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Method of Characteristic for Functional Equations in Polynomial Form

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Acta Mathematica Sinica,English Series 1997年第3期13卷 421-432页

作者： janusz matkowski (department of Mathematics,technical university of bielsko-biala 43-309 bielsko-biala,poland)zhang weinian (department of Mathematics,Sichung Union university,East Area,Chengdu 610041,China) department of Mathematics Technical University of Bielsko-Biala department of Mathematics Sichung Union University

Properties of continuous solutions of a second order polynomial-like iterated functional equation are given by considering its characteristic.A useful method to discuss the general case is described indeed in this pro... 详细信息

关键词： Functional equation Iterative root Characteristic equation Recursive construction

Thermodynamics calculation on the oxidation and sulfur removal abilities of slag in EAF dust pellet reduction process

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Journal of Central South university of Technology 2001年第1期8卷 64-68页

作者： PENG Bing 1.PENG Ji 1.zhang Chuan fu 1.Jonathan Lobel 2,{1. A. Kozinski 2 (1.department of Metallurgical Science and Engineering, Central South university, Changsha 41.083, China 2 department of Metallurgical Engineering, McGill university 1. department of Metallurgical Science and Engineering Central South University 410083 Changsha China 2. department of Metallurgical Engineering McGill University 3610 University Street H3A 2B2 Montreal QC Canada

The valuable metals in the dust can be recycled by mixing it with reducing agent carbon and lignosulfonate as the binder to make pellets, then returning the pellets to electric arc furnace (EAF) and adding ferro silicon. Part of valuable metals in the dust is reduced by carbon and part of them reduced by ferro silicon for the economical consideration. The reduced metals get into the steel in the stainless steel or special steel production. But the sulfur in the lignosulfonate may affect the quality of produced steel, which is dependent on the status of the smelting slag. The experiments were conducted in the way of changing the ratio of start iron, pellets, ferro silicon and lime. The content of the slag was checked by XRF for the calculation thermodynamics study. The active concentrations of materials in the slag, the slag abilities of oxidation and sulfur removal in EAF dust reduction process were determined by thermodynamics calculation study on CaO MgO FeO Fe 2O 3 SiO 2 S slag at 1.550 ℃. The oxidation ability of slag can be expressed as N (FetO)= N (FeO)+6 N (Fe 2O 3)+8 N (Fe 3O 4). The sulfur removal ability is dependent on the amount of added ferro silicon and the basicity of the slag. The calculation thermodynamics model was set up and it could be applied to the practical production.

关键词： thermodynamics calculation slag electric arc furnace dust

Cartesian closedness of categories of completely distributive lattices

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Chinese Science Bulletin 1998年第24期43卷 2059-2063页

作者： zhang Dexue {1. YANG Zhongqiang 2.1. department of Mathematics, Sichuan university, Chengdu 61.064, China 2. department of Mathematics, Shaanxi Normal university, Xi’an 71.062, China department of Mathematics Sichuan University Chengdu China department of Mathematics Shaanxi Normal University Xi’an China

The category of completely distributive lattices with Scott continuous functions is cartesian closed. Neither the category of completely distributive lattices with arbitrary union preserving mappings nor the category ... 详细信息

关键词： completely distributive lattice continuous lattice cartesian closedness.

FeS_(2) (pyrite) electrodeposition thin films and study of growth mechanism

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Science China(Technological Sciences) 2005年第6期48卷 601-611页

作者： DONG Youzhong1. ZHENG Yufeng1. zhang Xiaogang2, DUAN He1. SUN Yanfei1.& CHEN Yanhua1.1. {1. of Physics, Xinjiang university, Urumqi 830046, China 2. Institute of Applied Chemistry, Xinjiang university, Urumqi 830046, China 1. department of Physics Xinjiang University 830046 Urumqi China 2. Institute of Applied Chemistry Xinjiang University 830046 Urumqi China

Ferrous sulfide (FeS) thin films were initially electrodeposited on indium-tin oxide (ITO) substrates in the aqueous solution containing iron, sulfur elements and then annealed in the sulfur atmosphere. Thereby, we successfully obtained the single-phased iron pyrite (FeS2) thin films with good quality. The experimental parameters for electrodeposition and the post-growth thermal-dynamical conditions have been calculated so that more details about the effect of thermal-dynamical conditions on the micromechanism concerned with the iron pyrite crystal growth as well as the properties of the samples have been discussed.

关键词： electrodeposition, FeS2 (pyrite), thin films, growth dynamics.

Mathematical stencil and its application in finite difference approximation to the Poisson equation

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Science China Mathematics 2005年第10期48卷 1421-1429页

作者： FENG Hui~1.zhang Baolin~(1.2) & LIU Yang~1.1. {1. of Mathematics,Wuhan university,Wuhan 430072,China 2. Laboratory of Computational Physics,Institute of Applied Physics and Computational Mathematics,Beijing 1.0088. China 1. department of Mathematics Wuhan University 430072 Wuhan China 2. Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics 100088 Beijing China

The concept of mathematical stencil and the strategy of stencil elimination for solving the finite difference equation is presented, and then a new type of the iteration algorithm is established for the Poisson equation. The new algorithm has not only the obvious property of parallelism, but also faster convergence rate than that of the classical Jacobi iteration. Numerical experiments show that the time for the new algorithm is less than that of Jacobi and Gauss-Seidel methods to obtain the same precision, and the computational velocity increases obviously when the new iterative method, instead of Jacobi method, is applied to polish operation in multi-grid method, furthermore, the polynomial acceleration method is still applicable to the new iterative method.

关键词： mathematical stencil, stencil elimination, Poisson equation, finite difference, iterative algorithm,parallelism.

The regular representation and regular covariant representation of crossed products of Woronowicz C^(*)-algebras

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Science China Mathematics 2005年第9期48卷 1245-1259页

作者： zhang Xiaoxia~(1.2) & GUO Maozheng~(1.3) 1. School of Mathematical Sciences,Peking {1.,Beijing 1.0871.China 2. department of Mathematics,Yantai {1.,Yantai 264005,China 3. LMAM,Peking {1.,Beijing 1.0871.China 1. School of Mathematical Sciences Peking University 100871 Beijing China 2. department of Mathematics Yantai University 264005 Yantai China 3. LMAM Peking University 100871 Beijing China

In this paper,it is shown that the regular representation and regular covariant representation of the crossed products A×α G correspond to the twisted multiplicative unitary operators,where A is a Woronowicz C~*-algebra acted upon by a discrete group ***,it is also shown that the regular covariant C~*-algebra is the Woronowicz C~*-algebra which corresponds to a multiplicative ***,an explicit description of the multiplicative unitary operator for C(SU_q(2) )×α (?) is given in terms of those of the Woronowicz C~*-algebra C(SU_q(2) ) and the discrete group G.

关键词： multiplicative unitary operator, Woronowicz C*-algebra, crossed product.

Formation and Evolution of Ancient Lakes on South Coast Plain of Laizhou Bay

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Chinese Journal of Population,Resources and Environment 2005年第4期3卷 26-32页

作者： Han Mei 1. Zhou Baohua 2, Yang Peilin 1.Gao Guiqin 1.& zhang Weiying 1.1. {1. of Geography, Shandong Normal university, Jinan 25001., China 2. {1. of Geography, Jinan university, Jinan 250001. China department of Geography Shandong Normal University Jinan 250014 China department of Geography Jlnan University Jinan 250001 China

Based on the data of historical geography, the analysis of the stratigraphic section, and the textual research of place names and satellite photographic interpretations, the authors study the formation and evolution of ancient lakes on the south coast plain of Laizhou Bay where there were once three lakes: Judian Lake, Qingshuibo Lake and Biehua Lake. All the lakes formed 6000 years ago evolved from the lagoons near the estuary and went through two periods, the golden age in the Middle Holocene and the shrinking age in the Late Holocene. The disappearance of the lakes resulted from the drying climate, the migration of the river courses and the activities of human beings. Among the three reasons, the migration of the river courses is the main one.

关键词： ancient lake cause historical evolution south coast plain of Laizhou Bay

I-V and C-V properties of TiO_2 thin film by pulsed-laser reactive deposition

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Chinese Science Bulletin 1998年第16期43卷 1344-1349页

作者： FU Zhengwen 1. ZHOU Mingfei 1. zhang Shengkun 2,CHEN Lianyao 2 and QIN Qizong 1.1. Laser Chemistry Institute, Fudan {1., Shanghai 200433, China 2. department of Physics, Fudan {1., Shanghai 200433, China Laser Chemistry Institute Fudan University Shanghai China department of Pnysics Fudan University Shanghai China

TiO-2 thin films have bee deposited on p-Si(1.1. substrates by pulsed-laser ablation of metallic Ti target in the O-3 ambient. The current-voltage and capacitance-voltage of the Al/TiO-2/Si capacitors are measured. The results show that the dielectric constant of thin film after being annealed at 700℃ is found to be 46, and the border trap density and the interface state density at the TiO-2/p-Si interface are 1.8×1. 1. cm -2 and 2.1. 1. eV -1.cm -2, respectively. The conduction mechanisms of as-deposited films are also discussed.

关键词： TiO-2 dielectric properties electrical properties pulsed-laser deposition.

Persistence of bounded solutions to degenerate Sobolev-Galpern equations

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Science China Mathematics 2010年第11期53卷 2831-2846页

作者： ZHU ChangRong1.& zhang {1.2, 1.chool of Mathematics, Chongqing university, Chongqing 400044, China 2Yangtze Center of Mathematics and department of Mathematics, Sichuan university, Chengdu 61.064, China 1. School of Mathematics Chongqing University Chongqing 400044 China2. Yangtze Center of Mathematics and Department of Mathematics Sichuan University Chengdu 610064 China

In this paper the persistence of bounded solutions to degenerate evolution equations of Sobolev-Galpern type is discussed. In order to define the evolution operator well, we study the existence and uniqueness of solutions to its linear form. On this basis we discuss exponential dichotomies of the evolution operator and give the Fredholm alternative result for bounded solutions of nonhomogeneous linear degenerate equations. This result enables us to give a condition for the persistence of bounded solutions of a general degenerate nonlinear autonomous equation under a nonautonomous perturbation.

关键词： degenerate evolution equation Sobolev-Galpern type boundedness Fredholm alternative exponential dichotomy