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Robustness and breakup of the spiral wave in a two-dimensional lattice network of neurons

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Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 672-679页

作者： MA Jun 1,2, TANG Jun 2 , ZHANG AiHua 3.& JIA Ya 2 1 department of Physics, lanzhou university of Technology, lanzhou 73.050,{3. 2 department of Physics, Central{3. Normal university, Wuhan 43.079,{3. 3.College of Electrical and Information Engineering, lanzhou university of Technology, lanzhou 73.050,{3. 1. department of Physics Lanzhou University of Technology Lanzhou 730050 China2. Department of Physics Central China Normal University Wuhan 430079 China3. College of Electrical and Information Engineering Lanzhou University of Technology Lanzhou 730050 China

The robustness and breakup of spiral wave in a two-dimensional lattice networks of neurons are investigated. The effect of small- world type connection is often simplified with local regular connection and the long-range connection with certain probability. The network effect on the development of spiral wave can be better described by local regular connection and changeable long-range connection probability than fixed long-range connection probability because the long-range probability could be changeable in realistic biological system. The effect from the changeable probability for long-range connection is simplified by multiplicative noise. At first, a stable rotating spiral wave is developed by using appropriate initial values, parameters and no-flux boundary conditions, and then the effect of networks is investigated. Extensive numerical studies show that spiral wave keeps its alive and robust when the intensity of multiplicative noise is below a certain threshold, otherwise, the breakup of spiral wave occurs. A statistical factor of synchronization in two-dimensional array is defined to study the phase transition of spiral wave by checking the membrane potentials of all neurons corresponding to the critical parameters(the intensity of noise or forcing current)in the curve for factor of synchronization. The Hindmarsh-Rose model is investigated, the Hodgkin-Huxley neuron model in the presence of the channel noise is also studied to check the model independence of our conclusions. And it is found that breakup of spiral wave is easier to be induced by the multiplicative noise in presence of channel noise.

关键词： spiral wave factor of synchronization breakup multiplicative noise robustness

A NONLINEAR GALERKIN METHOD WITH VARIABLEMODES FOR KURAMOTO-SIVASHINSKY EQUATION

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Journal of Computational Mathematics 1999年第3期17卷 243-256页

作者： Yu-jiang wu(Depadrtment of Mathematics, Shanghai university, Jiadiap Shanghai 201800, china department of Mathematics,{3., lanzhou 750000, china) 上海大学数学系上海

This article proposes a kind of nonlinear Galerkin methods with variable modes for the long-term integration of Kuramoto-Sivashinsky equation. It consists of finding an appropriate or best number of modes in the correction of the method. Convergence results and error estimates are derived for this method. Numerical examples show also the efficiency and advantage of our method over the usual nonlinear Galerkin method and the classical Galerkin method.

关键词： Kuramoto-Sivaskinsky equation nonlinear Galerkin method approximation convergence

Syntheses,characterization,crystal structure and magnetic properties of copper(Ⅱ) α,β-unsaturated carboxylate complexes with trimethyl phosphate

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Chinese Science Bulletin 2001年第12期46卷 987-991页

作者： WANG Yaoyu, LIU Ping, SHI Qian, GAO Yici & SHI Qizhen1. department of Chemistry, Northwest university, Xi’an 710069, china 2. department of Chemistry, Wenzhou Teachers College, Wenzhou 3.5003. china 3. department of Chemistry, lanzhou university, lanzhou 73.000, china department of Chemistry Northwest University Xi’an China department of Chemistry Wenzhou Teachers College Wenzhou China department of Chemistry Lanzhou University Lanzhou China

Two ternary complexes Cu2A4[OP(OCH3.3.2 (A represents CH2=CH-COO- and CH2=C(CH3.-COO-) have been synthesized, and elemental analyses, IR, ESR, electronic reflectance spectra and magnetic studies were carried out. The single crystal X-ray diffraction shows that Cu2[CH2=C(CH3.-COO]4[OP(OCH3.3.2 is triclinic, with space group P1, a = 1.05128(13., b = 1.7559(5), c = 1.94479(3. nm, α =91.263.14)°,(β = 102.559(6)°,γ= 106.3.9(13.°, Z = 4 and R = 0.0668. Two copper(Ⅱ) atoms are bridged by four (a-methacrylate groups, and each copper(Ⅱ) atom is coordinated with a trimethyl phosphate molecule in the axial position, forming a distorted square pyramidal configuration. The symmetric center is between the two copper(Ⅱ) atoms, and the Cu-Cu bond distance is 0.26098(6) nm. The Cu-Cu distance and magnetic studies suggest that there exist anti-ferromagnetic interactions between the two copper(Ⅱ) atoms.

关键词： copper(Ⅱ ) complex α β-unsaturated carboxylate trimethyl phosphate magnetic property crystal structure.

Seasonal changes of endogenous ABA and cytokinins in environmental adaptation of different ecotypes of reed plants

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Journal of Environmental Sciences 1995年第4期7卷 449-454页

作者： Wang Hongliang , Zhang Chenglie(department of Biology, lanzhou university , lanzhou 73.000 ,{3.)

ＳｅａｓｏｎａｌｃｈａｎｇｅｓｏｆｅｎｄｏｇｅｎｏｕｓＡＢＡａｎｄｃｙｔｏｋｉｎｉｎｓｉｎｅｎｖｉｒｏｎｍｅｎｔａｌａｄａｐｔａｔｉｏｎｏｆｄｉｆｆｅｒｅｎｔｅｃｏｔｙｐｅｓｏｆｒｅｅｄｐｌａｎｔｓＷａｎｇＨｏｎｇｌ... 详细信息

ＳｅａｓｏｎａｌｃｈａｎｇｅｓｏｆｅｎｄｏｇｅｎｏｕｓＡＢＡａｎｄｃｙｔｏｋｉｎｉｎｓｉｎｅｎｖｉｒｏｎｍｅｎｔａｌａｄａｐｔａｔｉｏｎｏｆｄｉｆｆｅｒｅｎｔｅｃｏｔｙｐｅｓｏｆｒｅｅｄｐｌａｎｔｓＷａｎｇＨｏｎｇｌｉａｎｇ，ＺｈａｎｇＣｈｅｎｇｌｉ...

关键词： ABA cytokinin ecotype environmental adaptation Phragmites communis T.

STABILITIES OF (A,B,C) AND NPDIRK METHODS FOR SYSTEMS OF NEUTRAL DELAY-DIFFERENTIAL EQUATIONS WITH MULTIPLE DELAYS

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Journal of Computational Mathematics 2003年第3期21卷 375-382页

作者： Guo-feng Zhang (department of Mathematics, lanzhou university, lanzhou 73.000,{3.) department of Mathematics Lanzhou University Lanzhou 730000

Consider the following neutral delay-differential equations with multiple delays (NMDDE)where γ> 0, L, Mj and Nj are constant complex- value d×d matrices. A sufficient condition for the asymptotic stability of NMDDE system (0.1) is given. The stability of Butcher's (A,B,C)-method for systems of NMDDE are studied. In addition, we present a parallel diagonally-implicit iteration RK (PDIRK) methods(NPDIRK) for systems of NMDDE, which is easier to be implemented than fully implicit RK methods. We also investigate the stability of a special class of NPDIRK methods by analyzing their stability behaviors of the solutions of (0.1).

关键词： Neutral delay differential equations (A,B,C)-method RK method Parallel diagonally-implicit iteration RK method.

STUDY ON THE IMMOBILIZATION OF PAPAIN WITH A MACROPOROUS BEAD CARRIER OF COPOLYMER CONTAINING MONOMER UNITS OF NAMINOETHYL ACRYLAMIDE AND VINYL ALCOHOI

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Chinese Journal of Polymer Science 2000年第1期18卷 25-31页

作者： Yan-feng Li Jun-rong Li Lian-di Fu Yao-zeng Li department of Chemistry, lanzhou university, lanzhou 73.000,{3. Gansu Natural Energy Research Institute, lanzhou 73.000,{3. Gansu Provincial Institute of Drug Control, lanzhou 73.000,{3. 兰州大学甘肃兰州甘肃自然能源所甘肃兰州 730000 甘肃省药检所甘肃兰州 730000

A kind of macroporous bead carrier of copolymer containing monomer units of N-aminoethyl acrylamide and vinylalcohol was synthesized, i.e. the MR-AA carrier. Papain was immobilized on the carrier using glutaraldehyde as the couplingagent. The enzymatic activity of the immobilized papain was compared with free papain using casein as a substrate, and theeffects of glutaraldehyde concentration, pH, temperature, time and papain amount added on the activity recovery were alsoinvestigated. The results show that the MR-AA carrier contains reactive primary amine groups, hydrophilic amido links andhydroxyl groups, as well as macroporous structures based on its matrix (MR-AV matrix), furthermore, the activity recoveryof papain in the immobilization could reach 48%/～58%. In comparison with free papain, the resulting immobilized papainexhibits a remarkable thermostability and better reusability.

关键词： Immobilization Papain Proteolytic enzyme Macroporous bead carrier

On adjacent-vertex-distinguishing total coloring of graphs

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Science china Mathematics 2005年第3期48卷 289-299页

作者： ZHANG Zhongfu, CHEN Xiang’en, LI Jingwen, YAO Bing, LU Xinzhong & WANG Jianfang College of Mathematics and Information Science, Northwest Normal university, lanzhou 73.070, china {3. of Computer, lanzhou Normal College, lanzhou 73.070, china Institute of Applied Mathematics, lanzhou Jiaotong university, lanzhou 73.070, china College of Information and Electrical Engineering, lanzhou Jiaotong university, lanzhou 73.070, china Institute of Applied Mathematics, Chinese Academy of Sciences, Beijing 100080, china 1. College of Mathematics and Information Science Northwest Normal University 730070 Lanzhou China 2. department of Computer Lanzhou Normal College 730070 Lanzhou China 3. Institute of Applied Mathematics Lanzhou Jiaotong University 730070 Lanzhou China 4. College of Information and Electrical Engineering Lanzhou Jiaotong University 730070 Lanzhou China 5. Institute of Applied Mathematics Chinese Academy of Sciences 100080 Beijing China

In this paper, we present a new concept of the adjacent-vertex-distinguishing total coloring of graphs (briefly, AVDTC of graphs) and, meanwhile, have obtained the adjacent-vertex-distinguishing total chromatic number... 详细信息

关键词： graph, proper total coloring, adjacent-vertex-distinguishing total coloring, adjacent-vertex-distinguishing total chromatic number.

Synthesis and Efficiency of a SphericalMacroporous Epoxy-dicyandiamide ChelateResin for Preconcentrating and SeparatingTrace Au, Hg, Pd and Ru from Samples

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Chemical Research in Chinese Universities 2001年第2期17卷 168-174页

作者： GONG Bo-lin, LI Xue-qiang and WANG Feng-rong (department of Chemistry, Ningxia university, Yinchuan 750021, china) CHANG Xi-jun (department of Chemistry, lanzhou university, lanzhou 73.000, china) Ningxia Univ Dept Chem Yinchuan 750021 Peoples R China lanzhou Univ Dept Chem Lanzhou 730000 Peoples R China

A novel spherical macroporous epoxy-dicyandiamide chelate resin was synthesized simply and rapidly from epoxy resin and used for the preconcentration and separation of trace amounts of Au (Ⅲ ), Hg (Ⅱ ), Pd (Ⅳ) and Ru (Ⅲ) ions from solution samples. The analyzed ions can be quantitatively concentrated by the resin at a flow rate of 2. 0 mL/min at pH 4, and can also be desorbed with 15 mL of 4 mol/L HCl + 0. 3.g thiourea from the resin column with recoveries of 96. 5%-99. 0%. After the chelate resin was reused for 7 times, the recoveries of these ions were still over 92%, and 400-1 000 times of excess of Fe(Ⅲ ), Al(Ⅲ ), Ni( II), Mn( Ⅱ ), Cr (Ⅲ ), Cu ( Ⅱ ), Cd (Ⅱ ) and Pb (Ⅱ ) caused little interference with the determination of these ions by an inductively coupled plasma optical emission spectrometer (ICP-OES ). The capacities of the resin for the analytes are in the range of 0. 3.~0. 92 mmol/g. The RSDs of the proposed method are in the range of 1. 1 % ~4. 0% for each kind of the analyzed ions. The recoveries of a standard added in real solution samples are between 96. 5% and 98. 5%, and the results for the analyzed ions in a powder sample are in good agreement with their reported values.

关键词： Concentration Separation Macroporous epoxy-dicyandiamide chelate resin Gold Mercury Palladium and ruthenium.

X-ray spectra induced in highly charged 40Ar^q+ interacting with Au surface

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Science china(Physics,Mechanics & Astronomy) 2006年第2期49卷 203-212页

作者： ZHANG Xiao’an1,2, XIAO Guoqing1, YANG Zhihu1, CHEN Ximeng3. ZHAO Yongtao1, LI Fuli4, ZHANG Yinping1, CUI Ying3. ZHANG Hongqiang3. XU Xu3. SHAO Jianxiong3.& ZHAN Wenlong11. Institute of Modern Physics, Chinese Academy of Sciences, lanzhou 73.000, china 2. department of Physics, Xianyang Normal {3., Xianyang 712000, china 3. department of Modern Physics, lanzhou university, lanzhou 73.000, china 4. department of Applied Physics, Xi’an Jiaotong {3., Xi’an 710049, china 1. Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China 2. department of Physics Xianyang Normal University Xianyang 712000 China 3. department of Modern Physics Lanzhou University Lanzhou 730000 China 4. department of Applied Physics Xi’an Jiaotong University Xi’an 710049 China

By use of optical spectrum technology, the spectra of X-ray induced by highly charged 40Arq+ ions interacting with Au surface have been studied. The results show that the argon Kα X-ray were emitted from the hollow atoms formed below the surface. There is a process of multi-electron exciting in neutralization of the Ar16+ion, with electronic con-figuration 1s2 in its ground state below the solid surface. The yield of the projectile Kα X-ray is related to its initial electronic configuration, and the yield of the target X-ray is related to the projectile kinetic energy.

关键词： highly charged ion hollow multi-electron excitation X- ray.