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Status of study on biological and toxicological effects of nanoscale materials

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Science china Chemistry 2005年第5期48卷 385-394页

作者： WANG Bing1, FENG Weiyue1, ZHAO Yuliang1, XING Gengmei1, CHAI Zhifang1, WANG Haifang2 & JIA Guang3 1. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials (Nanosafety Lab), Institute of High Energy Physics, Chi-nese Academy of Sciences, Beijing 100049, china 2. College of Chemistry and Molecular Engineering, Peking university, Beijing 100871, china 3. department of Occupational and Environmental Health Sciences, School of Public Health, Peking university, Beijing 100083, china 1. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials (Nanosafety Lab) Institute of High Energy Physics Chinese Academy of Sciences 100049 Beijing China 2. College of Chemistry and Molecular Engineering Peking University 100871 Beijing China 3. department of Occupational and Environmental Health Sciences School of Public Health Peking University 100083 Beijing China

Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the envi-ronment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some ex-clusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new re-search field are also discussed.

关键词： nanomaterials, single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron, biological activity and toxicological effect.

GRAFTING OF HYDROPHILIC MONOMERS ONTO POLYURETHANE MEMBRANES BY SOLUTION OR PRE-ABSORBING METHODS FOR ACCELERATION OF CELL COMPATIBILITY

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Chinese Journal of Polymer Science 2001年第5期19卷 493-498页

作者： Chang-you Gao Jian-jun Guan Jia-cong Shen department of Polymer Science and Engineering Zhejiang university Hangzhou 310027, china Zhejiang Univ Dept Polymer Sci & Engn Hangzhou 310027 Peoples R China

Two grafting methods, i.e. solution grafting and pre-adsorbing, are introduced to covalently immobilizehydrophilic polymers on segmented polyurethane (SPU) to modify its hydrophilicity and to improve its cell *** grafting results in higher degree of grafting and rougher surface morphology. Cell culture evaluation demonstratesthat the modified membranes thus obtained are disadvantageous to the endothelial cell (ECs) growth probably because thehydrophilic groups on the surface are over-crowded. However, pre-absorbing grafting generates lower degree of grafting,which is detected and confirmed by ATR-FTIR spectra and water conted angle. Scanning electron microscopic (SEM)measurement shows that the latter method produces a plane and smooth morphology, which is similar to the SPU controlsample controlled. When grafting with lower monomer concentration, ECs could grow on SPU-g-PHEA [poly(2-hydroxyethyl acrylate)], SPU-g-PAAm (polyacrylamide), SPU-g-PDMA [poly(2-(dimethylamino)ethyl methacrylate)] orquatemized SPU-g-PDMA surface with elongated cell shapes. Hence, the cell compatibility of SPU is improved and a usefulmethod to construct a cell compatible layer on the polymer surface has been developed.

关键词： segmented polyurethane cell compatibility surface grafting endothelial cell

马克思主义政治经济学:投资结构理论的重要渊源

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商丘师范学院学报 2003年第6期19卷 77-80页

作者：李杰四川大学政治学院四川成都610064

现代投资结构研究仅从西方经济学中寻求理论依据是有失偏颇的,本文通过对马克思主义政治经济学有关资本的有机构成理论、产业资本循环理论和两大部类生产学说的剖析,说明马克思主义政治经济学是现代投资结构理论的重要理论渊源。

关键词：马克思主义政治经济学投资结构资本有机构成产业资本循环生产学说

ARITHMETIC PROPERTIES OF A CLASS OF CUBIC CYCLIC FIELDS

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Science china mathematics 1989年第8期32卷 922-928页

作者：蓝以中 department of mathematics Peking University

Quartic unramified Abelian extension fields of a class of cubic cyclic fields are given and the Hilbert class field of a cubic cyclic field with discriminant 607~2 iS obtained.

关键词： cubic cyclic field unramified Abelian extension Hilbert class field.

Preparation of nanocrystalline BaTiO_3 ceramics

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Science china(Technological Sciences) 2009年第6期52卷 1730-1734页

作者： DENG XiangYun1,2,LI DeJun1,LI JianBao2,WANG XiaoHui3 & LI LongTu3 1 College of Physics and Electronic Information,Tianjin Normal university,Tianjin 300387,china 2 Materials and Chemical Engineering Institute,Key Laboratory for Hainan Advantage Resources and Applied Technology in Chemical Engineering Material of Ministry of Education,Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti,Hainan university,Haikou 570228,china 3 department of Materials Science and Engineering,Tsinghua university,Beijing 100084,china College of Physics and Electronic Information Tianjin Normal University Tianjin 300387 China Materials and Chemical Engineering Institute Key Laboratory for Hainan Advantage Resources and Applied Technology in Chemical Engineering Material of Ministry of Education Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Hainan University Haikou 570228 China department of Materials Science and Engineering Tsinghua University Beijing 100084 China

The high-dense nanocrystalline BaTiO3(BT)ceramics with grain size smaller than 100nm have been successfully prepared by the two step sintering and the spark plasma sintering(SPS)*** successive transitions in nanograin BT ceramics from rhombohedral to orthorhombic,tetragonal and cubic transitions,similar to those in coarse BT ceramics,were revealed by in-situ temperature dependent Raman *** multiphase coexistence and the diffused phase transition character were demonstrated in the 8nm nanocrystalline BT ceramics.

关键词： nanocrystalline BaTiO3 ceramics preparation microstructure size effect

Numerical simulation of influence of the anomalies of theCentral-eastern Equatorial Pacific SST and Arctic seaice cover in summer on the atmospheric circulation

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Acta Oceanologica Sinica 1992年第3期11卷 401-411页

作者： Yang Xiuqun and Huang Shisong department of Atmospheric Sciences, Nanjing university, Nanjing 210008, china

A series of numerical experiments have been conducted with a perpetual July, nine-level general circulation spectral model to determine the effect of variation of the Arctic sea ice cover extent and the joint effect of anomalies of both the Arctic sea ice cover and the Central-eastern Equatorial Pacific sea surface temperature on the summer general circulation. Results show that the two factors,anomalously large extent of the Arctic sea ice cover and anomalously warm sea surface temperature over the Central-eastern Equatorial Pacific Ocean, play substantially the equal role in the effect on the summer general circulation, and either of them can notably induce the atmospheric anomalies. The main dynamical processes determining the effect of the Arctic sea ice and the equatorial SST anomalies are associated with two leading teleconnection patterns, i. e. the Asia North/American and Eurasian patterns observed in atmosphere. The results presented in this paper again prove that the general circulation is fundamentally motivated by the non-uniform heating between the equator and the pole on the rotating earth.

关键词： Numerical simulation of influence of the anomalies of theCentral-eastern Equatorial Pacific SST and Arctic seaice cover in summer on the atmospheric circulation SST

Ti/Al_2O_3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

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Journal of Materials Science & Technology 1999年第3期15卷 271-275页

作者： Yimin LI(Powder Metallurgy Research Institute, Central-South university of Technology, Changsha 410083, china)Ziqiao ZHENG(department of Materials Science and Engineering, Central-South university of Technology, Changsha 410083, china) Cent S Univ Technol Powder Met Res Inst Changsha 410083 Peoples R China Cent S Univ Technol Dept Mat Sci & Engn Changsha 410083 Peoples R China

Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2 mixture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2 mixture. In this way, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 298 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2O3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one

关键词： Al SHS Ti/Al2O3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

A Discussion on Evolution of Microstructures and Influence Factors during Continuous Rolling of Compact Strip Production

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Journal of Materials Science & Technology 2004年第3期20卷 274-278页

作者： Hongbo DONG Yonglin KANG Hao YU department of Materials Processing and Controlling, university of Science and Technology Beijing, Beijing 100083, china Dept. of Mat. Proc. and Control Univ. of Sci. and Technol. Beijing Beijing 100083 China

The evolution of microstructures and influence factors of ultrathin hot strips of low carbon steel produced by compactstrip production (CSP) techniques were investigated. The steel blocking samples of CSP six-passes were obtained,and microstructures at the different positions of workpiece for each pass were studied. At the same time, anexplicit finite element technique was used to reveal the continuous rolling process. By combining experiment resultswith simulation analysis, the effects of plastic strain, temperature, precipitation and interval time on evolution andrefinement of crystal grains have been investigated. The results are useful for the development of high strength hotstrips.

关键词： CSP Microstructure Strain Temperature Precipitation

AN MRA YIELDS AN ORTHONORMAL WAVELET BASIS——AN OPERATOR THEORETIC PROOF

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Applied mathematics(A Journal of Chinese Universities) 1996年第1期11卷 77-84页

作者： DAI XINGDE LU SHIJIE department of mathematics, UNCC, Charlotte, UN 28223, USA. department of Applied mathematics, Zhejiang university Hangzhou 310027

In this paper we show how to construct a scaling function and an orthonor-mal wavelet basis from a multiresolution approximation using an operator theoreticmethod.

关键词： Multiresolution approximation scaling function orthonormal wavlet conjugate linear operator.