Recently, Costa [4] introduced the concept of n-coherent rings. In this note we shall give
some further properties of n-coherent rings. Let R be a ring and na nonnegative integer …

The classes of FP-injective and weakly quasi-Frobenius rings are investigated. The
properties for both classes of rings are closely linked with embedding of finitely presented …

The classes of FP-injective and weakly quasi-Frobenius rings are investigated. The
properties of both classes of rings are closely related to the embedding of finitely presented …

Let R be a ring. A right R-module M is called f-projective if Ext1 (M, N)= 0 for any f-injective
right R-module N. We prove that (F-proj, F-inj) is a complete cotorsion theory, where F-proj …

Let R be a ring, na fixed non-negative integer and ℱℐ n (ℱ n) the class of all left (right) R-
modules of FP-injective (flat) dimension at most n. A left R-module M (resp., right R-module …

Let R be a ring, and n and d fixed non-negative integers. An R-module M is called (n, d)-
injective if Ext d+ 1 R (P, M)= 0 for any n-presented R-module P. M is said to be (n, d) …

In this article, we provide several descriptions of w-coherent rings in terms of modules. We
show that a ring R is w-coherent if and only if every direct product of flat modules is w-flat. To …

A ring R is right finitely pseudo Frobenius (FPF) if every finitely generated faithful right jR-
module generates the category of right jR-modules. In [2], C. Faith has shown that a …

Let R be a ring. A left R-module M (respectively right R-module N) is called FI-injective
(respectively FI-flat) if Ext1 (G, M)= 0 (respectively Tor1 (N, G)= 0) for any FP-injective left R …

Let m and n be fixed positive integers and M a right R-module. Recall that M is said to be (m,
n)-injective if for any (m, n)-presented right R-module P; M is called (m, n)-flat if for any (m, n) …