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Partial Oscillation of m-dimensional Logistic Ecologic Models

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wuhan university Journal of Natural sciences 1998年第1期3卷 5-10页

作者： Luo Qi(Department of Basic science, wuhan Yejin university of science and technology, wuhan 430081, china) wuhan Yejin university of science and technology Department of Basic Science Wuhan China (GRID:grid.412787.f) (ISNI:***)

We present and discuss the partial oscillation with respect to equilibrium state ofm-dimensional Logistic delay ecologic models, and obtain some simple criteria.

关键词： Logistic ecologic model partial oscillation diffusion constant Liapunov functional

A Constraction of General Solution for a Class of Non-Homogeneous Recurrence of Variable Coefficients with Two Indices

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wuhan university Journal of Natural sciences 2000年第4期5卷 379-385页

作者： Yu Chang-an college of Mathematics and Computer science, wuhan university, wuhan 430072,china wuhan university College of Mathematics and Computer Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

In this paper, we obtain an explicit formula of general solution for a class of the non-homogeneous recurrence of variable coefficients with two indices.

关键词： two indices variable coefficients non homogeneous recurrence explicit solution

Applications of semigroups of operators to non-elliptic differential operators

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Chinese science Bulletin 2000年第8期45卷 673-682页

作者： ZHENG QuanDepartment of Mathematics, Huazhong university of science and technology, wuhan 430074, china Department of Mathematics Huazhong University of Science and Technology Wuhan China

This paper treats systematically the semigroup method of non-elliptic differential operators, which was developed in the last ten years. In particular, a review of the applications of regularized semigroups to non-elliptic differential operators with constant coefficients or time-dependent coefficients, parabolic systems, correct systems, abstract differential operators and pseudodifferential operators is given here. It is also shown that the regularized semigroup is an appropriate tool for non-elliptic differential operators and is far superior to the integrated semigroup approach.

关键词： differential operator regularized semigroup integrated semigroup initial value problem Fourier multiplier.

Neural Nets:Another Paradigm for Decision Support

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Journal of Systems Engineering and Electronics 1995年第2期6卷 2-8页

作者： Feng Shan (Dept. of ACE, Huazhong university of science and technology, wuhan 430074, china) Dept. of ACE Huazhong University of Science and Technology Wuhan 430074 China

The paper presents an important aspect of Neural Nets application, i. e., their usefulness for decision support. The essential feature of the neural net approach to decision making is that it is a black-box approach, which means one does not try to model the underlying processes, but only looks for a tuning of the parameters of the neural net such that the black-box mimics the sensible behavior. Through the existing widespread applications in industry, business and science, the paper emphasizes their common property as a paradigm for decision support.

关键词： Neural network Neural-net controller Decision support Industrial applications.

Evolution of Bright Screening-photovoltaic Spatial Optical Solitons

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Chinese Journal of Lasers 2001年第5期10卷 28-33页

作者： LIU Jinsong (State Key Laboratory of Laser technology, Huazhong university of science and technology, wuhan 430074, china) 华中科技大学激光技术国家重点实验室湖北武汉

A numerical analysis of the dynamical evolution of bright screening photovoltaic (SP) spatial solitons in biased photovoltaic photorefractive materials in the case of neglecting the material loss and the diffusion is presented. When an incident optical beam is a bright SP soliton, the beam propagates along a linear path with its shape kept unchanged. When the incident optical beam is slightly different from a bright SP soliton, the beam reshapes itself and tries to evolve into a bright SP soliton after a short distance. However, when the incident optical beam is significantly different from a SP bright soliton, the beam cannot evolve into a stable bright SP soliton, and tends to experience periodic compression and expansion. For a low intensity input beam, the wave experiences a periodic process of compression first and then expansion during the initial part of the cycle. For a high intensity input beam, however, the wave will initially diffract and then experiences compression during the cycle.

关键词： nonlinear optics spatial optical solitons photorefractive effects

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, china 2. college of Urban Construction, wuhan university of science and technology, wuhan 430070, Hubei, china wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) wuhan university of science and technology College of Urban Construction Wuhan Hubei China (GRID:grid.412787.f) (ISNI:***) wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

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

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

Statistical Inference for Simple Tree Order in the Means of Stochastic Order on Stratified Contingency Tables

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wuhan university Journal of Natural sciences 2010年第2期15卷 93-98页

作者： YAN Guoyi1,2, CHEN Jingjing3 1.School of Mathematics and Statistics, wuhan university, wuhan 430072, Hubei, china 2. School of sciences, wuhan Institute of technology, wuhan 430074, Hubei, china 3. School of sciences, wuhan university of science and technology, wuhan 430081, Hubei, china School of Mathematics and Statistics Wuhan University Wuhan China School of sciences Wuhan Institute of Technology Wuhan China School of sciences Wuhan University of Science and Technology Wuhan China

In this paper, we consider testing the hypothesis that all multinomial populations in the stratified contingency table are identically distributed against the alternative that all these popula- tions are in simple tree order. We provide an asymptotic represen- tation of the order-restricted maximum likelihood estimate of the unknown parameters. The resulting estimators are proven to be ~n-consistent and asymptotically normal under appropriate conditions. A chi-squared test method is used for this hypothesis test problem. A real data set is applied to illustrate our theoretical result.

关键词： simple tree order chi-squared test asymptotic representation asymptotic distribution

Sea level variations in the South china Sea inferred from satellite gravity,altimetry,and oceanographic data

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science china Earth sciences 2012年第10期55卷 1696-1701页

作者： FENG Wei 1,2,ZHONG Min 1,3 & XU HouZe 1,3 1 State Key Laboratory of Geodesy and Earth’s Dynamics,Institute of Geodesy and Geophysics,Chinese Academy of sciences,wuhan 430077,china 2 Graduate university of Chinese Academy of sciences,Beijing 100049,china 3 Institute of Geophysics,Huazhong university of science and technology,wuhan 430074,china 1. State Key Laboratory of Geodesy and Earth’s Dynamics Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Institute of Geophysics Huazhong University of Science and Technology Wuhan 430074 China

Sea level variations(SLVs) can be divided into two major components:the steric SLV and the mass-induced *** two components of SLV in the South china Sea(SCS) are studied by using satellite altimetry,GRACE(Gravity Recovery and Climate Experiment) satellite gravity,and oceanographic data on annual and inter-annual *** the annual timescale,the geographic distribution of mass-induced SLV's amplitude jointly estimated from altimetry and the ECCO(Estimation of the Circulation and Climate of the Ocean) model agrees very well with that from *** observes obvious seasonal mass-induced SLV in the SCS with annual amplitude of 2.7±0.4 cm,which is consistent with the annual amplitude of 2.7±0.3 cm estimated from the steric-corrected *** the inter-annual timescales,the mean SLV in the SCS shows a large oscillation,which is mainly caused by the steric *** trend of mean SLV inferred from altimetry in the SCS is 5.5±0.7 mm/yr for the period of 1993-2009,which is significantly higher than the global sea level rise rate of 3.3±0.4 mm/yr in the same *** is no obvious trend signal in the mass-induced SLV detected from GRACE that indicates the water exchange between the SCS and its adjacent seas and land is in balance within the study period.

关键词： altimetry GRACE ECCO the South china Sea sea level variation