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Molecular dynamics simulation study on zwitterionic structure to maintain the normal conformations of Glutathione

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Science china Chemistry 2007年第5期50卷 660-664页

作者： YAN Han1, ZHU HaoMiao2.& SHEN Jian1,2.1 Jiangsu Research center of Surface and Interface Chemical Engineering and Technology, nanjing university,{2., china 2.Jiangsu Engineering Research center for Bio-medical function materials, nanjing Normal university, nanjing 2.0097, china Jiangsu Research center of Surface and Interface Chemical Engineering and Technology Nanjing University Nanjing China Jiangsu Engineering Research center for Bio-medical function materials Nanjing Normal University Nanjing China

Molecular dynamics simulations were applied to normal conformational Glutathione (GSH) and GSH over zwitterionic and hydrophobic surfaces respectively. Conformational analysis of GSH during the simulation time on RMSD, conformational flexibility and dihedral distribution were performed. The re- sults showed that zwitterionic structure maintains the normal conformations of GSH to a better extent, which should be a first good proof of the hypothesis of "maintain of normal structure".

关键词： protein-surface interactions, molecular dynamics simulation, zwitterionic structure, Glutathione, conformational changes, antithrombotic material

Sorption behavior of U(VI), ^(2.4)U(VI) and ^(2.8)U(VI) onto fracture-filling clays in Beishan granite, Gansu: Application to selecting the site of high-level radwaste repository in china

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Science china Earth Sciences 2005年第10期48卷 1649-1655页

作者： MIN Maozhong1,2. LUO Xingzhang3, WANG Ju4, JIN Yuanxin4 & WANG Rucheng1 1. Department of Earth Sciences, State Key Laboratory of Mineral Deposit Research, nanjing university, nanjing 2.0093,{2. 2. center of materials Analysis, nanjing university, nanjing 2.0093,{2. 3. Department of Environmental Science and Engineering, nanjing university, nanjing 2.0093,{2. 4. Beijing Geology Institute, Nuclear Industry, Beijing 10002.,{2. nanjing university Nuclear Industry

The first results of sorption experiments of U(VI), 2.4U(VI) and 2.8U(VI) onto original (unpurified) fracture-filling clays from No.1 monzonitic granite intrusion, Beishan area, Gansu Province, china are reported. The monzonitic granite intrusion is a potential location for a high-level radwaste (HLW) repository in china. The present experimental results show that the maximum U(VI) sorption reached 92. at near-neutral pH and the distribution coefficient (Kd) was 12.6 mL/g. A high sorption capacity of the fracture-filling clays in host rock on radioactive ele-ments is necessary for HLW deep geological disposal repository. No preferential sorption of 2.4U onto the clays was found. Finally, the sorption of U(VI) onto the clays was also modeled using a surface complexation model.

关键词： HLW geological disposal repository, granite, uranium, radionuclide, clay, sorption.

Seasonal variation of global stratosphere-troposphere mass exchange

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Progress in Natural Science:materials International 2007年第12期17卷 1466-1475页

作者： Guo Dong1,2. Lu Daren2.and Sun Zhaobo1(1. Institute of Atmospheric Sciences, nanjing university of Information Science and Technology, nanjing 2.0044,{2. 2. LAGEO, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 10002.,{2.) Institute of Atmospheric Sciences Nanjing University of Information Science and Technology Nanjing 210044 China LAGEO Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

By Wei formula in pressure coordinate, the stratosphere-troposphere mass exchange (STME) is diagnosed globally for 44 years from 1958 to 2.01 using the European center for Medium-Range Weather Forecasts (ECMWF) reanalysis datasets. Regions of mass flux into the stratosphere are found over Indonesia, bay of Bangladesh and the mid-west coast of South Africa. Compensating mass outflow from the stratosphere appears mainly over mid-latitudes near large-scale troughs. Upward and downward transport of mass at the middle and high latitudes accompany with each other. Mass flux into troposphere is stronger in autumn and winter than in spring and summer. Strong downward mass flux into the troposphere occurs in eastern Asia the whole year with nearly stable sites. Although the area of eastern Asia accounts for only 5.6% of that of the northern hemisphere (NH), its net mass exchange reaches 15.83% of that of the NH, which means that research on STME of eastern Asia is greatly important to that of the NH and even the global areas. Air across the tropopause enters more from stratosphere to troposphere than that from troposphere to stratosphere, which is possibly related with systematic bias of the assimilated datasets and with persistent rise of the tropopause height. Contributions of the mass exchange and the mass flux exchange in the NH and southern hemisphere (SH) on their latitudes increase from equator to pole, with larger contributions in the NH. Mass exchange and mass flux exchange per areas at high latitudes are larger than that at low latitudes, which means greater mass exchange efficiency at high latitudes.

关键词： stratosphere troposphere mass exchange seasonal variation.

Ultra-microbes are the minerogenetic constructors of oceanic polymetallic nodules

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Chinese Science Bulletin 1997年第8期42卷 617-624页

作者： CHEN Jianlin, ZHANG Fusheng and BIAN Lizeng1 Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012. china 2.center for {2. Analysis, nanjing university, nanjing 2.0093, china 3. Department of Earth Sciences, nanjing university, nanjing 2.0093, china Second Institute of Oceanography State Oceanic Administration Hangzhou China Centu for materials Analysis Nanjing University Nanjing China Department of Earth Sciences Nanjing University Nanjing China

Polymetallic nodules (mangnese nodules) are a typical kind of manganese oncolites The distribution of smooth sur-face and knobbly manganese nodules is closely related to the geological background of the mine field. A systematic study on their inner laminae structure and features suggests that they are the products of millions of years reproduction and accumulation of the recently found Miniactinomyces chinensis and Spirisophaerospora pacijica .

关键词： oceanic manganese nodule stromatolite ultra-microbe biolite.

Alkali-silica Reactivity of Different Aggregates from Mineral and Textural Characteristics

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Journal of Wuhan university of Technology(materials Science) 2008年第6期23卷 901-906页

作者：莫祥银 Analysis and Testing center & Jiangsu Key Laboratory of Biofunctional materials Nanjing Normal University

To identify the aggregates causing the alkali-silica reaction, and the reactivity of rocks in different parts of china, the mineral and texture characteristics of some typical coarse ag gregates and the alkali reactivity of these aggregates were systematically investigated. On one hand, petrographic examination of aggregates, combined with X-ray diffraction analysis, chemical analysis, scanning electron microscopy, was conducted for analyzing their mineralogy and texture. It was found that not only mineral characteristics, but also their interior structure would affect their potential alkali-silica reactivity. Furthermore, the alkali-silica reactivity of aggregates is due to their mineral compositions, such as containing different alkali-reactive minerals, while, different stuctures of those aggregates with similar minerals affect their reactivity to some extent. There are some amount of micro-aperture and cracks across the quartz in the aggregate, which may become the natural accesses for Na^＋, K^＋, and OH^- ions to intrude in the mortar or concrete during the process of alkali-silica reaction. Alkali-silica reactivity of the aggregates was detected by the accelerated mortar bars test. It was revealed that all the aggregates tested were alkali-silica reactive and the results were also in accordance with their mineral and structure analysis.

关键词： petrographic examination of aggregates study of thin sections x-ray diffraction analysis chemical analysis scanning electron microscopy

Seabed Classification Using BP Neural Network Based on GA

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Acta Oceanologica Sinica 2003年第4期22卷 523-531页

作者： Yang Fanlin1, Liu Jingnan2.1. GPS Engineering Research center, Wuhan university, Wuhan 430079,{2.. 2. Presidential Secretariat, Wuhan university, Wuhan 430079,{2. GPS Engineering Research center Wuhan University Wuhan 430079 China Presidential Secretariat Wuhan University Wuhan 430079 China

Side scan sonar imaging is one of the advanced methods for seabed study. In order to be utilized in other projects, such as ocean engineering, the image needs to be classified according to the distributions of different classes of seabed materials. In this paper, seabed image is classified according to BP neural network, and. Genetic Algorithm is adopted in train network in this paper. The feature vectors are average intensity, six statistics of texture and two dimensions of fractal. It considers not only the spatial correlation between different pixels, but also the terrain coarseness. The texture is denoted by the statistics of the co-occurrence matrix. Double Blanket algorithm is used to calculate dimension. Because a uniform fractal may not be sufficient to describe a seafloor, two dimensions are calculated respectively by the upper blanket and the lower blanket. However, in sonar image, fractal has directivity, i. e. there are different dimensions in different direction. Dimensions are different in acrosstrack and alongtrack, so the average of four directions is used to solve this problem. Finally, the real data verify the algorithm. In this paper, one hidden layer including six nodes is adopted. The BP network is rapidly and accurately convergent through GA. Correct classification rate is 92.5 % in the result.

关键词： BP network co-occurrence matrix fractal classification genetic algorithin

Game model of safety monitoring for arch dam deformation

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Science china(Technological Sciences) 2008年第S2期51卷 76-81页

作者： SU HuaiZhi1,2.WU ZhongRu1,2.GU YanChang1,2.HU Jiang1 & WEN ZhiPing3 1 College of Water Conservancy and Hydropower Engineering,Hohai university,nanjing 2.0098,{2. 2.National Engineering Research center of Water Resources Efficient Utilization and Engineering Safety,nanjing 2.0098,{2. 3 Department of Computer Engineering,nanjing Institute of Technology,nanjing 2.0013,{2. College of Water Conservancy and Hydropower Engineering Hohai University Nanjing China National Engineering Research center of Water Resources Efficient Utilization and Engineering Safety Nanjing China Department of Computer Engineering Nanjing Institute of Technology Nanjing China

Arch dam deformation is comprehensively affected by water pressure,temperature,dam's structural behavior and material properties as well as other *** them the water pressure and temperature are external factors(source factors) that cause dam deformation,and dam's structural behavior and material properties are the internal factors of deformation(resistance factors).The dam deformation is the result of the mutual game playing between source factors and resistance ***,resistance factors of structure and materials that reflect resistance character of arch dam structure are introduced into the traditional model,where structure factor is embodied by the flexibility coefficient of dam body and the maximum dam height,and material property is embodied by the elastic modulus of *** the basis of analyzing the correlation between dam deformation and resistance factors,the game model of safety monitoring for arch dam deformation is put forward.

关键词： arch dam deformation monitoring model flexibility coefficient game theory

IR STUDY ON MONOMOLECULAR PARTICLE AGGLOMERATES OF POLYSTYRENE OBTAINED BY FREEZE-DRYING OF ITS DILUTE SOLUTION

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Chinese Journal of Polymer Science 2002年第4期20卷 381-383页

作者： Song Wang Qing-hua Wang Rong-shi Cheng Research center of materials Beijing Institute of Technology Beijing 100081,{2. Department of Chemistry nanjing university nanjing 2.0093,{2. Research center of materials Beijing Institute of Technology 北京 100081 Department of Chemistry Nanjing University Nanjing 210093

The monomolecular particle agglomerates of polystyrenes were obtained by freeze-drying of its very dilute solutions of 1.3 x 10(-5)-2.0 x 10(-5) g/mL in benzene:cylcohexane (100:1) solvents, and they were annealed at room temperature for hundred days before use. According to C-13-NMR measurement the polystyrenes should be practically atactic. The number average molecular weights of the samples are 2.80 x 10(3), 2.00 x 10(4), and 1.55 x 10(6), respectively. The freeze-dried aPS with a molecular weight higher than 10(4) show two new IR absorption bands at 1098 and 12.1 cm(-1), which are absent in the normal aPS and freeze-dried styrene oligomer. It was also found that the low molecular weight samples can only form powders, whereas the freeze-dried aPS with higher molecular weight form a mixture of powders and fibrils, of which the longer fibrils show a much stronger 12.1 cm(-1) band than the shorter fibrils and the powder. It seems that the 12.1 cm(-1) band corresponds to the stacking behavior of monomolecular particles.

关键词： monomolecular particles atactic polystyrene FTIR spectroscopy

An SANS Study of Decomposition Kinetics in Amorphous Cu_(12.5)Ni_(10)Zr_(41)Ti_(14)Be_(2..5)

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Journal of materials Science & Technology 1998年第3期14卷 193-199页

作者： Junming LIU(National Laboratory of Solid State Microstructures, nanjing university and center for Advanced Studies in Scienceand Technology of Microstructures,{2., china) National Laboratory of Solid State Microstructures Nanjing University Center for Advanced Studies in Science and Technology of Microstructures Nanjing 210093 China

Phase decomposition in amorphous Cu12.5Ni10Zr411Ti14Be2..5 alloy as annealed in the super-cooled liquid range was studied by applying small angle neutron scattering (SANS). As annealed between 600 K and 700 K, the alloy was observed to decompose into two new amorphous phases,with the second phase precipitates embedded in the matrix of the first. Long time annealing of the alloy results in crystallization in addition to evolution of the decomposed *** kinetic diagram of the decomposition and crystallization for this alloy is given. The second phase precipitates have several nanometers in size and occupy a quite low volume fraction. The decomposition of the supercooled liquid in overall temperature range exhibits the features of spinodal reaction.

关键词： Be Zr SANS Ni Ti