检索结果-南通市图书馆

PADE APPROXIMANTS AS LIMITS OF RATIONAL FUNCTIONS OF BEST APPROXIMATION IN ORLICZ SPACE

在线全文

学校读者我要写书评

暂无评论

Analysis in Theory and Applications 1994年第2期10卷 74-82页

作者： Li Jialiang central China Normal university, China department of mathematics central Normal university 1. department of mathematics Central Normal University PR China

In this paper, we prove that the best rational approximation of a given analytic function in Orlicz space L~*(G), where G = {|z|≤∈}, converges to the Pade approximants of the function as the measure of G approaches ... 详细信息

关键词： Rational Math PADE APPROXIMANTS AS LIMITS OF RATIONAL FUNCTIONS OF BEST APPROXIMATION IN ORLICZ SPACE AS

Population-size-dependent branching processes in Markovian random environments

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第8期43卷 635-638页

作者： WANG Hanxing 1 and DAI Yonglong 2 1. department of mathematics, Shanghai university, Shanghai 201800, China 2. department of mathematics, Zhongshan university, Guangzhou 510275, China department of mathematics Shanghai University Shanghai China department of mathematics Zhongshan University Gunngzhou China

A branching model {Z n} n≥0is considered where the offspring distribution of the population’s evolution is not only dependent on the population size, but also controlled by a Markovian environmental process {ξ n} n≥0. For this model, asymptotic behaviour is studied such as limn→∞Z n and limn→∞Z n/m n in the case that the mean m k, θof the offspring distribution converges to m>1 as the population size k grows to ∞. In the case that {ξ n} n≥0is an irreducible positive recurrent Markov chain, certain extinction (i.e. P(Z n=0 for some n)=1) and noncertain extinction (i.e. P(Z n=0 for some n)<1) are studied.

关键词： Markov chains in random environments stochastic population models branching processes.

On characterizations of isometries on function spaces

在线全文

学校读者我要写书评

暂无评论

Science China mathematics 2008年第4期51卷 620-631页

作者： LI SongYing~(1+) RUAN YingBin~2 1 department of mathematics university of California Irvine CA 92697 usa 2 School of mathematics and Computer Science Fujian Normal university Fuzhou 350007 China 1. department of mathematics University of California Irvine CA 92697 USA 2. School of mathematics and Computer Science Fujian Normal University Fuzhou 350007 China

The paper gives characterization for an isometric isomorphism on little Bloch space, VMOA and holomorphic Besov space over the unit ball B n in ? n .

关键词： ismometry Besov spaces 32A17 47A15

EXISTENCE AND NONEXISTENCE OF GLOBAL POSITIVE SOLUTIONS FOR DEGENERATE PARABOLIC EQUATIONS IN EXTERIOR DOMAINS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2010年第3期30卷 713-725页

作者：曾宪忠刘振海 department of mathematics and Computational Science Hunan University of Science and Technology department of mathematics Central South University

This article deals with the degenerate parabolic equations in exterior domains and with inhomogeneous Dirichlet boundary conditions. We obtain that pc = （σ ＋ m ）n / （ n-σ- 2 ） is its critical exponent provided max{-1, [ （1- m ）n- 2] / （ n ＋ l ） } 〈 σ 〈 n- 2. This critical exponent is not the same as that for the corresponding equations with the boundary value 0, but is more closely tied to the critical exponent of the elliptic type degenerate equations. Futhermore, we demonstrate that if max（1, σ ＋ m）〈 p 〈 pc, then every positive solution of the equations blows up in finite time; whereas for p 〉 pc, the equations admit global positive solutions for some boundary values and initial data. Meantime, we also demonstrate that its positive solutions blow up in finite time provided n〈σ＋2.

关键词： Degenerate parabolic equations exterior domains -inhomogeneous dirichlet boundary conditions critical exponent blow-up global existence

Effects of Reducing River flow on Pulse Residence Time in Little Manatee River,usa

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin university 2009年第2期15卷 95-100页

作者： HUANG Wenrui,LIU Xiaohai(department of Civil Engineering,florida State university,Tallahassee,florida 32310-6046,usa) department of Civil Engineering Florida State University Tallahassee Florida 32310-6046 USA

Residence time is an important indicator for river environmental *** this paper,a 3D hydrodynamic model has been successfully applied to Little Manatee River to characterize the mixing and transport process and residence *** model employs horizontal curvilinear orthogonal grids to represent the complex river system that consists of branches and *** model has been satisfactorily calibrated and verified by using two continuous data *** data sets consist of hourly observations of all forcing boundaries,including freshwater inputs,tides,winds,salinity and temperatures at bay boundary,and air temperatures for model *** data sets also consist of hourly observations of water levels,salinity,and temperature at several river *** calibrated and verified hydrodynamic model was used to predict residence time in the Little Manatee *** the minimum flow of 0.312 m3/s,the pulse residence time(PRT) is 108 *** simulations were also conducted for 17 flow *** regression equations have been satisfactorily derived to correlate PRT to freshwater *** coefficient R2 is 0.982 for PRT.

关键词： hydrodynamic modeling estuary residence time tidal river

Perturbations of the radical of nest algebras

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第7期43卷 556-560页

作者： LU Fangyan 1 and LU Shijie 2 1. department of mathematics, Suzhou university, Suzhou 215006, China 2. department of mathematics, Zhejiang university, Hangzhou 310027, China department of mathematics Suzhou University Suzhou China department of mathematics Zhejiang University Hangzhou China

Let R N and K-N be the radical ideal and the compact operator ideal of nest algebra T(N) respectively. It is proved thatR-N+K-N=span{T∈T(N)∶TT(N)NCT}=span{T∈T(N): #σ′(ST)≤1, S∈T(N)}.

关键词： nest algebras radical perturbation.

The Degree of Symmetry of Certain Compact Smooth Manifolds II

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of mathematics,Series B 2007年第2期28卷 195-204页

作者： Bin XU department of mathematics, university of Science and Technology of China, Hefei 230026, China Chern Institute of mathematics, Nankai university, Tianjin 300071, China department of mathematics, Johns Hopkins university, Baltimore, MD 21218, usa. department of mathematics University of Science and Technology of ChinaHefei 230026 China

We give the sharp estimates for the degree of symmetry and the semi-simple degree of symmetry of certain compact fiber bundles with non-trivial four dimensional fibers in the sense of cobordism, by virtue of the rigidity theorem of harmonic maps due to Schoen and Yau (Topology, 18, 1979, 361-380). As a corollary of this estimate, we compute the degree of symmetry and the semi-simple degree of symmetry of CP2×V, where V is a closed smooth manifold admitting a real analytic Riemannian metric of non-positive curvature. In addition, by the Albanese map, we obtain the sharp estimate of the degree of symmetry of a compact smooth manifold with some restrictions on its one dimensional cohomology.

关键词： Degree of symmetry Fiber bundle Cobordism Non-positive Curvature Harmonic map First cohomology

Automorphisms with order three of affine Lie algebras

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第21期43卷 1793-1798页

作者： JIN Quanqin 1,2 and HOU Zixin 2 1. department of mathematics, Hebei university, Baoding 071002, China 2. department of mathematics, Nankai university, Tianjin 300071, China department of mathematics Hebei University Baoding China department of mathematics Nankai University Tianjin China

Some properties of automorphisms of affine Lie algebras are presented. Automorphisms with order three are classified up to conjugacy, and their fixed point sets are also computed. As a corollary, it is proved that two... 详细信息

关键词： affine Lie algebra automorphism of order three first (second) kind of automorphism.

Representations of Knot Groups and Twisted Alexander Polynomials

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2001年第3期17卷 5+362-380页

作者： Xiao Song LIN department of mathematics,university of California,Riversides,CA 92521.usa department of mathematics University of California Riverside USA

We present a twisted version of the Alexander polynomial associated with a matrix rep- resentation of the knot *** of two knots with the same Alexander module but different twisted Alexander polynomials are given.

关键词： Twisted Alexander polynomial Representation space Knot group