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Enhancing the capacitances of electric double layer capacitors based on carbon nanotube electrodes by carbon dioxide activation and acid oxidization

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Science china(Technological Sciences) 2010年第5期53卷 1234-1239页

作者： LI ChenSha1,2,QIAO YingJie1,WU JianJun2,WANG DaZhi2 & YUAN DianBo2 1 department of Materials Science,harbin engineering university,harbin 150001,china 2 department of Mechanical engineering,Tsinghua university,Beijing 100084,china 1. department of Materials Science Harbin Engineering University Harbin 150001 China2. Department of Mechanical Engineering Tsinghua University Beijing 100084 China

Polarizable electrodes of electric double layer capacitors(EDLCs) were made from carbon nanotubes(CNTs).Effect of carbon dioxide activation together with acid oxidation for the electrodes on the characteristics and performances of electrodes and EDLCs was *** dioxide activation changed the microstructure of the electrodes,increased the effective surface area of CNTs and optimized the distribution of apertures of the *** oxidization modified the surface characteristics of *** on the polarizable electrodes treated by carbon dioxide activation and acid oxidization,the performances of EDLCs were greatly *** specific capacitance of the electrodes with organic electrolyte was increased from 21.8 F/g to 60.4 F/g.

关键词： carbon nanotube electric double layer capacitor scan electron microscopy

CONVERGENCE PROPERTIES OF A MODIFIED BFGSALGORITHM FOR MINIMIZATION WITHARMIJO-GOLDSTEIN STEPLENGTHS

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Journal of Computational Mathematics 1999年第6期17卷 645-652页

作者： Nai-yang Deng Zheng-feng Li(department of Mathematics, Beijing agricultural engineering university, Beijing 100083,china) Beijing Agr Engn Univ Dept Math Beijing 100083 Peoples R China

The line search strategy is crucial for an efficient unconstrained optimization algorithm. One of the reason why the Wolfe line searches is recommended lies in that it ensures positive definiteness of BFGS updates. When gradient information has to be obtained costly, the Armijo-Goldstein line searches may be preferred. To maintain positive difiniteness of BFGS updates based on the Armijo-Goldstein line searches, a slightly modified form of BFGS update is proposed by I.D. Coope and C.J. Price (Journal of Computational Mathematics, 13 (1995), 156-160), while its convergence properties is open up to now. This paper shows that the modified BFGS algorithm is globally and superlinearly convergent based on the Armijo-Goldstein line searches.

关键词： BFGS methods convergence superlinear convergence

Efficient degradation of dye pollutants using dioxygen mediated by iron(Ⅱ) 2,2′-bipyridine loaded layered clay catalyst under visible irradiation

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Science china Chemistry 2006年第5期49卷 407-410页

作者： CHENG Mingming1,SUN Zhenying1,2,MA Wanhong1,CHEN Chuncheng1,ZHAO Jincai1 & WANG Zhengping2 1. Laboratory of Photochemistry,Center for Molecular Science,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100080,china 2. department of Chemical engineering,harbin engineering university,harbin 150001,china 1. Laboratory of Photochemistry Center for Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China 2. department of Chemical engineering Harbin Engineering University Harbin 150001 China

The organic-inorganic layered solid catalyst Fe(bpy)_3^(2+)-laponite was ableto photode-grade Rhodamine B (RhB) by activation of dioxygen under visible irradiation (λ > 420nm), while the homogeneous aqueous solution Fe(bpy)_3^(2+) showed no photoactivity. The catalystcould be repeatedly used and retained its reactivity. The hybrid catalyst could be separated fromthe suspension by centrifugation or sedimentation. The TOC removal yield of RhB was *** oxygen species (ROS) formed during degradation was detected by EPR. A possible mechanismwas proposed on the basis of the experimental results.

关键词： laponite, Rhodamine B, molecular oxygen, visible light.

Optical Limiting and ExcitedState Nonlinear Optical Properties in Lead Phthalocyanine

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Chinese Journal of Lasers 1997年第5期B6卷 424-428页

作者： LI Feng YANG Xuedong SONG Yinglin LUI Shutian LI Chunfei (department of Applied Physics, harbin Institute of Technology, harbin 150001, china)WU Yiqun ZUO Xia (department of Chemistry, Heilongjiang university, harbin 150001, china) harbin Inst of Technology Harbin China

The optical limiting response of lead phthalocyanine in toluene solution for 532 nm, 23 ps laser pulses is reported and this result is compared with that of *** nonlinear property of lead phthalocyanine in the first e... 详细信息

关键词： lead phthalocyanine optical limiting Z-scan excited state

The Double Integrable Couplings of Tu Hierarchy

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Communications in Theoretical Physics 2007年第7期48卷 14-18页

作者： FENG Bin-Lu HAN Bo department of Mathematics,harbin Institute of Technology,harbin 150001,chinaWEI Yuan department of Mathematics and Information,Binzhou university,Binzhou 256600,china department of Mathematics Harbin Institute of Technology department of Mathematics and Information Binzhou University

Two types of Lie algebras are presented,from which two integrable couplings associated with the Tuisospectral problem are obtained,*** of them possesses the Hamiltonian structure generated by a linearisomorphism and the quadratic-form *** approach for working out the double integrable couplings of the sameintegrable system is presented in the paper.

关键词： Lie algebra integrable couplings isospectral problem Hamiltonian structure

State feedback stabilization of discrete linear switching systems subject to nonsymmetrical state and control bounds

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控制理论与应用（英文版） 2012年第2期10卷 216-222页

作者： Zhiyuan LIU 1 , Guowei FAN 1 , Hong CHEN 2 1.department of Control Science and engineering, harbin Institute of Technology, harbin Heilongjiang 150001, china 2.department of Control Science and engineering, Jilin university, Changchun Jilin 130025, china department of Control Science and engineering Harbin Institute of Technology Harbin Heilongjiang China department of Control Science and engineering Jilin University Changchun Jilin China

Stabilization problem of discrete-time linear switching systems with bounds on the state and control input is solved in this paper. First, the synthesis of state feedback controllers that ensure the stability of closed-loop switching systems is studied under a sufficient condition. By using the idea of positive invariance, a stabilizing controller design methodology is proposed. Based on these results, the convergence rate problem is also discussed. A state feedback controller that guarantees the optimal convergence rate of closed-loop switching systems is obtained via optimization. Finally, an example made up of two subsystems is studied to show the application of our method.

关键词： Switching systems Constraints Stabilization problem Convergence rate problem

SPECTRAL AND PSEUDOSPECTRAL APPROXIMATIONS IN TIME FOR PARABOLIC EQUATIONS

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Journal of Computational Mathematics 1998年第2期16卷 107-120页

作者： Fa-yong Zhang (department of Mathematics, Heilongjiang university, harbin 150080, china) Heilongjiang Univ Dept Math Harbin 150080 Peoples R China

In this paper, spectral and pseudospectral methods are applied to both time and space variables for parabolic equations. Spectral and pseudospectral schemes are given, and error estimates are obtained for approximate ... 详细信息

关键词： spectral approximation pseudospectral approximation parabolic equation error estimate

ADAPTIVE LEARNING CONTROL OF CUTTING PARAMETERS FOR SCULPTURED SURFACE CUTTING BASED ON GENETIC ALGORITHMS AND NEURAL NETWORK

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Chinese Journal of Mechanical engineering 2002年第2期15卷 145-148页

作者： Fu Hongya Wang Yongzhang Lu Hua Fu Yunzhong department of Mechanical engineering, harbin Institute of Technology, harbin 150001, chinaTakaaki Nagao university of Tokyo, Japan department of Mechanical engineering Harbin Institute of Technology Harbin 150001 China ***

An adaptive learning control scheme intended to the on-lineoptimization of sculptured. The scheme uses a back-propagation neuralnetwork to learn the relationships between process inputs and processstates. The cutting parameters of the process model are optimizedthrough a genetic algorithms(GA). The capacity of the proposed schemefor determining optimum process inputs under a variety of processconditions and optimization strategies is evaluated on the basis ofmilling of a sculptured surface using a ball-end mill. Theexperimental results show that the neural network could model thecutting process efficiently, and the cutting conditions such asspindle speed could be regulated for achieving high efficiency andhigh quality. Therefore the proposed approach can be well applied tothe manufacturing of dies and molds.

关键词： neural network genetic algorith surface cutting

A family of transitive modular Lie superalgebras with depth one

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Science china Mathematics 2007年第10期50卷 1451-1466页

作者： Wen-de LIU~(1+) Yong-zheng ZHANG~2 ~1 department of Mathematics,harbin Normal university,harbin 150080,china ~2 department of Mathematics,northeast Normal university,Changchun 130024,china 1. department of Mathematics Harbin Normal University Harbin 150080 China 2. department of Mathematics Northeast Normal University Changchun 130024 China

The embedding theorem is established for Z-graded transitive modular Lie superalgebras g■■■(g-1)satisfying the conditions: (i)g0■■(g-1) and g0-module g-1 is isomorphic to the natural■(g-1)-module; (ii)dim g1=2/3n(2n^2+1),where n=1/2dim g-1. In particular,it is proved that the finite-dimensional simple modular Lie superalgebras satisfying the conditions above are isomorphic to the odd Hamiltonian *** restricted Lie superalgebras are also considered.

关键词： flag, divided power algebra, modular Lie superalgebra, embedding theorem