诱导的L—fuzzy拓扑空间的a—结构

本文研究Ｌ－ｆｕｚｚｙ拓扑空间的一类几乎开Ｌ－ｆｕｚｚｙ集的性质,在Ｌ－ｆｕｚｚｙ拓扑空间中引入了ａ－结构的概念,证明了由一般拓扑空间（Ｘ,Ｆ）诱导的Ｌ－ｆｕｚｚｙ拓扑空间（Ｌ＾Ｘ,ＷＬ（Ｔ））的ａ－结构必是Ｌ＾Ｘ上的Ｌ－ｆｕｚｚｙ拓扑,并且指出这个拓扑就是由一般拓扑空间（Ｘ,Ｔ）的ａ－结构诱导的,此外,本文还给出了与诱导的Ｌ－ｆｕｚｚｙ拓扑空间的ａ－结构相关的若干性质。     

分裂空间的一个性质

设Ｘ为一个拓扑空间，对于任意的Ａ∈Ｘ。存在可分度量空间Ｍ及连续映射ｆ：Ｘ→Ｍ，使得ｆ（Ｘ）＝Ｍ，Ａ＝ｆ＾－１（ｆ（Ａ）），则Ｘ称为分裂空间。本文证明了分裂空间Ｘ在广义连续统假设下：（１）若ｄ（Ｘ）≥２＾ω，则ｄ（Ｘ）＝｜Ｘ｜。（２）若（Ｘ）≤２＾ω，则对角线集△ｘ为Ｇδ集。并且（１）中的条件不能减弱。     

随机微分方程终值问题的弱解

设｛Ｗｔ．Ｆｔ．ｔ∈［０，Ｔ］｝为概率空间（Ω，Ｆ，Ｐ）上的标准α维Ｂｒｏｗｎｆｃｆｃ，Ｆｔ为由它生成的自然σ－代数流。本文讨论了如下随机微分方程终值问题弱解的存在性：Ｘｔ＝ξ＋∫ｔ＾Ｔｇ（ｓ，Ｘｓ，Ｙｓ）ｄｓ＋∫ｔ＾ＴＹｓｄＷｓ其中ξ∈Ｌ＾２（Ω，ＦＴ，Ｐ；Ｒ＾ｎ），ｇ：［０，Ｔ］×Ｒ＾ｎ×Ｒｎｄ→Ｒ＾ｎ为有界可测函数。此外，还讨论了它在金融市场期权定价问题中的应用。     

诱导的L-fuzzy拓扑空间的α-结构

本文研究Ｌ－ｆｕｚｚｙ 拓扑空间的一类几乎开Ｌ－ｆｕｚｚｙ 集的性质,在Ｌ－ｆｕｚｚｙ 拓扑空间中引入了α－结构的概念,证明了由一般拓扑空间（Ｘ,Ｔ）诱导的Ｌ－ｆｕｚｚｙ 拓扑空间（ＬＸ,ＷＬ（Ｔ））的α－结构必是ＬＸ 上的Ｌ－ｆｕｚｚｙ 拓扑,并且指出这个拓扑就是由一般拓扑空间（Ｘ,Ｔ）的α－ 结构诱导的．此外,本文还给出了与诱导的Ｌ－ｆｕｚｚｙ拓扑空间的α－结构相关的若干性质．     

L-Fuzzy θ-良紧空间

引入θ－拓扑和θ－良紧的概念,并对其作了较深刻的研究,主要结果有：（１）θ－良紧是半正则性质和Ｌ好的推广;（２）θ－良紧是弱同胚不变性质;（３）满层θ－良紧空间与θ－良紧空间与θ－良紧空间的积空间是θ－良紧;（４）对于弱艉导空间（Ｌ＾Ｘ〈δ）,它是θ－良紧当且仅当它的底空间（Ｘ,「δ」是θ－紧。     

模糊连续映射和开映射的新特征

给定模糊格Ｌ及ＬＦ拓扑空间（Ｌ＾ｘ,δ）,对Ｌ的素元素ｒ及分子ａ,在（Ｌ＾ｘ,δ）中引入了ｒ－开集及α－闭集的概念。证明了所有的ｒ－开集Ｏｒ（δ）和α－闭集Ｃａ（δ）分别形成一个ＬＦ拓扑和ＬＦ余拓扑,借助于它俩得到了ＬＦ连续映射和ＬＦ开映射的若干新特征。     

关于Lowen空间指数对象的一点注记

Ｌ－拓扑空间（Ｘ，△）称为一 Ｌｏｗｅｎ空间若△有一组由层特征函数构成的基，即△中形如ａ∧Ｕ，ａ∈Ｌ，Ｕ　Ｘ的元素构成△的一组基．若Ｌ＝［０，１］；则（Ｘ，△）是一Ｌｏｗｅｎ空间当且仅当（Ｘ，△）是一 Ｌｏｗｅｎ意义下的ｆｕｚｚｙ邻域空间．通过在函数空间上引入适当的Ｌ－拓扑结构，证明了若０∈Ｌ是一素元并且Ｌｏｗｅｎ空间（Ｘ，△）的开集格是一连续格，则（Ｘ，△）是Ｌｏｗｅｎ空间范畴中一指数对象．特别地，若一ｆｕｚｚｙ邻域空间的开集格连续，则它是ＦＮＳ中一指数对象．     

完备格上的上拓扑和区间拓扑

对完备格 Ｌ;记ｖ（Ｌ）为 Ｌ上的上拓扑之闭集格本文证明了完备格 Ｌ为 Ｆ－分配格当且仅当映射ｓｕｐ：ｖ（Ｌ）→Ｌ为满完备格同态;若Ｌ为Ｆ－分配的Ｂｏｏｌｅ格,则Ｌ同构于某幂集格、对Ｔ１格 Ｌ,证明了下述各条件等价。（１） Ｌ同构于某幂集格;（２） Ｌ上的区间拓扑是 Ｈａｕｓｄｏｒｆｆ的;（３）是有限分离的;（４） Ｌ是连续的对马空间（Ｘ,Ｏ（Ｘ））,进一步证明了 Ｏ（Ｘ）上的区间拓扑不可能为 Ｈａｕｓｄｏｒｆｆ的,除非（Ｘ, Ｏ（Ｘ））是离散空间．     

一个反应扩散过程的门槛结果

本文讨论反应扩散方程Ｃａｕｃｈｙ问题（ｕｔ－△ｕ＝ｕ＾ｐ－ｕ＾ｐ－ｕ，Ｘ∈Ｒ＾ｎ，ｔ∈（０，Ｔ），ｕ（ｘ，０）＝ｕ０（ｘ）≥０，Ｘ∈Ｒ＾ｎ，解的整体存在性，渐近性质和Ｂｌｏｗ－ｕｐ问题，其中１＜ｑ＜ｐ＜ｎ＋２／ｎ－２，ｎ≥３或者１＜ｑ＜ｐ＋∞，ｎ＝２．得到门槛结果。     

论算法的发展（Ⅰ）：组合优化的基本方法

用π＾（ｔ）－集合表示具有规定性质π＾（ｔ）的集合，π＾（ｔ）－对象是指具有规定结构的π＾（ｔ）－集合本身是具有空结构的π＾（ｔ）－对象。组合优化的问题ＸＹＺ是指：对于每一个π＾（ｔ）－集合，从其诸π＾（２）－对象中找出π＾（３）－优者。以最小生成的问题ＸＹＺ是指：对于每一个π＾（２）－对象中找出π＾（３）－优者，以最小生成林问题，平面凸壳问题及整序问题为实践背景，对于问题ＸＹＺ的一个实例Ｓ，把集     

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.     

On a class of self-similar processes with stationary increments in higher order Wiener chaoses

We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.     

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.     

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.     

On a class of Riemann surfaces

It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

<正>August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists     

Towards Excellence in Science Chinese Academy of Sciences

<正>May 26,2014,Beijing Science is a human enterprise in the pursuit of knowledge.The scientific revolution that occurred in the 17th Century initiated the advances of modern science.The scientific knowledge system created by