The purpose of this paper is to study the following two questions on AP-injective rings: (1) R is a regular ring if and only if R is a left PP-ring and R is left AP-injective; (2) Let R be a right .AP-injective ring. Then R is self-injective if and only if R is weakly injective. Hence we get some new results of P-injective rings.
给出了Abelian范畴A和复形范畴Ch(A)中X-Gorenstein内射对象及YX-Gorenstein内射对象的定义,其中XA,YX={Y∈Ch(A)|Y是正合复形且KerdnY∈X}。研究了这两类Gorenstein内射对象的同调性质及它们的区别和联系。证明了若X是包含所有内射对象的自正交的满子范畴,则X∈Ch(A)是YX-Gorenstein内射的当且仅当Xi都是X-Gorenstein内射的。在此基础上研究了两类范畴中X-Gorenstein内射维数和YX-Gorenstein内射维数以及它们之间的关系。在一定的条件下,YX-G I dim(X)=Sup{X-G I dim(Xi)|i∈Z}。
