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Dimensional synthesis of a 3-DOF parallel manipulator based on dimensionally homogeneous Jacobian matrix

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Science china(Technological Sciences) 2010年第1期53卷 168-174页

作者： SUN Tao1,SONG YiMin1,LI YongGang2 & LIU LinShan1 1 School of Mechanical Engineering,Tianjin university,Tianjin 300072,china 2 School of Mechanical Engineering,Tianjin university of technology and Education,Tianjin 300222,china 1. School of Mechanical Engineering Tianjin University Tianjin 300072 China2. School of Mechanical Engineering Tianjin University of Technology and Education Tianjin 300222 China

A study of dimensional synthesis of a 3-DOF parallel manipulator with coupling of translation and rotation is carried *** architecture of the manipulator is composed of a moving platform attached to a fixed base through three identical PRS(prismatic-revolute-spherical) serial limbs,whose unique topology leads to the physical unit inconsistency of the conventional Jacobian matrix and the emergence of the parasitic *** this paper introduces a kinetostatic performance index of the manipulator based on the condition of a dimensionally homogeneous Jacobian matrix,later,the workspace of the aforementioned manipulator is searched and the influence of the crucial design variables on the workspace is ***,a dimensional synthesis method of the manipulator is proposed,which may be regarded as a nonlinear programming problem with subject to the parasitic motion and other several engineering constraints.

关键词： PKMs(parallel kinematic machines) dimensional synthesis dimensionally homogeneous Jacobian 3-PRS manipulator workspace

Nafion/Silicon Oxide Composite Membrane for High Temperature Proton Exchange Membrane Fuel Cell

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Journal of Wuhan university of technology(Materials Science) 2007年第3期22卷 478-481页

作者：余军 State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology

Nafion/Silicon oxide composite membranes were produced via in situ sol-gel reaction of tetraethylorthosilicate （TEOS） in Nafion membranes. The physicochemical properties of the membranes were studied by FT-IR,TG-DSC and tensile strength. The results show that the silicon oxide is compatible with the Nation membrane and the thermo stability of Nation/Silicon oxide composite membrane is higher than that of Nation membrane. Furthermore, the tensile strength of Nation/Silicon oxide composite membrane is similar to that of the Nation membrane. The proton conductivity of Nation/Silicon oxide composite membrane is higher than that of Nation membrane. When the Nation/Silicon oxide composite membrane was employed as an electrolyte in H2/O2 PEMFC, a higher current density value （1 000 mA/cm^2 at 0.38 V） than that of the Nafion1135 membrane （100 mA/cm^2 at 0.04 V） was obtained at 110 ℃.

关键词： PEMFC composite membrane silicon oxide high temperature

Joint subcarrier and power allocation in uplink OFDMA systems based on stochastic game

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Science china(information Sciences) 2010年第12期53卷 2557-2566页

作者： WU Dan 1,CAI YueMing 1,2 & SHENG YanMing 1 1 Institute of Communications Engineering,PLA university of Science and technology,Nanjing 210007,china 2 National Mobile Communications Research Laboratory,Southeast university,Nanjing 210096,china 1. Institute of Communications Engineering PLA University of Science and Technology Nanjing 210007 China2. National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China

In uplink orthogonal frequency division multiplexing access(OFDMA) systems,efficient resource allocation can greatly improve system ***,in this paper,we present a game-theoretical approach to achieve a joint subcarrier and power allocation in a distributed ***,the subcarrier allocation problem is modeled as a multi-player discrete,stochastic and finite strategy game,where each of the subcarriers is viewed as a player to choose the most satisfying *** subcarriers of each user are allocated with equal *** the proposed game model,on the one hand,we exploit the support and programming methods to obtain the Nash equilibriums,and analyze their theoretical *** the other hand,we propose a lowcomplexity algorithm based on the linear reward-inaction(L R-I) algorithm to search for the Nash *** the relationship between the convergence results of this algorithm and the Nash equilibriums is *** simulation results demonstrate the effectiveness of the resource allocation game model and algorithm.

关键词： stochastic game OFDMA subcarrier allocation power allocation learning automata linear reward-inaction

Research on Human resource Management Based on Psychological Contract

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Research on Human Resource Management Based on Psychological...

Soil Evolution Features of Debris Flow Waste-Shoal Land

2012 IEEE 3rd International Conference on Emergency Management and ManagementSciences(ICEMMS 2012)

作者： Liu Ying 1 School of Mechanical Engineering beijing Institute of technology beijing china Zheng Yi 2 Wang Fangliang 3 Yan Han 4 Peking university 2 Ambow Education Holding Ltd. 3 Taiyuan university of technology 4 beijing china 2 beijing china 3 Taiyuan china 4

In modern business environment, psychological contract management has increasingly become enterprise’s strategic means to improve human resource competitive power. The article establishes the psychological contract’s forming and developing mechanism model through analyzing its definition, formation and carrier, and then presents the human resource management strategies based on psychological contract referring to the psychological contract violation and breach theories.

关键词： Psychological Contract Forming and Developing Mechanism Model Human resource Management

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Journal of Mountain Science 2009年第2期6卷 181-188页

作者： CUI Peng GE Yonggang ZHUANG Jianqi WANG Daojie Key Laboratory of Mountain Hazards and Land Surface Processes Chinese Academy of Sciences Chengdu 610041 China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Graduate university of Chinese Academy of Sciences Beijing 100049 China

The reclamation and utilization of debris flow waste-shoal land plays an important role in the mitigation and control of debris flow hazards, which thus contributes a lot to the exploitation of insufficient land resources in mountainous areas and the reduction of losses caused by debris flow. The aim of this paper is to discuss the features and mechanism of soil evolution of debris flow waste-shoal land so as to search for the available modes of its reclamation and utilization. The Jiangjiagou Ravine, a typical debris flow ravine, was selected to study soil evolution features of debris flow waste-shoal land based on the analysis of soil physicochemical properties and soil microstructure. It was found that the soil evolution rates of debris flow waste-shoal land varied with different modes of reclamation. For the land which had been reclaimed for less than 10 years, soil evolved most rapidly in paddy fields, and more rapidly in dry farmland than in naturally restored waste-shoal land. For the land which had been used for more than 10 years, the soil evolution rates of dry farmland, naturally restored waste-shoal land and paddy farmland decreased in the file. For the same utilization period of time, significant differences were recognized in soil evolution features under different modes of reclamation. Analysis data showed that soil clay content, soil thickness, the psephicity of skeleton particles and contents of microaggregates (naturally restored waste-shoal land, and those of paddy farmland were superior to those of naturally restored waste-shoal land. Paddy farmland characterized by rapid pedogenesis, stable evolution and high utilizability was the priority candidate for the reclamation and utilization of debris flow waste-shoal land.

关键词： Debris flow waste-shoal land Reclamation mode Utilization time Soil properties Soil microstructure

Electrochemical characteristics of ternary and quadruple lithium silicon nitrides as anode material for lithium ion batteries:the influence of precursors

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Rare Metals 2008年第2期27卷 170-174页

作者： WEN Zhongsheng TIAN Feng SUN Juncai JI Shijun XIE Jingying Institute of Materials and technology Dalian Maritime University Dalian 116026 China Shanghai Institute of Microsystem and information technology Chinese Academy of Sciences Shanghai 200050 China

Ternary and quadruple lithium silicon nitride anode materials for lithium ion batteries with different precursors were prepared by the simple process of high-energy ball milling. High capacity and excellent cyclability were obtained. The influence of precursor introduction on the electrochemical performance of products was investigated. This research reveals that the electrochemical performance of lithium silicon hitilde can be enhanced significantly by doping O. The cyclability of quadruple lithium silicon nitfide can be optimized remarkably by controlling the introduction quantity of the precursors. It is possible for the composite to be used as a capacity compensator within a wide voltage cut-off window.

关键词： lithium ion batteries high-capacity electrode material high-energy ball milling lithium silicon nitride wide voltage cut-off window

Weathered Mantle Hosted Gold Deposit atShewushan, Hubei, Central china

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Journal of china university of Geosciences 2001年第1期12卷 60-67页

作者： Hong Hanlie Wang Qinyan The Center for Material Research and Testing, Wuhan university of technology, Wuhan 430070 Bian Qiujuan faculty of Earth Sciences, china university of Geosciences, Wuhan 430074 The Center for Material Research and Testing Wuhan University of Technology faculty of Earth Sciences China University of Geosciences

A supergene gold deposit is located at Shewushan, south Hubei, Central china. The Au mass fraction of the supergene deposits ranges from 1.0.10-6 to 19.5 10-6, with an average of about 2.2 10-6. Primary gold mineralization is closely associated with the well developed faults and fractures mainly on the crest of the reverse anticline with gold mass fraction exceeding1.0 X 10-6(average 0.6 X 10-6 ), the gold occurs as small Ag-bearing particles in association with illite and kaolinite, and partly incorporated within the lattice of pyrite. Fluid inclusion studies on the gold mineralization yield trapping temperatures and pressures from 110 to 290 and 410 105 to 460 105 pa, respectively. The salinities of mineralization fluids range from 2. 6 % to 8. 4 % w(NaCl, equivalent). Calculated (18O) values and measured (D) data of the hypogene fluids indicate a meteoric origin. These fluids underwent extreme 18 O enrichment by reacting with country carbonate rock. Supergene gold minerali- zation is confined largely to the lower portion at the weathered mantle; the gold occurs as small native gold particles accompanied by clay minerals, kaolinite and illite and Mn and Fe oxides. Geochemical investigation shows that Au, together with As and Sb, decreases progressively from the top of ore body to some 2 kilometers away and define a lateral dispersion halo. It is proposed that the gold is mobilized by surficial leaching and concentrated at the lower portion of the weathering profile, and thio-sulfate may play an active role in gold dissolution and re-precipitation.

关键词： gold deposit weathering inclusion temperature stable isotopes Shewushan.

Hybrid particle swarm cooperative optimization algorithm and its application to MBC in alumina production

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Progress in natural Science:Materials International 2008年第11期18卷 1423-1428页

作者： Shengli Song~(a,b) Li Kong~a Yong Gan~b Rijian Su~(a,b) a Department of Control Scienee and Engineering,Huazhong university oF Science and technology,Wuhan 430074,china b College of Computer and Communication Engineering,Zhengzhou university of Light Industry,Zhengzhou 450002,china Department of Control Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China College of Computer and Communication Engineering Zhengzhou University of Light Industry Zhengzhou 450002 China

An effective hybrid particle swarm cooperative optimization(HPSCO)algorithm combining simulated annealing method and sim- plex method is *** main idea is to divide particle swarm into several sub-groups and achieve optimization through coop- erativeness of different sub-groups among the *** proposed algorithm is tested by benchmark functions and applied to material balance computation(MBC)in alumina *** show that HPSCO,with both a better stability and a steady convergence,has faster convergence speed and higher global convergence ability than the single method and the improved particle swarm optimization *** importantly,results demonstrate that HPSCO is more feasible and efficient than other algorithms in MBC.

关键词： PSO Simulated annealing Simplex Cooperative optimization

Wave decomposition phenomenon and spectrum evolution over submerged bars

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Acta Oceanologica Sinica 2009年第3期28卷 82-92页

作者： LI Benxia YU Xiping National Marine Environmental Forecasting Center State Oceanic Administration Beijing 100081China Department of Hydraulic Engineering Tsinghua University Beijing 100084 China

Wave decomposition phenomenon and spectrum evolution over submerged bars are investigated by a previously developed numerical model. First, the computed free surface displacements of regular waves at various locations are compared with the available experimental data to confirm the validity of the numerical model, and satisfactory agreements are obtained. In addition, variations of decomposition characteristics with incident wave parameters and the change of energy spectrum for regular waves are also studied. Then the spectrum evolution of irregular waves over submerged bars, as well as the influence of incident peak wave period and the steepness of the front slope of the bar on spectrum evolution, is investigated. Wave decomposition and spectral shape are found to be significantly influenced by the incident wave conditions. When the upslope of the bar becomes 1：2, the length of the slope becomes shorter and will not benefit the generation of high frequency energy, so spectrum evolution is not significant.

关键词： wave decomposition spectrum evolution nonlinear waves irregular waves submerged bars