In view of complete accumulation point and >1 accumulation point, some characterizations of Lindel[AKo¨D]f space are given.
从完全聚点以及大于1-聚点角度出发,给出了Lindel¨of空间的一些刻画,主要有以下定理:空间X为Lindel¨of空间的充要条件为任给X的子集A,若|A|ω1,则A有完全聚点;空间X为Lindel¨of空间的充要条件是X为metaLindel¨of空间,并且任给势为ω1的子集A,A有大于1-聚点。
Introduces the notions of a- - complete accumulation point and a -complete accumulation point in L -fuzzy topological spaces and presents new characterizations of N compactness, strong fuzzy and compactness fuzzy compactness.
在L-Fuzzy拓扑空间中引入了α-完全聚点与α完全聚点的概念并借之给出了良紧集,强F紧集及F紧集的新特征。
Shaping mechanism of bright area on the test screen and the sharp focusing effect;
完全聚焦作用与测试屏幕上亮区的形成机理
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