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Support vector machine for SAR/QSAR of phenethyl-amines

Acta Pharmacologica Sinica 2007年第7期28卷 1075-1086页

作者： Bing NIU~2,Wen-cong LU~(2,3,6),Shan-sheng YANG~2,Yu-dong CAI~(3,4,6),Guo-zheng LI~5 ~2 College of Material science and engineering,shanghai university,shanghai 200444,china ~3 Laboratory of Chemical Data Mining,Department of Chemistry,College of sciences,shanghai university,shanghai 200444,china ~4 Department of Combinatorics and Geometry,CAS-MPG Partner Institute for Computational Biology,shanghai Institutes for Biological sciences,Chinese Academy of sciences,shanghai200031,china ~5 school of computer science and engineering,shanghai university,shanghai 200072,china College of Material science and engineering Shanghai University Shanghai China Department of Chemistry Laboratory of Chemical Data Mining College of Sciences Shanghai University Shanghai China Department of Combinatorics and Geometry CAS-MPG Partner Institute for Computational Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China school of computer science and engineering Shanghai Univeristy Shanghai China

Aim:To discriminate 32 phenethyl-amines between antagonists and agonists,and predict the activities of these ***:The support vectormachine (SVM) is employed to investigate the structure-activity relationship(SAR)/quantitative structure-activity relationship (QSAR) of phenethyl-aminesbased on molecular ***:By using the leave-one-out cross-vali-dation (LOOCV) test,1 optimal SAR and 2 optimal QSAR models for agonists andantagonists were *** accuracy of prediction for the classification ofphenethyl-amines by using the LOOCV test is 91.67%,and the accuracy of predic-tion for the classification of phenethyl-amines by using the independent test is100%;the results are better than those of the Fisher,the artificial neural network(ANN),and the K-nearest neighbor models for this real world *** RMSE(root mean square error)of antagonists' QSAR model is 0.5881,and the RMSE ofagonists' QSAR model is 0.4779,which are better than those of the multiple linearregression,partial least squares,and ANN models for this real world ***:The SVM can be used to investigate the SAR and QSAR of phenethyl-amines and could be a promising tool in the field of SAR/QSAR research.

关键词： support vector machine QSAR phenethylamines antagonists agonists

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Optical and acoustic phonon modes confined in gallium phosphide nanoparticles

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Rare Metals 2010年第6期29卷 561-566页

作者： ZHANG Zhaochun and ZHANG Neng school of Material science and engineering,shanghai university,shanghai 200072,china school of Material science and engineering Shanghai University Shanghai China

The main aim of this paper is to discuss the confinement effects on the optical and acoustic phonon vibrational modes in gallium phosphide（GaP） nanoparticles（cylindric grain）.The Raman scattering from the GaP nanoparticles was *** was found that the red-shifts of the longitudinal optical（LO） mode and transverse optical（TO） mode were 15 cm？1 and 13.8 cm？1,*** is generally accepted that the red-shifts of the optical phonon modes are due to the presence of smaller nanosized particles（～1.2 nm） acting as the nanoclustered building blocks of the GaP *** the low frequency Raman spectrum,a set of Stokes lines with almost the same spacing was clearly *** scattering feature originates from the discrete phonon density of states of the nanoclustered building *** to Lamb＇s vibrational theory,the Raman shift wavenumbers of the spheroidal mode and torsional mode of the lowest energy surface modes for the nanoclustered building blocks were *** agreement can be achieved between the calculated results and the observed scattering *** results indicate that the corresponding Raman peaks are due to scattering from the localized acoustic phonons in the nanoclustered building blocks in the GaP nanoparticles.

关键词： spectroscopy phonon mode Raman scattering gallium phosphide nanoparticles confinement effects

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Influence of Mo on the microstructure and mechanical properties of TiC-based cermets

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Rare Metals 2010年第4期29卷 346-350页

作者： WANG Xingqing,HE Xiaoxiang,and GUO Hailiang school of Materials science and engineering,shanghai university,shanghai 200072,china school of Materials science and engineering Shanghai University Shanghai China

The microstructures and mechanics properties of TiC-based cermets composed of TiC, WC, Ni, Co, Mo, and Cr3C2 were investigated. The results show that Mo has a great effect on the sintering densification, microstructures, and mechanical properties. The microstructures and distribution of Mo and Ti in the TiC-based cermets were analyzed. It was indicated that a new phase with Ti, Mo, W, and C was formed on the rim of （Ti,W）C grains by means of an addition of Mo into the TiC-based cermets. The new phase with a surrounding structure was of great aid to improve the wettability of the liquid phase on the solid phase surface of TiC, decrease the porosity and refine the grains of the hard phase, which gave rise to the increase in strength and hardness. The properties of the TiC-based cermets could be further improved to some extent by adding WC, Cr2C3, and Co.

关键词： TiC-based cermets Mo effect sintering densification microstructure mechanical properties

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An interpolating boundary element-free method (IBEFM) for elasticity problems

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science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 758-766页

作者： REN HongPing 1 , CHENG YuMin 2 & ZHANG Wu 1 1 school of computer engineering and science, shanghai university, shanghai 200072, china 2 shanghai Institute of Applied Mathematics and Mechanics, shanghai university, shanghai 200072, china school of computer engineering and science Shanghai University Shanghai China shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China

The paper begins by discussing the interpolating moving least-squares (IMLS) method. Then the formulae of the IMLS method obtained by Lancaster are revised. On the basis of the boundary element-free method (BEFM), combining the boundary integral equation method with the IMLS method improved in this paper, the interpolating boundary element-free method (IBEFM) for two-dimensional elasticity problems is presented, and the corresponding formulae of the IBEFM for two-dimensional elasticity problems are obtained. In the IMLS method in this paper, the shape function satisfies the property of Kronecker δ function, and then in the IBEFM the boundary conditions can be applied directly and easily. The IBEFM is a direct meshless boundary integral equation method in which the basic unknown quantity is the real solution to the nodal variables. Thus it gives a greater computational precision. Numerical examples are presented to demonstrate the method.

关键词： moving least-squares (MLS) approximation interpolating moving least-squares (IMLS) method boundary integral equation meshless method boundary element-free method (BEFM) interpolating boundary element-free method (IBEFM) elasticity problem

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Convexity and Positivity of Bivariate Quadratic Bézier Surfaces over a Rectangle

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Journal of shanghai university(English Edition) 2001年第1期5卷 20-28页

作者： DING You dong school of computer engineering and science, shanghai university, shanghai 200072, china school of computer engineering and science Shanghai University Shanghai China

With the help of several discriminants about the zero points of a quartic polynomial, the sufficient and necessary conditions for the positivity and nonnegativity of the quartic polynomial over an interval I(-∞,+∞) was derived. Based on these conclusions, the sufficient and necessary conditions for the positivity and convexity of the 2×2 Bézier surface over a rectangle were obtained. A simple sufficient condition was deduced also and finally several examples were given.

关键词： Bézier surface convexity positivity discriminant

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Electrochemical Characteristic of Decarburization Reaction

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 27-30页

作者： Xionggang Lu Fushen Li Lifen Li Kouchih Chou (Applied science school, university of science and Technology Beijing, Beijing 100083, china)(Material science and engineering school, shanghai university, shanghai 200072, china) Applied science school University of Science and Technology Beijing Beijing 100083 China Material science and engineering school Shanghai University Shanghai 200072 China

The electrochemical mechanism of the reaction between Fe-C melts and CaO-SiO2-Al2O3-FeOx slag systems has been carried out. The experimental results suggest that the final content of carbon in melt increases as the partial oxygen pressure of gas decreases no matter whether there is electronic conductor or not. However, the final content of carbon in the system with electronic conductor is much lower than that without electronic conductor. It can be deduced that the transfer ability of oxygen in slag is dominated by electrons. When an electronic conductor exists, an easy pathway for the electrons is provided and the oxygen transfer rate is accelerated.

关键词： melt-slag reaction decarburization electrochemistry electronic conductor

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Effect of Process Factors on Microstructure of Semisolid Continuous Casting Billets

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 242-245页

作者： Shuming Xing, Qijie Zhai, Hanqi Hu ( Department of Mechanical engineering, Tsinghua university, Beijing 100084, china school of Material science and engineering, shanghai university, shanghai 200072, china Material science and engineering school, Univer Department of Mechanical engineering Tsinghua University Beijing 100084 China school of Material science and engineering Shanghai University Shanghai 200072 China Material science and engineering school University of Science and Technology Beijing Beijing 100083 China

Semisolid continuous casting (SSCC) is a new technology to produce billets for semisolid metal forming (SSMF). The effect of process factors, such as pouring temperature, stirring rate, preheating temperature and thermal conductivity of stirring chamber, on the microstructure of SSCC billets was studied by means of the factorial experimental method. The results show that the microstructure of SSCC billets can be controlled by the above-mentioned four process factors. In order to obtain fine and rounded granular grains in an SSCC billet, the pouring temperature, preheating temperature and stirring rate should be kept in a moderate range, and the thermal conductivity of stirring chamber should be high. The regression equations with the process factors connecting the microstructure was also set up based on experimental data.

关键词： semisolid metal continuous casting process factors microstructure Metallurgy

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Sorption of a triazol derivative by soils: importance of surface acidity

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Journal of Environmental sciences 2003年第3期15卷 383-387页

作者： WU De-yi (school of Environmental science and engineering, shanghai Jiaotong university, shanghai 200240, china.) school of Environmental science and engineering Shanghai Jiaotong University 上海 200240

The sorption of a triazol derivative, 1-(4-chlorophenyl)- 4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)penten-3-ol with a common name of S3307D, on fifteen soils and three H_2O_2-treated soils was investigated. The sorption isotherm for each untreated and treated soil was non-linear, and was best fitted to Freundlich sorption equation. Soils containing high amount of clay content or organic matter or both sorbed much higher amounts of the chemical than soils that had low contents of these soil constituents. H_2O_2-treated soils showed considerable sorptive affinity for S3307D. It was concluded that both organic matter and mineral fraction in natural soils contributed to the sorption of the basic compound. Sorption by the H_2O_2 treated soils increased as suspension pH decreased, but all suspension pHs exceeded the pKa of the compound by more than two units. This implies that organic base protonation can occur on surfaces of soil components, and surface acidity (exchangeable acidity ) is important in sorption process of the organic base rather than suspension pH.

关键词： sorption organic base soil surface acidity

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A Resistivity Gradient Piezoelectric FGM Actuator

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Journal of Materials science & Technology 2000年第4期16卷 383-386页

作者： S. U.Adikary and Zhongyan MENG (school of Materials science and engineering, shanghai university, shanghai 201800, china) Dengren JIN (school of Materials science and engineering, shanghai Jiaotong university, shanghai 200030, china) school of Materials science and engineering Shanghai University Shanghai 201800 China school of Materials science and engineering Shanghai Jiaotong University Shanghai 200030 China

A resistivity gradient actuator based on lead zirconate titanate ceramics was successfully developed and the bending deflections up to 140 μm were obtained. The actuator material was a matrix of PZT ceramic into which smooth gradient of piezoelectric activity was introduced. The application of an electric field then causes the actuator to bend due to differential strains induced by the piezoelectric effect. The resistivity gradient of the actuator was achieved by doping PZT with suitable donor and acceptor dopants. PZT powder was modified and synthesized by using two stage powder fabrication method. The actuator was fabricated by uniaxial pressing followedby isostatic pressing with two layers of different resistivities.

关键词： PZT FGM

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THE INVESTIGATION ON THE RHEOLOGICAL BEHAVIOR OF SEMI-SOLID ALUMINUM ALLOY DURING DIE CASTING

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Acta Metallurgica Sinica(English Letters) 2002年第6期15卷 511-516页

作者： X.J. Yang and J.Liu school of Mechanic & Electronic engineering, Nanchang university, Jiangxi 330029, china school of Mechanic & Electronic engineering, shanghai university, shanghai 200072, china Sch. of Mech. and Electron. Eng. Nanchang Univ. Nanchang 330029 China Sch. of Mech. and Electron. Eng. Shanghai Univ. Shanghai 200072 China

Under the condition of die casting and reheating temperature of 570-580 degC, the rheological behavior of semi-solid aluminum alloy (A356) is pseudoplasticity at the shearrate of 2X10^-1X10^4s^(-1), and also shows dil... 详细信息

关键词： shear rate apparent viscosity viscosity model thixocasting

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