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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 730050, China 2.department of Physics, Central China normal University, Wuhan 430079, China 3 college of Electrical and Information Engineering, lanzhou University of Technology, lanzhou 730050, China 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

Molecular modeling and spectroscopic studies on the binding of guaiacol to human immunoglobulin

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Science China Chemistry 2006年第6期49卷 550-559页

作者： HE Wenying1,2. YAO Xiaojun1, LIU Pengjun2. GAO Zhenxia2.& HU Zhide1 1. department of Chemistry, lanzhou University, lanzhou 730000, China 2. department of Chemistry, Hainan normal University, Hainan 571158, China 1. department of Chemistry Lanzhou University Lanzhou 730000 China 2. department of Chemistry Hainan Normal University Hainan 571158 China

The fluorogenic property of guaiacol was exploited for the first time to analyze the interaction with target protein as a probe by molecular modeling, fluorescence, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy. Molecular docking was performed to reveal the possible binding mode or mechanism and suggested that guaiacol can strongly bind to human immu- noglobulin (HIgG). It is considered that guaiacol binds to HIgG mainly by a hydrophobic interaction and there are two hydrogen bond interactions between the drug and the residues LEU 80 and ASP 65, which is in good agreement with the results from the experimental thermodynamic parameters (the enthalpy change △H0 and the entropy change △S0 were calculated to be 65.55 kJ·mol-1 and 132.95 J·mol-1·K-1 according to the Vant’ Hoff equation). Data obtained by the fluorescence spectroscopy indicated that binding of guaiacol with HIgG leads to dramatic enhancement in the fluorescence emission intensity along with significant occurrence of efficient Frster resonance energy transfer (FRET) from the residue of HIgG to the protein bound guaiacol. From the low value of fluorescence anisotropy (r = 0.06), it is argued that the probe molecule is located in the motionally unrestricted environment of the protein. The alterations of protein’s secondary structure in the presence of guaiacol in aqueous solution were quantitatively calculated by the evidences from FT-IR and CD spectroscopes.

关键词： guaiacol, human immunoglobulin, molecular modeling, fluorescence enhancement, Fourier transform infrared (FT-IR) spectroscopy, circular dichroism (CD).

X-ray spectra induced by slow highly charged Ar^(q+) ions in collision with Nb surface

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Science China(Physics,Mechanics & Astronomy) 2008年第10期51卷 1463-1469页

作者： YANG ZhiHu1, CUI Ying2. CHEN XiMeng2. SONG ZhangYong1, SHAO JianXiong2. RUAN FangFang1, ZHANG HongQiang2. DU Juan2. LIU YuWen2. GAO ZhiMing2. ZHANG XiaoAn3, ZHU KeXin1, YU DeYang1 & CAI XiaoHong1 1 Institute of Modern Physics, Chinese Academy of Sciences, lanzhou 730000, China 2.department of Modern Physics, lanzhou University, lanzhou 730000, China 3 department of Physics, Xianyang normal college, Xianyang 712.00, China 1. Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China 2. department of Modern Physics Lanzhou University Lanzhou 730000 China 3. department of Physics Xianyang Normal College Xianyang 712000 China

The X-ray spectra of Nb surface induced by Arq+ (q =16,17) ions with the energy range from 10 to 2. keV/q were studied by the optical spectrum technology. The experimental results indicate that the multi-electron excitation occurred as a highly charged Ar16+ ion was neutralized below the metal surface. The K shell electron of Ar16+ was excited and then de-excited cascadly to emit K X-ray. The intensity of the X-ray emitted from K shell of the hollow Ar atom decreased with the increase of projectile kinetic energy. The intensity of the X-ray emitted from L shell of the target atom Nb increased with the increase of projectile kinetic energy. The X-ray yield of Ar17+ is three magnitude orders larger than that of Ar16+.

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

Short cycle structures for graphs on surfaces and an open problem of Mohar and Thomassen

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Science China Mathematics 2006年第2期49卷 212-224页

作者： REN Han & DENG Mo department of Mathematics, East China normal University, Shanghai 2.0062. China {2. of Mathematics & Information Science, Northwest normal University, lanzhou 73.070, China 1. department of Mathematics East China Normal University Shanghai 200062 China 2. college of Mathematics & Information Science Northwest Normal University Lanzhou 730070 China

In this paper we investigate cycle base structures of a (weighted) graph and show that much information of short cycles is contained in an MCB (i.e., minimum cycle base). After setting up a Hall type theorem for base-transformation, we give a sufficient and necessary condition for a cycle base to be an MCB. Furthermore, we show that the structure of MCB in a (weighted)graph is unique. The property is also true for those having a longest length (although much work has been down in evaluating MCB, little is known for those having a longest length). We use those methods to find out some unknown properties for short cycles sharing particular properties in (unweighted) graphs. As applications, we determine the structures of short cycles in an embedded graph and show that there exist polynomially bounded algorithms in finding a shortest contractible cycle and a shortest two-sided cycle provided such cycles exist. Those answer an open problem of B. Mohar and C. Thomassen.

关键词： cycle base facial cycle graph embedding.

Synthesis, characterization, and biological activities of Pt(Ⅱ) and Pd(Ⅱ2.,3',4',5,7-pentahydroxy flavone

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Rare Metals 2004年第1期23卷 38-42页

作者： TANGHui＇An WANGXiaofang YANGSheng WANGLiufang Chemistrydepartment TianshuiNormalUniversityTianshui741018.China collegeofChemistryandChemicalEngineering LanzhouUniversityLanzhou730000.China

Pt(Ⅱ) and Pd(Ⅱ) complexes with 2.,3′,4′,5,7-pentahydroxy-flavone weresynthesized and characterized by elemental analysis, molar conductance, IR, ~1HNMR, TG-DTA, UV-Visspectroscopic techniques, and fluorescence analysis. The scavenging effect on the superoxide radical(O_2.-) and the inhibitory effect on lipid peroxides were also investigated. Both the ligand andthe complexes exhibit scavenging effect on superoxide radicals, and the effect of the complexes isgreater than that of the ligand. The Pt(Ⅱ) complex exhibits the strongest scavenging *** Pt(Ⅱ) and Pd(Ⅱ) complexes have the inhibitory effect on lipid peroxides, and the effect ofthe complexes is greater than that of the ligand, but the Pt(Ⅱ) complex has a high effect ofpromoting lipid peroxides.

关键词： inorganic chemistry metal complex 2.,3′,4′,5,7-pentahydroxy-flavone scavenging effect on superoxide radicals inhibitory effect on lipid peroxides

(2.1)-Dimensional Electron Acoustic Solitary Waves in an Unmagnetized Collisionless Plasma with Vortex-Like Hot Electrons

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Communications in Theoretical Physics 2007年第2期47卷 339-342页

作者： LIN Mai-Mai DUAN Wen-Shan department of Physics,Northwest,normal University,{2. 73.070,China department of Physics Northwest Normal University

In this paper,(2.1)-dimensional electron acoustic waves (EAW) in an unmagnetized collisionless plasmahave been studied by the linearized method and the reductive perturbation technique,*** dispersionrelation and a modified Kadomtsev Petviashvili (KP) equation have been obtained for the EAW in the plasma consideringa cold electron fluid and a vortex-like hot *** is found from some numerical results that the parameter β (theratio of the free hot electron temperature to the hot trapped electron temperature) effects on the amplitude and thewidth of the electron acoustic solitary waves (EASW).It can be indicated that the free hot electron temperature andthe hot trapped electron temperature have very important effect on the characters of the propagation for the EASW.

关键词： electron acoustic solitary wave vortex-like hot electrons reductive perturbation method

Oleanane-triterpene Saponins from Clinopodium urticifolium

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Chinese Chemical Letters 2003年第10期14卷 1041-1044页

作者： Li Ming GAO, Xiao Mei WEI, Dong Liang CHENGdepartment of Chemistry, National Laboratory of Applied Organic Chemistry,lanzhou University, lanzhou 730000 department of Chemistry, Northwest normal University, lanzhou 73.070 department of Chemistry National Laboratory of Applied Organic Chemistry department of Chemistry Northwest Normal University

Four new oleanane triterpene saponins were isolated and purified from the whole plant of Clinopodium urticifolium. They were 3B 16B, 2., 2.-tetrahydroxyoleana-9 (11), 12.13)-diene-3-yl-[B-D-glucopyranosyl-(1-2.]-[B-D-glucopyranosyl-(1-3)]- B-D-fucopyranoside 1; 3B, 16B, 2.B, 2., 2.-pentahydroxyoleana-9(11), 12.13)-diene-3-yl-[B-D-glucopyranosyl-(1-2.]-[B-D-glucopyranosyl-(1-3)]- B-D-fucopyranoside 2. 3B, 16B, 2., 2.-tetrahydroxyoleana-9(11), 12.13)-diene-3-yl-[B-D-glucopyranosyl-(1-6)-B-D-glucopyranosyl-(1-3)]-[B-D-glucopyranosyl-(1-2.]-B-D-fucopyranoside 3; 3B, 16B, 2., 2.-tetrahydroxyoleana-9(11), 12.13)-diene-3-yl-[B-D-gluco-pyranosyl-(1-4)-B-D-glucopyranosyl-(1-6)-B-D-glucopyranosyl-(1-3)]-[B-D-glucopyranosyl-(1-2.]- B-D-fucopyranoside 4. Their structures were elucidated on the basis of interpretation of NMR and MS data and from chemical evidence.

关键词： Clinopodium urticifolium Labiatae oleanane triterpene saponins.

Determination of Trace Amount of Yttrium with Bromopyrogallol Red by solid-phase Spectrophotometry

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Rare Metals 2001年第3期20卷 202-204页

作者： Jinzhang Gao,Gang Ni, Li Yuan, Jingwan Kang department of Chemistry, Northwest normal University,{2., China NW normal Univ Dept Chem Lanzhou 730070 Peoples R China

A simple and sensitive method for the determination of trace amount of yttrium by solid-phase spectrophotometry has been studied. Yttrium can form a 1 : 1 complex with bromopyrogallol red (BPR) on resin, which was determined directly at 605 nm, pH=6.5. It has a highly sensitivity (epsilon = 6.3 x 10(6)) which is 300-fold higher than the corresponding spectrophotometry in solution. The method was applied to the determination of yttrium in churchite.

关键词： solid-phase spectrophotometry bromopyrogallol red (BPR) yttrium

MOLECULAR　RECOGNITION　BY　MODIFIED　CYCLODEXTRINS　──FLUOROMETRIC　STUDY　ON　THE　INCLUSION　COMPLEX　OF　CYCLODEXTRIN　DERIVATIVES　WITH　NAPHTHALENE　DERIVATIVES

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Chinese Chemical Letters 1996年第8期7卷 763-766页

作者： You Ming ZHANG Bac Jian SHEN Lin Hut TONG(department of Chemistry, Northwest normal Unibersity, {2., 73.070)({2. Institute of Chemical Physis,Academia Sinica,tonzhea, 730000) NW normal UNIV DEPT CHEMLANZHOU 730070PEOPLES R CHINA ACAD SINICA LANZHOU INST CHEM PHYSLANZHOU 730000PEOPLES R CHINA

The molecular recognition of the naphthalene derivatives of 2.6dimethyl-β-CD, (1); mono-[6-deoxy-6-(2.aminoethylamine)]-β-CD, (2. andmono-[6-deoxy-6-(6-aminohexylamine)]-β-CD, (3) was studied by fluorescence. The formation constants of the inclusion complexes were estimatedbased on the variation of fluorescent intensity and the modified BenesiHildebrand equations.

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