最新刊期
卷 43 ， 期 2 ， 2011
- 摘要：Abstract:Catalytic oxidation of HCl to Cl2 is very important to efficient recycling of chlorine. In this paper, temperature-programmed analysis technology (TPAT) was used to study the adsorption of HCl and release of Cl2 on 14 different metal oxides. The reaction mechanisms of metal oxides and HCl、residual chlorine after reaction and thermodynamic data were explored by using XRD、XPS and Gaussian 03 program. It is significant to the development of the reaction catalyst and process. The results showed that CoO has a better absorption of HCl(absorption rate:85.4%) and release of Cl2(release rate:85.2%). Residual chlorine after reaction was 12.8% and CoO was still better during much recycled use. Therefore CoO was the optimal catalyst in the two-step catalytic oxidative reaction of HCl to Cl2. In the temperature range studied, chlorination reaction was exothermic、spontaneous and irreversible. Oxidation reaction was the opposite.关键词：metal oxide;HCl;catalysis;chlorine;Benson
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发布时间：2023-11-14 - 摘要：Abstract:Abstract: Activated carbon was prepared from pyrolusite-added sewage sludge by ZnCl2 activation method. Its structure and performance were characterized by BET, SEM, FT-IR, XRD, O2-TPO and TGA, and the impact of pyrolusite to preparing process of activated carbon was analyzed. The result showed that the specific surface area, total pore volume, micro-pore volume, average pore radius and iodine adsorption of activated carbon from pyrolusite-added sewage sludge can reach 354.198m2/g, 0.8096cm3/g, 0.159cm3/g, 4.6nm and 558.05mg/g respectively under the experiment condition, and the above performance parameters were increased in a great extent compared with activated carbon from sewage sludge. Pyrolusite catalyzed the decomposition of organics in the sewage sludge, supply the new generated carbon more framework, facilitated the carbon deposit and contributed to the formation of microcrystalline structure simultaneously in the preparing process of activated carbon from pyrolusite-added sewage sludge.关键词：pyrolusite, sewage sludge , activated carbon
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发布时间：2023-11-14 - 摘要：Abstract:Abstract: A yeast strain S3 screened from the fruits was applied successfully to the close-circulating ethanol fermentation in the PDMS membrane bioreactor. Three parallel pure cultures in flakes were conducted for yeast strain S3. The max cell concentration, ethanol productivity and ethanol yield on glucose were 5.37 g/L, 1.90 g/L/h, 0.449g/g, respectively. With incubating S3 into the PDMS membrane bioreactor, the close-circulating ethanol fermentation was conducted, and the ferment experiment was steadily going on for 524.4h. The ethanol productivity was 1.48 g/L/h, and the glucose utilization 3.55 g/L/h. The yeast cell viability was still over 30% at the termination of fermentation. The ethanol yield on glucose was 0.416g/g, higher than that of strain S0 under similar ferment process. The ethanol yield on biomass and the specific ethanol formation rate of S3 through the ferment process were 77.63 g/g and 0.148 g/g/h, more 57% and 71% than those of S0, respectively. The experimental results indicated that strain S3 might be acclimatized and evolved to some extent in process of the close-circulating ethanol fermentation in the PDMS membrane bioreactor, and behave superior fermentation features to industrial Angel yeast strain S0.关键词：PDMS membrane bioreactor;yeast;breeding;acclimatization
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发布时间：2023-11-14 - 摘要：Abstract:A type of bioreactor using wood sawdust as solid support inoculated with Thiobacillus sp. was developed for the removal of H2S in waste gases. The bacteria were isolated from a hot spring in Sichuan province. The results showed that wood sawdust provided high bacteria adsorption capacity. The maximum removal capacity was 530 g·m-3·h-1 (removal efficiency of 80 %) for gas flow rates in the low rage of 6~18 L·h-1. However, in the high gas flow rates of 21~36 L·h-1, there was no evident critical point of inlet S-loading. The effect on the production of SO42- was also studied. The concentration of SO42- was increased as gas flow rate increasing at the constant inlet S-loading. And when the gas flow rate was constant, the concentration of SO42- was high at low inlet S-loading (<450 g·m-3·h-1). On the contrary, if the inlet S-loading was higher than 450 g·m-3·h-1, the production rate of SO42- was extremely low and the conversion products were mainly sulfur. Thus the range is helpful to recover elementary sulfur. The removal rate of H2S in the bioreactor was modelled using a modified Michaelis-Menten type model. Good non-linear regression coefficients of R2 (>0.95) between experimental data and the predicted curves were found.关键词：desulfurization;Hydrogen sulphide;Bioreactors;Wood sawdust
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发布时间：2023-11-14 - 摘要：Abstract:On the base of thermodynamic analysis of pure nickel and iron oxides' hydrogen reduction, direct hydrogen reduction process of a low-grade complex laterite-nickel ores has been studied, the influence of reduction temperature, reduction time, hydrogen content of nitrogen and hydrogen mixture on the reduction degree were investigated, and also the phase analysis of reduction product. Result shows that as the complexity of the laterites’ composition, the reduction rate decreased because of bonding and coating generated from the formation of eutectic phase at high temperature. Optimum condition as reduction temperature 850℃, reduction time 40min, hydrogen content 65% in gas mixture, nickel and iron reduction rates are 43% and 62%. The reduction of iron oxides is a fractional process.
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发布时间：2023-11-14 - 摘要：Abstract:The aging of polyacrylate latex films (PLF) in simulating acid rain is complicated, involving crosslink, degradation and etching. This paper focused on the aging mechanism of PLF in simulation acid rain on molecular scale through studying the change of the free volume by positron lifetime spectrum. Via examining the variations of weight, gel content, absorption of water and the microstructure of PLF with ageing time in simulating of environment, it is found that the dominating mechanism of PLF aging in acid rain has three stages: crosslinking first, followed by degradation and erosion finally.关键词：simulated acid, polyacrylate latex films, aging mechanism,free volume, positron lifetime spectrum
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发布时间：2023-11-14 - 摘要：Abstract:A novel photo-electro-chemical catalytic reactor with single/double compartment was designed. TiO2/Ti thin film electrode was used as photo-anodes, graphite as cathode and a saturated calomel electrode (SCE) as the reference electrode in the reactor. It is different that the anodic compartment and the cathodal compartment was partitioned off from each other and connected through salt bridge in the dougle-compartment reactor, while the same one in the single-compartment reator. The performance on the degradation of methyl red(MR) and methyl orange(MO) were compared between these two reactors. The effects of initial pH value and accumulative concentration of H2O2 on the decolorization rate of MR were investigated. It showed the MR was degradated effectively in these two reactors and the percent degradation were 96.9% (double-compartment) and 76.2% (single-compartment) respectively. The degradations all decreased with pH value changed from 3.0 to 7.0, while all increased with pH value changed from 7.0 to 12.0. It was more effective in the double-compartment reactor than in the single-compartment reactor during the degradation. And it was result from the higher concentration of H2O2 in the double-compartment reactor. Because in the single-compartment reactor, H2O2 generated during cathodal reaction diffused to the anode and was consumed, which could be prevented in the double-compartment reactor because of the clapboard. Under the conditions of cathodic potential Ec at -0.6V, initial solution pH at 3.0 and initial solution concentration 30 mg•L-1, the catalytic degradation of MR and MO were both pseudo-first order reactions.关键词：reactor;photo-electro-chemical catalysis;methyl red;methyl orange
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发布时间：2023-11-14 - 摘要：Abstract:Abstract: In order to investigate the phenomenon of hydrogen absorption and decrepitation of NdFeB alloy, the diffusion time of hydrogen in HD process of NdFeB alloy was theoretically calculated with the Fick diffusion equation. When NdFeB alloy whose granularity was 5 millimeters was treated with hydrogen decrepitation at 25℃, the total diffusion time of hydrogen which successively entered the center of the alloy granule, Nd-rich phase and Nd2Fe14B phase was 31.5 minutes calculated with the Fick diffusion equation, while the actual time of hydrogen decrepitation was 30 minutes. The results showed that the theoretically calculated hydrogen diffusion time coincides well with the practically needed time in HD process of NdFeB alloy, and indicated that the mathematical model of hydrogen diffusion in HD process of NdFeB alloy based on the Fick diffusion equation tallys well with the practical HD process.关键词：NdFeB;hydrogen decrepitation;diffusion;mathematical model
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发布时间：2023-11-14 - 摘要：Abstract:If carbon fiber is added to common concrete, then the common concrete becomes smart concrete with self-diagnostic functional characteristic. By using the functional characteristics of the intellectual concrete, the health monitoring of the civil engineering structure and infrastructure is expected to achieve. In this paper, the continuous carbon fiber-bundle was used to replace the chopped carbon fiber in the traditional carbon fiber reinforced concrete. The changing rule of the resistance of the part-stromatolithic carbon fiber cement-based materials three-point-bending beams was studied when they were loaded on monotonous or cyclic tension stress. The strain resistance effect of part-stromatolithic carbon fiber cement-based materials was analyzed and compared with that of the continuous carbon fiber cement-based materials. The results showed that: (1) the part-stromatolithic carbon fiber cement-based materials was near 23 times the gauge factor of the continuous carbon fiber cement-based materials, but their stability was worse. (2) The resistance of the part-stromatolithic carbon fiber cement-based materials increased along with the increase of tension strain and decreased along with the decrease of tension strain. The part-stromatolithic carbon fiber reinforced cement-based materials were expected to performance the health monitoring of the civil engineering structure and infrastructure.关键词：part-stromatolithic;carbon fiber-bundle;cement-based;strain resistance effect
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发布时间：2023-11-14 - 摘要：Abstract:The main purpose of chromate treatment is to improve anti-corrosion by conversioning a metal surface.But hexavalent Chrome (Cr, Cd, Pb, Hg) is considered carcinogenic and has been banned in many areas of the World. This paper made a Coating Layer Structure and anti-corrosiveness study on Tannic Acid-H2TiF6/SiO2 composite coating from hot-dip galvanized steel sheet，it is Investigating the coating Corrosion relations on PMT, pH and film thickness. The optimum operation condition is at pH = 3 and in the PMT range of 60-80 degree centigrade.
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发布时间：2023-11-14 - 摘要：Abstract:The new test material which was SA508-3 steel used for nuclear power has been subjected to tensile test in the six temperature levels(800℃～1300℃) by solidifying methods on Gleeble-1500D thermal simulation testing machine to analysis the microstructure changes. It was found that the strain, the reduction in area and the thermal strength were all the most value at 1000℃ temperature; the fracture organization of six temperatures were all different form lath martensite; the maximum hardness of 800℃, 1000℃ and 1300℃ test sample were at 10mm, 14mm and 18mm，respectively, the hardness range ability of 1000℃was the lesser, the two other were the larger extent; The fracture morphology of low temperature plastics was main inter granular brittle fracture, which provided the basic parameters has important practical value for weld numerical simulation.关键词：SA508-3 steel, high temperature tensile test, microstructure
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发布时间：2023-11-14 - 摘要：Abstract:In order to solve the problem of traditional median filter that filtering algorithms are very time consuming and can't meet the need of real time processing, a novel fast median filtering algorithm was proposed, which changed the process of finding median element from quick sorting into binary searching. The new algorithm didn't rely on filtering window shape and the relative information of adjacent windows, and effectively reduced the time complexity of standard median filter from O(nln n) to O(n). Experiments showed that the new algorithm is at least three times faster than standard median filter and computing time is increasing linearly with filtering window size, which proved that it has special value in large-scale image real time processing.关键词：median filter;fast algorithm;time complexity;image processing
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发布时间：2023-11-14 - 摘要：Abstract:For the demands of real-time, reliability and energy-efficiency in dependable embedded systems, a new scheduling algorithm was proposed for aperiodic real-time tasks. Based on the essential characteristics of aperiodic real-time tasks, the schedule slacks of tasks were used to reduce energy consumption by dynamic voltage/frequency scaling mechanism. Low time complexity, minimal system energy consumption, and non-violated high reliability and hard real-time, are main advantages of the proposed algorithm. The superiorities of our algorithm on reliability and energy efficiency were also showed by experiments.关键词：Embedded System, Energy Efficiency, Reliability, Real Time System, Scheduling Algorithms
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发布时间：2023-11-14 - 摘要：Abstract:In this paper, a new switched modified function projective synchronization(SMFPS) problem of chaotic system and the application in secure communication is researched.Based on Lyapunove stability theory and active control method, nonlinear feedback controller and the parameters update laws were presented for the switched modified function projective synchronization(SMFPS) between two identical hyperchaotic system with completely unknown parameters.Then this method was applied to secure communication through chaotic masking . The information signal, through function transformations,was masked by the state variables of the drive system and sent to the receiver as a drive signal, then the information signal was recovered at the receiver by eliminating the scaling function and the anti-function transformation. The control strategy had stronger security and practicality. The corresponding numerical simulations demonstrated the effectiveness of the proposed methods.关键词：Hyperchaotic system;Switched modified function projective synchronization;adaptive;secure communication
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发布时间：2023-11-14 - 摘要：Abstract: According to the transmission principle of two-tooth difference swing movable teeth transmission, the force analysis of two-tooth difference swing movable teeth transmission was carried out. It was found that the normal distortions of contact points of the swing movable teeth along with the surge wheel submit to sine distribution. The explicit calculation formulae of the forces were derived, which were acted on the main parts of the transmission: swing movable teeth，the surge wheel，movable tooth spar pegs，and the internal gear. The method of strength calculation of two-tooth difference swing movable teeth transmission was put forward.Aiming at the main failure forms of two-tooth difference swing movable teeth transmission, based on the Hertz theory of elasticity mechanics, the calculation formulas of contact fatigue strength for meshing pairs between swing movable teeth and the surge wheel, meshing pairs between swing movable teeth and the internal gear in two-tooth difference swing movable teeth transmission were derived. The method to compute bending strength of the movable tooth spar peg in two-tooth difference swing movable teeth transmission was investigated. And the corresponding calculation formulae were derived. A numerical example was given for illustration.The results showed that above-mentioned calculation formulas of forces and strength are correct.The research results can be used as a theoretical basis for the design of two-tooth difference swing movable teeth transmission.关键词：two-tooth difference;swing;movable teeth transmission;force analysis;strength calculation
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发布时间：2023-11-14 - 摘要：Abstract:A permanent magnetic and vacuum mixed adsorption wall-climbing robot for ship rust removal is designed, which has the characteristics as big loading and weight robot body, and there is water jet kick and vacuum negative pressure force in normal direction of wall surface. The static models for glide and tip back are established. According to the three forced states in normal direction of wall surface, the glide and the tip back models are analyzed, and the forced state of permanent magnetic unit between glide and tip back are compared. Simulation and experimental results show that the vacuum negative pressure force improves the adsorption capacity obviously, the permanent magnetic and vacuum mixed adsorption may reduce the adsorption force greatly, and in the robot normal work, the robot can attach the wall in low vacuum negative pressure.关键词：Ship rust removal Wall climbing robot Simulation analysis Wall-attachment performance Static model
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发布时间：2023-11-14 - 摘要：Abstract:Through the analysis for the kinetic equation of over-actuated parallel manipulator, it is proved that the partial actuator failure can be avoided by reasonably distributing torque output of each actuator, thus the first occurrence of failure can be deferred. The capacity of each actuator is first discussed in this paper, and then the concept of the output margin is proposed. The drive torque optimization model is accordingly put forward. With the selection criteria of the weighted coefficient constructed from output margin, independent mediation of each drive is achieved. The torque distribution method under balanced output margin and mean output margin of partial actuator is conducted, so the loading of each actuator is coordinated. With a planar three DOF redundant actuated parallel manipulator, the result of calculation and analysis shows that the proposed method is helpful to regulate the balanced margin output of each actuator and thus prevent partial actuators from over loading.关键词：parallel manipulator;redundant actuation;weighted coefficient
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发布时间：2023-11-14 - 摘要：Abstract:Based on expounding the engagement theory of the planar envelopment hourglass worm, principle of dummy gyration center was analyzed detailedly and applied to machining the worm. The planar wormgear were finishing ground on the THM63100Ⅳ. Machining error of wormgear was tested and transmission error of worm gears was measured by the motion property testing and analysing system(FMT). Bachlash was adjusted and contact marks were observed during assembling. The results of error detection show that the accuracy of wormgear is up to 5 degree in china GB 10095-88 and the worm gears drives smoothly. The results of assembly show that backlash is adjusted successfully in the range of 0.003~0.025mm and contact marks are consistent with theoretical contact zones. It is concluded that the harding teeth surface of planar wormgear and its worm can be ground simply and the backlash of worm gears can be adjusted easily. Research and development of the planar worm gears is valuable.关键词：worm gears;grinding worm gear;principle of dummy gyration center;assembly;error analysis
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发布时间：2023-11-14 - 摘要：Abstract:Ambient vibration is the main factor that influence on the structure stability of inertial confinement fusion (ICF) solid state laser driver. The ambient vibration includes broadband ambient vibration, local vibration and so on, which effect on the design of optical and build of environment control system. The stability of optical elements is analyzed in this paper by the method do pseudo excitation and gets the weights formulation of all kinds of vibration. Muti-channel micro vibration measurement equipment is used to analyze the ambient vibration of Shengguang-Ⅲ technical integrate line (SG-Ⅲ TIL) and get the weights coefficient of HVAC ( high ventilation air condition) vibration, vacuum set vibration and broadband ambient vibration, which are 0.457,0.281 and 0.162. The weights coefficients are different from NIF, which is important for the designing optimization and improving the vibration control level of TIL and the more large-scale ICF driver.关键词：ICF driver;ambient load;pseudo excitation;weight coefficient
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发布时间：2023-11-14 - 摘要：Abstract:Abstract：Aimed at the problems of low control accuracy and weak robustness influenced by external disturbance force, friction force, parameter variation, modeling errors and other issues in flexible joint robot control system, a new structure robust controller based on adaptive fuzzy sliding mode control is proposed in this paper. The controller consists of two parts: the nominal section of the system including the parameter relative to robot structure, deterministic disturbance and the linear part of the friction force can be controlled effectively by computed torque and feed-forward compensation of controller; The other influence of the uncertainty such as the external uncertainty disturbance, nonlinear friction force, parameter variation, modeling error and so on can be eliminated by adaptive fuzzy sliding mode control controller. Finally, experiments relative to the controller are carried out on the arm of a HIT type four degree of freedom flexible manipulator. The results show that the controller is of a good position tracking performance and a strong anti-disturbance.关键词：flexible manipulators;adaptive fuzzy sliding mode control;nonlinear system;uncertainty disturbance
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发布时间：2023-11-14 - 摘要：Abstract:The oil leakage under too high temperature which occurred in the course of shock absorber’s work process is not only a key problem which troubled the reliability design of the shock absorber, but also one of important factors to affect the vehicle ride. To investigate the influence rules of thermo-physical properties of the shock absorber on its reliability design, the transmission model of heat transfer rate and physical heat-transfer model of the twin-tube hydraulic gas-charged shock absorber was built and the equations of heat conduction, heat convection, as well as radiation heat transfer were derived, furthermore its thermodynamic model was established by the first law of thermodynamics. The temperature and the work time when the shock absorber had reached the thermal equilibrium were calculated by iterative algorithm, and the effects of thermo-physical properties on its temperature rising were analyzed innovatively, moreover the associated sensitivity analysis was carried on it finally. The simulation results show that four kinds of thermo-physical properties of the shock absorber affect its temperature rising characteristics. The references, which are used to enhance the reliability design of the shock absorber, can be provided from the analysis conclusions.关键词：shock absorber;thermo-physical properties;iterative algorithm;thermal equilibrium
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发布时间：2023-11-14 - 摘要：Abstract:Based on document review of the 849 papers published in 24 issues of “Journal of Sichuan University (Engineering Science Edition) ” from 2006 to 2009, the statistical data including the load of issued papers and citations, the language, category, and publish year of citations, etc. was analyzed with the methods of quantitative bibliometrics. Systematic and scientific data was provided, the change and development of JSCU were studied. The result shows that the load of papers issued in JSCU is steadily up especially in 2009. On average annual paper load is 212 and 87.5% of the issued papers are fund-supported. All the papers have citations. The average number of citations is 12 for each paper. The citations in English cover 52.9% and the citations form journals cover 70.4%. The Price index is going up during the last three years and the average is 38.95%. This indicates that the novelty of papers is increasing. The analysis provides ample evidence to illustrate the innovation and academic level of JSCU.关键词：citation analysis;Journal of Sichuan University;bibliometrics
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发布时间：2023-11-14
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