Regularity of Weak Solutions of Nonlinear Equations with Discontinuous Coefficients

In this paper, we prove that the weak solutions u∈Wloc^1, p （Ω） （1 〈p〈∞） of the following equation with vanishing mean oscillation coefficients A（x）： -div[（A（x）△↓u·△↓u）p-2/2 A（x）△↓u＋│F（x）│^p-2 F（x）]=B（x, u, △↓u）, belong to Wloc^1, q （Ω）（A↓q∈（p, ∞）, provided F ∈ Lloc^q（Ω） and B（x, u, h） satisfies proper growth conditions where Ω ∪→R^N（N≥2） is a bounded open set, A（x）=（A^ij（x）） N×N is a symmetric matrix function.     

人口问题中广义三维GINZBURG-LANDAU模型方程

本文讨论三维广义Ginzburg-Landau模型方程的初边值问题ut=-a1↓△^4u a2↓△^2u ↓△^2g(u) G(u),σu/σv=0,σ△u/σv=0,u(x,0)=u0(x)解的整体存在性、唯一性、渐近性质和爆破。     

Energy Scattering for the Generalized Davey—Stewartson Equations

Abstract Considring the generalized Davey-Stewartson equation i-△u+λ│u│~pu+μE(│u│~q)│u│~(q-2)u=0,where λ>0,μ≥0,E=F~(-1)(ξ_1~2│ξ│~2)F,we obtain the existence of scattering operator in ∑(R~n):u{u∈H~1(R~n):│x│u∈L~2(R~n)}.     

一类周期变号的非线性Schroedinger方程解的存在性

讨论非线性Schroedinger方程-△u q（x）u=λu Q（x）│u│^p-1u x∈R^N的解的存在性,其中q(x),Q(x)满足周期性条件,而且Q（x)变号,λ∈R落在-△ q的谱隙中,1＜p＜N 2/N-2。     

方程—△↓（｜△↓u｜^p—2△↓u）=ρ（x）u^α在R^N存在有界解的充分必要条件

考虑全空间R^R上的空间－△↓(|△↓u|^p-2△↓u)=ρ（x)u^α存在有界解的充分必要条件。     

Extinction and Positivity for a Doubly Nonlinear Degenerate Parabolic Equation

The aims of this paper are to discuss the extinction and positivity for the solution of the initial boundary value problem and Cauchy problem of ut = div（[↓△u^m｜p-2↓△u^m）. It is proved that the weak solution will be extinct for 1 〈 p ≤ 1 ＋ 1/m and will be positive for p 〉 1 ＋ 1/m for large t, where m 〉 0.     

EXISTENCE AND UNIQUENESS OF BV SOLUTIONS FOR THE POROUS MEDIUM EQUATION WITH DIRAC MEASURE AS SOURCES

The aim of this paper is to discuss the existence and uniqueness ofsolutions for the porous medium equation ut-(u^m)xx=μ（x） in （x,t）∈R×（0,+∞） with initial condition u(x,0)=u0(x) x∈（-∞,+∞）,where μ(x) is a nonnegative finite Radon measure, u0∈L^1 (R)∩L^∞ (R) is a nonnegative function, and m>1, and R≡(-∞, +∞).     

不可微泛函拟极小问题解的正则性

本文对P＞1的情形给出不可微泛函I(u,G)= ∫FG（x,u, ↓△）dx的(1 cR^2u）一极小问题解梯度的Holder连续性证明。     

一类非线性Schrdinger-Maxwell方程基态解的存在性

本文研究了如下Schrdinger-Maxwell方程基态解的存在性问题{-△u+V(x)u+K(x)φ(x)u=b(x)|u|p-1u+λg(x,u)in R~3,-△φ=K(x)u~2in R~3,其中λ0,V(x)∈C~1(R~3,R),且V(x)0.△在K,g,b满足一定的假设条件下,且0p1时,利用变分法和临界点理论,获得了基态解的存在性.该结论推广了文献[7]的结果.     

Bakry-Emery型Ricci曲率下两类抛物方程正解的梯度估计

本文考虑完备黎曼流形上,在Bakry-Emery型Ricci曲率有下界的条件下两类抛物方程?u/?t=△Vu+au log u 和(△v-?/?t)u(x,t)+p(x,t)uβ(x,t)+q(x,t)u(x,t)=0正解的梯度估计,这里α,β ∈(R),△V(·):=△+(V,▽(·)).由于引入了 △V,相应地,在...     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years （2001-2005）. The main topics are： convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.     

A REPRESENTATION FORMULA RELATED TO SCHR(O)DINGER OPERATORS

Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.     

CONTENTS OF VOLUME 30

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Instructions for contributions

正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with     

Journal of Mathematical Research with Applications Guide for Authors

正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.     

Staircase transportation problems with superadditive rewards and cumulative capacities

A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].     

Boundedness for commutators of multipliers on Hardy type spaces

In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p（R^n） into the Lebesgue space L^p with p 〈 1.     

A unified approach to certain problems of best local approximation

In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.