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Analytical solution and semi-analytical solution for anisotropic functionally graded beam subject to arbitrary loading

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science china(Physics,Mechanics & Astronomy) 2009年第8期52卷 1244-1256页

作者： HUANG DeJin1,2,DING HaoJiang1 & CHEN WeiQiu3.1 Key Laboratory of Soft Soils and Geoenvironmental engineering,Ministry of Education,Zhejiang university,Hangzhou 3.0027,china 2 {3. of engineering,Ningbo university,Ningbo 3.5211,china 3.Department of engineering Mechanics,Zhejiang university,Hangzhou 3.0027,china Key Laboratory of Soft Soils and Geoenvironmental engineering Ministry of Education Zhejiang University Hangzhou China faculty of engineering Ningbo University Ningbo China Department of engineering Mechanics Zhejiang University Hangzhou China

Analytical and semi-analytical solutions are presented for anisotropic functionally graded beams subject to an arbitrary load,which can be expanded in terms of sinusoidal *** plane stress problems,the stress function is assumed to consist of two parts,one being a product of a trigonometric function of the longitudinal coordinate(x) and an undetermined function of the thickness coordinate(y),and the other a linear polynomial of x with unknown coefficients depending on *** governing equations satisfied by these y-dependent functions are *** expressions for stresses,resultant forces and displacements are then deduced,with integral constants determinable from the boundary *** the analytical solution is derived for the beam with material coefficients varying exponentially or in a power law along the thickness,the semi-analytical solution is sought by making use of the sub-layer approximation for the beam with an arbitrary variation of material parameters along the *** present analysis is applicable to beams with various boundary conditions at the two *** numerical examples are presented for validation of the theory and illustration of the effects of certain parameters.

关键词： anisotropic material functionally graded arbitrary loading stress function analytical solution semi-analytical solution

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Oxidation-induced strengthening behavior of reaction formed Al_4SiC_4 ceramics

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Rare Metals 2007年第S1期26卷 94-98页

作者： HUANG Xiaoxiao1,2),WEN Guangwu1,3.,LIU Ruitang2),and ZHENG Xin1)1) School of materials science and Technology,Harbin Institute of Technology,Harbin 150001,china 2) School of material science and chemical engineering,Harbin engineering university,Harbin 150001,china 3. School of materials science and Technology,Harbin Institute of Technology at Weihai,Weihai 264209,china Harbin Inst Technol Sch Mat Sci & Technol Harbin 150001 Peoples R China Harbin Inst Technol Sch Mat Sci & Chem Engn Harbin 150001 Peoples R China Harbin Inst Technol Sch Mat Sci & Technol Weihai 264209 Peoples R China

The bending strengths of Al4SiC4 ceramics were investigated from room temperature to 13.0 ℃ in air and in vacuum,*** is a novel property that the bending strength increases with increasing test temperatures up to 13.0 ℃ in *** strength value of Al4SiC4 ceramics is 449.7 MPa at 13.0 ℃ in air,which is about 1.5 times of that at room temperature(3.0 MPa).The self-healing behavior of the flaws on the specimen surface due to the oxidation of the surface layer of the Al4SiC4 ceramics is considered as the main enhancement mechanism at high temperatures.

关键词： calcination and hot pressing surface strength Al_4SiC_4

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Formation and evolution mechanisms of large-clusters during rapid solidification process of liquid metal Al

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science china(Physics,Mechanics & Astronomy) 2005年第1期48卷 101-112页

作者： LIU Rangsu, DONG Kejun, LIU Fengxiang, ZHENG Caixing, LIU Hairong & LI Jiyong Department of Applied Physics, Hunan university, Changsha 410082, china College of materials {3. and engineering, Hunan university, Changsha 410082, china College of Chemistry and chemical engineering, Hunan university, Changsha 410082, china Department of Applied Physics Hunan University Changsha 410082 China College of materials science and engineering Hunan University Changsha 410082 China College of Chemistry and chemical engineering Hunan University Changsha 410082 China

A molecular dynamics simulation study has been performed for the formation and evolution characteristics of nano-clusters in a large-scale system consisting of 400000 atoms of liquid metal Al. The center-atom method combined with pair-bond analysis technique and cluster-type index method (CTIM) has been applied here to describe the structural configurations of various basic clusters. It is demonstrated that both the 1551 bond-type and the icosahedral cluster (12 0 12 0) constructed by 1551 bond-types are dominant among all the bond-types and cluster-types, respectively, in the system and play a critical role in the microstructure transitions of liquid metal Al. The nano-clusters (containing up to 150 atoms) are formed by the combination of some middle and small clusters with distinctly different sizes, through mutual competition by unceasing annex and evolution in a seesaw manner (in turn of obtaining and losing),which do not occur as the multi-shell structures accumulated with an atom as the center and the surrounding atoms are arranged according to a certain rule. This is the essential distinction of nano-cluster in liquid metal from those obtained by gaseous deposition, ionic spray methods, and so on. Though the nano-clusters differ from each other in shape and size, all of them possess protruding corners that could become the starting points of various dendrite structures in the solidification processes of liquid metals.

关键词： liquid metal, solidification process, large-cluster configuration, evolution mechanism, computer simulation.

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AGING PRECIPITATION OF Cu-Zr AND Cu-Zr-Si ALLOYS AND AFFECTED BY COLD WORKING

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Acta Metallurgica Sinica(English Letters) 1990年第3期3卷 222-225页

作者： DONG Zhili TANG Xiangyun Tsinghua university,Beijing,chinaHORI Sgigenori FUJITANI Wataru faculty of {3.,Osaka university,Japan DONG Zhili Dept.of material science and {3.,Tsinghua university,Beijing 100084,china

The hardness and electrical conductivity of Cu-Zr and Cu-Zr-Si alloys varying with differ- ent aging regimes were measured and the factors influencing the electrical conductivity were *** is believed that a little Si can refine the precipitates and improve the resistance to *** improvement of materials properties by aging and the effect of cold work were also discussed.

关键词： aging precipitation Cu-Zr alloy

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Reverse extraction of early-age hydration kinetic equation from observed data of Portland cement

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science china(Technological sciences) 2010年第6期53卷 1540-1553页

作者： WANG Lin1,YANG Bo2,ZHAO XiuYang1,2,CHEN YueHui2 & CHANG Jun3.1 School of Computer science and Technology,Shandong university,Jinan 250101,china 2 Provincial Key Laboratory for Network-based Intelligent Computing,university of Jinan,Jinan 250022,china 3.School of material science and engineering,university of Jinan,Jinan 250022,china School of Computer science and Technology Shandong University Provincial Key Laboratory for Network-based Intelligent Computing University of Jinan

The early-age hydration of Portland cement paste has an important impact on the formation of microstructure and development of ***,manual derivation of hydration kinetic equation is very difficult because there are multi-phased,multi-sized and interrelated complex chemical and physical reactions during cement *** this paper,early-age hydration kinetic equation is reversely extracted automatically from the observed time series of hydration degree of Portland cement using evolutionary computation method that combines gene expression programming and particle swarm optimization *** order to reduce the computing time,GPUs are used for acceleration in *** have shown that according to the extracted kinetic equation,simulation curve of early-age hydration is in good accordance with the observed experimental ***,this equation still has a good generalization ability even changing chemical composition,particle size and curing conditions.

关键词： Portland cement hydration kinetic equation reverse extraction gene expression programming particle swarm optimization

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New development of materials used in BFCs

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化工进展 2010年第S1期29卷 551-556页

作者： WANG Li (faculty of Environmental and biological engineering,Shenyang university of {3. Technology,Shenyang,110142,china)

Electrodes,catalysts,membranes,if present,are three main components in constructing an MFC for harvesting desired maximum power density and achieving higher coulombic efficiency (CE).Great improvements have been made,based on previous researches,in developing and diversifying materials,aside from *** most familiar to us are widely used carbon *** anodes,carbon matrix composites(e.g.,a combination of polyaniline(PANI)with TiO2 using carbon as substrate)have gained special attention,though carbon material itself can exhibit excellent performance by diversifying molecular structures such as carbon nanotubes(CNTs).In the meanwhile,the evolution of MFC architectures,heading to the direction of improving power generation,contributes to the combination of membranes and cathodes from separate modes to diverse assemblies,on which all sorts of catalysts,such as from commonly used Pt to iron phthalocyanine (Pc),metal tetramethoxyphenylporphyrin(TMPP),MnOx,or pyrolyzed iron(Ⅱ)phthalocyanine (pyr-FePc),can be immobilized through synthesis of these catalysts with polymer such as Nafion 117 (Dupont Co.,USA)or tetrafluoroethylen(eTeflon)containing functional groups or Polypyrrol(ePPy).In addition,catholytes with aqueous cathode immersed or flowing through the surface of air-cathode are favorably proposed containing transition metal redox couples or iron chelates.

关键词： BFCs anode cathode membrane catholyte

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Formulation Design of the Multi-component Cement Additive by Using engineering Statistics

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Journal of wuhan university of Technology(materials {3.) 2010年第3期25卷 538-544页

作者：黄弘沈晓冬 State Key Laboratory of materials-oriented chemical engineering College of Material Science and EngineeringNanjing University of Technology

A novel methodology for the formulation design of the multi-component cement additive for the low early strength blend cement was presented by using engineering *** of cement additive such as triethanolamine,chloride,saccharide and a kind of divalent alcohol were simultaneously tested according to the arrangement of response surface *** models were established to express the quantitative relationship between the chemical components of cement additive and the compressive strength of treated blend *** effectiveness and the possible interactions of these four chemicals contributing to the strength development of blend cement were further explored by the pareto chart and the contour *** according the performance analysis of four chemicals,the optimized formulations were brought forward and were validated in practical trials by Turkey＇s multiple comparison.

关键词： cement additive blend cement effectiveness interaction engineering statistics

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A　New　Kind　of　Structural　Model：Constrained　Lateral　Extrusion　in　Western　Ordos　Basin　and　Its　Adjacent　Regions

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Journal of Earth science 1996年第2期15卷 189-192页

作者： Liu Shaofeng(Department of Geology, Northwest university, Xi’an 710069)Li Sitian Yang Shigong(faculty of Earth Resources, china university of geosciences,{3.)

A new kind of structural model, the constrained lateral extrusion, is presented based on the study of the Jurassic deformation style, combinatory pattern of several structural belts and the prototype basin development in western Ordos basin and its adjacent regions. The constitution,material movement and geodynamical process of the structural model are proposed. The formation mechanism and genetic relation between structural belts and prototype basins are fully studied.

关键词： western Ordos basin constrained lateral extrusion geodynamical process

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Granulite Genesis and Tectonic Evolution in Tongbai Area:Single Zircon Evaporation Ages and Nd Isotopic Geochemistry

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Journal of Earth science 1998年第3期17卷 31-36页

作者： Zhang Hongfei Gao Shan Zhang Li Zhong Zengqiu Ling Wenli Wang Linsen faculty of Earth sciences, china university of geosciences,{3.

According to the age measurements of single zircon evaporation method, combined with the study of Nd isotopic geochemistry in Tongbai area, the protolith age of basic granulites is about 1 010 Ma; the protolith age of intermediate acid granulites is probably more than 904 Ma, which is close to the age of the basic granulites. The basic granulites would be the nature occurrence of basic magma underplating beneath the base of lower crust in the North Qinling crustal vertical growth event at about 1 000 Ma. However, the intermediate acid granulites were the result of the mixing fusion between the lower crust material and the underplating basic magma, which shows a strong crust mantle interaction. The 470-480 Ma are the peak metamorphic ages of the basic and intermediate acid granulites, which related to the crust bi direction shortening and crust thickening due to the Erlangping back arc basin southward subduction and the paleo Qinling oceanic plate northward subduction.

关键词： granulite zircon evaporation geochronology Nd isotopic geochemistry lower crust genesis tectonic evolution Tongbai area.

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Effect of electrolytes on electrochemical properties of graphene sheet covered with polypyrrole thin layer

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Progress in Natural science:materials International 2011年第6期21卷 460-466页

作者： Ya-meng CAI~(1,2),Zong-yi QIN~1,Long CHEN~2 1.State Key Laboratory for Modification of chemical Fibers and Polymer materials, Donghua university,Shanghai 201620,{3. 2.College of material science and engineering,Donghua university,Shanghai 201620,{3. State Key Laboratory for Modification of chemical Fibers Donghua University State Key Laboratory for Modification of and Polymer Materials Donghua University College of material science Donghua University College of Engineering Donghua University

Graphene sheet(GS) was successfully covered with a polypyrrole(PPy) thin layer through in situ chemical oxidative polymerization of pyrrole monomers in aqueous solution by using GS as a support material and ferric trichloride as an *** resulting nanocomposite was studied by field emission scanning electron microscopy(FE-SEM),Fourier transform infrared spectroscopy(FT-IR) and electrical measurements,including cyclic voltammetry(CV),galvanostatic charge/discharge experiment (GCD),and impedance spectroscopy(EIS).It has been found that the nanocomposite exhibited a typically curved and layer-like structure,and conformational change of PPy chains occurred due to the n-n stacking interaction between the graphitic structures in GS and aromatic rings of the PPy *** attention was paid to the effect of electrolytes on electrochemical properties of the nanocomposites,as expected,electrochemical performance was dependent on the nature of the electrolyte,and the neutral electrolytes containing alkali metal ions were found to be very suitable for GS/PPy *** with the pure PPy,the nanocomposite possessed larger specific capacitance and lower internal impedance,indicating that the nanocomposite can be a promising candidate as electrode material for supercapacitors.

关键词： nanocomposites graphene polypyrrole electrochemical property electrolyte

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