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The Crack of Harden Cement Paste Observed with Multi-technique

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Journal of wuhan university of technology(Materials science) 2010年第6期25卷 1057-1060页

作者：沈卫国 Key Laboratory for silicate Materials science and engineering of Ministry of Education Wuhan University of Techoology school of Materials science and engineering Wuhan University of Technology

The shrinkage of the cement paste with low water-cement ratio at different relative humidity was observed and analyzed with EsEM and deformation map *** crack morphology was observed with different magnification with sEM and FEsEM,and the formation of the crack was observed with AFM between two C-s-H nano *** observation by multi technique at multi scale indicated that the shrinkage was increase with the decrease of the humidity due to the increase of the pressure of the capillary pressure,the morphology of the crack in smaller scale was similar to that in the bigger scale,the smaller crack distributed in the latticework of the bigger ones,and the crack propagated along the gap between two nano particles of C-s-H with weaker bonding.

关键词： crack cement paste shrinkage muli technique multi-scale

Optimality strategy of a sealed-offer simultaneous bargaining protocol

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science China(Information sciences) 2011年第1期54卷 79-90页

作者： ZHANG LinLan1,2,CHEN XueGuang2 & HONG Liu2 1school of Business,Hubei university,wuhan 430062,China 2Institute of systems engineering,Huazhong university of science and technology.wuhan 430074,China 1. school of Business Hubei University Wuhan 430062 China2. Institute of Systems Engineering Huazhong University of Science and Technology Wuhan 430074 China

Alternating-offer bargaining protocol is the most predominant way for solving bilateral bargaining ***,alternating-offer may consume much time and cause a low effciency in some ***, a deadlock in which both negotiators are unwilling to concede or refuse to disclose more information may arise. Then mediation is *** paper presents an agent-based sealed-offer simultaneous bargaining protocol by introducing a nonbiased *** information of both agents is considered completely *** our agent-based model,both agents simultaneously submit their respective offers to the mediate *** offers of each agent are not revealed to the *** design can discourage counter-speculation and effectively control fraud and misrepresentation in a certain ***,we analyze how an agent can exploit the available information in selecting a strategy that maximizes its expected utility and give the optimal offers of each agent at each stage of the *** groups of automated experiments are conducted to evaluate the performance of the proposed automated negotiation procedure.

关键词： automated negotiation bargaining sealed-bid optimal strategy

Wafer level bonding using localized radio-frequency induction heating

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science China(Technological sciences) 2010年第5期53卷 1252-1257页

作者： CHEN MingXiang1,2,LIU WenMing1,2,XI YanYan1,2,LIN ChangYong1,2 & LIU sheng1,2 1 school of Mechanical science & engineering,Huazhong university of science and technology.wuhan 430074,China 2 Division of MOEMs,wuhan National Laboratory for Optoelectronics,wuhan 430074,China 1. school of Mechanical science & engineering Huazhong University of Science and Technology Wuhan 430074 China2. Division of MOEMS Wuhan National Laboratory for Optoelectronics Wuhan 430074 China

A wafer level bonding technique by localized induction heating has been developed and demonstrated in this paper.A suitable fabrication process scheme has also been established for the localized induction heating and *** takes only about 20 seconds to complete the bonding *** temperatures of solder loops and the central area of solder loops are above 300°C and below 70°C,*** to the solder reflow,robust and hermetic glass wafer bonding is accomplished,and the average tensile strength is 6.42 ***-heated or over-heated bonding has been found to result in cracks at bonding interfaces and sputtering layer,which degrades the bonding qualities.

关键词： wafer bonding induction heating MEMs MEMs packaging

Fractal Analysis of Gas Diffusion Layer in PEM Fuel Cells

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Journal of wuhan university of technology(Materials science) 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

Experimental study on high viscosity fluid micro-droplet jetting system

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science China(Technological sciences) 2010年第1期53卷 182-187页

作者： sHU XiaYun1,2,ZHANG HongHai1,2,LIU HuaYong1,2,XIE Dan1,2 & XIAO JunFeng1,2 1 school of Mechanical science and engineering,Huazhong university of science and technology.wuhan 430074,China 2 Division of MOEMs,wuhan National Laboratory of Optoelectronics,wuhan 430074,China 1. school of Mechanical science and engineering Huazhong University of Science and Technology Wuhan 430074 China2. Division of MOEMS Wuhan National Laboratory of Optoelectronics Wuhan 430074 China

Fluid dispensing is a method by which fluid materials(such as epoxy,adhesive,and encapsulant) are delivered in a controlled manner in electronics *** jetting,derived from inkjet technology,is a noncontact,data-driven fluid dispensing *** ideal fluid materials for packaging are usually high viscous,which is difficult to realize by traditional inkjet *** this paper,a mechanical micro-droplet jetting system for high viscosity fluid was *** consists of dispensing valve,motion stage,temperature control subsystem,pneumatic subsystem,driving circuit for solenoid valve,and system control *** of this system under various circumstances was studied by changing several parameters,including working temperature,stroke length,back pressure and drive pulse *** droplets of 0.35 mm in diameter were produced by stainless steel nozzle of 0.2 mm in diameter in the experimental study.

关键词： high viscosity fluid micro-jetting microelectronics packaging

synthesis, Characterization and Flame-retardant Properties of Epoxy Resins and AACHH Composites

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Journal of wuhan university of technology(Materials science) 2009年第5期24卷 763-767页

作者：秦麟卿 state Key Laboratory of Advanced technology for Materials synthesis and Processing Wuhan University of Technology

Flame retardant epoxy resins were prepared by a simple mixed method using ammonium aluminum carbonate hydroxy hydrate （AACHH） as a halogen-free flame retardant. The prepared samples were characterized by X-ray diffraction, thermogravimetric and differential scanning calorimetry, scanning electron microscope and limiting oxygen index（LOI） experiments. Effects of AACHH content on LOI of epoxy resins/AACHH composite and flame retardant mechanism were investigated and discussed. Results show that AACHH exhibites excellent flame-retardant properties in epoxy resin（EP）. When the content of AACHH was 47.4%, the LOI of EP reached 32.2%. Moreover, the initial and terminal decomposition temperature of EP increased by 48 ℃ and 40 ℃, respectively. The flame retarded mechanism of AACHH is due to the synergic flame retardant effects of diluting, cooling, decomposition resisting and obstructing.

关键词： epoxy resin(EP) flame retardant ammonium aluminum carbonate hydroxy hydrate (AACHH) composite

synthesis of PEG-MAH Crystalline Polymer and Its Thickening Traits to LPMC

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Journal of wuhan university of technology(Materials science) 2008年第3期23卷 403-406页

作者：秦岩 school of Materials science and engineering Wuhan University of Technology

A kind of PEG-MAH（maleic anhydride to modify polyethylene glycol） crystalline polymer whose melting point was approximately 64 ℃ was synthesized, and its thickening traits to LPMC were also investigated. The analysis of rheological properties indicates that the dosage and adding methods of crystalline polymer have a direct effect on the viscosity of LPMC, and that the thickening method of using melting dispersal and freezing is propitious to the thickening process of sMC. Additionally, it is also shown that sMC＇ s viscosity decreases along with the elevation of temperature, and that it reduces rapidly at the medium range of temperature, which is propitious to the dispersal of sMC in mould, and to its low pressure molding as well.

关键词： crystallization thickening LPMC molding viscosity

VIBRATION AND CONTROL IN RING ROLLING PROCEss

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中国有色金属学会会刊：英文版 1999年第2期9卷 9-13页

作者： Hua Lin1, 2, Mei Xuesong2 and Wu Xutang2 1 school of Materials science and engineering,wuhan Automotive Polytechnic university, wuhan 430070, P. R. China2.school of Mechanical engineering,Xian Jiaotong university, Xian 710049, P. R. China 武汉汽车工业大学材料科学与工程学院湖北武汉西安交通大学机械工程学院陕西西安

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关键词： ring rollingvibrationstabilityprocess control

Evaluation of a Novel Bioabsorbable PRGD/PDLLA/β-TCP/NGF Composites in Repair of Peripheral Nerves

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Journal of wuhan university of technology(Materials science) 2009年第3期24卷 409-414页

作者：王永红李世普 Hospital Wuhan University of Technology Biomedical Materials and engineering Research Center Wuhan University of Technology

Peripheral nerve regeneration using a novel nerve conduit （PRGD/PDLLA/β TCP/NGF） was evaluated, which was made of RGD peptide modified poly{（lactic acid）-co-[（glycolic acid）-alt-（L-lysine）]} （PRGD）, poly（d,l-lactic acid）（PDLLA） and β-tricalcium phosphate （β-TCP）. And the effectiveness was compared with that of PRGD/PDLLA/β-TCP, PDLLA and autograft in terms of nerve regeneration across a gap. Both of biodegradablity and cell-biocompatibility of the novel nerve conduit were evaluated in vitro. The results show that PRGD/PDLLA/β-TCP/NGF composite ma terials have better biodegradation properties and cell affinity than PDLLA, and could promote the RsC96 schwann cells adhesion, proliferation and growth on the surface of materials. PRGD/PDLLA/ β-TCP/NGF composite conduit was significantly superior to that of the PDLLA conduit in histological and axon morphologic index. PRGD/PDLLA/β-TCP/NGF conduit is more beneficial to nerve regeneration than PDLLA conduit. The biodegradable PDLLA/PRGD/β-TCP/NGF conduit has a good biocompatibility with rats tissue and it could effectively promote the nerve regeneration after bridging sciatic nerve defect of rats, the effect is as good as that of the autograft nerve, significantly superior to the PRGD/PDLLA/β-TCP conduit and PDLLA conduit. PDLLA/PRGD/β-TCP/NGF composite conduit is a potential ideal conduit.

关键词： peripheral nerve nerve conduit PDLLA/PRGD/β-TCP/NGF composite regeneration