item water quality dynamic analysis and the plan dynamic change chart;⑤ the explanation of the fuzzy appraisal parameter choice ,⑥Constructs the concrete membership function, ⑦Draws up the fuzzy subordination functional arrangement,⑧Gives the weight computation chart, ⑨Draws up the fuzzy appraisal outcomes space distribution map,⑩Carries on the specialized interpreting and the explanation to the results and so on.。关键词：water source comprehensive evaluation groundwater water quality assessment
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发布时间：2023-11-14 - 摘要：Abstract:To perfecting the emergency disposal work and the post-disaster rehabilitation and reconstruction work of the landslide lake, choosed seven indexes based on the natural and social property to constitute the risk evaluation system of landslide lake. Including landslide lake scale, composition makeup of landslide dam, landslide dam height, rainwater-collecting area, population density, economy density and psychology panic degrees. And then made a risk evaluation of the nine landslide lakes reduced by Wenchuan Earthquake base on the generalized entropy method. The result showed the social property indexes have an obvious effection to landslide lake risk, so the social property risk factor should be paid more attention to in the emergency disposal work and the post-disaster rehabilitation and reconstruction work.关键词：landslide lake;risk evaluation;social property;natural property
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发布时间：2023-11-14 - 摘要：Abstract:Based on model experiment，the velocities of jet flow along the axis were measured, using the CQY—Z8a velocimeter. The velocity attenuation of jet flow along the axis under different conditions has been studied respectively. The effects of aeration concentration, jet velocity at entry and thickness of jet flow on the velocity attenuation of jet flow have been analyzed. Through analysis we could see that the velocity attenuation of jet flow along the axis changed in laws. It was demonstrated by the test results that under the experimental conditions，the velocity along the axis decreased linearly; the higher the air concentration, the faster the velocity decayed；the thinner the jet flow, the faster the velocity decayed. The jet velocity itself at entry had no influence on the law of velocity attenuation，as the lines of velocity attenuation at different velocities at entry were practically parallel. Therefore, improving the air concentration of jet flow and dispersing the jet flow in the plunge pool could reduce the influence of jet flow on scour.关键词：jet flow;aeration concentration;velocity
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发布时间：2023-11-14 - 摘要：Abstract:The sediment with different size have different effects on the biodegradation of pollutants in water with sediment.This article chosed diluted sewage as simulate pollutants，fine sediment of natural river as the experimental materials and adopted the method of attenuation BOD concentration,to study the effect of sediment with different size on the biodegradation of pollutants in water with sediment in some combinations of working conditions.The article analysed the degradation kinetics, five days biochemical oxygen demand，half-life and degradation rate constants of water samples with different combinations of particle size,and initially obtained the law of coexistent effect of sediment with different size on the biodegradation of pollutants in water with sediment. The results showed that: when the concentration of pollutants was low，the biodegradation process of pollutants in water with sediment coincided with the first order reaction kinetics；in the condition of different size combinations, five days biochemical oxygen demand，half-life and degradation rate constants of water samples had no significant difference; coexistence of sediment with different size had no remarkable effect on the biodegradation of pollutants in water with sediment.关键词：BOD;sediment diameter;biodegradation;DO;first order reaction kinetics
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发布时间：2023-11-14 - 摘要：Abstract:Copula assessment method is a innovation way for solving the topic of assessment. Copula function is used to construct joint distribution functions for studying the correlation degree of assessment indexes and the relevance pattern of assessment criteria. Hereby the assessment model is established, both the comprehensive assessment indexes values of samples and the comprehensive assessment criteria values of category are defined. Accordingly, based on the comprehensive assessment criteria values, the comprehensive assessment indexes values are classified, and then the assessment conclusion can be summarized. Case study of eutrophication of lake water quality assessment shows that Copula assessment method is of clear principle, stable performance and reasonable results which provides new ideas for the hydrological assessment.关键词：Copula function;joint distribution function;assessment;eutrophication
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发布时间：2023-11-14 - 摘要：Abstract:The series of overland flow experiments were conducted by changing slope degree including 15。, 20。 and 25。 on the smooth and adhering sand slope, the hydraulic parameters including velocity and depth have been obtained in different flow different slope location and discharge, furthermore, the thin layer overland flow resistance characteristic has been also discussed according to the average Weisbach-Darcy coefficient method and improved calculating method considering the variations of hydraulic factors along slope distance. The results show that the overland flow velocity and the depth varies from the monitoring distance in the experiment slope, e.g., the velocity increases with slope distance increase on smooth and adhering sand slope, however, the peak and lower value appears on the adhering sand slope with larger slope degree. On the other hand, the traditional resistance method, the average Weisbach-Darcy coefficient method is not feasible to analyze the flow resistance in smooth slope and roughness slope with steep degree, while improved method considering variations of hydraulic factors along slope distance may be better to calculate the overland flow resistance.关键词：smooth bed, sand slope, overland flow, resistance
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发布时间：2023-11-14 - 摘要：Abstract: Based on the theory of components mass conservation, the movement of the turbidity currents was approximated as a transfer process of sediment which was one component of the muddy sediment in the water, established the species equation and solved it coupled with the RNG k-ε equations which considered the vortex flow in the average flow, used the widely used commercial FLUENT software to calculate the model, and used the model experiment to demonstrate the numerical results. The results showed: the model could effectively simulate plunging and forward movement of the turbidity currents and it provided a new method for the turbidity currents research relative to reservoir, lake and river entrance. At the end used this model to simulate the movement of the turbidity currents for one reservoir when flooding.关键词：Turbidity Currents;Species Transport Model;RNG k-ε Model
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发布时间：2023-11-14 - 摘要：Abstract:Dams cut off the migratory route of fish, especially to these migratory and half migratory fish, affects their growth and breeding greatly. A dam is on which some kinds of migratory fish’s migratory way, such as Ptychobarbus conirostris and Schizothora plagionstomus. In order to protect rare fishes, a vertical slot type fish way has been built. This study has carried on a series of model experiments upon the fish way, and found that in the prototype, velocity in these measure points which at the main stream approached to the fish burst speed. Meanwhile, flow regime in the prototype was disorder, these factors caused lots of difficulties for fishes’ migratory. Then we put forward a new kind of structure which has three-levels of fall-off bank and a groove in every pool. The contrast experiments showed that velocity in the new fish way has been cut down 30 percent at least, and flow regime has also changed gently. As the conclusion, the new fish way is better for migratory. Besides，the groove can provide resting place for fish as water in it is nearly static.关键词：migratory;fish;slot type;fish way;structure
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发布时间：2023-11-14 - 摘要：Abstract:Filter tests on gravelly base soil and the filter are conducted using a new large-scale permeameter. Based on a series of filter tests, the influence of the gravel content in the base soil, the grading and dry density of the filter on the internal erosion resistance has been studied. The results show that: the influence of the filter grading and dry density on the coefficient of permeability of the sample is far less than the gravel content in the base soil. The critical gradient of the sample decreases with increasing gravel content in the base soil and increase with the increasing dry density of the filter. When coarser filters are used the critical gradients are significantly reduced. In order to make sure the effectiveness of the filter., the grading and dry density of the filter or the controlling constriction size of the filter should be strictly controlled in the actual project.关键词：filter test;gravelly core soil;high water pressure;permeameter;controlling constriction size
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发布时间：2023-11-14 - 摘要：Abstract:Combining with rheological equation of bingham fluid and time-dependent characteristic of fluid viscosity, the rheological equation and seepage motion equation based on bingham fluid of time-dependent behavior were established. Spherical penetration grouting mechanism and bar penetration grouting mechanism about them were deduced on the basis of some assumptions and were validated by means of designing two groups of indoor grouting experiments. Experiment results show that theory diffusion radius calculated by penetration mechanism formula in view of bingham fluid of time-dependent behavior have about 20% of the differences with the actual measurement diffusion radius by indoor grouting experiments, but they are all within the acceptable error limits. Therefore, it could better reflect grouting infiltration law based on bingham fluid of time-dependent behavior in the general and may play a guiding role and some reference valuable in the design, construction and theoretical research of grouting technique.关键词：time-dependent behavior;Bingham fluid;penetration grouting mechanism
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发布时间：2023-11-14 - 摘要：Abstract:Compare and analyze the change rules of high liquid limit clay and high liquid limit silt on Wetting-drying cycles by analyzing the test results of the two soils’height, mass and compression coefficient. The change rules of high liquid limit clay and high liquid limit silt are also studied from the mechanism aspect. From the research results, it can be found that the change rule of mass and height of high liquid limit clay is similar with that of high liquid limit silt.The Rate of mass change and height change tend to smooth with the increase in the number of wet and dry cycles in these two soils.The change rule of compression coefficient is also similar in these two soils.But after one Wetting-drying compression coefficient visibly increased,the increasing rate of compression coefficient of high liquid limit silt is between 40% -180%, the increasing rate of compression coefficient of high liquid limit clay is between 40% -180%. The compression coefficient of these two soil tend to smooth after three Wetting-drying cycles. The compression coefficient of these two soil tend to equal after five Wetting-drying cycles.But the compression coefficient of high liquid limit silt is less than that of high liquid limit clay in Wetting-drying cycles.It also can be found that the Wetting-drying cycle is an irreversible process for the two soils.关键词：high liquid limit,clay,silt,strength of compression, wetting-drying cycle
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发布时间：2023-11-14 -
Study on Mechanical and Deformation of Tunnel with Small Clear Spacing in Collapse Accumulative Rock
摘要：Abstract:During the construction of small clear space tunnel the collapse of tunnel face and the stability of middle pillar exist commonly. Take Leigongpu small spacing tunnel for example, analysis of the surrounding rock was carried out, and some monitoring tasks have been performed at the exit of collapsed accumulative rock segment, including the ground settlement, crown settlement, convergence, the displacement of middle pillar, the axial force of bolt, pressure of surrounding rock and the stress of steel arch, etc. Then simulation and calculation were done aiming at K72+520 cross-section by finite element method. Monitoring and numerical simulation results show that the construction of three-step method in collapsed accumulative rock in outlet section has stability problem, and the reserved soil core method can effectively improve the stability of excavation face; Excavation of later hole has great influence on stress distribution and stability of first hole. The rock of the middle pile are wholly in the disturbed state, and bolt’s anchoring force has not been well play, the vault and arch waist position was prone to stress concentration. The experience and conclusions presented here can provide reference to design, construction and research of similar tunnels.关键词：small clear spacing tunneling;collapse accumulative rock;site monitoring;numerical simulation- 1935
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发布时间：2023-11-14 - 摘要：Abstract:Based on three-dimensional elastoplastic finite element theory, a computational method considering interface damage and continuous crack under high pressure is introduced. Interface elements are modeled on potential sliding surface of diversion tunnel plug, then research the damage degree of interface element on the condition of water pressure. The interface will disengage at serious damage section. Internal water will enter the disengaged interface contacts to it, which may causes continuous crack of interface elements. In the end, effective action surface between diversion tunnel plug and externality and the damage degree of interface can be obtained. The cohesion of interface elements is reduced based on the degree of damage. Then the safety factor of diversion tunnel plug can be calculated. This method is used to calculate the stability of diversion tunnel plug at Mao’ergai hydropower station and has gained a good effect, which indicates that the proposed method is effective and reliable.关键词：finite element method;plug;stability analysis;interface;damage;security coefficient
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发布时间：2023-11-14 - 摘要：Abstract:August 13,2010,heavy rainfall happened in LongChi,Dujiangyan.The recorded rainfall was 75mm in one hour from 16:00 to 17:00 o’clock, The heavy rain caused powerful flood in the catchments, which triggered material sources and destroyed prevention dams in the Bayi gully. Then the giant debris flow were formed. Based on field investigation and analysis: formation conditions of the debris flow，like topography, water source and sediment source, were firstly analyzed; Then, elaborated characteristics and formation of debris flow；Third, dynamic parameters were calculated: density is 1.88g•cm－３，discharge is 1 082m３•ｓ－１, yield stress of debris flows is more than 6700 Pa, The total volume of sediment in debris flows were estimated at 116×104ｍ3,the large boulder involving in debris flows in depositional fans have powerful impact force.Finally,the development trend of the debris flow was predicted: Because there are a lot of collapse and landslide in the drainage basins, so it have maximum possibility of happening large-scale debris flow in continuous heavy rainfall.关键词：earthquake debris flow characteristics formation prediction
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发布时间：2023-11-14 - 摘要：Abstract: Radiation force from ultrasound has been used to excite monochromatic waves in tissues. The shear wave propagation speed is related to the shear elasticity and shear viscosity of the tissue. In previous researches, the thinking that shear wave propagation speed is a constant in isotropic media was widely used to estimate the viscoelastic modulus. Nevertheless, our research shows that shear wave propagation speed in isotropic media follows the fact that it’s not a constant but regularly vary with vibration phase of measuring point in shear direction, which appears sinusoidal change approximately with phase . Our work indicates that the variance of shear wave propagation speed is mainly caused by the change of local density with time. The modified formulas of shear wave propagation speed and density are presented. Finally, shear elasticity modulus is deduced respectively with constant speed and modified, which demonstrates the essential of modification and the error of shear elasticity modulus fall by more than 10%.关键词：shear wave speed;viscoelastic;Finite Element Model;density
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发布时间：2023-11-14 - 摘要：Abstract:Aiming at the technical route and method system problem of the geo-hazard risk assessment, taking landslide hazard as an example, this thesis carries out the research and application of the hazard risk assessment technology based on intelligent learning. From data preparation, analysis and modeling to calculation and checkout, a complete technical route and method theory system of landslide hazard risk assessment based on GIS has been put forward. Taking Wanzhou district of Chongqing as the study area, the research of risk assessment has been implemented, the analysis results of these approaches have been scientifically evaluated, different landslide hazard risk continual distribution maps and zonation maps that conform to the existent landslide distribution have been successfully made, based on the intelligent learning method, data-driven method, GIS technology, and so on. At last, the method and technology was verified efficiently by the experiments on the study area.关键词：Intelligent learning;GIS;risk assessment;landslide hazard;data-driven type
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发布时间：2023-11-14 - 摘要：Abstract: Leaching process of Mn from low grade pyrolusite with SO2 in liquid phase was studied. Effects of agitation speed, leaching temperature, SO2 concentration and pH on Mn extraction rate were determined. Changes of particle size and surface element content of pyrolusite were determined. The results indicate that effect of outward diffusion can be eliminated when agitation speed at 400r/min. Mn extraction rate increases with increasing temperature, SO2 concentration and decreasing pH. A decrease of pyrolusite particle size at 20%, a decrease of Mn at 73% and a increase of Si at 18% on pyrolusite surface were found when Mn extraction rate at 80%. The leaching kinetics showed that the leaching reaction is controlled by both chemical reaction on particle surface and diffusion across the product layer. The determined activation energy was found to be 36.85 kJ/ mol and the reaction orders with respect to SO2 concentration and H+ were 1.5995 and 0.5884, respectively.关键词：sulfur dioxide;low grade pyrolusite;leaching;kinetics;limited step
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发布时间：2023-11-14 - 摘要：Abstract:Solvent extraction and separation of titanium and iron by a variety of extractants including of D2EHPA、TOPO、TBP、TOA and N1923 from HCl solutions of different concentration was investigated on the basic of the Altair hydrochloride TiO2 pigment process and theoretical analysis. It is showed that separation of titanium and iron can be achieved by D2EHPA from 8~12M HCl solution or by TOA from 8~12M HCl solution, solvent extraction of titanium together with iron can be realized by TOPO-D2EHPA from 6~12M HCl solution.关键词：extraction and separation;titanium;iron;HCl;a variety of extractants
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发布时间：2023-11-14 - 摘要：Abstract:Black liquor produced from refined cotton production is highly concentrated refractory organic wastewater containing complicated components. Pretreatment by physical-chemical processes is preferred. The pretreatment of the black liquor by acidification was studied. Reaction conditions such as pH and retention time were investigated. UV-vis scanning, GC-MS and acute toxicity test were used for analyzing the changes of the composition before and after the acidification. The results showed that the pH of 2 and the retention time of 90 mins were the best conditions. COD decreased from 5 400 mg?L^-1 to 3 180 mg?L^-1 by the ratio of 41.1%. The removal rate of chromaticity could reach 43.5%. Both species and content of organic compounds decreased to a certain extent. Organic compounds with carbon chain number of nine or more were precipitated or degraded. The dilution ratio of LIR50 (50% of luminosity inhibition rate) decreased from 250 to 140, reducing the acute toxicity by 44%. Acidification for black liquor achieved good effect, providing favorable conditions for subsequent biological treatment.关键词：acidification;refined cotton;black liquor;organic wastewater;acute toxicity
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发布时间：2023-11-14 - 摘要：Abstract:Fe2+ is oxidized by air in the leaching solution of flue gas desulfurization with pyrolusite pulp, the effects of Fe2+ concentration, oxygen partial pressure, hydrogen ion concentration and temperature on reaction rate are studied. It’s showed that oxidative reaction rate is quicker with the increase of Fe2+ concentration, oxygen partial pressure and temperature, while slower with the increase of hydrogen ion concentration. It’s showed by the study on the kinetics that the grade for Fe2+ concentration is 2, oxygen partial pressure is 1, and for hydrogen ion concentration is -1, the activation energy Ea is 101.4308kJ/mol, and the pre-exponential factor A0 is 2.48×1014s-1.关键词：pyrolusite;air;Ferrous;kinetics
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发布时间：2023-11-14 - 摘要：Abstract:The surface of X70 pipeline steel was processed with the technique of hot-dipped aluminum, the morphologies and the change of chemical elements of X70 pipeline steel before and after hot-dipped aluminum were observed with SEM (Scanning Electron Microscope) and EDS (Energy Dispersive Spectrdmeter), respectively, its phase before and after the salt spray corrosion were analyzed with XRD (X-Ray Diffractomer), the effect of hot-dipped aluminum treatment on salt spray corrpsion of X70 pipeline steel were researched. The results show that pitting corrosion of the primitive sample is relatively serious after the salt spray corrosion, a dense Al2O3 layer is formed on the sample by hot-dipped aluminum, which availably prevents the contact between the corrosive medium Cl- ion and active Fe of the substrate; there are a number of educts in the dipped aluminum layer of X70 pipeline steel after hot-dipped aluminum treatment, the dust-colour material on its surface is FeAl, that effectively restrains the occurring of surface corrosive pitting; the content of Fe in the sample in primitive state is higher, produce the active irons, that is the main factor of corrosive pitting.关键词：X70 pipeline steel;hot-dipped-aluminum treatment;salt spray corrosion;corrosion-pitting
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发布时间：2023-11-14 - 摘要：Abstract:The surface of X70 pipeline steel welded joint was strengthened with the technology mechanical shot peening, the tensile mechanical properties of X70 pipeline steel substrate, welded joint in primitive state and the processed sample by shot peening treatment were analyzed through the tensile test, the fracture morphologies were observed with Scanning Electron Microscopy (SEM), and the fracture mechanisms were analyzed. The experimental results show that the substrate of X70 pipeline steel has the continuous yield feature, no significant yield platform, its elongation rate is 38％, the tensile fracture appears the layered cracking. After the X70 pipeline steel is welded, its yield strength, tensile strength, shrinkage are obviously less than those of the substrate, and the tensile strength, yield strength and elongation rate of X70 pipeline steel welded joint have increased significantly after shot peening treatment. The plastic deformation is produced on the welded joint surface, and the decrease of holes and cracks is the main factor of improving the tensile strength of X70 pipeline steel welded joint after shot peening.
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发布时间：2023-11-14 - 摘要：Abstract:To a large extent, the structure of pore space determines its macroscopic properties, therefore, it is significant to analysis and research the structure of pore space. However, its description of structure and performance has always been focus and difficulty using traditional methods. To investigate effective, accurate and objective characterization methods of pore space structure, in this work, the two-dimensional (2D) sequence images of porous material were obtained from MicroCT. Level set method based on Chan-Vese (C-V) model for segmentation was introduced to capture, reproduce and visualize the exact three-dimensional (3D) structure of porous material. Then a set of geometric parameters, such as pore volume, pore surface area, average pore diameter, porosity and connectivity based on 3D data were measured by using image analysis techniques. The 3D pore parameters obtained in this work have been proved objective and accurate to quantitatively describe the structure of pore of porous materials. Further more, it has provided a new research method to characterize pore structure of porous materials.关键词：porous material, MicroCT, C-V level set, porosity, pore diameter
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发布时间：2023-11-14 - 摘要：Abstract:In this paper, Oil was classified according to polar and nonpolar, the effect of magnetic field modification on surface tension of oil is studied. The result shown with the increase of magnetic intensity, magnetic field modification make surface tension of nonpolar oil rise by 0.3% ~ 4%, and surface tension of nonpolar oil present cyclical change, interfacial tension of water-oil can be reduced, nonpolar oil dispersivity in water can be improved, however, magnetic field modification making surface tension of polar oil decrease, is similar to that of water. After nonpolar oil is mixed with polar oil, when polar oil is minor, nonpolar oil take the leading role, magnetic field modification make surface tension of nonpolar- polar oil mixture rise , however, with the increase of polar oil component in nonpolar- polar oil mixture, polar oil take the leading role gradually, magnetic field modification make surface tension of nonpolar- polar oil mixture decrease.关键词：Magnetic fields;Oil fuel;Surface tension;Interface tension
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发布时间：2023-11-14 - 摘要：Abstract:A novel measure indicator of anti-blockage capacity—anti-blockage coefficient was developed to sudden blockage in air transportation. When the airport capacity dropped due to bad weather or other reasons, the coefficient used the discrete time loss queuing algorithm to get the anti-blockage capacity, which calculated the probability transition matrix and theoretical maximum flow. Then, the coefficient was verified by simulation results.关键词：Air Transportation;Ant-blockage;Maximum Flow;Discrete Time;Queuing
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发布时间：2023-11-14 - 摘要：Abstract:A multiple Baldwin effect based clonal selection algorithm (SAMBCSA) was proposed to deal with complex optimization problems. First, the ability of immune evolving was enhanced by the scheme of learning difference information between different antibodies to find the promising solution regions. Second, an immune response strategy pool and a statistical self adaptive learning framework were designed in order to improve the universality of the algorithm. Then, the time complexity and the convergence of the algorithm were analyzed. Finally, the experimental results on 16 state-of-the-art benchmark functions indicated that, compared with clonal selection algorithm and some other algorithms, SAMBCSA achieves good performance with high solution quality and good robustness on most problems.关键词：intelligent computing;clonal selection;multi-modal optimization
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发布时间：2023-11-14 - 摘要：Abstract:To improve the transmission efficiency and save the storage space of GPS data in the traffic control and management. A differential preprocessing method was presented according to the characteristics of GPS data, and the compressibility was further enhanced by the converts the time type. Besides, the dynamic Huffman algorithm was adopted to compress the GPS data. By theoretical analysis and reality testing，it could be seen that the compression ratio was more than 60%, and this scheme did not change the urban traffic facilities of existed, and the GPS positioning data which was transmitted to monitoring center by GPRS would be mostly reduced，and the communicating cost would be also decreased. at the same time, the channel used by GPRS would be shorten，the performance of real-time positioning would be improved.关键词：Data compression;data preprocessing;Huffman coding;Global positioning system (GPS)
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发布时间：2023-11-14 - 摘要：Abstract:In this paper, a multi-focus image fusion method based on the weighted non-negative matrix factorization is presented to improve image fusion method based on non-negative matrix factorization. The method analyzed the relationship between the point spread function in optical system and imaging processing, and built a weight matrix U by determining the focal point on multi-focus images. Finally, the weighted non-negative matrix algorithm was applied for image fusion and got a new image that all parts of the image were clear. Experimental results showed that the image fusion method is better than non-negative matrix factorization method, wavelet transform fusion method and Laplacian pyramid fusion method.关键词：image fusion;Multi-focus image;Non-negative matrix factorization;focal point;weighted
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发布时间：2023-11-14 - 摘要：Abstract:In this work, we present an automated method for identifying chromosome in fluorescence stained medical cell images. The detection of the candidate cell images is based on dynamical similarity segment algorithm. For the elimination of false findings, which come from illumination, dye concentration and morphological variation, the identification method based on characteristic parameters was applied. Salient features characterizing the area, chromaticity, shape, compactness were extracted from the candidate chromosome regions and the identification procedure was accomplished with the application of fuzzy comprehensive evaluation. By setting up the membership functions in a fuzzy system, the chromosomes in cells can be identified effectively. The proposed method was evaluated on a set of cell images and compared with the methods of the classified identification and the single characteristic identification. The result showed that the proposed method produces more accurate result, and the accuracy is up to 95% with a real-time performance.关键词：chromosome identification;color image segmentation;fuzzy comprehensive evaluation;membership function
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发布时间：2023-11-14 - 摘要：Abstract:Container code is composed of 11 characters, in practice, the 11 code characters can be arranged in many ways, and the distances between neighbor characters in different images vary largely. Traditional methods of automatic container code recognition (ACCR) from visual images are based on isolated character segmentation and isolated character recognition. For those images with code characters being closely arranged, as the characters are difficult to be segmented apart, current methods are difficult to work. To address this problem, a new method, which introduced in HMM based continuous character recognition technique, for ACCR from visual images is proposed. Firstly，in the character segmentation phase, if there are some characters closely arranged, they’ll be extracted as a character region；and for those characters arranged with some distance they’ll be extracted isolatedly. Secondly，in the character recognition phase, for isolated character, a RBF neutral network based isolated character recognition technique is employed, and for closely arranged characters, which are extracted as a string region, HMM based continuous characters recognition technique is employed. Experiment results show that the container code images under various situations can be effectively recognized.关键词：Character Recognition;Computer Vision;Hidden Markov Models;Image Processing
- 2416
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- 20
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- 0
发布时间：2023-11-14 - 摘要：Abstract:It is very important to improve the quality of off-line signature recognition methods. To this end, this paper introduces an off-line signature recognition system based on HTM(Hierarchical Temporal Memory), which employs the hierarchical structure and spatio-temporal feature for transfer-invariant and scale-invariant signature recognition. The experimental results illustrate that the accurate rate is about 95%. Combining parameter maxdistance in the algorithm, this paper also analysis and improves the recognition result.关键词：Off-line Signature, Handwritten Signature Recognition, Hierarchical Temporal Memory algorithm, Spatio-temporal Feature
- 2016
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- 52
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发布时间：2023-11-14 - 摘要：Abstract: Aimed at applying the sound recognition technology on the target recognition in border and coastal surveillance systems, a new method of feature extraction was proposed based on the optimum wavelet packet basis. According to the frequency characteristics of the collected border and coastal surveillance sound signals, these sound signals were analyzed by selective multi-scale wavelet packet decomposition and the optimum wavelet tree was obtained. From the high dimensional coefficients of the corresponding optimum wavelet packet basis, the meaningful and compact energy feature vectors were built. After that, these vectors were inputted in a BP neural network to train the network. The trained BP network was then used to detect border and coastal surveillance sound signals. The simulation results indicated that the identification ratio is up to 94% using this feature extraction method under noisy environment, improved 6% compared with the method based on wavelet packet decomposition.关键词：border and coastal surveillance;sound signal;wavelet packet;optimum wavelet packet decomposition;BP neural network
- 1689
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- 50
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- 0
发布时间：2023-11-14 - 摘要：Abstract:In video-based automatic gesture recognition, interfering factors such as hand occlusion and color closeness between background and skin of the signer often result in errors in hand segmentation and hand tracking. In light of this, this article introduces a method to differentiate left and right hand in videos of signing. Through the differentiation of each hand, hand segmentation in videos can be assisted, and left/right hand tracking error due to hand occlusion can be diminished. In this method, feature of histograms of oriented gradients (HOG) in the training samples using single hand, either left or right hand, was firstly extracted. Next, principal component analysis (PCA) was carried out on hand feature, and the three different patterns of left hand, right hand, and hand occlusion were then generated through eliminating redundant information. Lastly, left-right hand differentiation was realized through pattern matching. The results of the experiment showed that the method adopted in this study helped realize relatively sound recognition rate.关键词：Gesture recognition;image classification;Histograms of oriented gradients (HOG);Principal component analysis (PCA);feature extraction
- 1603
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- 14
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- 0
发布时间：2023-11-14 - 摘要：Abstract:A new method based on ultrasonic radiofrequency signal has been proposed for normal liver and fatty liver steatosis degree, especially diagnose mild fatty liver. In this paper, we analyze the RF signal in two domains: the time domain and the frequency domain. Firstly, in the time domain, the power of RF signal was in accord with normal distribution, and the mathematical expectation (ME) of liver RF signal was extracted as the feature parameter. In the frequency domain, wavelet transforming was used to analyze RF signal, and low-frequency wavelet coefficients mean (LWCM) and wavelet transform modulus maximum mean (WMMM) were extracted as feature parameter. Finally, back-propagation (BP) artificial neutral network was employed to classify these RF signals. The accuracy rates with BP neural network are 90.0% for normal liver RF signal, 86.7% for mild fatty liver RF signal, 83.3% for moderate fatty liver RF signal, and 90.0% for severe fatty liver RF signal. The result shows that the ME, the LWCM and the WMMM can successfully describe the features of liver RF signal. This study shows that the ultrasonic RF signal is effective in diagnosing liver fatty degree, and so far, there is no reports about grading fatty liver based on ultrasonic RF signal. This paper provides a new direction for computer-aided diagnosis of fatty liver.关键词：fatty liver;radio-frequency;wavelet transform;BP artificial neutral network
- 2169
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- 72
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发布时间：2023-11-14 - 摘要：Abstract: For the fixed group structure (GOP) is not use of the correlation between video frames fully, a new adaptive GOP was proposed. The proposed algorithm estimated the bit rate necessary for successful decoding of Wyner-Ziv frames, which relied on distribution modeling the statistics of the residual between the side information and the WZ frame. Then, the encoder dynamically selected the image group structure by means of bit rates. The new algorithm can further improve the performance of the entire coding system by exploiting the correlation between video frames. The simulation results showed a significant gain in the average PSNR that can reach 0.4~0.7dB compared with the fixed-GOP coding, meanwhile maintaining a low encode complexity.关键词：Distributed Video Code;Wyner-Ziv;adaptive GOP structure;side information
- 1638
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- 26
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- 0
发布时间：2023-11-14 - 摘要：Abstract:A Fixed threshold is usually used for synchronous detection in traditional Frequency Shift Keying (FSK) system based on Discrete Fourier Transform (DFT). The disadvantage of the fixed threshold is that it cannot adjust itself dynamically to the change of signal fading and noise jamming in a time-varying channel, which makes the system unsuitable for practical applications. To solve this problem, a novel adaptive threshold demodulation method based on random signal detection and estimation theory is proposed. Then the rigorous theoretical proofs are shown, and the definite expression of the adaptive threshold is given in this study. Finally, simulation results show that the adaptive threshold can adapt to the channel condition change under different signal-to-noise ratios (SNR). And the false alarm and detection probabilities agree well with the theoretical analyses. The algorithm can effectively resolve the problem of the threshold-choosing in the time-varying channel.关键词：adaptive algorithm;Frequency Shift Keying ( FSK );maximum likelihood estimation;Discrete Fourier Transform ( DFT );power spectrum estimation
- 1738
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- 10
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- 0
发布时间：2023-11-14 - 摘要：Abstract:Aiming the degrading performance of cooperative detection for cognitive radio brought by the inaccurate detection of the cognitive users with low SNR, a cooperative detection algorithm in which the user with high SNR can transmit its detection information to the user with low SNR as a relay. In the proposed algorithm, the user with high SNR transmits its detection information to all the users whose SNR is lower than it, and every user combines all the received detection information including the local detection information to attain the local decision which can maximize the detection probability through choosing the optimal weighing genes. Then the coordinator combines all the users’ decisions to obtain the final decision about primary user. Simulation shows the detection probability of the proposed algorithm outperforms that of the tradition algorithm, and when the average SNR increases, the detection probability of the proposed algorithm will increase greatly.关键词：cognitive radio;energy detection;cooperative detection;relay transmission
- 1601
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- 12
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- 0
发布时间：2023-11-14 - 摘要：Abstract:In this paper, fractional Fourier transform (FrFT) angle was regarded as a kind of time-frequency combined resource, and a novel multi-stream orthogonal frequency division multiplexing (OFDM) technology based on FrFT angle division multiple access (ADMA) was proposed in IEEE802.11g wireless local area network (WLAN) by designing optimal allocation criteria for improving data transmission rate. At the transmitter, multiple streams were modulated by inverse FrFT with different angles, and at the receiver, due to the mutual orthogonality between base functions of identical stream at different sub-channels, and the nearly mutual orthogonality between base functions of different streams at same sub-channels, the inter-stream interference could be perfectly suppressed by correlative detection in FrFT domain. The final simulation results showed that the transmission rate could be improved greatly, comparing with conventional single-stream OFDM technique in IEEE802.11g.关键词：communication transmission technique;IEEE802.11g;OFDM;fractional Fourier transform;angle division multiple access
- 2233
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- 26
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- 0
发布时间：2023-11-14 - 摘要：Abstract: This paper presents and investigates the performance of new STBC-MIMO systems with opportunistic scheduling (OS) and transmit antenna selection (Tx-AnSS), where the user and the antenna subset are adaptively selected according to channel state information (CSI), which is feedback from the receive side. First, we derive both analytical forms and approximation expressions for the average effective SNR and outage probability, showing that combining multiuser diversity (MUD) and Tx-AnSS provides much larger diversity and better performance than the scheme without MUD or Tx-AnSS. Further, the diversity gain of outage probability is also quantified through asymptotic analysis. Finally, we verify the analytical results through corresponding simulation results.关键词：MIMO;STBC;Antenna subset selection;Opportunistic scheduling;Multiuser diversity
- 1758
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- 50
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- 0
发布时间：2023-11-14 - 摘要：Abstract:Cooperative Spectrum Sensing (CSS) is one of the vital mechanisms of cognitive radio (CR), however, its security area has attracted very little attention, which is vulnerable to the SSDF attacks. To counter the SSDF attacks, an accumulated suspicious level-based algorithm was proposed. It calculated the accumulated suspicious level based on the distances of all secondary users’ reporting histories. With appropriate thresholds, the scheme distinguished honest secondary users and malicious secondary users. Only the secondary users that had been rectified can be used in the decision combination at the fusion centre (FC). Unlike other existing security schemes, the algorithm did not assume any a priori information about the strategy of attackers and can detect the intelligent attackers. Extensive simulations illustrated the effectiveness of the proposed scheme by showing that the scheme can effectively detect different types of SSDF attackers and decrease the negative impacts of SSDF attacks in CSS.关键词：cognitive radio;cooperative spectrum sensing;accumulated suspicious level;sensing security;spectrum sensing data falsification
- 2109
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- 60
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- 0
发布时间：2023-11-14 - 摘要：Abstract: In order to put the direct force to effort more effectively, and improve the work efficiency of pulse thrusters and the precision of tracking control instruction, the fire algorithm of pulse thrusters based on fuzzy control theory is proposed. Taking the ERINT-1 as research object, missile rigid body six-degree-of-freedom compound control mode is established. To the characteristic of pulse thrusters distributing, using the infinity maximal approach characteristic, the fir controller of pulse thrusters is designed. The example simulation shows that compared with conventional fire algorithm, this method can reduce the using number of pulse thrusters, shorten missile response time, add missile mobile available load, and have higher control precision and Robust quality.关键词：fuzzy control;fire algorithm;direct force control;compound control
- 1333
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- 12
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- 0
发布时间：2023-11-14 - 摘要：Abstract:The mechanical vibration acceleration signals, which indicate the equipment running state, are complex. This imposes a strict requirement on measuring and diagnosis. Based on PXI and power analysis software, this paper presents the design of a monitoring and diagnosis system for vibration acceleration of axial flow pump. And the system realizes the signal feature extraction by analyzing vibration intensity and amplitude spectrum of frequency division. The results of experiments show that the monitoring and diagnosis system can monitor vibration acceleration of radial, tangential and axial on-line. Experimental results also show that the system can judge mechanical failure, such as axis eccentricity, impeller eccentricity and wear ring abrasion. In short, the design requirement is met.关键词：axial flow pump;vibration acceleration;feature extraction;mechanical failure
- 1544
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- 14
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- 0
发布时间：2023-11-14 - 摘要：Abstract:In order to accurately learn the interior temperature distribution condition of the vehicular shock absorber, and thus lay the foundation for its reliability design, a high accuracy fluid grid model which described the throttle valve was established on the basis of the symmetry structural characteristics of a vehicular shock absorber. By applying the computational fluid dynamics (CFD) numerical method and using the CFX simulation software, it was simulated under a harmonic excitation and the heat transfer process of forced convection in the working cylinder tube was calculated, furthermore the heat generation process and temperature field distribution situation of oil in the shock absorber was obtained. The study results show that by using this simulation method, the temperature rising process and heat generation mechanism of the vehicular shock absorber can be clarified, in addition some references which are used to improve the research on the temperature rising theory of the shock absorber, can be provided from the analysis conclusions.关键词：shock absorber;temperature distribution;forced convection;heat transfer;heat generation mechanism
- 1558
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- 88
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- 0
发布时间：2023-11-14 -
Simulation Study on the Best Engine-Propeller Associated Control Method of Ship Accelerating Process
摘要：Abstract:A simulation model of Combine Diesel And Diesel propulsion system is built in Matlab/SIMULINK environment, and the model is integrated and improved using MFC. The simulation model is verified by the trial data, and the result shows the data from the simulation model is close to the trial data. Two “Engine-Propeller” control methods of accelerating process of this propulsion system are proposed, one is symmetrical accelerating process, of which the engine speed and the proprller pitch increase equably; the other is changeable accelerating process, in which the increase rate of the engine speed or the proprller pitch is changeable. Both of the two control method are designed and simulated. The simulation results show that when adopting the second control method, the flexibility of the ship accelerating process improved remarkably.关键词：accelerating process;“Engine-Propeller” associated control;simulation;mixed-programming- 1293
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- 4
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发布时间：2023-11-14 - 摘要：Abstract: Because of the design of a manipulator was one the important issues in the field of multi-joint robots, based on the theory of the physical model of the solution space, the design of the planar 6-DOF manipulators was discussed. Analyzing the features of the design of 6-Dof multi-joint robot with small load, it proposed a method which is from the task of the end work load to put out the driving force and power required for each bar to select the driving components and design the mechanism. Mathematical models of forward and inverse solutions were established to resolve the anti-kinematic analytical solution problem by Jacobi matrix and the velocity of each joint with multi-joint robot was obtained. On the basis of selected speed, it calculated the torque and selected the motors and reducers with the considering of the cost-effective. According to the dimensions of the motors and reducers, body shape was designed from the end of the multi-joint robot. The design example proved that the robot possesses an better kinematic characteristics and provided a simple and useful way for the design of the multi-joint robots.关键词：robot;Jacobi;kinematics
- 2138
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- 8
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发布时间：2023-11-14 - 摘要：Abstract:In order to study the protection efficiency of water hammer by non-slam air valve, a mathematical model of non-slam air valve was set up based on the mathematical model of conventional air valve and the working principles of non-slam air valve. Solution method for the mathematical model of non-slam air valve was presented by using the theory of water hammer and the method of characteristics. Calculations were carried out for comparing the protection efficiency between the conventional air valve and the non-slam air valve. The influence factors of protection efficiency by the non-slam air valve were analyzed and optimum values of the factors were recommended. The calculation results show that the non-slam air valve can be used to decrease the water hammer negative pressure and positive pressure effectively. Its protection efficiency is related to the critical pressure of the throttle plate position change and the area ratio between the throttle plate orifice and the air valve orifice. Research results presented herein provide the scientific basis for the design, operation and management of non-slam air valve.关键词：non-slam air valve;water hammer;pressure conduit;water supply project
- 1928
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- 24
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发布时间：2023-11-14
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