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Study on the two and three-parameter working stability regions of 3.-TZP suspension

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Science china(Technological Sciences) 2006年第5期49卷 547-568页

作者： CHEN Youqiang1, 2, ZHANG Xinni3. CHEN Sha’ou3.& QI Ping3.1. department of Chemistry, Qingdao University, Qingdao 266071, china 2. department of Chemistry, Tsinghua University, Beijing 100084, china 3. department of Physics, Qingdao University, Qingdao 266071, china department of Chemistry Qingdao University Qingdao China department of Chemistry Tsinghua University Beijing China department of Physics Qingdao University Qingdao China

We determined the variation tendency of viscosity (η) at various solids load- ing (α) for 3.-TZP suspension as a function of dispersant concentration (Cw) using vis- cosity measurement, measured the diameter of particles as a function of Cw in very dilute suspension using light scattering method, and obtained the surface features of the sedi- ment of suspension with different Cw using SEM. We also discussed the influence of the microstructure of adsorbed polymer layers on particles and their interactions in the dis- persing medium on the stability of suspension. Then two different stable states and two different unstable states for 3.-TZP suspension were given. Accordingly, the (Cw, η), (Cw, α), and (α, η) two-parameter, and (Cw, α, η) three-parameter stability maps were con- structed. Based on the DLVO theory calculations, the dispersant concentration, particle distance (r), and interparticle potential energy (VT) maps with various solids loading for 3.-TZP aqueous suspension were also constructed. In (Cw, r) two-parameter coordinate system, the stable motion region map for particles was established. The Cw, α, and VT,max (the highest potential energy) surface of the potential barrier map was obtained through calculation and simulation on the basis of the surfaces of Cw, r, VT maps introduced above. The (Cw, α) two-parameter stability map was then obtained from the Cw, α, VT,max map. The results showed that this theoretical map can qualitatively prove the experimentally obtained results—the existence of different dispersed states of particles in suspension system and the variation tendency of suspension stability with changing each parame- ter—were reasonable.

关键词： 3.-TZP, suspension, stability, DLVO theory, interparticle potential energy.

Analysis on cohesive crack opening displacement considering the strain softening effect

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2 & ZHAO Xiqiang3.1. Mechanics department, Shandong University of technology, Zibo 255049, china 2. Civil Engineering department, Dalian University of technology, Dalian 116024, china 3. Mathematics department, Ocean University of china, Qingdao 266071, china Mechanics department Shandong University of Technology Zibo China Civil Engineering department Dalian University of Technology Dalian China Mathematics department Ocean University of China Qingdao China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.

Influence of moisture content and time on the mechanical behavior of polymer material

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Science china(Technological Sciences) 2004年第5期47卷 595-607页

作者： ZHENG Gaofei1, 2, KANG Yilan1, SHENG Jing3. QIN Qinghua1, WANG Huaiwen1 & FU Donghui1 1. department of Mechanics, tianjin University, tianjin 3.0072, {3. 2. department of Mechanics, tianjin Polytechnic University, tianjin 3.0160, {3. 3. department of Material Engineering, tianjin University, tianjin 3.0072, {3. Correspondence should be addressed to Kang Yilan department of Mechanics Tianjin University Tianjin China department of Mechanics Tianjin Polytechnic University Tianjin China department of Material Engineering Tianjin University Tianjin China

The effects of moisture content and time on mechanical behavior of polymer materials are investigated both theoretically and experimentally in this paper. An equivalence relationship between time intervals and the moisture content for polymer nylon-6 has been established by way of experimental observation and measured results. The relationship shows that there exists equivalence between moisture and service time in affecting mechanical properties. In other words, an increase in moisture can be replaced by prolonging acting time in producing the same effect on material properties. Consequently, a moisture-time superposition principle is presented based on the experimental results and the analogy of temperature-time superposition principle. Numerical results such as stress-strain curves with different moisture contents are presented to verify the applicability and correctness. The proposed method appears very promising in study on the effect of moisture content on mechanical behavior of polymer materials.

关键词： equivalence relationship of moisture-time, moisture content, mechanical properties, shift function.

Rank of loop, constraint degree of path, coupling degree of graph and their application

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Progress in Natural Science:Materials International 2005年第2期15卷 79-85页

作者： YANG Tingli1*, LUO Yufeng2, ZHANG Ce3.and YAO Fanghua1(1. SINOPIC Jinling Petrochemical Corp., Nanjing 21003., china 2. department of Mechanical Engineering, Nanchang University, Nanchang 3.0029, china 3. department of Mechanical Engineering, tianjin University, tianjin 3.0072, china) Jinling Petrochemical Corp. SINOPIC Nanjing 210037 China Dept. of Mechanical Eng. Nanchang Univ. Nanchang 330029 China Dept. of Mechanical Eng. Tianjin Univ. Tianjin 300072 China

Some new concepts (rank of a loop, degree of freedom of a graph, path unit and ordered path arrangement, constraint degree of path, coupling degree of a graph, basic graph, etc.), formulas, and algorithms, are proposed in this paper. Based on these concepts, a new systematic theory and practical method for the design of topological structure, kinematics and dynamics of mechanical systems is established. Some conjectures and problems needed to be researched are also put forward. The concepts, formulae and algorithms presented in this paper will find wide potential applications.

关键词： rank of loop degree of freedom of graph constraint degree of path coupling degree of graph

On the periodic solutions of a type of differential-iterative equations

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Chinese Science Bulletin 1998年第3期43卷 204-206页

作者： GE Weigao 1, LIU Zhengrong 2 and YU Yuanhong 3.1. department of Applied Mathematics, Beijing Institute of technology, Beijing 100081, china 2. department of Mathematics, Yunnan University, Kunming 650091, china 3. Institute of Applied Mathematics, C department of Applied Mathematics Beijing Institute of Technology Beijing China department of Mathematics Yunnan University Kunming China Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

Sufficient conditions for the existence of periodic solutions to a type of nonautonomous differential_iterative equations are given.

关键词： differential_iterative equation periodic solution fixed point.

Mathematic Expression of Kinetic Compensation Effect and Relationship between the Exothermic Decomposition Temperature and Critical Temperature of Thermal Explosion of Eighty-six Energetic Materials

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含能材料 2001年第1期9卷 8-9页

作者： HU Rong zu 1, YANG De suo 2, ZHANG Jiao qiang 3. (1. department of Chemistry,Northwest University, Xi′an 710065, china 2. department of Chemistry and Chemical Engineering, Baoji College of Arts and Science, Baoji 721007, china 3. department of 西北大学陕西西安 710065 宝鸡文理学院陕西 721007 西北工业大学陕西西安 710072

Two relationships are established using the least squares method,between the kinetic parameters (the apparent activation energy and pre exponential constant),and the exothermic decomposition temperature and ther... 详细信息

关键词： critical temperature of thermal explosion decomposition temperature DSC energetic materials.

SrGa_2S_4∶Ce blue TFEL in new structure

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Chinese Science Bulletin 1998年第7期43卷 603-605页

作者： XU Chunxiang+1, LOU Zhidong+2, XU Zheng+3.and XU Xurong+3.. National Laboratory of Molecular and Biomolecular Electronics, Southeast University, Nanjing 210096, china 2. department of Applied Physics, tianjin University, tianjin 3.003., china 3. Institu National Laboratory of Molecular and Biomolecular Electronics Southeast University Nanjina China department of Applied Physics Tianjin University Tianjin China Institute of Photoelectronic technology Northern Jiaotong University Beijing China

SrGa-2S-4∶Ce blue TFEL device with a novel structure was prepared by electron beam evaporation. The dielectric constant of insulator layer in this structure is far less than that in the conventional structure, so the hot-electrons can be accelerated in SiO-2 layers. The stable TFEL with good chromaticity was achieved and the basic characteristics were investigated.

关键词： SrGa-2S-4∶Ce bule TFEL low dielectric constant insulator layer.

Synthesis and Characterization of Mg_3.PO_4)_2-coated Li_(1.05)Ni_(1/3.Mn_(1/3.Co_(1/3.O_2 Cathode Material for Li-ion Battery

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Journal of Wuhan University of technology(Materials Science) 2009年第3期24卷 347-353页

作者：陈玉红 department of Chemical and Environmental Engineering Hebei Chemical & Pharmaceutical Vocational Technology Colege

Mg3.PO4）2-coated Li1.05Ni1/3.n1/3.Co1/3.2 cathode materials were synthesized via co-precipitation method. The morphology, structure, electrochemical performance and thermal stability were characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, cyclic voltammetry（CV）, electrochemical impedance spectroscopy（EIS）, charge/discharge cycling and differential scanning calorimeter （DSC）. SEM analysis shows that Mg3.PO4）2-coating changes the morphologies of their particles and increases the grains size. XRD and CV results show that Mg3.PO4）2-coating powder is homogeneous and has better layered structure than the bare one. Mg3.PO4）2-coating improved high rate discharge capacity and cycle-life performance. The reason why the cycling performance of Mg3.PO4）2-coated sample at 55 ℃ was better than that of room temperature was the increasing of lithium-ion diffusion rate and charge transfer rate with temperature rising. Mg3.PO4）2-coating improved the cathode thermal stability, and the result was consistent with thermal abuse tests using Li-ion cells： the Mg3.PO4）2 coated Li1.05Ni1/3.n1/3.o1/3.2 cathode did not exhibit thermal runaway with smoke and explosion, in contrast to the cells containing the bare Li1.05Ni1/3.n1/3.o1/3.2.

关键词： lithium-ion batteries cathode materials Li1.05Ni1/3.n1/3.o1/3.2 co-precipitation

Morphology and electrical conductivity of PACS

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Journal of Environmental Sciences 2000年第3期12卷 319-324页

作者： GAO Bao\|yu\+1, LIU Zong\|gang\+2, YUE Qin\|yan\+3. ZHAO Hua\|zhang\+3.(1. department of Environmental Engineering, Shandong University, Jinan 250100, china 2. Environmental Monitoring Station of Huaiyin, Jinan 250022, china 3. department of Environ 山东大学山东济南 2 50 1 0 0 山东济南市槐荫区环境监测山东济南 2 50 0 2 2

Polyaluminium chlorides with sulfate ion(PACS) were prepared by using AlCl 3.6H 2O, Al(SO 4) 3.18H 2O and Na 2CO 3.as raw materials. The effects of basicity ( r ), Al 3. /SO 4 2- molar ratio and aging time on the morphology of PACS were observed by transmission electrical microscope. The influence of aging time on charge neutralization and coagulation effect of PACS was studied. The effects of basicity ( r ), Al 3. /SO 4 2- molar ratio and aging time on the electrical conductivity of PACS solution were also investigated. The experimental results show that the degree of polymerization of polyaluminium chloride(PAC) increases when SO 4 2- ion is added. The higher the basicity( r ) and the longer the aging time, the larger the size of polymer PACS. The ability of PACS neutralizing the charge on Kaolinite decreases with the increase of aging time. The electrical conductivity of PACS solution(the concentration of Al 3. ion is 0.18 mol/L) with different aging time is the function of the basicity and Al 3. /SO 4 2- molar ratios and has its maximum at r =0.5 and Al 3. /SO 4 2- =12.

关键词： coagulant PACS morphology transmission electron microscope electrical conductivity coagulation