J-clean环的推广（英文）

如果R中每个元素(对应地,可逆元)均可表示为一个幂等元与环R的Jacobson根中一个元素之和,则称环R是J-clean环(对应地,UJ环).所有的J-clean环都是UJ环.作为UJ环的真推广,本文引入GUJ环的概念,研究GUJ环的基本性质和应用.进一步地,研究每个元素均可表示为一个幂等元与一个方幂属于环的Jacobson根的元素之和的环.     

拟fine环和2-fine环（英文）

称环R是fine环,如果R中每个非零元素均可以表示为一个可逆元与一个幂零元之和.Fine环的概念由Cǎlugǎreanu和Lam在[J.Algebr Appl.,2016,15(9):1650173,18 pp.]中给出,fine环和单环密切相关.本文研究如下两类环:每个非幂零元素均可表示为一个可逆元与一个幂等元之和的环以及每个元素均可表示为一个可逆元与两个幂零元之和的环.     

交换局部环上强J-clean矩阵（英文）

环中元素称为强J-clean,如果它可写成幂等元与其Jacobson根中元素之和,并且它们可交换.本文研究了交换局部环上强J-clean 2×2矩阵,进而确定了素数p生成的素理想的局部化环Z_(p)和p-adic整数环Z_p上强J-clean 2×2矩阵.     

群环上的强J-clean矩阵

设R是一个环,J(R)表示R的Jacbson根.R的一个元素称为强J-clean的,如果能够表示成一个幂等元和一个J(R)中元素的和且这两个元素可交换.对于一个可交换局部环R满足2∈J(R),得到一个在RG上2×2矩阵是强J-clean的充要条件,其中G={1,g}是一个群.同时给出了强clean性的上应用.     

关于群环的Jacobson根

设R为有1结合环.G为群,H为G的子群,本文对群环RG的Jacobson根作了一些刻化,从而得出了在不同条件下J(RG)、J(RH)、(RG)之间的一些关系式:J(RG)=J(RH)RG.J(RH)RG=(RG),J(RH)=(RH)=UJ(RW)等,其中J(RG)、(RG)分别表示RG的Jacobson根和Baer根.     

关于F-环

如果环R含有一有限非零元集X,使得任意非零αR与X相交不空,则称R为F-环。本文证明了:一个不含非零幂零元的F-环为有限个除环的直和。 我们推广傅昶林一文[1]中的概念如下: 定义 如果环R含有一有限非零元集X,使得任意非零αR与X相交不空,则称R为F-环。如果有一个这样的集合XZ(R),称R为FZ-环(Z(R)表示R的中心)。 本文将证明:一个不含有非零幂零元素的F-环R为有限个除环的直和。以下R_1表示R的左零化子,P(R)表示R的质根,J(R)表示R的Jacobson根,(0:A)表示集合{x∈R|Ax=0},这里AR。     

有关Kegel猜测的若干结果

Kegel曾经提出如下猜测:若环R可以表示为它的两个局部幂零子环S、T之和,即有R=S+T,问R是否必是局部幂零的?本文证明:若Kegel猜测不真,则必存在一个本原环可以表示为它的两个局部幂零子环之和.另外,还得到两个与Kegel猜测有关的很有趣的结果.     

关于受限制的弱准素环的一点注记

交换环R称为(受限制的)弱准素环,如果R中的每个(非零)主理想都是准素理想.本文证明了一个没有单位元的交换环R是受限制的弱准素环当且仅当R是每个元素都是幂零元的交换环或者R是仅含一个真素理想P的没有单位元的交换环并且P不真包含R的任何非零理想.     

无穷矩阵环上的导子

讨论无穷矩阵环上的导子,证明了环R上有限个元素不为零的无穷矩阵坏的每个导子均可表示为两个特殊导子之和。     

局部单位元半群分次环

设S为有限局部单位元半群,R为S—分次环.首先定义了S—分次环R在半群S上的冲积R#S*,证明了模范畴R#S*-M od与分次模范畴(S,R)-g r之间的等价性,并进一步研究了局部单位元半群分次环的分次Jacobson根及其相关的自反根的关系,得到重要关系式J(R#S*)=JS(R)#S*及Jref(R)=(J(R#S*))↓=JS(R).     

Rings with 2-UJ property

Abstract

Rings in which the square of each unit is a sum of an idempotent and an element from the Jacobson radical are said to be 2-UJ. Properties of 2-UJ rings are discussed, and the 2-UJ property is applied to characterize some known notions of rings.     

Matrices over a commutative ring as sums of three idempotents or three involutions

Motivated by Hirano-Tominaga’s work on rings for which every element is a sum of two idempotents and by de Seguins Pazzis’s results on decomposing every matrix over a field of positive characteristic as a sum of idempotent matrices, we address decomposing every matrix over a commutative ring as a sum of three idempotent matrices and, respectively, as a sum of three involutive matrices.     

Clean Semiprime f-Rings with Bounded Inversion

Abstract

An element in a ring is called clean if it may be written as a sum of a unit and idempotent. The ring itself is called clean if every element is clean. Recently,Anderson and Camillo (Anderson,D. D.,Camillo,V. (2002). Commutative rings whose elements are a sum of a unit and an idempotent. Comm. Algebra 30(7):3327–3336) has shown that for commutative rings every von-Neumann regular ring as well as zero-dimensional rings are clean. Moreover,every clean ring is a pm-ring,that is every prime ideal is contained in a unique maximal ideal. In the same article,the authors give an example of a commutative ring which is a pm-ring yet not clean,e.g.,C(?). It is this example which interests us. Our discussion shall take place in a more general setting. We assume that all rings are commutative with 1.     

Exchange rings in which all regular elements are one-sided unit-regular

Let R be an exchange ring in which all regular elements are one-sided unit-regular. Then every regular element in R is the sum of an idempotent and a one-sided unit. Furthermore, we extend this result to exchange rings satisfying related comparability.     

A Property Satisfying Reducedness over Centers

This article concerns a ring property called pseudo-reduced-over-center that is satisfied by free algebras over commutative reduced rings.The properties of radicals of pseudo-reduced-over-center rings are investigated,especially related to polynomial rings.It is proved that for pseudo-reduced-over-center rings of nonzero characteristic,the centers and the pseudo-reduced-over-center property are preserved through factor rings modulo nil ideals.For a locally finite ring R,it is proved that if R is pseudo-reduced-over-center,then R is commutative and R/J(R) is a commutative regular ring with J(R) nil,where J(R) is the Jacobson radical of R.     

具有对合运算的$n$-clean环

A *-ring is called *-clean if every element of the ring can be written as the sum of a projection and a unit. For an integer n ≥ 1, we call a *-ring R n-*-clean if for any a ∈ R,a = p + u1 + ··· + unwhere p is a projection and ui are units for all i. Basic properties of n-*-clean rings are considered, and a number of illustrative examples of 2-*-clean rings which are not *-clean are provided. In addition, extension properties of n-*-clean rings are discussed.     

分次Abel正则环的结构

首先给出了 gr-正则环为分次除环的两个充要条件 ,其次讨论了分次正则环r G(R)和分次 Jacobson根 JG(R)之间的关系 ,最后给出了分次 Abel正则环的结构定理 .     

On Rings Whose Elements are the Sum of a Unit and a Root of a Fixed Polynomial

A ring R with identity is called “clean” if for every element a ? R there exist an idempotent e and a unit u in R such that a = e + u. Let C(R) denote the center of a ring R and g(x) be a polynomial in the polynomial ring C(R)[x]. An element r ? R is called “g(x)-clean” if r = s + u where g(s) = 0 and u is a unit of R and R is g(x)-clean if every element is g(x)-clean. Clean rings are g(x)-clean where g(x) ? (x ? a)(x ? b)C(R)[x] with a, b ? C(R) and b ? a ? U(R); equivalent conditions for (x² ? 2x)-clean rings are obtained; and some properties of g(x)-clean rings are given.     

Regularity and Related Rings

A ring R is a Garcia ring provided that the product of two regular elements is unit-regular. We prove that every regular element in a Garcia ring R is the sum/difference of an idempotent and a unit. Furthermore, we prove that every regular element in a weak Garcia ring is the sum of an idempotent and a one-sided unit. These extend several known theorems on (one-sided) unit-regular rings to wider classes of rings with sum summand property.     

On Strongly Clean Matrix and Triangular Matrix Rings

A ring R with identity is called “clean” if every element of R is the sum of an idempotent and a unit, and R is called “strongly clean” if every element of R is the sum of an idempotent and a unit that commute. Strongly clean rings are “additive analogs” of strongly regular rings, where a ring R is strongly regular if every element of R is the product of an idempotent and a unit that commute. Strongly clean rings were introduced in Nicholson (1999 Nicholson , W. K. (1999). Strongly clean rings and Fitting's lemma. Comm. Algebra 27:3583–3592. [CSA] [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) where their connection with strongly π-regular rings and hence to Fitting's Lemma were discussed. Local rings and strongly π-regular rings are all strongly clean. In this article, we identify new families of strongly clean rings through matrix rings and triangular matrix rings. For instance, it is proven that the 2 × 2 matrix ring over the ring of p-adic integers and the triangular matrix ring over a commutative semiperfect ring are all strongly clean.