一类特殊的LF-网空间

本文研究了LF-网空间和它的几个子空间类,考虑了LF-k-网空间与几类广义度量化空间的关系,并且给出了LF-k-网空间的一个等价条件.     

关于可数网络的注记

通过各种可数网的讨论，给出了可分度量空间的１序列覆盖、序列覆盖象的内在刻划。     

具有局部可数K网空间的注记(英文)

证明了一个正则空间有局部可数K网当且仅当它有局部可数CS网，作为其应用，本文建立了具有局部可数K网空间的完备逆映象定理。     

关于有局部可数K—网的空间

应用局部可数k-网来刻划局部可分度量空间的闭s-像以及局部可分的度量空间.     

WEAK SEQUENCE-COVERING MAPPING AND CS-NETWORK

A mapping f: X→Y is called weak sequence-covering if whenever {ya} is a sequence in Y converging to y ∈ Y, there exist a subsequence {ynk} and xk∈f^-1(ynk)(k∈N) ,x∈f^-1 (y) such that xk→x. The main results are: (1) Y is a sequential, Frechet, strongly Frechet space iff every weak sepuence-covering mapping onto Y is quotient, pseudo-open, countably bi-quotient respectively, (2) weak sequence-covering mapping preserves cs-network and certain k-(cs-)networks, thus some new mapping theorems on k-(cs-)notworks are proved.