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Journal of Materials Science & technology 2001年第3期17卷 375-382页

作者： Mingshi SONG, Chen ZHANG and Guixian HU Research Institute of Polymeric Materials, Beijing university of chemical technology, Beijing 100029, china E-mail: wangzhchen@*** Res. Inst. of Polymeric Mat. Beijing Univ. of Chem. Technol. Beijing 100029 China

Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) over dot), psi (10)((gamma) over dot) and shear rate ((gamma) over dot), and topologically constrained dimension number n ' and a were derived. Linear viscoelastic parameters (eta (0) and G(N)(0)) and topologically constrained dimension number (n ' a and )over bar>) as a function of the primary molecular weight (M-n), molecular weight between entanglements (M-C) and the entanglement sites sequence distribution in polymer chain were determined. A new method for determination of viscoelastic parameters (eta (0), psi (10), G(N)(0) and J(e)(0)), topologically constrained dimension number (n ', a and v) and molecular weight (M-n, M-c and M-e) from the shear flow measurements was proposed. It was used to determine those parameters and structures of HDPE, making a good agreement between these values and those obtained by other methods. The agreement affords a quantitative verification for the molecular theory of nonlinear viscoelasticity with constrained entanglement in polymer melts.

关键词： Rheological Behavior for Polymer Melts and Concentrated Solutions A Quantitative Verification for the Molecular Theory of Non-linear Viscoelasticity with Entanglement Constraints in Polymer Melts Part

Two Families of Liapunov Functions for Functional Differential Systems

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Acta Mathematica Sinica,English Series 1999年第2期15卷 197-206页

作者： Yi Zhang, Department of Computer Science and Engineering, university of Electronic Science and technology of china, Chengdu 610054, P. R. chinaMeijuan Wang, Department of Basic Studies, east china university of technology, 516 Jungong Road Shanghai 200093, P. R. china Department of Computer Science and Engineering University of Electronic Science and Technology of China Chengdu P. R. China Department of Basic Studies East China University of Technology Shanghai P. R. China

Two families of Liapunov functions are employed to study the global stability and bound- edness of functional differential systems. New stability and boundedness theorems are obtained. Ap- plications of these theorems... 详细信息

关键词： Liapunov Function Razumikhin Technique Stability Infinite Delay

On edge dislocation in a multilayered laminate

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Theoretical & Applied Mechanics Letters 2011年第2期1卷 25-28页

作者： Xu Wang~(a) School of Mechanical and Power Engineering,east china university of Science and technology,Shanghai 200237, china School of Mechanical and Power Engineering East China University of Science and Technology Shanghai 200237 China

We investigate the elastic field induced by an edge dislocation in a multilayered laminated composite composed of(N—2)thin bonded elastic layers sandwiched between two semi-infinite elastic media.A simple closed-form solution is obtained when all the phases have equal shear modulus but different Poisson's ratios,and when the dislocation is located in the upper semi-infinite *** image force acting on the dislocation due to its interaction with the multilayered structure is also derived. Several specific examples are discussed in detail to illustrate the mobility of the edge dislocation. Some interesting behaviors of the dislocation are *** results indicate that it is possible to find at most(N—2)equilibrium positions for the edge dislocation in an N-phase composite structure.

关键词： laminated composite edge dislocation image force equilibrium position

Preparation, characterization and salt-resistance of a coal based super absorbent composite

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Mining Science and technology 2010年第6期20卷 864-871页

作者： CHU Mo, HUANG Zhanbin, XU Bang, FANG Tao, DUAN Hui School of chemical and Environmental Engineering, china university of Mining & technology, Beijing 100083, china [a] School of chemical Environmental Engineering China University of Mining & Technology Beijing 100083 China

Potassium humate was extracted from brown coal. A novel super absorbent composite, poly （acrylic acid-co-acryla- mide）/potassium humate （PAA-AM/KHA）, was prepared by graft polymerization of acrylic acid, acrylamide and coal based potassium humate using N, N＇-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator. The effects of reaction temperature, degree of neutralization of the poly （acrylic acid） and the amounts of crosslinker, initiator and potassium humate were investigated. Salt resistance tests were also carded out. The composite prepared under optimal conditions had a potassium bumate content of 10% and exhibited a water absorption of 770 g/g in distilled water, and 349, 286 and 41 gig in 0.5 mol/L KC1, MgC12 and A1CI3 solutions respectively. The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly （acrylic acid-co-acrylamide） because of the collaborative effect of functional groups of the coal based potassium humate. The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy. Introduction of potassium humate into the poly （acrylic acid-co-acrylamide） structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments. The salt resisting property of the composite is improved, production costs are reduced and the growth stimulant effect is still present.

关键词： brown coal coal based potassium humate superabsorbent salt-resistant property

Reverse atom transfer radical polymerization of methyl methacrylate initiated by AIBN/FeCl_3/isophthalic acid system

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Chinese Science Bulletin 2001年第13期46卷 1077-1079页

作者： ZHANG Guosheng, ZHU Shenmin & YAN DeyueSchool of Chemistry and chemical technology, Shanghai Jiao Tong university, Shanghai 200240, china School of Chemistry technology Shanghai Jiao Tong University Shanghai 200240 China

The reverse ATRP of MMA using AIBN/FeCl3/ isophthalic acid as the initiating system was successfully performed. The new initiating system can be used to synthesize PMMA with high molecular weight and narrow polydis-persity index. The polymerization shows ’living’/controlled characteristics. Compared with other initiating system used in reverse ATRP, the easy availability and non-toxicity of isophthalic acid make it very attractive.

关键词： reverse ATRP MMA nontoxic ligand AIBN/FeCI3/isophthalic acid system.

X-ray and Magnetoresistance Measurements of Electrodeposited Cu-Co Granular Films

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Journal of Materials Science & technology 2005年第3期21卷 307-310页

作者： Suwei YAO, Haixia WU, Weiguo ZHANG and Hongzhi WANG Sugiyama Laboratory of Surface technology, Department of Applied Chemistry, School of chemical Engineering and technology, Tianjin university, Tianjin 300072, china Department of Applied Chemistry School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

Granular CoxCu1-x alloy films were prepared by electrodeposition at room temperature directly onto semiconducting Si substrate. X-ray diffraction (XRD) revealed that the as-deposited films formed single phase metastable fcc alloy structure. The fcc lattice parameter α was found to decrease linearly with increasing Co concentration x in the studied range. The giant magnetoresistance (GMR) of the films was improved after annealing. Pure Co fcc diffraction peaks were observed in the diffractogram of the annealed sample, indicating phase separation occurred upon annealing. The optimal annealing temperature was 450℃. The maximum of magnetoresistance (MR) ratio 8.21% was obtained for the Co20Cu80 thin film after annealing at 450℃ for 1 h. The saturation field decreased upon annealing in the MR curves of Co20Cu80 film.

关键词： Electrodeposition Giant magnetoresistance (GMR) Granular Phase separation

A HYBRID POLYMER GEL AND ITS STATIC NONERGODICITY

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Chinese Journal of Polymer Science 2002年第3期20卷 269-274页

作者： Yue Zhao Chi Wu The Open Laboratory of Bond Selective Chemistry Department of chemical Physics, university of Science and technology of china Hefei 230026 china Department of Chemistry The Chinese university of Hong Kong Shatin, N.T., Hong Kong china Univ Sci & Technol china Dept Phys Chem Open Lab Bond Select Chem Hefei 230026 Peoples R China Chinese Univ Hong Kong Dept Chem Shatin Hong Kong Peoples R China

We used a thermally reversible hybrid gel made of billions of physically jam-packed swollen thermally sensitivepoly(N-isopropyl-acrylamide) chemical microgels. Laser light scattering study on a series of such hybrid gels formed atdifferent gelling rates and temperatures revealed that the position-dependence of the scattering speckle pattern(staticnonergodicity) came from large voids formed during the sol-gel transition. With a proper preparation, such a nonergodicitycould be completely removed, indicating that the static nonergodicity generally observed in a gel is not indinsic, but comesfrom the clustering "island" structure formed during the gelation process.

关键词： Polymer gel Nonergodicity Dynamic light scattering

The geodetic numbers of graphs and digraphs

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Science china Mathematics 2007年第8期50卷 1163-1172页

作者： Chang-hong LU~(1,2) 1 Department of Mathematics,east china Normal university,Shanghai 200062,china 2 Institute of Theoretical Computing,east china Narnal university,Shanghai 200062,china 1. Department of Mathematics East China Normal University Shanghai 200062 China 2. Institute of Theoretical Computing East China Narnal University Shanghai 200062 China

For every two vertices u and v in a graph G, a u-v geodesic is a shortest path between u and v. Let I(u, v) denote the set of all vertices lying on a u-v geodesic. For a vertex subset S, let I(S) denote the union of all I(u, v) for u, v ∈ S. The geodetic number g(G) of a graph G is the minimum cardinality of a set S with I(S) = V (G). For a digraph D, there is analogous terminology for the geodetic number g(D). The geodetic spectrum of a graph G, denoted by S(G), is the set of geodetic numbers of all orientations of graph G. The lower geodetic number is g ?(G) = minS(G) and the upper geodetic number is g +(G) = maxS(G). The main purpose of this paper is to study the relations among g(G), g ?(G) and g +(G) for connected graphs G. In addition, a sufficient and necessary condition for the equality of g(G) and g(G × K 2) is presented, which improves a result of Chartrand, Harary and Zhang.

关键词： convex set digraph distance geodesic geodetic number 05C12 05C20

Friction-reducing and antiwear behavior of metal halide-stabilized linear phosphazene derivatives as lubricants for a steel-on-steel contact

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Science china(Technological Sciences) 2005年第3期48卷 282-291页

作者： ZHU Jiamei 1,2 , LIU Weimin 2 & LIANG Yongmin 2 1. School of chemical Engineering and technology, china university of Mining and technology, Xuzhou 221008, china 2. State Key Laboratory of Solid Lubrication, Lanzhou Institute of chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, china 1. School of chemical Engineering and technology China University of Mining and Technology 221008 Xuzhou China 2. State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences 730000 Lanzhou China

A series of novel metal halide-stabilized linear phosphazene derivatives were synthesized. The friction-reducing and antiwear abilities of the resulting products as the lubricants for a steel-on-steel contact were comparatively investigated on an Optimol SRV oscillating friction and wear tester. The morphology of the worn steel surface was observed on a scanning electron microscope, while the chemical states of some typical elements on the worn steel surface were examined by means of X-ray photoelectron spectroscopy. It was found that both the side branch structures and central metals influenced the friction-reducing and antiwear behaviors of the synthetic derivatives as the lubricants, which was related to the different adsorption activities of the organic compounds composed of different organic ingredients and metallic ions on a nascent metal surface. All the synthetic lubricants except for the iron (III) derivative showed increased antiwear abilities with increasing metallic ionic radius. A protective layer originated from the tribochemical reaction together with the adsorbed boundary lubricating layer containing organic fluorine compounds, nitrogen oxide, and Fe 3 (PO 4 ) 2 plays an important role in improving the friction and wear behavior of the steel-on-steel system.

关键词： metal halide-stabilized linear phosphazene derivatives,lubricant,steel,tribological properties.

STUDY ON THE MORPHOLOGY OF POLYVINYL CHLORIDE/POLYSTYRENE BLENDS BY ELECTRON MICROPROBE ANALYSIS

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Chinese Journal of Polymer Science 2000年第5期18卷 437-441页

作者： Zheng-ping Fang Gen-lin Wang Guo-ping Cai Cheng-wei Xu Jie Qian Institute of Polymer Composites, Zhejiang university, Hangzhou 310027, china College of chemical Engineering, Zhejiang university of technology, Hangzhou 310014, china Zhejiang Univ Inst Polymer Composites Hangzhou 310027 Peoples R China Zhejiang Univ Technol Coll Chem Engn Hangzhou 310014 Peoples R China

The morphology of polyvinyl chloride/polystyrene (PVC/PS) blend samples with different mass ratios, prepared by means of solution casting and melt mixing, have been successfully examined by electron microprobe analysis (EMP). This experiment was performed in a scanning electron microscope attached to an energy dispersive X-ray analyzer. Differential scanning calorimetry was also used to investigate the phase separation of the blends. The results show that PVC and PS are incompatible and the blends have sea-islands phase structures. Blends prepared via melt mixing have finer phase-dispersion than those prepared via solution casting.

关键词： electron microprobe analysis polyvinyl chloride/polystyrene blends morphology