This paper gives internal characterizations of some sequence covering compact images and compact covering compact images of paracompact locally compact spaces, which improve some results on compact images of locally...This paper gives internal characterizations of some sequence covering compact images and compact covering compact images of paracompact locally compact spaces, which improve some results on compact images of locally compact metric spaces.展开更多
证明了如下结果：（1）如果X=multiply from t∈∑ Xτ是∑-仿紧空间,则X是subortho-紧空间当且仅当F∈[∑]〈ε,X=multiply from τ∈F Xτ是subortho-紧空间.（2）设X=multiply from i∈ω Xi是可数仿紧的,则下列3y条等价：X是subort...证明了如下结果：（1）如果X=multiply from t∈∑ Xτ是∑-仿紧空间,则X是subortho-紧空间当且仅当F∈[∑]〈ε,X=multiply from τ∈F Xτ是subortho-紧空间.（2）设X=multiply from i∈ω Xi是可数仿紧的,则下列3y条等价：X是subortho-紧的;F∈[ω]〈ω,X=multiply from i∈F Xi是subortho-紧的;n∈ω,multiply from i≤n Xi是subortho-紧的.展开更多
We give an explicit construction of the completely regular paracompact reflection pL of a completely regular locale L described as a sublocale of the Stone-tech compactification βL of L.
Some characterizations of paracompact maps are given in this note, and some equivalent statements of collectionwise normal maps are discussed. And also we show that if f ： X→Y is a closed collectionwise normal map, ...Some characterizations of paracompact maps are given in this note, and some equivalent statements of collectionwise normal maps are discussed. And also we show that if f ： X→Y is a closed collectionwise normal map, and f^-1（y） is a semistratifiable subspace of X for any y ∈ Y, then f is a paracompact map.展开更多
文摘This paper gives internal characterizations of some sequence covering compact images and compact covering compact images of paracompact locally compact spaces, which improve some results on compact images of locally compact metric spaces.
文摘证明了如下结果：（1）如果X=multiply from t∈∑ Xτ是∑-仿紧空间,则X是subortho-紧空间当且仅当F∈[∑]〈ε,X=multiply from τ∈F Xτ是subortho-紧空间.（2）设X=multiply from i∈ω Xi是可数仿紧的,则下列3y条等价：X是subortho-紧的;F∈[ω]〈ω,X=multiply from i∈F Xi是subortho-紧的;n∈ω,multiply from i≤n Xi是subortho-紧的.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.10331010&10125104).
文摘We give an explicit construction of the completely regular paracompact reflection pL of a completely regular locale L described as a sublocale of the Stone-tech compactification βL of L.
基金The Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality.
文摘Some characterizations of paracompact maps are given in this note, and some equivalent statements of collectionwise normal maps are discussed. And also we show that if f ： X→Y is a closed collectionwise normal map, and f^-1（y） is a semistratifiable subspace of X for any y ∈ Y, then f is a paracompact map.
