关于自内射环的类

总假定R为含幺有限交换环,τ为正整数,本文证明了R与其一种有限单扩张同时具有自内射性,从而给出“R上任一延迟τ步弱可逆线性有限自动机都有线性延迟τ步弱逆的充要条件是R为自内射环”的一个新证明。     

关于AP-内射环的一个注记

本文的主要目的是讨论AP-内射环中的两个问题:(1)环R是正则的当且仅当R是左AP-内射的左PP-环;(2)如果R是左AP-内射环,那么R是内射环当且仅当R是弱内射环.因此我们推广了内射环的一些结果,与此同时我们还取得了一些新的结果.     

关于拟AP内射模的注记

Let R be a ring.A right R-module M with S=End(MR)is called aquasi AP-injective module,if,for any s ∈ S,there exists a left ideal X_s of S such thatl_s(ker s)=SsX_s.Let M be a quasi AP-injective module which is a self-generator.We show that for such a module,if S is semiprime,then every maximal kernel of S isa direct summand of M.Furthermore,if ker(a_1)ker(a_2a_1)ker(a_3a_2a_1)satisfy the ascending conditions for any sequence a_1,a_2,a_3,...∈ S,then S is rightperfect.In this paper,we give a series of results which extend and generalize resultson AP-injective rings.     

自内射环的余Hopf性

本文证明了自内射环R是余Hopf的当且仅当R满足stablerangeone.于是得到了Varadarajan在[9]中的公开总是对于自内射环是成立的,即M_n(R)是余Hopf的当且仅当R是余Hopf的.作为应用证明了Goodeal的一个公开问题对于自内射正则环有肯定的回答.     

关于S-Gorenstein内射模的注记

研究了S-Gorenstein内射模的性质,证明了模的S-内射cosyzygy与S-Gorenstein内射cosyzygy之间的关系.     

关于AP-内射环和AGP-内射环(英文)

本文研究了AP-内射环和AGP-内射环的von Neumann正则性问题.利用P-内射环和Y J-内射环的研究方法及GW-理想的性质,得到了AP-内射环和AGP-内射环是(强)正则环的一些条件.推广了文献[7,12,14]中的相关结果.     

自内射环与线性自动机的线性(弱)逆

设R为含幺有限交换环 ,τ为非负整数 .证明了 :(i)R上任意延迟 0步弱可逆的线性有限自动机都有线性延迟 0步弱逆 ;对τ≥ 1 ,R上任一延迟τ步弱可逆的线性有限自动机都有线性延迟τ步弱逆的充要条件是R为自内射环 . (ii)下列条件等价 :i)R为自内射环 ,ii)R上任一延迟τ步可逆的线性有限自动机都有线性延迟τ步逆 ,iii)对R上任一延迟τ步可逆的线性有限自动机 ,总存在τ′≥τ,使得它有线性延迟τ′步逆     

环的几种内射性的关系

我们研究了关于广义自内射环(P-内射环,GP-内射环,AP-内射环,单内射环,n-内射环)的一些关系.     

关于左A—内射环

本文主要证明了：（1）适合右零化子升链条件的左A－内射环为QF环。（2）适合左零化子升链条件的左f-内射环为QF环。（3）若对环R的任意左理想A，B和右理想I满足r(A∩B）=r(A) r(B),rι(I)=I，则R为半完全环且有本质左基座，特别地，右CF的左A－内射环（或E(RR)为投射左R－模）为QF环。     

关于拟GP-内射模

在本文中,我们定义了拟GP-内射模,并且得到了关于它的一些结果.这些结果总结了GP-内射环和拟P-内射模的一些结果.     

Main Injective Rings

We refer to those injective modules that determine every left exact preradical and that we called main injective modules in a preceding article, and we consider left main injective rings, which as left modules are main injective modules. We prove some properties of these rings, and we characterize QF-rings as those rings which are left and right main injective.     

New Characterizations of Quasi-Frobenius Rings

In this article, we give several new characterizations of Quasi-Frobenius rings by using mininjectivity, simple injectivity, and small injectivity, respectively. Several known results on Quasi-Frobenius rings are reproved as corollaries.     

Cyclically Presented Modules Over Rings of Finite Type

A ring is of finite type if it has only finitely many maximal right ideals, all two-sided. In this article, we give a complete set of invariants for finite direct sums of cyclically presented modules over a ring R of finite type. More generally, our results apply to finite direct sums of direct summands of cyclically presented right R-modules (DCP modules). Using a duality, we obtain as an application a similar set of invariants for kernels of morphisms between finite direct sums of pair-wise non-isomorphic indecomposable injective modules over an arbitrary ring. This application motivates the study of DCP modules.     

一类广义遗传环

称环R为左亚遗传环，如果内射左R－模的商模是FG－内射的，给出了左亚遗传环的一些刻划，给出了左亚遗传环的半单环的条件，并研究了左亚遗传环的一些性质。     

n- Gorenstein环上的 Gorenstein内射模(英文)

用 Gorenstein内射模刻画了 n-Gorenstein环 .     

Rings all of whose right ideals are U-modules

The notion of a U-module was introduced and thoroughly investigated in [11 Ibrahim, Y., Yousif, M. F. (2017). U-modules. Comm. Algebra, doi:https://doi.org/10.1080/00927872.2017.1339064.[Crossref] , [Google Scholar]] as a strict and simultaneous generalization of quasi-continuous, square-free and automorphism-invariant modules. In this paper a right R-module M is called a U*-module if every submodule of M is a U-module, and a ring R is called a right U*-ring if R_R is a U*-module. We show that M is a U*-module iff whenever A and B are submodules of M with A?B and A∩B = 0, A⊕B is a semisimple summand of M; equivalently M = X⊕Y, where X is semisimple, Y is square-free, and X &; Y are orthogonal. In particular, a ring R is a right U*-ring iff R is a direct product of a square-full semisimple artinian ring and a right square-free ring. Moreover, right U*-rings are shown to be directly-finite, and if the ring is also an exchange ring then it satisfies the substitution property, has stable-range 1, and hence is stably-finite. These results are non-trivial extensions of similar ones on rings all of whose right ideals are either quasi-continuous or auto-invariant.     

Soc-Injective Rings and Modules*

If M and N are right R-modules, M is called Socle-N-injective (Soc-N-injective) if every R-homomorphism from the socle of N into M extends to N. Equivalently, for every semisimple submodule K of N, any R-homomorphism f : K → M extends to N. In this article, we investigate the notion of soc-injectivity.     

Weakly $I$-Semiregular Rings and $I$-Semiregular Rings

Let $I$ be an ideal of a ring $R$. We call $R$ weakly $I$-semiregular if $R$/$I$ is a von Neumann regular ring. This definition generalizes $I$-semiregular rings. We give a series of characterizations and properties of this class of rings. Moreover, we also give some properties of $I$-semiregular rings.     

A Note on Range-Inclusive Maps in Rings with Idempotents

Let A be a ring, let M be an A-bimodule, and let C be the center of M. A map F: A → M is said to be range-inclusive if [F(x), A] ? [x, M] for every x ? A. Recently, Bre?ar proved that if A is a unital ring and M a unital A-bimodule such that A contains wide idempotents, then every range-inclusive additive map F: A → M is of the form F(x) = λx + μ(x) for some λ ?C and μ: A → C. Our main purpose is to remove the assumption of unitality in the above result.