关于S-Lindelof 空间及其子空间

本文是在半开集理论中提出了S-Lindelf空间的概念.指出S-Lindelf空间是S-紧空间的一种推广,并对该空间及其子空间所具有的性质进行了一些有益的讨论.     

单位球上加权Begrman空间和Hardy空间上的保范复合算子

作者证明了复合算子C_φ是单位球上加权Begrman空间上的保范算子当且仅当φ是旋转变换.对单位球上的Hardy空间上的保范复合算子仅得到部分结果.     

Fuzzy蕴涵代数的素MP-滤子空间(英文)

In this paper,the topological space(PF_MP（X）,T) based on prime MP-filters of a lattice FI-algebra X is constructed firstly and we proved that it is a compact T₀-space if X with condition（P）.Secondly,we restricted T to the set of all maximal MP-filters MF_MP（X） of X and concluded that(PF_MP（X）,T |_PFMP（X） )is a compact T₂ space if X with conditions（P） and（S）.     

广义Besov空间到Zygmund空间的广义Cesàro算子与复合算子的积(英文)

We characterize the boundedness and compactness of the product of extended Cesaro operator and composition operator T_gC_φ from generalized Besov spaces to Zygmund spaces,where g is a given holomorphic function in the unit disk D,φ is an analytic self-map of D and T_gC_φ is defined by T_gC_φf(z) = f(φ(t))g~’(t)dt from t=0 to z.     

关于乘子的几个端点估计

In this paper,the author proves that Multiplier operator is bounded on BMO（Rⁿ）,LMO（Rⁿ） and CBMO^ρ,λ（Rⁿ）respectively if some concellation conditions are satisfied.     

Ext_F-投射生成子与Ext_F-内射余生成子

设A是Abel范畴,F是Ext_A~1(-,-):A~(op)×A→A的加法子双函子.首先研究了Ext_(F-)投射生成子与Ext_F-内射余生成子的同调性质,其次引入了W_F-Gorenstein模的概念.特别地,证明了如果重复W_F-Gorenstein模的定义程序将不会产生新的模类.最后,统一并推广了许多参考文献中的结论.     

α-Bloch空间到H∞的加权复合算子

The article not only presents the boundedness and compactness of the weighted composition operator fromα-Bloch spaces(or littleα-Bloch spaces) to H~∞,but also gives some estimates for the norm of the weighted composition operator.     

全函数空间和置换空间的一些性质

In this paper, an equivalent relation among the reflexivity, weak sequential completeness and bounded completeness in full function space is given. Some results on weakly sequential compactness of subset and the property （u） in substitution spaces are obtained.     

Hilbert空间中的Bessel列构成的 $C^*$-代数 $B_H(I)$

Let H be a separable Hilbert space, B H(I), B(H) and K(H) the sets of all Bessel sequences {f i}i∈I in H, bounded linear operators on H and compact operators on H, respectively. Two kinds of multiplications and involutions are introduced in light of two isometric linear isomorphisms αH : B H(I) → B(?2), β : B H(I) → B(H), respectively, so that B H(I) becomes a unital C*-algebra under each kind of multiplication and involution. It is proved that the two C*-algebras(B H(I), ?, ?) and(B H(I), ·, *) are *-isomorphic. It is also proved that the set F H(I) of all frames for H is a unital multiplicative semi-group and the set R H(I) of all Riesz bases for H is a self-adjoint multiplicative group, as well as the set K H(I) := β-1(K(H)) is the unique proper closed self-adjoint ideal of the C*-algebra B H(I).     

关于含渐近等距于$l^{\beta}(0<\beta<1)$子空间的赋$\beta$范空间

We get the characterizations of the family of all nonnegative, subadditive,β-absolutely homogeneous and continuous functionals defined on X, when the ;3-normed space X contains an asymptotically isometric copy of l^β. Moreover, it is proved that if a closed bounded β-convex subset K of a β-normed space contains an asymptotically isometric β-basis, then K contains a closed β-convex subset C which fails the fixed point property.     

基于{2}-逆的广义逆的构造及其性质

从代数的角度出发,分别给出了基于{2}-逆的三种广义逆:{2,3}-逆,{2,4}-逆以及{2,3,4}-逆,得到了代数上的各种构造和一些几何特性,从而补充了对广义逆的研究.     

Null Sequences in Coechelon Spaces

Rotundity of finite -dimensional Orlicz spaces l^?_n equipped with the Luxemburg norm is considered. It is proved that criteria for rotundity of l^?_nfor n ≥ 3 does not depend on n and are the same as the criteria for rotundity of the inhite-dimensional subspace h^? of an Orlicz sequence spacel^?. Criteria for rotundity of l^?₂ are different. Next, criteria for exposed points, (H)- points, strongly exposed points and LUR- points of the unit sphere of l^? and of its subspace h^? are given.     

On the Limits of Lagrange Projectors

This article addresses a question of Carl de Boor (In: Constructive theory of functions, Varna 2005, pp. 51–63, Marin Drinov Academic, Sofia, [2006]): What ideal projectors are the limits of Lagrange projectors? The results of this paper answer the question in the sense that for every ideal projector P, we prescribe finitely many computations that determine whether the projector P is a limit of Lagrange projectors.     

行分块矩阵值域上正交投影的展开式

We give in this note some expansion formulas for the orthogonal projectors onto the range of the row block matrix [ A, B ], and use the expansion formulas to examine relations among the orthogonal projectors onto the ranges of A, B and [A, B]. In particular, we present some identifying conditions for a pair of orthogonal projectors of the same size to commute.     

A Null Space Approach for Solving Nonlinear Complementarity Problems

In this work, null space techniques are employed to tackle nonlinear complementarity problems （NCPs）. NCP conditions are transform into a nonlinear programming problem, which is handled by null space algorithms, The NCP conditions are divided into two groups, Some equalities and inequalities in an NCP are treated as constraints, While other equalities and inequalities in an NCP are to be regarded as objective function. Two groups are all updated in every step. Null space approaches are extended to nonlinear complementarity problems. Two different solvers are employed for all NCP in an algorithm.     

两类函数空间上的乘子

本文在C~n中单位球上讨论了空间F(p,q,s)到Bloch型空间β~α上的点乘子,对乘子空间M(F(p,q,s),β~α)进行了完整刻画。     

构作正交空间中的一类Cartesian认证码

利用正交几何构作出一类Cartesian认证码,并且计算了它们的参数.假定信源和编码规则都按等概率分布选取,求出了认证码的成功的模仿攻击概率PI和成功的替换攻击概率PS.本文构作的Cartesian认证码的成功的模仿攻击概率PI均达到了其下界.     

幂等算子线性组合的幂等性

设P与Q是Hilbert空间中的两个不同的幂等算子.本文主要刻画了幂等算子P与Q的线性组合仍是幂等算子的充要条件,从而推广了Baksalary与Baksalary (2000)的结论.值得指出的是,我们通过严密的推理发现,其定理的条件P_1P_2≠P_2P_1是非必要的.     

Null controllability of a class of Newtonian filtration equations

In this paper, we study the null controllability of a class of Newtonian filtration equations. Using the properties of finite extinction time and finite speed of propagation, we construct a control function in feedback form, such that system is exactly null controllable at any time T>0. If we put a nonnegative constraint on the control function, this system is not exactly null controllable any more, but approximately null controllable for a long time.     

两点齐性的Finsler流形

该文证明任何一个两点齐性的Finsler流形一定是黎曼流形．证明过程中作者将泛函分析中经典的Mazur定理推广到不一定是绝对齐次的Minkowski空间上．