(n, d)-Injective covers, n-coherent rings, and (n, d)-rings

W Li, B Ouyang - Czechoslovak Mathematical Journal, 2014 - Springer
It is known that a ring R is left Noetherian if and only if every left R-module has an injective
(pre) cover. We show that (1) if R is a right n-coherent ring, then every right R-module has an …

DG-injective covers,#-injective covers

A Iacob - Communications in Algebra, 2011 - Taylor & Francis
Full article: DG-Injective Covers, #-Injective Covers Skip to Main Content Taylor and Francis
Online homepage Taylor and Francis Online homepage Log in | Register Cart 1.Home 2.All …

Relative projective modules and relative injective modules

L Mao, N Ding - Communications in Algebra®, 2006 - Taylor & Francis
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) …

A note on existence of envelopes and covers

J Chen, N Ding - Bulletin of the Australian Mathematical Society, 1996 - cambridge.org
We prove the following results for a ring R.(a) If C is a class of right R-modules closed under
direct summands and isomorphisms, then every right R-module has an epic C-envelope if …

On (m, n)-injective modules and (m, n)-coherent rings

X Zhang, J Chen, J Zhang - Algebra Colloquium, 2005 - World Scientific
Let R be a ring. For two fixed positive integers m and n, a right R-module M is called (m, n)-
injective in case every right R-homomorphism from an n-generated submodule of Rm to M …

On divisible and torsionfree modules

L Mao, N Ding - Communications in Algebra®, 2008 - Taylor & Francis
A ring R is called left P-coherent in case each principal left ideal of R is finitely presented. A
left R-module M (resp. right R-module N) is called D-injective (resp. D-flat) if Ext1 (G, M)= 0 …

On relative injective modules and relative coherent rings

L Mao, N Ding - Communications in Algebra®, 2006 - Taylor & Francis
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) …

On n -Coherent Rings and ( n , d )-Rings

D Zhou - 2004 - Taylor & Francis
We introduce the concepts of (n, d)-injective and (n, d)-flat as generalizations of injective, flat
modules and homological dimensions, and use them to characterize right n-coherent rings …

[HTML][HTML] Almost uniserial rings and modules

M Behboodi, S Roointan-Isfahani - Journal of Algebra, 2016 - Elsevier
We study the class of almost uniserial rings as a straightforward common generalization of
left uniserial rings and left principal ideal domains. A ring R is called almost left uniserial if …

On n-coherent rings and (n, d)-injective modules

D Zhang, B Ouyang - Algebra Colloquium, 2015 - World Scientific
Let R be a ring, n, d be fixed non-negative integers, the class of (n, d)-injective left R-
modules, and the class of (n, d)-flat right R-modules. In this paper, we prove that if R is a left …