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PROPERTIES AND MORPHOLOGY OF UNSATURATED POLYESTER/ACRYLATE-TERMINATED POLYURETHANE/ORGANO-MONTMORILLONITE NANOCOMPOSITES

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Chinese Journal of Polymer Science 2005年第5期23卷 471-478页

作者： Chang-jiang You Jin-guo Xu Song Xi Xiao-xia Duan Jie Shen and De-min Jia College of Materials Science and Engineering,south china university of technology,Guangzhou 510640,china College of Materials Science and Engineering South China University of Technology Guangzhou 510640 China

Unsaturated polyester resin （UPR）/acrylate-terminated polyurethane （ATPU）/organo-modified montmorillonite （OMMT） nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared by the sequential mixing, i.e. mixture of the ATPU and styrene （S） and OMMT were prepared in the first step; UPR was then added to the pre-intercalates of ATPU/S/OMMT. Results indicate that the mechanical properties and thermal properties of UPR/ATPU/OMMT nanocomposites greatly depend on the amount of ATPU and OMMT. Results show that the addition of ATPU could increase the impact strength of UPR/ATPU composites, but the tensile strength, flexural strength and heat resistance of the materials are obviously decreased. When the weight ratio between UPR, ATPU and OMMT were 82：15：3, the impact strength and heat distortion-temperature of nanocomposite were greatly improved, meanwhile there was little change for other properties of the nanocomposites. The synergistic enhancement effects of ATPU and OMMT on the composites were observed. The structures and morphology of the composites were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy.

关键词： Unsaturated polyester Acrylic terminal polyurethane Organo-modified montmorillonite Nanocomposite.

Analysis of Road Base Uniformity via the Deviation of Modulus of Asphalt Mixtures

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Journal of Wuhan university of technology(Materials Science) 2007年第2期22卷 367-370页

作者：职雨风 Road Research Institute South China University of Technology

The modulus deviation of base material calculated from the data of falling weight deflectometer （FWD） was used to evaluate the uniformity of road base so as to reflect the construction quality. Four parameters,the repeatability standard deviation of the data in the same driveway, the reproducibility standard deviation of the data in the different driveway, the consistency statistics value of the data in the different driveway, and the consistency statistics value of the data in the same driveway, were introduced for the construction uniformity analysis. The experimental result shows that the materials modulus calculated from FWD has a highly correlative relationship with the uniformity of road base.

关键词： road base material modulus falling weight deflectometer (FWD)

NUMERICAL ANALYSIS AND COMPUTER SIMULATION OF FORMATION OF RESIDUAL STRESSES IN GRINDING PROCESS

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Chinese Journal of Mechanical Engineering 1997年第4期10卷 2-8,65页

作者： Hu Huanan Zhou Zehua Chen Chengzhou south china university of technology

A theoretical method of solution for residual stresses in ground surface is developed. A new model for analysing the residual stresses is proposed, and a finite element analysing software for solution of two dimension thermal elasto plastic problem with moving loading is developed. Numerical analysis and computer simulation of formation of residual stresses in grinding process are conducted by means of this software. The theoretical basis is provided for controlling residual stresses of machined surface, and for precisely machining.

关键词： Grinding Residual stress Finite element method Computer simulation

Mechanically Driven Alloying and Structural Evolution of Nanocrystalline Fe_(60)Cu_(40) Powder

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Journal of Materials Science & technology 1997年第4期13卷 354-358页

作者： Yuanda DONG and Xueming MA(School of Materials Science and Engineering, Shanghai university, Shanghai 200072, china)Yuanzheng YANG(Dept. of Mechanical Engineering(2), south china university of technology, Guangzhou 510641, china)Fangxin LIU and Genmiao WA School of Materials Science and Engineering Shanghai University Shanghai 200072 China Dept. of Mechanical Engineering(2) South China University of Technology Guangzhou 510641 China Lab. of Structure Analysis University of Science and Technology of China Hefei 230026 China

Highly supersaturated nanocrystalline fcc Fe60Cu40 alloy has been prepared by mechanical alloying of elemental powders. The phase transformation is monitored by X-ray diffraction (XRD),Mossbauer spectroscopy and extended X-ray absorption fine structure (EXAFS). The powder obtained after milling is of single fcc structure with grain size of nanometer order. The Mossbauer spectra of the milled powder can be fitted by two subspectra whose hyperfine magnetic fields are 16 MA/m and 20 MA/m while that of pure Fe disappeared. EXAFS results show that the radial structure function (RSF) of Fe K-edge changed drastically and finally became similar to that of reference Cu K-edge, while that of Cu K-edge nearly keeps unchanged in the process of milling. These imply that bcc Fe really transforms to fcc structure and alloying between Fe and Cu occurs truly on an atomic scale. EXAFS results indicate that iron atoms tend to segregate at the boundaries and Cu atoms are rich in the fcc lattice. Annealing experiments show that the Fe atoms at the interfaces are easy to cluster to α-Fe at a lower temperature, whereas the iron atoms in the lattice will form γ-Fe first at temperature above 350℃, and then transform to bcc Fe

关键词： Mechanically Driven Alloying and Structural Evolution of Nanocrystalline Fe MA Cu Powder Figure

STUDIES ON REVERSE OSMOSIS SEPARATION OF AQUEOUS ORGANIC SOLUTIONS BY PAA/PSF COMPOSITE MEMBRANE

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Chinese Journal of Polymer Science 2000年第2期18卷 115-122页

作者： Jun Fang De-min Jia Ji-cai Huang Qun-hui Guo Feng-lian Wu south-china university of technology, Guangzhou 510641, china Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650, china 华南理工大学广东广州中科院广州化学所广东广州

The reverse osmosis (RO) separation of aqueous organic solutions, such as alcohols, amines, aldehydes, acids, ketones, and esters etc., by PAA (polyacrylic acid)/PSF (polysulfone) composite membrane has been studied. It was found that the separation results for aliphatic alcohols, amines and aldehydes are satisfactory, the solute rejection (R-a) and the volume fluxes of solutions (J(V)) for 1000 ppm ethanol, ethylamine and ethyl aldehyde are 66.2%, 61.0%, 84.0% and 0.90 x 10(-6), 0.35 x 10(-6), 0.40 X 10(-6) m(3)/m(2) . s, respectively, at 5.0 MPa and 30 degrees C. R-a increased with increasing molecular weights of alcohols, amines and aldehydes, and the R-a for n-amyl alcohol, n-butylamine and n-butyl aldehyde reached 94.3%, 88.6% and 96.0%, respectively. Satisfactory separation results (R-a > 70%) for ketones, esters, phenols and polyols have been obtained with the PAA/PSF composite membrane. The effect of operating pressure on the properties of reverse osmosis has also been investigated. Analysis of experimental data with Spiegler-Kedem's transport model has been carried out and the membrane constants such as reflection coefficient sigma, solute and hydraulic permeabilities omega and L-p for several organic solutes have been obtained.

关键词： PAA/PSF composite membrane reverse osmosis separation of aqueous organic solution

ON CRITICAL SINGULAR QUASILINEAR ELLIPTIC PROBLEM WHEN n=p

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Acta Mathematica Scientia 2006年第2期26卷 209-219页

作者：姚仰新沈尧天 School of Mathematical Sciences south china university of technology Guangzhou 510640China

This article deals with the problem-△pu=λ｜u｜p/-2｜x｜pIn^p R/｜x｜＋f（x,u）,x∈Ω;u=0,x∈δΩ,where n = p. The authors prove that a Hardy inequality and the constant （p/p-1）^p is optimal. They also prove the ex... 详细信息

关键词： Elliptic equation Hardy inequality critical singularity Mountain PassLemma

Gap Property of Bi-Lipschitz Constants of Bi-Lipschitz Automorphisms on Self-similar Sets

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Chinese Annals of Mathematics,Series B 2010年第2期31卷 211-218页

作者： Lifeng XI Ying XIONG Institute of Mathematics Zhejiang Wanli University Ningbo 315100 Zhejiang China. Department of Mathematics South China University of Technology Guangzhou 510641 China.

For a given self-similar set ERd satisfying the strong separation condition,let Aut(E) be the set of all bi-Lipschitz automorphisms on *** authors prove that {fAut(E):blip(f)=1} is a finite group,and the gap property of bi-Lipschitz constants holds,i.e.,inf{blip(f)=1:f∈Aut(E)}>1,where lip(g)=sup x,y∈E x≠y(|g(x)-g(y)|)/|x-y| and blip(g)=max(lip(g),lip(g-1)).

关键词： Fractal Bi-Lipschitz automorphism Self-similar set

Transitional function of DG to CA3 in the hippocampus

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Progress in Natural Science:Materials International 2007年第12期17卷 1436-1444页

作者： Yan Chuankui1 and Liu Shenquan2(1. Department of Mathematics, Hangzhou Normal university, Hangzhou 310036, china 2. Department of Applied Mathematics, School of Mathematical Sciences, south china university of technology, Guangzhou 510640, china) Department of Mathematics Hangzhou Normal University Hangzhou 310036 China Department of Applied Mathematics School of Mathematical Sciences South China University of Technology Guangzhou 510640 China

Using single cell channel model, the transmission features of CA3-DG network in the hippocampus are investigated. The influence of the stimulation on discharge pattern of pyramidal neurons is analyzed, which shows that it starts with period spiking discharges, followed by period-doubling bifurcation to chaos, and period 3 discharge evolving into chaos, and ultimately a period of bursting discharges. By the synaptic model, the CA3-DG network model is constructed, which analyzes the summation of postsynaptic currents in the network, the influence of postsynaptic current on discharge rhythm as well as the mechanism of bursting discharges. The strong capacity of spatiotemporal encoding in the network indicates the features of CA3 network during the information transmission process in the hippocampus. The modeling result with time delay of the synaptic transmission is in accordance with the experimental phenomena of action potential in the hippocampus.

关键词： hippocampus CA3-DG period-doubling bifurcation chaos.

Free Quadratic Bialgebra

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Acta Mathematica Sinica,English Series 1996年第3期12卷 244-248页

作者： Hao Zhifeng, Department of Applied Mathematics south china university of technology Guangzhou, 510641 chinaTong Wenting, Department of Mathematics Nanjing university Nanjing, 210008 china Department of Applied Mathematics South China University of Technology Guangzhou China Department of Mathematics Nanjing University Nanjing China

In this paper, we obtain the following main theorem for a free quadratic bialgebra J: (a) For p≠0, J is a pointed cosemisimple coalgebra. For p=0, J is a hyperalgebra. (b) For p≠0 and q≠0, J has antipode S iff p·q+2=0 and S(x)=x. Forp=0 or q=0, J has antipode and S(x)=-x. (c) All left J*-modules are rational. Also, we give some applications in homological theory and algebraic K-theory.

关键词： Free quadratic bialgebra Antipode Cosemisimple Rational module