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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, lanzhou university, 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

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 730000 , China)

ＳｅａｓｏｎａｌｃｈａｎｇｅｓｏｆｅｎｄｏｇｅｎｏｕｓＡＢＡａｎｄｃｙｔｏｋｉｎｉｎｓｉｎｅｎｖｉｒｏｎｍｅｎｔａｌａｄａｐｔａｔｉｏｎｏｆｄｉｆｆｅｒｅｎｔｅｃｏｔｙｐｅｓｏｆｒｅｅｄｐｌａｎｔｓＷａｎｇＨｏｎｇｌ... 详细信息

ＳｅａｓｏｎａｌｃｈａｎｇｅｓｏｆｅｎｄｏｇｅｎｏｕｓＡＢＡａｎｄｃｙｔｏｋｉｎｉｎｓｉｎｅｎｖｉｒｏｎｍｅｎｔａｌａｄａｐｔａｔｉｏｎｏｆｄｉｆｆｅｒｅｎｔｅｃｏｔｙｐｅｓｏｆｒｅｅｄｐｌａｎｔｓＷａｎｇＨｏｎｇｌｉａｎｇ，ＺｈａｎｇＣｈｅｎｇｌｉ...

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

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 730070, China Department of Computer, lanzhou Normal College, lanzhou 730070, China Institute of Applied Mathematics, lanzhou Jiaotong university, lanzhou 730070, China College of Information and Electrical Engineering, lanzhou Jiaotong university, lanzhou 730070, China Institute of Applied Mathematics, Chinese Academy of Sciences, Beijing 100080, China College of Mathematics and Information Science Northwest Normal University Lanzhou China Department of Computer Lanzhou Normal College Lanzhou China Institute of Applied Mathematics Lanzhou Jiaotong University Lanzhou China College of Information and Electrical Engineering Lanzhou Jiaotong University Lanzhou China Institute of Applied Mathematics Chinese Academy of Sciences 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.

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 730000, China) 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.

A computer simulation of nucleation and growth of thin films

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Science China(Physics,Mechanics & Astronomy) 2004年第4期47卷 442-451页

作者： ZHENG Xiaoping1,ZHANG Peifeng2,HE Deyan2,LIU Jun2& MA Jiantai3 1. Key Laboratory of Opto-Electronic Technology and Intelligent Control, Ministry of Education, lanzhou Jiaotong university, lanzhou 730070, China 2. School of Physical Science and Technology, lanzhou university, lanzhou 730000, China 3. School of Chemistry and Chemistry Engineering, lanzhou university, lanzhou 730000, China Key Laboratory of Opto-Electronic Technology and Intelligent Control Ministry of Education Lanzhou Jiaotong University Lanzhou China School of Physical Science and Technology Lanzhou University Lanzhou China School of Chemistry and Chemistry Engineering Lanzhou University Lanzhou China

A three-dimensional kinetic Monte Carlo technique has been developed for simulating the nucleation and growth of thin films. This model involves incident atom attachment, surface diffusion of the atoms on the growing surface and atom detachment from the growing surface. It takes some new effects into account, such as a significant improvement in calculation of activation energy for the atom diffusion, which renders the model more reasonable. In addition three optimum temperatures and the consistency of their dependence on deposition rate have been found out; the dependence of the surface roughness and relative density on the deposition rate has been discussed; and the approximation of freezing neighbour atoms and periodic boundary conditions has been applied.

关键词： Monte Carlo, thin film, nucleation, surface roughness, relative density.

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 730000, China Gansu Natural Energy Research Institute, lanzhou 730000, China Gansu Provincial Institute of Drug Control, lanzhou 730000, China 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

Effects of additives on the aggregation of surfactants: binding domination

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Chinese Journal of Chemistry 1992年第3期10卷 237-244页

作者： LEI, Xue-Gong Department of Chemistry, lanzhou university, lanzhou 730000 Department of Chemistry Lanzhou University Lanzhou 730000

The effects of electrolytes, alcohols, and urea on the aggregation of SDS, CTAB, and Triton X-100 at 25℃ have been investigated by fluorescence probing of pyrene. Both electrolytes and alcohols reduce the critical micelle concentration (CMC) of the ionic surfactants, while the effect of the former is more pronounced. It is shown that the effects of electrolytes mainly depend on the concentrations and especially the valence of the opposite charge ions, and only slightly depend on the same charge ions in respect of ion aggregate of micelle. The logarithm of CMC is not linearly correlated with the concentrations of the counter ion or the electrolytes. The results are rationalized in terms of Hartley's model. Propanol increases the CMC of TX-100, while electrolytes and urea do not. In all the three kinds of surfactant micelles the excitation spectrum of pyrene slightly red-shifts (ca. 4 nm) from that in water, but is not affected by the additives. The micropolarity of the environment in which pyrene molecule resides in SDS micelle decreases with the increase of the concentrations of electrolytes. This is not the case when alcohols and urea were added to SDS or to TX-100. It is suggested that the addition of electrolytes would result in more orderly orientation of SDS molecules. It is the binding strength of the counter ions that dominates the effects of additives on the aggregation of surfactants.

关键词： CMC binding domination Effects of additives on the aggregation of surfactants

Synthesis of 3-(3-Hydroxypropyl)-phthalide and Pedicellosine

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Chinese Chemical Letters 1999年第2期10卷 109-110页

作者： Qiang GAO Shao Bai LI(National Laboratory of Applied Organic Chemistry, lanzhou university, lanzhou 730000) Natl. Lab. of Appl. Organ. Chemistry Lanzhou University LanZhou 730000 China

3-(3-hydroxypropyl)-phthalide 1, a phthalide isolated from the flowers of G. pedicellata Wall. has been synthesized in high yield from 2-carboxybenzaldehyde 3 in 2 steps. Reaction of 1 with 2,3-dihydroxybenzoic acid a... 详细信息

关键词： 3-(3-hydroxypropyl)-phthalide pedicellosine synthesis

Synthesis and Characterization of New Schiff Base and Polyoxa-azaCryptands and Their Rare Earth Cryptates with [1+1] Condensation and Reduction Methods

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Chinese Chemical Letters 1999年第12期10卷 995-998页

作者： Zhen MA Ru Dong YANG Lan YAN(Department of Chemistry, lanzhou university, lanzhou, Gansu 730000) Department of Chemistry Lanzhou University Lanzhou Gansu 730000 China

The Schiff base cryptand and its cryptates were synthesized with the methods of [1+1] condensation of trialdehyde and tris(2-aminoethyl)amine and obtained in 60-65%, 5-25% and 70-80% yields respectively with or without some rare earth elements as templates. The polyoxa-aza cryptand was produced in 72% and 60-70% yields with reduction of Schiff base and its cryptates respectively.

关键词： Schiff base polyoxa-aza cryptand rare earth condensation