极小内射模、极小平坦模与某些环

Mininjective Modules,Minflat Modules and Some Rings

称一个右R-模M是极小平坦的,如果对任一极小左理想I,自然同态M RI→M RR是单的.环R称为左极小遗传的,如果R的每个极小左理想都是投射的.环R称为左极小正则的,如果R的每个极小左理想都是RR的直和项.环R称为左极小凝聚的,如果R的每个极小左理想是有限表现的.给出了极小内射模和极小平坦模的一些刻划,并用极小内射模和极小平坦模刻划了极小遗传环、极小正则环和极小凝聚环.

Let R be a ring.A right R-module M is said to be minflat if for every minimal left ideal I the canonical homomorpism M_RI→M_RR is monic.R is called left minhereditary,if every minimal left ideal of R is projective.R is called left minregular,if every minimal left ideal of R is a direct summand.R is called mincoherent,if every minimal left ideal of R is finitely presented.Some characterizations of mininjective modules and minflat modules are given respectively.Minhereditary rings are characterized by mininjective modules,and minregular rings,and mincoherent rings are characterized by mininjective modules and minflat modules.