we show that the category of convergence approach spaces is a simultaneously reective and coreective subcategory of the category of latticevalued limit spaces. further we study the preservation of diagonal conditions, which characterize approach spaces. it is shown that the category of preapproach spaces is a simultaneously reective and coreective subcategory of the category of lattice-valued p...

urbanisation is still one of the social themes in developing countries. in china, the rapid process of urbanisation and economic growth bring to people not only more opportunities for creating new life and pursuing happiness, but also the challenge to face various and complex social, economical and environmental problems. among them some are outstanding, like the shrinking plowland devoured by ...

in this paper we obtain lower and upper estimates for the essential norms of generalized composition operators from weighted dirichlet spaces or bloch type spaces to $q_k$ type spaces.

in this paper, we introduce a method by which we can find a close connection between the set of prime $z$-ideals of $c(x)$ and the same of $c(y)$, for some special subset $y$ of $x$. for instance, if $y=coz(f)$ for some $fin c(x)$, then there exists a one-to-one correspondence between the set of prime $z$-ideals of $c(y)$ and the set of prime $z$-ideals of $c(x)$ not containing $f$. moreover, c...

statement of problem: nowadays, evaluation of the development of occlusion in deciduous teeth for creating corrective occlusion in permanent teeth is one of the most important objectives of pediatric dentistry. in other countries, a vast number of researches have been accomplished on the details of occlusion in deciduous teeth. but, unfortunately, there is still no accurate information about th...

in this paper, we consider a generalization of the real normed spaces and give some examples.