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Effects of Fibre Additive on the High Temperature Property of Asphalt Binder

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Journal of wuhan University of technology(Materials {2.) 2006年第1期21卷 118-120页

作者：吴少鹏 Key Laboratory for Silicate Materials science and engineering of Ministry of Education Wuhan University of TechnologyWuhan 430070 China

Polyester fibre and floc xylogen fibre were used to prepare fibre-asphalt binder. An SHRP＇ s dynamic shear rheometer （DSR） was employed to inwtigate the rheology characteristics of fibre-asphalt binder, and the flow resistance of binder was revealed by combining the rutting parameter, G＂ / sinδ . The results indicate that both kinds of fibres remarkably improved the high temperature performance of asphalt binder. At the same time, the reinforcement mechanism of the fibres in the asphalt binder was also analyzed.

关键词： fibre asphalt proerty reinforcement

Large-eddy simulations and vortex structures of turbulent jets in crossflow

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science china(Physics,Mechanics & Astronomy) 2007年第1期50卷 118-132页

作者： GUAN Hui1,2.& WU ChuiJie2.1 School of Mechanical and Power engineering,East china University of {2. and technology,Shanghai 2.02.7,china 2.Research Center for Fluid Dynamics,PLA University of {2. and technology,Nanjing 2.1101,china 1. School of Mechanical and Power engineering East China University of Science and Technology Shanghai 200237 China 2. Research Center for Fluid Dynamics PLA University of Science and Technology Nanjing 211101 China

Using the method of large-eddy simulation, the 3-dimensional turbulent jets in crossflow with stream-wise and transverse arrangements of nozzle are simulated, emphasizing on the dynamical process of generation and evolution of vortex structures in these flows. The results show that the basic vortex structures in literatures, such as the counter-rotating vortex pair, leading-edge vortices, lee-side vortices, hanging vortices, kidney vortices and anti-kidney vortices, are not independent physical substances, but local structures of the basic vortex structure of turbulent jets in crossflow-the 3-D stretching vortex rings originating from the orifice of the nozzle, which is discovered in this study. Therefore, the most important large-scale structures of turbulent jets in crossflow are unified to the 3-D vortex rings which stretch and twist in stream-wise and swing in transverse directions. We also found that the shedding frequencies of vortex rings are much lower than the one corresponding to the appearance of leading-edge and lee-side vortices in the turbulent jets.

关键词： turbulent jet in crossflow coherent structure large-eddy simulation

Particle swarm optimization algorithm for partner selection in virtual enterprise

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Progress in Natural science:Materials International 2008年第11期18卷 1445-1452页

作者： Qiang Zhao~a Xinhui Zhang~(b,*) Renbin Xiao~c a School of Mechanical science and engineering,{2. University of science and technology,wuhan 43.074,china b Department of Biomedical,Industrial & Human Factors engineering,Wright State University,Dayton,OH 45435,USA c institute of Systems engineering,{2. University of science and technology,wuhan 43.074,china School of Mechanical science and engineering Huazhong University of Science and Technology Wuhan 430074 China Department of Biomedical Industrial & Human Factors Engineering Wright State University Dayton OH 45435 USA institute of Systems engineering Huazhong University of Science and Technology Wuhan 430074 China

Partner selection is a fundamental problem in the formation and success of a virtual *** partner selection problem with precedence and due date constraint is the basis of the various extensions and is studied in this paper.A nonlinear integer program model for the partner selection problem is *** problem is shown to be NP-complete by reduction to the knapsack problem,and therefore no polynomial time algorithm *** solve it efficiently,a particle swarm optimization(PSO)algorithm is adopted,and several mechanisms that include initialization expansion mechanism,variance mechanism and local searching mechanism have been developed to improve the performance of the proposed PSO algorithm.A set of experiments have been conducted using real examples and numerical simulation,and have shown that the PSO algorithm is an effective and efficient way to solve the partner selection problems with precedence and due date constraints.

关键词： Virtual enterprise Partner selection PSO NP-complete

Analysis for twinning and slip in face-centered cubic crystals under axisymmetric co-deformation

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science china(Technological sciences) 2006年第5期49卷 521-536页

作者： CHEN Zhiyong1,2. CAI Hongnian1, ZHANG Xinming2. WANG Fuchi1 & TAN Chengwen1,3 1. School of Material science and engineering, Beijing {2. of technology, Beijing 100081, china 2. School of Material science and engineering, Central South University, Changsha 410083, china 3. School of Material science and engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, china 1. School of Material science and engineering Beijing Institute of Technology Beijing 100081 China 2. School of Material science and engineering Central South University Changsha 410083 China 3. School of Material science and engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China

The maximum work principle of Bishop-Hill was developed to analyze the axisymmetric co-deformation in face-centered cubic crystals (f.c.c.) for twinning on {111} 112.and slip on {111} 110 systems. The influence of ξ , the ratio of critical re- solved shear stress for twinning to slip, on the yield stress states and corresponding active slip or/and twinning systems for orientations in the standard stereographic triangle of cubic crystal was investigated systematically. The Taylor factors and the anisotropy of yield strength for three important orientations [100], [110] and [111] in orientation space were analyzed. It is found that the yield strength asymmetry for the case of axisymmetric de- formation of tension and compression can be explained based on the microscopic theory of crystal plasticity. The concept of orientation factor for twinning ability was proposed and the deformation mechanism map in the orientation space was established for the case of axisymmetric deformation. The deformation texture formation and development of f.c.c. crystals with low stacking fault energy for axisymmetric tension can be explained qualita- tively on the basis of analyzed results.

关键词： twinning slip face-centered cubic crystals axisymmetric co-deformation Bishop-Hill maximum work principle yield strength anisotropy

CLASSIFICATION OF GEAR FAULTS USING HIGHER-ORDER STATISTICS AND SUPPORT VECTOR MACHINES

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Chinese Journal of Mechanical engineering 2002年第3期15卷 243-247页

作者： Lai Wuxing Zhang Guicai Shi Tielin Yang ShuziSchool of Mechanical science and engineering, {2. University of science and technology,wuhan 43.074, china *** School of Mechanical science and engineering Huazhong University of Science and Technology Wuhan 430074 China

Gears alternately mesh and detach in driving process, and then workingconditions of gears are alternately changing, so they are easy to be spalled and worn. But becauseof the effect of additive gaussian measurement noises, the signal-to-noises ratio is low; theirfault features are difficult to extract. This study aims to propose an approach of gear faultsclassification, using the cumulants and support vector machines. The cumulants can eliminate theadditive gaussian noises, boost the signal-to-noises ratio. Generalisation of support vectormachines as classifier, which is employed structural risk minimisation principle, is superior tothat of conventional neural networks, which is employed traditional empirical risk minimisationprinciple. Support vector machines as the classifier, and the third and fourth order cumulants asinput, gears faults are successfully recognized. The experimental results show that the method offault classification combining cumulants with support vector machines is very effective.

关键词： Support vector machine Gear Fault diagnosis Cumulant Featureextraction

Fractal Analysis of Gas Diffusion Layer in PEM Fuel Cells

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Journal of wuhan University of technology(Materials {2.) 2006年第1期21卷 22-25页

作者：石英肖金生 State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070ChinaSchool of Automation Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070ChinaSchool of Automotive EngineeringWuhan University of Technology Wuhan 430070China

The aim of this study is to show how fractal analysis can be effectively used to characterize the texture of porous solids. The materials under study were carbon papers, the backing material of the gas diffusion layer （GDL） in Proton Exchange Membrane Fuel Cell （PEMFC）. The fractal dimensions were calculated by analyzing data from mercury porosimetry. The polytotrafluoroethylene （PTFE） treated carbon paper shows a significantly high fractal dimension value than pare sample, and the high fractal dimension signifies that the physical complexity of the pore surface is enhanced. The fractal dimension can be used as a valid parameter to monitor the textural evolution of the samples as the treatment progresses, as this behaves in a similar way to other textural parameters. The use of fractal analysis in conjunction with the results of classical characterization methods leads to a better understanding of textural modificatious in the processing of materials.

关键词： PEMFC gas diffusion layer fractal dimension mewury porosimetry

Earthquake Disaster Management and Insurance

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地球科学进展 2004年第S1期19卷 1-8页

作者： TANG Ai-ping~1, WEN Ai-hua~2.1. School of Civil engineering, Harbin institute of {2., Harbin 150090, china 2. School of science, Harbin institute of {2., Harbin 150090, china)

As one of the most powerful tools to reduce the earthquake loss, the Earthquake Disaster Management [EDM] and Insurance [EI] have been highlighted and have had a great progress in many countries in recent years. Earthquake disaster management includes a series of contents, such as earthquake hazard and risk analysis, vulnerability analysis of building and infrastructure, earthquake aware training, and building the emergency response system. EI, which has been included in EDM after this practice has been...

关键词： Earthquake risk analysis Disaster management Earthquake insurance GIS.

A SEMI-ANALYTICAL AND SEMI-NUMERICAL METHOD FOR SOLVING 2.D SOUND-STRUCTURE INTERACTION PROBLEMS

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Acta Mechanica Solida Sinica 2003年第2期16卷 116-126页

作者： Xiang Yu Huang Yuying (College of Civil engineering and Mechanics,huazhong University of {2. and technology,wuhan 43.074,china) CollegeofCivilengineeringandMechanics HuazhongUniversityofScienceandTechnologyWuhan430074China

Based on the transfer matrix method and the virtual source simulation technique, this paper proposes a novel semi-analytical and semi-numerical method for solving 2.D sound- structure interaction problems under a harmonic *** any integration segment, as long as its length is small enough,along the circumferential curvilinear coordinate,the non- homogeneous matrix differential equation of an elastic ring of complex geometrical shape can be rewritten in terms of the homogeneous one by the method of extended homogeneous capacity proposed in this *** the exterior fluid domain,the multi-circular virtual source simulation technique is *** source density distributed on each virtual circular curve may be ex- panded as the Fourier's *** with the inverse fast Fourier transformation,a higher accuracy and efficiency method for solving 2.D exterior Helmholtz's problems is presented in this *** the aspect of solution to the coupling equations,the state vectors of elastic ring induced by the given harmonic excitation and generalized forces of coefficients of the Fourier series can be obtained respectively by using a high precision integration scheme combined with the method of extended homogeneous capacity put forward in this *** to the superposition princi- ple and compatibility conditions at the interface between the elastic ring and fluid,the algebraic equation of system can be directly constructed by using the least square *** of acoustic radiation from two typical fluid-loaded elastic rings under a harmonic concentrated force are *** results show that the method proposed is more efficient than the mixed FE-BE method in common use.

关键词： sound-structure interaction acoustic radiatlon multi-circular virtual source simulation technique transfer matrix method inverse fast Fourier transformation semi-analytical and semi-numerical method

Structure and Mechanical Properties of Ni-based Porous Superalloy

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Journal of wuhan University of technology(Materials {2.) 2010年第1期25卷 73-77页

作者：米国发 School of Materials science and engineering Henan Polytechnic University

The porous superalloy materials with hollow spherical and oriented linear pores were fabricated by means of powder metallurgy using Ni-based superalloy powders. Structure observation revealed that the pores of the porous material exhibited uniform distribution and the pores were of the same size in principle. The sintering necks created between adjacent particles on metal skeleton after sintering. The porosity of the porous material increased with increasing the addition of pore forming agent, and the hollow spherical porous material with a porosity of 81.62. were obtained when the addition of pore forming agent was 40%. The compression test indicated that this kind of materials possesses excellent energy absorption capability, and the compression resistance decreased with the increasing of porosity and pore size.

关键词： porous superalloy powder metallurgy hollow spherical pores oriented linear pores