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Phylogeny Constructed by Using Diversity Increment

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wuhan University Journal of Natural Sciences 2003年第S1期8卷 303-306页

作者： Shi Feng, Li Na-na, Li Yuan-xiang, Zhou Huai-beiSchool of mathematics and Statistics, wuhan University, wuhan 430072,hubei,chinaAdvanced Research Center for Science and Technology, wuhan University, wuhan 430072, hubei,chinaState key laboratory of Software Engineering, wuhan University, wuhan 430072,hubei,china School of mathematics and Statistics Wuhan University Wuhan Hubei China Advanced Research Center for Science and Technology Wuhan University Wuhan Hubei China State key laboratory of Software Engineering Wuhan University Wuhan Hubei China

A new approach based on the concept of the diversity increment is applied to reconstruct a phylogeny. The phylogeny of the Eutherian orders use concatenated H-stran-ded amino acid sequences, and the result is consiste... 详细信息

关键词： diversity indicator phylogeny distance

Electronic Structure and Thermoelectric Properties of Na and Ni-doped Ca_3Co_2O_6

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Journal of wuhan University of Technology(Materials Science) 2006年第3期21卷 94-96页

作者：闵新民 Department of applied Chemistry Wuhan University of Technology Wuhan 430070 ChinaState Key Laboratory of Advanced Technology for Materials Synthesis and ProcessingWuhan University of Technology Wuhan 430070China

The electronic structures of Ca3Co2O6, Na and Ni doped models were studied by the quantum chemical software of Cambride Serial Total Energy Package （CASTEP） that is based on deusity function theory （DFT） and psendo-potential. The electronic conductivity, seebeck coefficient, thermal conduetivity and figure of merit （Z） were computed. The energy band structure reveals the form of the impurity levels due to the substitutional imapurity in semiconductors. Na-doped model stunts the character of p-type semiconductor, but Xi-doped model is n-type semiconductor. The calculation results show that the electric conduetirity of the doped model is higher than that of the non-doped model, while the Seebeck coefficient and thermal conductivity of the doped model are lower than those of the non-doped one. Because of the great increase of the electric conductivity, Z of Na- doped model is enhanced and thermoelectric properties are improved. On the other hand, as the large decline of Seebeck coefficient, Z of Ni-doped model is less than that of the non-doped model.

关键词： cobalt oxide substitutional impurity quantum chemical calculation electronic structure thermoelectric property

Global analysis on slope stability and its engineering application

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Science china(Technological Sciences) 2009年第2期52卷 507-512页

作者： ZHENG Hong1,2 & ZHOU ChuangBing3 1 State key laboratory of Geomechanics and Geotechnical Engineering, wuhan 430071, china 2 china Three Gorges University, key laboratory of Geological Hazards on Three Gorges Reservoir Area, Ministry of Education, Yi Chang 443002, china 3 School of Civil Engineering, wuhan University, wuhan 430072, china State key laboratory of Geomechanics and Geotechnical Engineering Wuhan China china Three Gorges University Key Laboratory of Geological Hazards on Three Gorges Reservoir Area Ministry of Education Yi Chang China School of Civil Engineering Wuhan University Wuhan China

In hydraulic engineering, sometimes it is necessary to consider the stability of sliding bodies with lateral frictional boundaries. Neither the existing three dimensional limit equilibrium methods nor the commercial software products are able to treat such situations. The three dimensional factor of safety is accordingly underestimated; while the shearing strength based on the three dimensional back analysis is overestimated. In this study, the lateral boundaries are regarded as the part of the slip surface. Based on the expression of the normal pressure on the slip surface and the patch interpolation, a rigorous solution for the three dimensional limit equilibrium analysis is realized. Meanwhile, the proposed procedure is applied to the stability analysis of the slope with a cable platform on the right bank in Da Gang Shan hydraulic project under construction.

关键词： slope stability the limit equilibrium methods three dimensional problems

Long-Term Cumulative Damage Model of Historical Timber Member under Varying Hygrothermal Environment

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wuhan University Journal of Natural Sciences 2009年第5期14卷 430-436页

作者： WANG Xueliang,QU Weilian hubei key laboratory of Roadway Bridge and Structure Engineering,wuhan University of Technology,wuhan 430070,hubei,china hubei key laboratory of Roadway Bridge and Structure Engineering Wuhan University of Technology Wuhan China

A long-term damage cumulative model for the duration of load effect of structural timber is proposed in this paper, which is economical in analysis as well as involving long-term hygrothermal effect. Based on the Miner linear damage cumulative theory, the cumulative damage model is applied to analyze the annual hygrothermal, daily cyclic thermal and daily cyclic relative humidity＇s effect on load-duration behavior and to calculate the sum of damage in one year. The results indicate that the annual and daily hygrothermal effect should be taken into consideration when calculating the damage accumulation, in which the influence levels from large to small are annual hygrothermal, daily relative humidity and daily thermal effect, Considering both annual and daily hygrothermal variations as external loads the long-term model is determined. Its application to service-life prediction of a historic timber structure verifies the feasibility and high-efficiency of the proposed approach.

关键词： daily hygrothermal effect annual hygrothermal effect structural timber long-term cumulative damage model

Convergence analysis of the adaptive finite element method with the red-green refinement

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Science china mathematics 2010年第2期53卷 499-512页

作者： ZHAO XuYing 1, 3 , HU Jun 2,? & SHI ZhongCi 1 1 State key laboratory of Scientific and Engineering Computing, Institute of Computational mathematics and Scientific/Engineering Computing, Academy of mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190, china 2 key laboratory of mathematics and applied mathematics (Peking University), Ministry of Education and School of Mathematical Sciences, Peking University, Beijing 100871, china 3 Graduate University of Chinese Academy of Sciences, Beijing 100190, china State key laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing China key laboratory of mathematics and applied mathematics (Peking University) Ministry of Education and School of Mathematical Sciences Peking University Beijing China

In this paper, we analyze the convergence of the adaptive conforming P 1 element method with the red-green refinement. Since the mesh after refining is not nested into the one before, the Galerkin-orthogonality does not hold for this case. To overcome such a difficulty, we prove some quasi-orthogonality instead under some mild condition on the initial mesh (Condition A). Consequently, we show convergence of the adaptive method by establishing the reduction of some total error. To weaken the condition on the initial mesh, we propose a modified red-green refinement and prove the convergence of the associated adaptive method under a much weaker condition on the initial mesh (Condition B).

关键词： red-green refinement adaptive finite element method convergence non-nested local refinement

Electronic Structures and Bonding Properties of Ti_2AlC and Ti_3AlC_2

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Journal of wuhan University of Technology(Materials Science) 2007年第1期22卷 27-30页

作者：闵新民 Department of applied Chemistry School of Science Wuhan University of Technology State key laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

The relation among electronic structure, chemical bond and property of Ti2AlC, Ti3AlC2 and doping Si into Ti2AlC was studied by density function and the discrete variation （DFT-DVM） method. After adding Si into Ti2AlC, the interaction between Si and Ti is weaker than that between Al and Ti, and the strengths of ionic and covalent bonds decrease both. The ionic and covalent bonds in Ti3AlC2, especially in Ti-Al, are stronger than those in Ti2AlC. Therefore, in synthesis of Ti2AlC, the addition of Si enhances the Ti3AlC2 content instead of Ti2AlC. The density of state （DOS） shows that there is mixed conductor characteristic in Ti2AlC and Ti3AlC2. The DOS of Ti3AlC2 is much like that of Ti2AlC. Ti2SiAl1-xC has more obvious tendency to form a semiconductor than Ti2AlC, which is seen from the obvious difference of partial DOS between Si and Al 3/7.

关键词： Ti2AlC Ti3SiC2 doping electronic structure chemical bond

VARIABILITY SETS AND HAMILTON SEQUENCES

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Chinese Annals of mathematics,Series B 2005年第4期26卷 543-550页

作者： SUN NA WU SHENGJIAN key laboratory of Pure and applied mathematics School of Mathematical Sciences Peking University Beijing 100871 China.

This paper studies extremal quasiconformal mappings. Some properties of the variability set are obtained and the Hamilton sequences which are induced by point shift differentials are also discussed.

关键词： Quasiconformal mapping Point shift differentials Hamilton sequence Extremal mapping

EXISTENCE OF GLOBAL SMOOTH SOLUTION TO INITIAL BOUNDARY VALUE PROBLEM FOR A VISCOELASTIC MODEL WITH RELAXATION

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Acta Mathematica Scientia 2004年第2期24卷 265-274页

作者：阮立志朱长江 laboratoryofNonlinearAnalysis Dept.ofMath.CentralChinaNormalUniversityWuhan430079China

This paper is concerned with the initial boundary value problem for a viscoelastic model with relaxation. Under the only assumption that the C^0-norm of the initial data is small, without smallness hypothesis for the C^1-norm, the existence of the global smooth solution to the corresponding initial boundary value problem is proved. The analysis is based on some a priori estimates obtained by the 'maximum principle' of first-order quasilinear hyperbolic system.

关键词： Viscoelastic model relaxation a priori estimates maximum principle

Cluster identification and characterization of physical fields

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Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1610-1618页

作者： ZHANG GuangCai,XU AiGuo,LU Guo & MO ZeYao National key laboratory of Computational Physics,Institute of applied Physics and Computational mathematics,Beijing 100088,china National key laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing China

The description of complex configuration is a difficult *** present a powerful technique for cluster identification and *** scheme is designed to treat and analyze the experimental and/or simulation data from various *** main steps are as *** first divide the space using face or volume elements from discrete ***,we combine the elements with the same and/or similar properties to construct clusters with special physical *** the algorithm,we adopt an administrative structure of a hierarchy-tree for spatial bodies such as points,lines,faces,blocks,and *** fast search algorithms with the complexity lnN are *** establishment of the hierarchy-tree and the fast searching of spatial bodies are general,which are independent of spatial ***,it is easy to extend the method to other *** a verification and validation,we applied this method and analyzed some two-dimensional and three-dimensional random data.

关键词： spatial hierarchical tree fast search complex configuration dynamic physical fields cluster identification