In this paper, we discuss the relationship between k-semi-stratifiable spaces and quais-Nagata spaces and some mapping properties of quasi-Nagata spaces. We get following results: sequence-covering closed mapping pres...In this paper, we discuss the relationship between k-semi-stratifiable spaces and quais-Nagata spaces and some mapping properties of quasi-Nagata spaces. We get following results: sequence-covering closed mapping preserve quasi-Nagata spaces, and finite-to-one open mappings don't preserve quasi-Nagata spaces.展开更多
In this paper,we introduce the notions of a cs * regular base,a cs * development and the discretely cs * θ expandability for topological spaces and use these notions to give some metrization theorems. That is a gener...In this paper,we introduce the notions of a cs * regular base,a cs * development and the discretely cs * θ expandability for topological spaces and use these notions to give some metrization theorems. That is a generaliztion of several theorems in [1].展开更多
文摘In this paper, we discuss the relationship between k-semi-stratifiable spaces and quais-Nagata spaces and some mapping properties of quasi-Nagata spaces. We get following results: sequence-covering closed mapping preserve quasi-Nagata spaces, and finite-to-one open mappings don't preserve quasi-Nagata spaces.
文摘In this paper,we introduce the notions of a cs * regular base,a cs * development and the discretely cs * θ expandability for topological spaces and use these notions to give some metrization theorems. That is a generaliztion of several theorems in [1].
