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 共查询到19条相似文献,搜索用时 453 毫秒
1.
本文利用邻域约定证明了线性层空间是单调正规的,并且从单调正规的角度得到了线性层空间的一个刻画.  相似文献   

2.
王铁平 《数学杂志》1989,9(3):273-278
本文讨论Ω-紧空间与Ω-网空间,Ω-Frschet空间,或Ω-邻域空间乘积的正规性,得到了它们乘积正规的充要条件。  相似文献   

3.
Pontriagin空间上算子的交换性   总被引:1,自引:1,他引:0  
杨海涛  苏桂贤 《数学学报》2006,49(2):451-458
证明了:当Pontrjagin空间上的正规算子A没有零性不变子空间时,Putnam- Fuglede定理成立;当正规算子A有零性不变子空问时,通过构造反例说明此时Putnam- Fuglede定理不成立,并对Π1空间上算子相关的交换性条件进行了讨论,得到了Π1空间上算子代数的二次交换定理.  相似文献   

4.
k-完满正规空间   总被引:10,自引:0,他引:10  
蒋继光 《数学学报》1992,35(2):204-212
本文给出 k-集体正规空间的一组刻画;引入 k-完满正规空间的概念并给出这类空间的一系列刻画;证明它恰为 Morita 用来刻画 X×I~(?) 的正规性的重要空间类;给出 T_2仿紧空间的新刻画.  相似文献   

5.
陈奕俊 《数学学报》2002,45(3):425-432
Noel Lohoue证明了复对称空间上形如的极大函数的可和性可归结为 的可和性及f(x)叫的可和性.本文利用正规实型对称空间上热核的一个上界估计,证明了上述结果对正规实型对称空间亦成立.  相似文献   

6.
滕辉 《数学学报》1989,32(4):474-480
本文讨论一个空间和一个特殊的序空间,即序数(其上带有序拓扑)乘积的正规性.所得到的结果中有些改进了已有的相应结果.例如下面的定理:定理 设 cf(α)>ω.若 t(X)相似文献   

7.
许春根 《数学杂志》1999,19(1):79-84
我们讨论了非正曲率度量空间(NPC空间)的弱收敛、弱紧性、正规结构、不动点性质,证明了该空间具有正规结构以及在有界闭凸集上的非扩张映射具有不动点。  相似文献   

8.
数学家 N.Kemoto,T.Nogura,K.D.Sm ith和 Y .Yajim a 1996年证明了两个序数乘积的子空间的正规性、集体正规性、收缩性是等价的 .本文把这个命题进行了推广 ,得到了两个 GO -空间乘积的任意子空间的正规性、集体正规性、收缩性是等价的 .  相似文献   

9.
单位球上Dirichlet空间上的分式线性复合算子   总被引:1,自引:0,他引:1  
周泽华  袁程 《中国科学A辑》2009,39(3):333-343
本文主要研究单位球上Dirichlet空间上的分式线性复合算子的伴随算子,讨论了该空间以及它与常值函数的商空间上此类算子的正规性和本性正规性,并得到非椭圆型分式线性映射和其伴随映射的复合为椭圆或抛物型分式线性映射的结论.  相似文献   

10.
本文对“每一个GO-空间都是可数仿紧的”这一性质进行了推广,得到了“每一个GO-空间都是1:x∈[LX-X]}仿紧的”;论证了在一定条件下,一个拓扑空间和一个GO-空间乘积的正规性与这个拓扑空间和一个正则不可数基数的乘积正规性是等价的;并在这两个结论的基础上,又得出了一些重要的定理.  相似文献   

11.
We investigate the set theoretical strength of some properties of normality, including Urysohn's Lemma, Tietze-Urysohn Extension Theorem, normality of disjoint unions of normal spaces, and normality of Fσ subsets of normal spaces.  相似文献   

12.
《数学季刊》2016,(2):155-161
In this paper, we obtain a class of common fixed point theorems for generalized Lipschitz mappings in cone metric spaces with Banach algebras without the assumption of normality of cones. The results greatly generalize some results in the literature. Moreover, we give an example to support the main assertions.  相似文献   

13.
《Quaestiones Mathematicae》2013,36(1-3):23-43
A concept of normality for nearness spaces is introduced which agrees with the usual normality in the case of topological spaces, is hereditary, and is preserved under the taking of the nearness completion. It is proved that the nearness product of a regular contigual space and a normal nearness space is always normal. The locally fine nearness spaces are studied, particularly in relation to normality conditions.  相似文献   

14.
In the paper, the spaces of weakly additive τ-smooth and Radon functionals are investigated. It is proved that the functors of weakly additive τ-smooth and Radon functionals weakly preserve the density of Tychonoff spaces, and the functor of weakly additive τ-smooth functionals forms a monad in the category of Tychonoff spaces and their continuous mappings. Examples and remarks are given showing that these functors fail to satisfy certain Shchepin normality conditions. Problems having positive solutions for normal functors are presented.  相似文献   

15.
Huang and Zhang reviewed cone metric spaces in 2007 [Huang Long-Guang, Zhang Xian, Cone metric spaces and fixed point theorems of contractive mappings, J. Math. Anal. Appl. 332 (2007) 1468-1476]. We shall prove that there are no normal cones with normal constant M<1 and for each k>1 there are cones with normal constant M>k. Also, by providing non-normal cones and omitting the assumption of normality in some results of [Huang Long-Guang, Zhang Xian, Cone metric spaces and fixed point theorems of contractive mappings, J. Math. Anal. Appl. 332 (2007) 1468-1476], we obtain generalizations of the results.  相似文献   

16.
In this work the strain and stress spaces constitutive relations for isotropic and transversely isotropic softening materials are developed. The loading surface is considered in the strain space and the normality rule; the stress relaxation is proportional to the gradient of the loading surface, is adopted. It is found that the strain space plasticity theory allows us to describe the hardening, perfectly plastic and softening materials more accurately. The validity of the strain space constitutive relation for transversely isotropic materials are confirmed by comparing with the experimental data for fiber reinforced composite materials. Some numerical examples in two and three dimensional elasto-plastic problems for various loading–unloading conditions are presented, and give a very good agreement with the existing results.  相似文献   

17.
The notion of quasi-perfect normality which generalizes the notion of usual perfect normality is introduced and the behavior of the dimension functions in this class of spaces is investigated.  相似文献   

18.
We identify some remnants of normality and call them rudimentary normality, generalize the concept of submetacompact spaces to that of a weakly subparacompact space and that of a weakly? subparacompact space, and make a simultaneous generalization of collectionwise normality and screenability with the introduction of what is to be called collectionwise σ-normality. With these weak properties, we show that,1) on weakly subparacompact spaces, countable compactness = compactness, ω1-compactness = Lindelöfness;2) on weakly subparacompact Hausdorff spaces with rudimentary normality, regularity = normality = countable paracompactness; and3) on weakly subparacompact regular T1-spaces with rudimentary normality, collectionwise σ-normality = screenability = collectionwise normality = paracompactness.The famous Normal Moore Space Conjecture is thus given an even more striking appearance and Worrell and Wicke?s factorization of paracompactness (over Hausdorff spaces) along with Krajewski?s are combined and strengthened. The methodology extends itself to the factorization of paracompactness on locally compact, locally connected spaces in the manner of Gruenhage and on locally compact spaces in that of Tall, and to the factorization of subparacompactness and metacompactness in the genre of Katuta, Chaber, Junnila and Price and Smith and that of Boone, improving all of them.  相似文献   

19.
In this paper, we introduce and characterize several types of normality in double fuzzy topological spaces. The effects of some types of functions on these types of normality are introduced.  相似文献   

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