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SOLUTION CRYSTalLIZATION OF METalLOCENE SHORT CHAIN BRANCHED POLYETHYLENE:MORPHOLOGY AND MECHANISM

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Chinese Journal of Polymer science 2000年第1期18卷 45-49页

作者： Qiang Fu Rong-ni Du Fang-Chyou Chiu Department of Polymer science & Materials, sichuan university, chengdu, sichuan 610065, china Department of Chemical engineering, Chang Gong university, Taoyun, Taiwan, china sichuan Univ Dept Polymer Sci & Mat Chengdu 610065 Sichuan Peoples R China Chang Gong Univ Dept Chem Engn Tao Yuan Taiwan

Solution crystallization of metallocene short chain branched polyethylene (SCBPE) was carried out and very nice single crystals were obtained. Compared with single crystals grown from linear polyethylene, SCBPE single crystals are dirty due to intermolecular heterogeneity The crystal morphology changes with crystallization temperatures. Lozenge, truncated lozenge, hexagonal, rounded and elongated crystal morphologies have been found at much lower crystallization temperature than in linear polyethylene. The electron diffraction shows there is a possibility that the single crystals may have hexagonal packing in a crystallization temperature range. The lateral habits of single crystal are discussed based on roughening theories.

关键词： metallocene SCBPE single crystal roughening face growth mechanism

New-generation biomedical materials:Peptide dendrimers and their application in biomedicine

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science china Chemistry 2010年第3期53卷 458-478页

作者： GU ZhongWei,LUO Kui,SHE WenChuan,WU Yao & HE Bin National engineering Research Center for Biomaterials,sichuan university,chengdu 610064,china 1. National engineering Research Center for Biomaterials Sichuan University Chengdu 610064 China

Peptide dendrimers are attractive synthetic polymers and have been widely used as a new generation of biomaterials in recent *** dendrimers,as well as general dendrimers,may be synthesized to reach nano sizes,and display well-defined architectures,highly-branched structures,high density of functional terminal groups,and controllable molecular *** the other hand,peptide dendrimers have properties similar to proteins and some special characteristics,such as good biocompatibility,water solubility and resistance to proteolytic *** to these advantages,peptide dendrimers have received considerable attention in *** review focuses on the development of peptide dendrimers with emphasis on their applications both in diagnostics and in therapy.

关键词： peptide dendrimers molecular probes drug delivery gene delivery

Theoretical study of ZnO adsorption and bonding on al_2O_3(0001) surface

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science china(Physics,Mechanics & Astronomy) 2004年第6期47卷 664-675页

作者： LI Yanrong1,YANG Chun1,2,XUE Weidong1,LI Jinshan3 & LIU Yonghua3 1.institute of Microelectronics and Solid State Electronics,university of Electronic science and Technol- ogy of china,chengdu 610054,china 2.institute of Mathematics and Software science,sichuan Normal university,chengdu 610068,china 3.institute of Chemical Materials,china Academy of engineering Physics,Mianyang 621000,china institute of Microelectronics and Solid State Electronics University of Electronic Science and Technology of China Chengdu 610054 China institute of Mathematics and Software science Sichuan Normal University Chengdu 610068 China institute of Chemical Materials China Academy of Engineering Physics Mianyang 621000 China

ZnO adsorption on sapphire (0001) surface is theoretically calculated by using a plane wave ultrasoft pseudo-potential method based on ab initio molecular dynamics. The results reveal that the surface relaxation in the first layer al-O is reduced, even eliminated after the surface adsorption of ZnO, and the chemical bonding energy is 434.3(±38.6) kJ·mol?1. The chemical bond of ZnO (0.185 ± 0.01 nm) has a 30° angle away from the adjacent al-O bond, and the stable chemical adsorption position of the Zn is deflected from the surface O-hexagonal symmetry with an angle of about 30°. The analysis of the atomic populations, density of state and bonding electronic density before and after the adsorption indicates that the chemical bond formed by the O2 of the ZnO ? and the surface al3+ has a strong ionic bonding characteristic, while the chemical bond formed by the Zn2+ and the surface O2 has an obvious covalent characteristic, which ? comes mainly from the hybridization of the Zn 4s and the O 2p and partially from that of the Zn 3d and the O 2p.

关键词： α-al2O3 (0001) ZnO ab initio molecular dynamics chemical adsorption density of states

Bioinformatics Data Distribution and Integration via Web Services and XML

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Genomics, Proteomics & Bioinformatics 2003年第4期1卷 299-303页

作者： Xiao Li and Yizheng ZhangCollege of Life science, sichuan university/sichuan Key Laboratory of Molecular Biology and Biotechnology,chengdu 610064, china. College of Life science Sichuan University/Sichuan Key Laboratory of Molecular Biology and Biotechnology Chengdu 610064 China.

It is widely recognized that exchange, distribution, and integration of biological data are the keys to improve bioinformatics and genome biology in post-genomic era. However, the problem of exchanging and integrating biological data is not solved satisfactorily. The extensible Markup Language (XML) is rapidly spreading as an emerging standard for structuring documents to exchange and integrate data on the World Wide Web (WWW). Web service is the next generation of WWW and is founded upon the open standards of W3C (World Wide Web Consortium) and IETF (Internet engineering Task Force). This paper presents XML and Web Services technologies and their use for an appropriate solution to the problem of bioinformatics data exchange and integration .

关键词： biological data integration extensible Markup Language (XML) web services extensible Stylesheet Language (XSL)

Monitoring the Cultivated Slope Land in the Three Gorges Reservoir Area Based on Remote Sensing and GIS

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Wuhan university Journal of Natural sciences 2006年第4期11卷 915-921页

作者： ZHOU Jieming1, ZHOU Qigang 2, 3 ,HUANG Zhiqin 2, 3, 4 1. The Faculty of Geography and Resources science, sichuan Normal university, chengdu 610066, sichuan, china 2. institute of Mountain Hazards and Environment, Chinese Academy of sciences, chengdu 610041, sichuan, china 3. Graduate university of the Chinese Academy of sciences, Beijing 100049, china 4. Information Center of Land and Resources Department of sichuan Province, chengdu 610041, sichuan, china The Faculty of Geography Resources science Sichuan Normal University 610066 Chengdu Sichuan China institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate university of the Chinese Academy of sciences 100049 Beijing China Information Center of Land Resources Department of sichuan Province 610041 Chengdu Sichuan China

By means of combining auto-extraction with manual interpretation, the current distribution information about cultivated land is obtained. The distribution information of 1992 is extracted from the dynamic polygons of 2002. The monitoring mini-system of the cultivated slope land is established. In the system, detailed surveys, focused on the resources of cultivated slope land, are carried out. The results indicate that the area of the cultivated slope land is very large. Meanwhile, there are lots of cultivated steep slopes with gradient above 35°. The areas of steep land cultivated had been slowly reduced from 1992 to 2002. At the same time, the pressures of returning farm land to forestry are great in all counties. The conflicts between population growth, insufficient grain supply and stagnant economic development sharpen increasingly. It is inevitable to improve the agricultural structure.

关键词： slope land cultivated remote sensing geography information system (GIS) the pressure of returning farm land to forestry Three Gorges Reservoir Area

Synthesis of a novel benzoxazine containing benzoxazole structure

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Chinese Chemical Letters 2010年第5期21卷 558-562页

作者： Po Yang,Yi Gu State Key Laboratory of Polymer Materials engineering,College of Polymer science and engineering, sichuan university,chengdu 610065,china [a] State Key Laboratory of Polymer Materials engineering College of Polymer Science engineering Sichuan University Chengdu 610065 China

A high-purity benzoxazine（Boz-BOA） containing benzoxazole structure was successfully synthesized by three-step synthetic method using 2-（4-aminophenyl）-1H-benzoxazole-5-amine（BOA） and *** structure of Boz-BOA was confirmed by FTIR and;H NMR *** DSC was utilized to probe the curing behavior of Boz-BOA and exhibited a narrow melting peak and curing exothermic peak.

关键词： Benzoxazine Benzoxazole Synthesis Characterization

Theoretical study on the hydrolysis mechanism of N,N-dimethyl-N′-(2′,3′-dideoxy-3′-thiacytidine)formamidine

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science china Chemistry 2008年第10期51卷 911-917页

作者： ZHANG Chang1 & XUE Ying2? 1 College of Chemistry and Environment Protection engineering, Southwest university for Nationalities, chengdu 610041, china 2 College of Chemistry, sichuan university, chengdu 610064, china 1. College of Chemistry and Environment Protection engineering Southwest University for Nationalities Chengdu 610041 China 2. College of Chemistry Sichuan University Chengdu 610064 China

The hydrolysis mechanisms of N,N-dimethyl-N′-(2′,3′-dideoxy-3′-thiacytidine)formamidine (FA-3TC) in the gas phase and in aqueous solution were studied by use of the density functional theory B3LYP/6-31+G(d, p) method. Two possible reaction pathways in the title reaction were considered. In one pathway water attacks the C=N double bond first (path A) while in the other water attacks the C—N single bond first (path B). The calculated results indicate that the first step in both pathways is the rate-limiting process and path A is more favorable than path B in the gas phase. The effect of solvent water on the title reaction was assessed at the B3LYP/6-31+G(d, p) level of theory based on the po-larizable continuum model (CPCM). In water the first mechanism (path A) is also favored.

关键词： N N-dimethyl-N′-(2′ 3′-dideoxy-3′-thiacytidine)formamidine hydrolysis solvent effect B3LYP polarizable continuum model

Effect of sediment on concentration of dissolved phosphorus in the Three Gorges Reservoir

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International Journal of Sediment Research 2011年第1期26卷 87-95页

作者： CAO Zhijing~1,ZHANG Xinbao~2,and AI Nanshan~3 institute of Architecture and Environment,sichuan university,chengdu 610065,china, institute of Mountain Hazards and Environment,Chinese Academy of sciences,chengdu 610041, china, institute of Architecture and Environment,sichuan university,chengdu 610065,china, [a] Lecturer institute of Architecture and Environment sichuan university chengdu 610065 china [b] Prof. institute of Mountain Hazards and Environment Chinese Academy of sciences chengdu 610041 china [c] Prof. institute of Architecture and Environment sichuan university chengdu 610065 china

Eutrophication and algal bloom has been occurring in the Three Gorges Reservoir ever since the reservoir’s impoundment in *** concentration of dissolved phosphorus(DP) is one of the main controlling factors for algal *** sediment adsorbs DP thereby affecting the concentration of DP. The effect of the sediment reduction on the DP concentration of the Three Gorges Reservoir is discussed in this *** were taken from the Yangtze River and its tributaries,*** Minjiang River and the Tuojiang *** DP concentration of the water samples and the available phosphorus,total phosphorus,and phosphorus-fixing capacity of the sediment samples were *** amount of phosphorus adsorbed by the sediment was about 3%of the total DP load in the Yangtze *** experiment was done in the lab simulating the DP concentration,sediment concentration,and turbulence. The results showed that quite a high amount of DP was adsorbed by the *** adsorption capacity of the sediment was 135 mg/kg and the highest rate of adsorption was 29 mg/kg·*** Xiluodu Dam is located at nearly 1,100 km upstream of the Three Gorges *** Xiloudu Dam will trap sediment and thence reduce the sediment load entering the Three Gorges Reservoir after impoundment in *** is estimated that the sediment reduction due to the Xiluodu Dam may result in an increase of the DP concentration in the Three Gorges Reservoir by 6.8%.

关键词： Dissolved phosphorus Sediment load reduction Three Gorges Reservoir Adsorption capacity Eutrophication

Studies on the analytical potential energy function of diatomic molecular ion XY^+ using variational method

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science china(Physics,Mechanics & Astronomy) 2004年第2期47卷 154-164页

作者： LIU Guoyue1,3, SUN Weiguo1,2 & FENG Hao1 1. institute of Physics, sichuan university, chengdu 610065, china 2. College of Chemical engineering, sichuan university, chengdu 610065, china 3. Mianyang Teacher抯 College, Mianyang 621000, china Correspondence should be addressed to Sun Weiguo (e-mail: weiguosun@*** or guoyueliu@ ***) 1. institute of Physics Sichuan University 610065 Chengdu China 2. Mianyang Teacher's College 621000 Mianyang China 3. College of Chemical engineering Sichuan University 610065 Chengdu China

A new analytical potential energy function for diatomic molecular ion XY+ is proposed based on the energy consistent method (ECM). The Coulomb potential included in the new ionic potential contains multipole corrections, converges quickly and is variationally, changeable. The new potential and the ECM are applied to variationally studying the potential energies of eight electronic states of several diatomic molecular ions: the A2π state of CO+, the X2∑ g + state of Li 2 + , the X2∑ g + state of He 2 + , the 12∏u state of Na 2 + , the A2∏u state of N 2 + , the X1∑+ state of KrH+, the X2∑+ state of SiO+ and the A2π state of SO+ ion. The present results agree excellently with the experiment-based Rydberg-Klein-Rees (RKR) potentials, and are superior to the commonly used Huxley-Murrell-Sorbie (HMS) analytical potentials, and are better in some cases than some quantum mechanicalab initio potentials in the ionic asymptotic and dissociation regions.

关键词： potential energy, diatomic ion, electronic state, variational method.