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AN ANALYSIS OF RECURVATURE AND DECAY OF THE TROPICAL CYCLONE ‘MADI’(2013) OVER THE BAY OF BENGAL

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Tropical Cyclone Research and Review 2015年第1期4卷 27-37页

作者： S.K.BHATTACHARYA S.D.KOTAL P.K.KUN DU India Meteorological department,NWP Division department of mathematics,jadavpur university India Meteorological department NWP Division department of mathematics Jadavpur University

The track of tropical cyclone‘Madi’showed almost 180° turn around,while immediately after recurvature it decayed rapidly in the following 24 *** surface temperature(SST)analyses rule out confrontation with low SST as cause of *** 0000 UTC of 9 December 2013 diabatic heating(DH),potential vorticity(PV)and vertical wind shear(VWS)were favourable for ***,a dry area close to the system centre at mid-troposphere subsequently engulfed the middle strata and the mid-tropospheric relative humidity(MTH)drastically reduced on 0000 UTC of 10 December *** MTH further reduced on 0000 UTC of 11 December *** of moisture in mid-troposphere apparently caused a mutation within the structure causing a sudden decrease in *** the system dried up,reduction in convection above 400 h Pa hindered latent heat *** above 400 h Pa decreased ***,there was a spurt of VWS at 1200 UTC of the 10December *** opposite wind flow between lower level and upper level whisked away the top of the system to *** the influence of the net northeasterly flow in lower to middle troposphere,the miniature vortex recurved southwestward and the vertical distortion due to shear weakened the system into a depression.

关键词： decay recurvature mid-tropospheric humidity steering current

THE PHYSICAL ENTROPY OF SINGLE CONSERVATION LAWS

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Journal of Computational mathematics 1998年第5期16卷 437-444页

作者： (department of mathematics, Peking university, Beijing 100871, China) Beijing Univ Dept Math Beijing 100871 Peoples R China

By means of the comparisons with the formulas in statistical mechanics and thermodynamics, in this paper it is demonstrated that for the single conservation law partial derivative(t)u + partial derivative(x)f(u) = 0, if the flux function f(u) is convex (or concave), then, the physical entropy is S = -f(u); Furthermore, if we assume this result can be generalized to any f(u) with two order continuous derivative, from the thermodynamical principle that the local entropy production must be non-negative, one entropy inequality is derived, by which the O.A. Olejnik's famous E- condition can be explained successfully in physics.

关键词： conservation laws entropy entropy production

Sufficient and Necessary Conditions for Limit Laws on Lag Sums of I. I. D. R. V. S

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Acta Mathematica Sinica,English Series 1998年第1期14卷 113-124页

作者： Zhang Lixin department of mathematics, Hangzhou university, Hangzhou 310028, China department of mathematics Hangzhou University

Let {X, Xn;n≥1} be a sequence of i.i.d.r.v.s with EX=0 and EX2=σ2（0n=sum from i=1 to n Xl We obtain some sufficient and necessary conditions for lim sup max max |SN-SN-j|/{2σ2k（log N/k+log logk）}1/2=1 a,s to hol... 详细信息

关键词： Strong approximation Wiener process Lag sums of i.i.d.r.v.s Chernoff function

NONOVERLAPPING DOMAIN DECOMPOSITION METHOD WITH MIXED ELEMENT FOR ELLIPTIC PROBLEMS

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Journal of Computational mathematics 1996年第4期14卷 291-300页

作者： H.X. Rui(mathematics department, Shandong university, Jinan) SHANDONG UNIV DEPT MATHJINAN 250100PEOPLES R CHINA

In this paper we consider the nonoverlapping domain decomposition method based on mixed element approximation for elliptic problems in two dimentional space. We give a kind of discrete domain decomposition iterative algorithm using mixed finite element, the subdomain problems of which can be implemented parallelly. We also give the existence, uniqueness and convergence of the approximate solution.

关键词： Zhang NONOVERLAPPING DOMAIN DECOMPOSITION METHOD WITH MIXED ELEMENT FOR ELLIPTIC PROBLEMS EV

Some Results on the Multiplier Conjecture for the Case n=5n_1

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Acta Mathematica Sinica,English Series 1998年第4期14卷 535-540页

作者： Wan Zhaoze, department of mathematics, Peking university, Beijing 100871, China department of mathematics Peking University Beijing China

Using the method presented in [1], we obtain some new results which improve on the result of MacFarland’s theorem (see [2]) in this case.

关键词： Difference sets Multiplier CH-equations

L-R smash products for bimodule algebras

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Progress in Natural Science:Materials International 2006年第6期16卷 580-587页

作者： ZHANG Liangyun (department of mathematics, Nanjing Agricultural university, Nanjing 210095, China department of mathematics, Nanjing university, Nanjing 210008, China) [a] department of mathematics Nanjing Agricultural University Nanjing China [b] department of mathematics Nanjing University Nanjing China

In this paper, we prove that the L-R smash product A(?)H is exactly the twisted smash product A * H if H is a finite dimensional cocommutative Hopf algebra, and give a sufficient and necessary condition for L-R smash products to be bialgebras (Hopf algebras) . For any finite dimensional coquasitriangular Hopf algebra (H,σ), we prove that the L-R smash product H(?)H is semisimple Artinian if H is semisimple and H * is unimodular. In particular, the L-R smash product D(H)* (?)D(H)* semisimple Artinian if the Drin-fel'd double D(H) is semisimple.

关键词： bimodule algebras L-R smash products coquasitriangular Hopf algebras Long bialgebras.

L~∞ CONVERGENCE OF TRUNC ELEMENT FOR THE BIHARMONIC EQUATION

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Journal of Computational mathematics 1997年第1期15卷 14-22页

作者： M. Wang(department of mathematics, Beijing university, Beijing, China) 北京大学数学系北京

The paper considers the L∞ convergence for TRUNC finite elements solving the boundary value problems of the biharmonic equation. The nearly optimal L∞ estimates for the error of first order derivatives are *** TRUNC plate element is proposed and developed by Argyris et al.. The numerical experiences show that the element has very good .***,[1l2]. The mathematicalproof of convergence of the TRUNC element is given by Shi Zong-ci in paper [3]. Thispaper will consider the L~∞ convergence for the TRUNC plate element.

关键词： Biharmonic equations Convergent boundaries Shape functions Vertices Interpolation Weighting functions Integers

RESERVOIR DESCRIPTION BY USING A PIECEWISE CONSTANT LEVEL SET METHOD

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Journal of Computational mathematics 2008年第3期26卷 365-377页

作者： Hongwei Li Center for Integrated Petroleum Research,university of Bergen,Norway department of mathematics,Capital Normal university,Beijing 100037,China Xuecheng Tai department of mathematics,university of Bergen,Norway Division of Mathematical Sciences,School of Physical and Mathematical Sciences,Nanyang Technological university,Singapore Sigurd Ivar Aanonsen Center for Integrated Petroleum Research,university of Bergen,Norway department of mathematics,university of Bergen,Norway Center for Integrated Petroleum Research University of Bergen Norway department of mathematics Capital Normal University Beijing 100037 China department of mathematics University of Bergen Norway Division of Mathematical Sciences School of Physical and Mathematical Sciences Nanyang Technological University Singapore

We consider the permeability estimation problem in two-phase porous media flow. We try to identify the permeability field by utilizing both the production data from wells as well as inverted seismic data. The permeability field is assumed to be piecewise constant, or can be approximated well by a piecewise constant function. A variant of the level set method, called Piecewise Constant Level Set Method is used to represent the interfaces between the regions with different permeability levels. The inverse problem is solved by minimizing a functional, and TV norm regularization is used to deal with the ill-posedness. We also use the operator-splitting technique to decompose the constraint term from the fidelity term. This gives us more flexibility to deal with the constraint and helps to stabilize the algorithm.

关键词： Inverse problem Level set method Piecewise constant Operator splitting,Reservoir description

Boundary Layer Theory and the Zero-Viscosity Limit of the Navier-Stokes Equation

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Acta Mathematica Sinica,English Series 2000年第2期16卷 207-218页

作者： Weinan E department of mathematics and Program in Applied and Computational mathematics,Princeton university,USA department of mathematics and Program in Applied and Computational mathematics Princeton University Princeton USA

A central problem in the mathematical analysis of fluid dynamics is the asymptotic limit of the fluid flow as viscosity goes to *** is particularly important when boundaries are present since vorticitv is typically generated at the boundary as a result of boundary layer *** boundary laver theory,developed by Prandtl about a hundred years ago,has become a standard tool in addressing these *** at the mathematical level,there is still a lack of fundamental understanding of these questions and the validity of the boundary layer *** this article,we review recent progresses on the analysis of Prandtl’s equation and the related issue of the zero-viscosity limit for the solutions of the Navier-Stokes *** also discuss some directions where progress is expected in the near future.

关键词： Boundary layer Blow-up Zero-viscosity limit Prandtl’s equation