数学学报杂志 北大期刊 CSCD期刊 统计源期刊

An Isometric Embedding of Moebius Band with Positive Gaussian Curvature

作者：HuiXiaHE; ZiZhouTANG 刊期：2004年第06期

The main purpose of this paper is to show that there is an isometric embedding from Moebius band to R4 with positive Gaussian curvature.

The Existence of Solutions of Elliptic Equations with Neumann Boundary Condition for Superlinear Problems

作者：ChongLI 刊期：2004年第06期

In this paper, we study and discuss the existence of multiple solutions of a class of non-linear elliptic equations with Neumann boundary condition, and obtain at least seven non-trivial solutions in which two are positive, two are negative and three are sign-changing. The study of problem (1.1):{-△u+αu=f(u),x∈Ω, x...

Weak Uniform Normal Structure and Fixed Points of Asymptotically Regular Semigroups

作者：LuChuanZENG 刊期：2004年第06期

Existence of Entire Solutions of a Singular Semilinear Elliptic Problem

作者：Wei; Jie; FENG; Xi; Yu; LIU 刊期：2004年第06期

In this paper, we obtain some existence results for a class of singular semilinear elliptic problems where we improve some earlier results of Zhijun Zhang. We show the existence of entire positive solutions without the monotonic condition imposed in Zhang's paper. The main point of our technique is to choose an appro...

The Cauchy Boundary Value Problems on Closed Piecewise Smooth Manifolds in C^n

作者：LiangYuLIN; ChunHuiQIU 刊期：2004年第06期

Suppose that D is a bounded domain with a piecewise C^1 smooth boundary in C^n. Let ψ∈C^1+α(δD). By using the Hadamard principal value of the higher order singular integral and solid angle coefficient method of points on the boundary, we give the Plemelj formula of the higher order singular integral with the Boehner...

A Filtration of Wick Algebra and Its Application to Quantum SDEs

作者：CaiShiWANG; ZhiYuanHUANG 刊期：2004年第06期

A family of closed snbalgebras, indexed by R(the set of real numbers), of the Wick algebra is constructed. Fundamental properties of tile family are shown including the increasing property and the right-continuity. The notion of adaptedness to the family is defined for quantum stochastic processes in terms of general...

Weak and Strong Convergence for Fixed Points of Asymptotically Non-expansive Mappings

作者：ZeQingLIU; ShinMinKANG 刊期：2004年第06期

A few weak and strong convergence theorems of the modified three-step iterative sequence with errors and the modified Ishikawa iterative sequence with errors for asymptotically non-expansive mappings in any non-empty closed convex subsets of uniformly convex Banach spaces are established. The results presented in thi...

Some Limit Theorems on the Increments of l^p-valued Multi-Parameter Gaussian Processes

作者：ZhengYanLIN; SeaungHyuneLEE; KyoShinHWANG; YongKabCHOI 刊期：2004年第06期

In this paper, we establish some limit theorems on the increments of an l^p-valued multiparameter Gaussian process under weaker conditions than those of Csoergoe-Shao theorems published in Ann. Probab. (1993).

Weierstrass Type Representation of Willmore Surfaces in S^n

作者：Qiao; Ling; XIA; Yi; Bing; SHEN 刊期：2004年第06期

In this paper, we reformulate the Euler-Lagrange equations of Willmore surfaces in S^n as the flatness of a family of certain loop algebra-valued 1-forms. Therefore we can give the Weierstrass type representation of conformal Willmore surfaces. We also discuss the relations between conformal Willmore surfaces in S^n ...

Universal Jensen＇s Equations in Banach Modules over a C^＊-Algebra and Its Unitary Group

作者：ChunGilPARK 刊期：2004年第06期

In this paper, we prove the generalized Hyers-Ulam-Rassias stability of universal Jensen's equations in Banach modules over a unital C^*-algebra. It is applied to show the stability of universal Jensen's equations in a Hilbert module over a unital C^*-algebra. Moreover, we prove the stability of linear operators in a...

Nonlinear Internal Damping of Wave Equations with Variable Coefficients

作者：ShaoJiFENG; DeXingFENG 刊期：2004年第06期

For wave equations with variable coefficients on regions which are not necessarily smooth, we study the energy decay rate when a nonlinear damping is applied on a suitable subrigion.

A Different Version of Flett＇s Mean Value Theorem and an Associated Functional Equation

作者：ThomasRIEDEL; MaciejSABLIK 刊期：2004年第06期

In this paper we present a mean value theorem derived from Flett's mean value theorem. It turns out that cubic polynomials have the midpoint of the interval as their mean value point. To answer what class of functions have this property, we consider a functional equation associated with this mean value theorem. This ...

Takesaki-Takai Duality Theorem in Hilbert C^＊-Modules

作者：MaoZhengGUO; XiaoXiaZHANG 刊期：2004年第06期

In this paper, we generalize the Takesaki-Takai duality theorem in Hilbert C^*-modules; that is to say, if (H, V, U) is a Kac-system, where H is a Hilbert space, V is a multiplicative unitary operator on H×H and U is a unitary operator on H, and if E is an J-compatible Hilbert A-module, then E×^↑J×J≌E×K(H), where K...

The Representation Theorem of onto Isometric Mappings between Two Unit Spheres of l^1（Γ） Type Spaces and The Application to the Isometric Extension Problem

作者：GuangGuiDING 刊期：2004年第06期

In this paper, we first derive the representation theorem of onto isometric mappings in the unit spheres of l^1（Γ） type spaces, and then conchlde that such mappings can be extended to the whole space as real linear isometries by using a previous result of the author.

A Note on the Mean Value of Numbersof the Solutions of x^α≡ 1（modn）

作者：Xiu; Yuan; YU 刊期：2004年第06期