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Numerical simulation of the transient multiphase field during plasma deposition manufacturing composite materials

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science china(Physics,Mechanics & Astronomy) 2009年第4期52卷 508-517页

作者： KONG FanRong1,2.ZHANG HaiOu1 & WANG GuiLan3.1 state Key Laboratory of Digital Manufacturing Equipment and technology,Huazhong university of science and technology,Wuhan 43.074,china 2.Research Center for Advanced Manufacturing,southern Methodist university,3.01 Dyer street,Dallas,Texas 752.5,UsA 3.College of material science and Engineering,Huazhong university of science and technology,Wuhan 43.074,china 1. state Key Laboratory of Digital Manufacturing Equipment and technology Huazhong University of Science and Technology Wuhan 430074 China 2. Research Center for Advanced Manufacturing Southern Methodist University 3101 Dyer Street Dallas Texas 75205 USA 3. College of material science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

A solid/liquid/gas unified model has been developed to investigate the gradient composition formation during the plasma deposition manufacturing(PDM) composite materials process. In this model,an enthalpy porosity model was applied to deal with the melting and solidification of the deposited layer,and a level-set approach was introduced to track the evolution of the free surface of the molten pool and the deposited layer. Moreover,complicated physical phenomena occurring at the liquid/gas interface,including forced convection heat loss,heat emission and plasma heat source,have been incorporated into the governing equations by source terms. In this study,the numerical experiment of nickel base alloy powder deposited on the medium steel substrate by PDM technique was implemented based on the staggered grid and sIMPLEC algorithm. Concentration gradient distribution of the solute material at the composite material interface,fluid flow and temperature distribution in the molten pool and the deposited layer have been investigated in detail.

关键词： plasma deposition manufacturing composite material solid/liquid/gas unified model level-set approach

Effect of Pb, Hg and Cd in soil on scavenging system of activated oxygen in tobacco leaves

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Chinese science Bulletin 1999年第S2期44卷 91-93页

作者： YAN Chongling~(1,2., HONG Yetang~1, WANG shijie~1, LIN Peng~3. YANG Xianke~2. FU shunzhen~2. ZHU Keyong~2.and WU shanqi~2.1. state Key Laboratory of Environmental Geochemistry, Chinese Academy of sciences, Guiyang 550002. china 2. Guizhou Institute of Environmental Protection, Guiyang 550002. china 3. {2.ent of Biology, Xiamen university, Xiamen 3.1005, china state Key Laboratory of Environmental Geochemistry Chinese Academy of Sciences Guiyang 550002 China Guizhou Institute of Environmental Protection Guiyang 550002 China department of Biology Xiamen University Xiamen 361005 China

Pb, Hg and Cd will affect human health by vegetative chain. In recent years, people more and more are concerned about heavy metal pollution of the soil-plant system. Many researchers studied the effect of single heavy metal on growth, photosynthesis, respiration and quality of plants, but few systematicstudies of the effect of heavy metals on the scavenging system of activated oxygen of plants. This note systematically studies the effect of Pb, Hg and Cd in soil on the scavenging system of activated oxygen in tobacco leaves. 1 material and methods material: Tobacco (Nicoticana tabacum L). Methods: Cultivating and measuring methods were according to reference. 2.Results Results of this study indicate that the common effect of Pb, Hg and Cd on activity of CAT is obvi-

关键词： Pb Hg and Cd scavenging system of activated oxygen tobacco.

The Antifreeze Critical strength of Low-temperature Concrete Effected by Index

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Journal of Wuhan university of technology({2.s science) 2011年第2期26卷 355-360页

作者：刘军 school of material science and Engineering Shenyang Jianzhu University

The antifreeze critical strength and the pre-curing time of low-temperature concrete were studied by means of guaranteed rate of compressive strength and antifreeze performance for the structural safety requirement of concrete engineering,suffering once freeze damage under air *** is shown that the antifreeze critical strength is 3.7-4.4MPa,pre-curing time is 18-3.0}h by guaranteed rate of compressive strength,and the antifreeze critical strength is 3.7-4.4MPa,pre-curing time is 18-3.0}h by guaranteed rate of antifreeze *** can be found that the method of guaranteed rate of compressive strength is sensitive to the defect which generated by freeze damage in the concrete *** method is fit to evaluate the antifreeze critical strength of low-temperature concrete.

关键词： guaranteed rate of compressive strength guaranteed rate of antifreeze performance antifreeze critical strength once freeze under air environment

study on the isothermal oxidation behavior in air of Ti_(3.AlC_(2. sintered by hot pressing

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science china(Technological sciences) 2006年第5期49卷 513-520页

作者： XU Xuewen1, 2. LI Yangxian1, MEI Bingchu2. ZHU Jiaoqun2. LIU Heyan1 & QU Jingping1 1. school of {3. science and Engineering, Hebei university of {2., Tianjin 3.013., china 2. state Key Laboratory of Advanced {2. for {3.s synthesis and Processing, Wuhan Univer- sity of {2., Wuhan 43.070, china 1. school of material science and Engineering Hebei University of Technology Tianjin 300130 China 2. state Key Laboratory of Advanced technology for materials synthesis and Processing Wuhan University of Technology Wuhan 430070 China

The isothermal oxidation behavior at 900–13.0°C for 2. h in air of bulk Ti3.lC2.with 2.8 wt% TiC sintered by means of hot pressing was investigated in the work. The isothermal oxidation behavior generally followed a parabolic rate law. The parabolic rate constants increased from 1.3.×10[10] kg[2.·m[4]·s[1] at 900°C to 5.56×10[9] kg[2.·m[4]·s[1] at 13.0°C. The calculated activation energy was 13..45 kJ/mol. It was demonstrated that Ti3.lC2.had excellent oxidation resistance due to the continuous, dense; adhesive protect scales consisted of a mass of α-Al2.3. a little of TiO2./or Al2.iO5. In principle, the oxide scale was grown by the inward diffusion of O[2.; the outward diffusion of Ti[4+]; Al[3.]. The rapid outward diffusion of cations usually resulted in the formation of cracks, gaps,; holes.

关键词： Ti3.lC2. oxidation behavior, kinetics.

Molecular dynamics simulation of thermal stability of nanocrystalline vanadium

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science china(Technological sciences) 2006年第4期49卷 400-407页

作者： WEI Mingzhi1, XIAO shifang1, YUAN Xiaojian2.& HU Wangyu1,2.1. material science and Engineering College, Hunan {3., Changsha 410082.{2. 2. department of Applied Physics, Hunan {3., Changsha 410082.{2. material science Engineering College Hunan University Changsha 410082 China department of Applied Physics Hunan University Changsha 410082 China

The microstructure and thermal stability of nanocrystalline vanadium with an average grain size ranging from 2.86 to 7.50 nm are calculated by means of the analytic embedded-atom method and molecular dynamics. The grain boundary and nanocrystal- line grain atoms are differentiated by the common neighbor analysis method. The results indicate that the fraction of grain boundary increases with the grain size decreasing, and the mean energy of atoms is higher than that of coarse crystals. The thermal-stable tem- peratures of nanocrystalline vanadium are determined from the evolution of atomic energy, fraction of grain boundary and radial distribution function. It is shown that the stable tem- perature decreases obviously with the grain size decreasing. In addition the reasons which cause the grain growth of nanocrystalline vanadium are discussed.

关键词： nanocrystalline, embedded-atom method, molecular dynamics, thermal stability.

One-pot synthesis of crystalline snO_2.nanoparticles and their low-temperature ethanol sensing characteristics

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science china(Physics,Mechanics & Astronomy) 2009年第10期52卷 1601-1605页

作者： CHEN YuJin1,2.3.ZHU ChunLing4,WANG LiJiao3.& WANG TaiHong2.1 school of materials science and Engineering,Beijing Institute of {3.,Beijing 100081,{2. 2.Micro-Nano Technologies Research Center,Hunan university,Changsha 410082.{2. 3.College of science,Harbin Engineering university,Harbin 150001,{2. 4 College of material science and Chemical Engineering,Harbin Engineering university,Harbin 150001,{2. school of materials science and Engineering Beijing Institute of Technology Beijing 100081 China Micro-Nano Technologies Research Center Hunan University Changsha 410082 China College of science Harbin Engineering University Harbin 150001 China College of material science and Chemical Engineering Harbin Engineering University Harbin 150001 China

Crystalline snO2.nanoparticles(NPs) with a diameter less than 6 nm are synthesized using potassium stannate trihydrate as the precursor in a basic *** synthesized NPs can detect ethanol at a ppm level even at 100℃.Furthermore,the NPs have good selectivity to *** excellent ethanol sensing performances are attributed to the small size effect according to the space-charge model.

关键词： snO2 nanoparticles sensing characteristics

Research progress in the inner surface modification of metal tubes by plasma processing

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Progress in Natural science:materials International 2006年第11期16卷 1119-1126页

作者： ZHANG Guling~ 1,2.**, WU Xingfang~1, GU Weichao~2. CHEN Guangliang~2. FENG Wenran~2. NIU Erwu~2. LI Li~2. L Guohua~2. CHEN Huan~2. FAN songhua~2. LIU Chizi~2.and YANG size~2.1. school of material science and Engineering, university of science and {2. Beijing, Beijing 100083. china 2. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of sciences, Beijing 100080, china) school of material science and Engineering University of Science and Technology Beijing Beijing 100083 China Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The recent progress in inner surface hardening of tubes by plasma processing is summerized. several techniques of inner surface plasma source ion implantation and deposition are introduced, and their advantages and disadvantages are discussed. The basic principles, technical features and new progress of inner surface plasma source ion implantation methods for metal tubes, which were developed in our laboratory, are described in detail. And perspectives of the future technical development for inner surface ion implantation of tubes are presented.

关键词： PsII metal tubes inner surface surface modification.

Complete multiple round quantum dense coding with quantum logical network

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Chinese science Bulletin 2007年第9期52卷 1162-1165页

作者： LI ChunYan1,2.LI XiHan1,2.DENG FuGuo1,2.3.ZHOU Ping1,2.& ZHOU HongYu1,2.3.1 Key Laboratory of Beam technology and material Modification of Ministry of Education,Beijing Normal {2.,Beijing 100875,china 2.Institute of Low Energy Nuclear Physics,and department of material science and Engineering,Beijing Normal {2.,Beijing 100875,china 3.Beijing Radiation Center,Beijing 100875,china Key Laboratory of Beam technology and material Modification of Ministry ofEducation Beijing Normal University Beijing 100875 China

We present a complete multiple round quantum dense coding scheme for improving the source ca-pacity of that introduced recently by Zhang et al. The receiver resorts to two qubits for storing the four local unitary ope... 详细信息

关键词：量子通信多重量子紧凑编码量子逻辑网络量子纠缠

Dilatancy equation of rockfill material under the true triaxial stress condition

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science china(Technological sciences) 2011年第S1期54卷 175-184页

作者： XIAO Yang 1,2.LIU HanLong 1,2.ZHU JunGao 1,2.& sHI WeiCheng 1,3.1 Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai {3.,Nanjing 2.0098,china 2.Geotechnical Research Institute,Hohai {3.,Nanjing 2.0098,china 3.school of Civil Engineering and Architecture,Changzhou Institute of technology,Changzhou 2.6}china 1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai University Nanjing 210098 China2. Geotechnical Research Institute Hohai University Nanjing 210098 China3. School of Civil Engineering and Architecture Changzhou Institute of Technology Changzhou 213002 China

Rockfill material is widely used for construction of high rockfill dam due to its facility,economical cost,high strength and effective aseismatic *** is provoked profoundly to propose a suitable constitutive model for a better application of this *** dilatancy equation of rockfill material plays a significant role in the constitutive *** the sake of simplicity,a dilatancy equation is established by the linear least square method on the basis of the rearranged data of rockfill material in the true triaxial *** on the fact that the rearranged data at different initial confining pressures are aligned in a narrow band,the dilatancy behavior of rockfill material is independent of the initial confining ***,different from the initial confining pressure,both the intermediate principal stress ratio and the specimen density exhibit a remarkable influence on the dilatancy behaviors of rockfill ***,the predictions of the proposed dilatancy equation are in a good agreement with the rearranged test data of rockfill material at different specimen densities and stress paths.

关键词： rockfill material dilatancy equation true triaxial test density stress path initial confining pressure