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Fabrication of Ti_2AlC by Spark Plasma Sintering from Elemental Powders and Thermodynamics Analysis of Ti-Al-C System

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Journal of wuhan university of technology(Materials Science) 2007年第2期22卷 325-328页

作者：王苹 State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology

A ternary-layered carbide Ti2AlC material could be synthesized by spark plasma sintering（SPS） technology using elemental powder mixture of Ti, Al and active carbon. By means of XRD and SEM, phases were identified and microscopically evaluated. The experimental results show that the main phase in the product was fully crystallized Ti2AlC with small particle size when sintered at 1200℃. The synthesis temperature of SPS was 200-400℃ lower than that of hot pressing （HP） or hot isostatic pressing （HIP）. Through thermodynamics calculations, the mechanism of Ti2AlC was studied by calculating changes of Gibbs free energy of reactions.

关键词： Ti2AlC spark plasma sintering elemental powder thermodynamics analysis

Heat capacity and thermodynamical properties of the crystal of [RE_2(Glu)_2(H_2O)_8](ClO_4)_4·H_2O (RE = Nd, Eu, Dy)

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Science china Chemistry 2009年第7期52卷 862-867页

作者： WU XinMin1, LI Wei1, TAN ZhiCheng2 & QU SongSheng3.1 Department of Chemical Engineering, Beijing Institute of Petro-chemical technology, Beijing 102617, china 2 Thermochemistry Laboratory, Dalian Institute of Chemical physics, Chinese Academy of Sciences, Dalian 116023. china 3.college of Chemistry and Molecular Science, wuhan university, wuhan 430072. china Department of Chemical Engineering Beijing Institute of Petro-chemical Technology Beijing China Thermochemistry Laboratory Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China college of Chemistry and Molecular Science Wuhan University Wuhan China

Thermodynamical data of rare earth complexes with amino acid are important for engineering chemistry and fundamental chemistry. However, they have rarely been reported. In this work, a series of crystalline complexes of rare earth perchlorate coordinated with glutamic acid have been synthesized in water medium, and their thermodynamical data, including the heat capacity in low temperature range and the standard enthalpy of formation, were determined. These complexes were identified to be [RE2(Glu)2(H2O)8](ClO4)4·H2O (RE = Nd, Eu, Dy) by using thermogravimetric analysis (TG), differential thermal analysis (DTA), and chemical and elementary analyses. Their purity has been determined. No melting points were observed for all the three complexes. The heat capacity of the complexes was measured by an adiabatic calorimeter from 79 to 3.0 K. Abnormal heat capacity values were detected for two of the complexes and the decomposition range of one complex was found. The temperature, enthalpy change and entropy change of the decomposition processes of the three complexes were calculated. The polynomial equations of heat capacity in the experimental temperature range have been obtained by least squares fitting. The standard enthalpy of formation was determined by an isoperibol reaction calorimeter at 298.15 K.

关键词： complex of rare earth, [RE2(Glu)2(H2O)8](ClO4)4·H2O (RE = Nd, Eu, Dy Glu = glutamic acid), low-temperature heat capacity, standard enthalpy of formation

HMM in Predicting Protein Secondary Structure

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wuhan university Journal of Natural Sciences 2003年第S1期8卷 307-310页

作者： Huang Jing, Shi Feng, Zou Xiu-fen,Li Yuan-xiang,Zhou Huai-beiSchool of Mathematics and Statistics, wuhan university, wuhan 430072.Hubei, {3.Advanced Research Center for Science & technology , wuhan university,wuhan 430072.Hubei,{3.State Key Laboratory of Software Engineer, wuhan university, wuhan 430072.Hubei, {3. School of Mathematics and Statistics Wuhan University Wuhan Hubei China Advanced Research Center for Science & technology Wuhan University Wuhan Hubei China State Key Laboratory of Software Engineer Wuhan University Wuhan Hubei China

We introduced a new method---duration Hidden Markov Model (dHMM) to predicate the secondary structure of Protein. In our study, we divide the basic second structure of protein into three parts: H (a-Helix), E (B-sheet) and O (others, include coil and turn). HMM is a kind of probabilistic model which more thinking of the interaction between adjacent amino acids (these interaction were represented by transmit probability), and we use genetic algorithm to determine the model parameters. After improving on the model and fixed on the parameters of the model, we write a program HMMPS. Our example shows that HMM is a nice method for protein secondary structure prediction.

关键词： hidden markov Model Viterbi algorithm protein secondary structure

The microscopic approach of sdgIBM-1 and study of the ^(192,190,188)Os isotopes

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Nuclear Science and Techniques 1998年第2期9卷 69-73页

作者： Zhang Zhan-Jun Sang Jian-Ping Pan Wu-Ming Liu Yong (Institute of Particle physics, Hua-Zhong Normal university, wuhan 43.079, Department of physics,wuhan university, wuhan 430072. Department of physics, Hua-Zhong Normal university, wuhan 43.079) Institute of Particle physics Hua-Zhong Normal University Wuhan 430079 China Department of physics Wuhan University Wuhan 430072 China Department of physics Hua-Zhong Normal University Wuftan 430079 China

From the shell model configurations, valence nucleon effective interactions and fermion E2 transition operator, the sdgIBM-1 Hamiltonian and boson E2 transition operator are derived micoscopically with the help of Dyson boson expansion technique. Spectra and reduced E2 matriX elements are calculated for the 192,190,188Os isotopes. Present theoritical results fit experimental data quite well.

关键词：锇同位素研究微观方法

Application of PowerBuilder User Objects in Developing Distributed Programs

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wuhan university Journal of Natural Sciences 2001年第4期6卷 822-825页

作者： Wang Li\|fu 1, Li Hua\|ming 2 1. Human Source Department, wuhan Telecom Industry Group Co. Ltd., wuhan 43.074, china 2.School of {3. and technology, wuhan university,wuhan 430072.china Human Source Department Wuhan Telecom Industry Group Co. Ltd. Wuhan China School of physics and technology Wuhan University Wuhan China

User Objects are the basement in developing distributed PowerBuilder applications. There are two kinds of PowerBuilder objects: visual objects and non-visual objects. Usually we use non-visual objects to perform the PowerBuilder distriuted application. This paper introduces the method of developing PowerBuilder distributed application program, mainly discusses the application of nonvisual objects when developing PowerBuilder distributed application programs.

关键词： Key words PowerBuilder user object shared object remote object server push

Multifractal Decomposition of Statistically Self-Similar Sets

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Acta Mathematica Sinica,English Series 2001年第3期17卷 507-516页

作者： Jing Hu YU wuhan Institute of physics and Mathematics,The Chinese Academy of Sciences,wuhan 43.071,P.R.{3. E-mail:ding@wipm.whcnc.ac.cnDi He HU college of Mathematics and Statistics.wuhan university,wuhan 430072.P.R.{3. E-mail:dhhu@*** wuhan Institute of physics and Mathematics The Chinese Academy of Sciences Wuhan 430071 P. R. China college of Mathematics and Statistics Wuhan University Wuhan 430072 P. R. China

Let K be a statistically self-similar set defined by *** this paper,we construct a random measure ρ which is supported by K and study the multifractal decomposition for K with p. Under such a decomposition,we obtain ... 详细信息

关键词： Statistically self-similar sets Multifractal decomposition Spectrum function

Bose-Einstein Condensation in Linear Sigma Model at Hartree Approximation

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Communications in Theoretical physics 2008年第5期49卷 1261-1264页

作者： SHU Song~(1,+) LI Jia-Rong~21 Faculty of physics and Electronic technology,Hubei university,{3. 43.062,china2 Institute of Particle physics,Huazhong Normal university,{3. 43.079,china Faculty of physics and Electronic technology Hubei University Institute of Particle physics Huazhong Normal University

The BEC of charged pions is investigated in the framework of O(4) linear sigma *** using Cornwall-Jackiw- Tomboulis formalism,we have derived the gap equations for the effective masses of the mesons at finite tempera-ture and finite isospin *** critical temperature and phase diagram of BEC are discussed in the non-chiral limitat Hartree approximation.

关键词： finite temperature field theory Bose-Einstein condensation phase transitions

TiO_2 thin film photocatalyst

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Rare Metals 2004年第4期23卷 289-295页

作者： YUJiaguo StateKeyLaboratoryofAdvancedtechnologyforMaterialsSynthesisandProcessing WuhanUniversityofTeclmologyWuhan430070China

It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties of TiO_2 thin films. Therefore, it is necessary toelucidate the influence of the preparation process and post-treatment conditions on thephoto-catalytic activity and surface microstructures of the films. This review deals with thepreparation of TiO_2 thin film photo-catalysts by wet-chemical methods (such as sol-gel,-reversemicellar and liquid phase deposition) and the comparison of various preparation methods as well astheir advantage and disadvantage. Furthermore, it is discussed that the advancement ofphotocatalytic activity, super-hydrophilicity and bactericidal activity of TiO_2 thin filmphotocatalyst in recent years.

关键词： inorganic non-metal materials TiO_2 thin films preparation sol-gel method liquid phase deposition method reverse micellar method photocatalytic activity super-hydrophilicity bactericidal activity

Polarity for a Class of Levy Processes

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wuhan university Journal of Natural Sciences 2002年第4期7卷 394-398页

作者： Wu Chuan ju 1,2 , Liu Lu qin 1 1. School of Mathematics and Statistics, wuhan university, wuhan 430072. Hubei, {3. 2. college of Urban Construction, wuhan university of Science and technology, wuhan 43.070, Hubei, {3. School of Mathematics and Statistics Wuhan University Wuhan Hubei China college of Urban Construction Wuhan University of Science and Technology Wuhan Hubei China

Polar set of Markov processes is an important concept in probabilistic potential theory, but it is not easy to judge the polarity of the sets. In this paper, we give some results which can be easily used to examine the polarity of the sets whenX t belongs to a special class of Levy processes. We also give a result about polar functions of symmetric stable processes.

关键词： Levy process subordinator (essentially) polar set polar function