Notes on Rings with Strong 2-Sum Property

A ring is said to satisfy the strong 2-sum property if every element is a sum of two commuting units.In this note,we present some sufficient or necessary conditions for the matrix ring over a commutative local ring to have the strong 2-sum property.

局部环及其扩张的强二和性质

称环R的元有强二和环性质如果它可以写成该环中两个可换单位的和。如果环R的每个元都有强二和性质,则称R为强二和环。局部环是非常重要的环类,局部环及其扩张在环论、模论和同调代数等的研究中都有非常重要的地位。本文首先给出了局部环是强二和环的一个刻画,然后研究了局部环的幂级数扩张、平凡扩张和矩阵扩张等的强二和性。

On weakly nil-clean rings

We obtain the structure of the rings in which every element is either a sum or a difference of a nilpotent and an idempotent that commute. This extends the structure theorems of a commutative weakly nil-clean ring, of an abelian weakly nil-clean ring, and of a strongly nil-clean ring. As applications, this result is used to determine the 2-primal rings R such that the matrix ring Mn（R） is weakly nil-clean, and to show that the endomorphism ring EndD（V） over a vector space VD is weakly nil-clean if and only if it is nil-clean or dim（V） = 1 with D Z3.

特征为2的素环上强保持k-交换性的映射

令R是特征为2,且含有非平凡幂等元与单位元的素环.假设f:R→R是满射,k=2,3.证明了,f满足[f(x),f(y)]k=[x,y]k=[[x,y]k-1,y]对所有元x,y∈R成立当且仅当存在映射μ:R→C和元λ∈C使得f(x)=λx+μ(x)对所有元x∈R成立,其中λk+1=1,C是R的扩展中心.

Two theorems on QF rings

It is proved that a left QF-2 ring R is QF if R is either an artinian strongly right bounded ring, or a finite strongly left bounded and left Kasch ring with Soc(RR) = Soc( RR).

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.

交换局部环上的强二和3×3矩阵（英文）

称环R的元有强二和性质,如果它可以写成环中两个可交换单位的和.如果环R的每个元都有强二和性质,则称环R为强二和环.本文研究了3×3阶矩阵环的两个子环L(R)和■(R)的强二和性质.证明了对一交换局部环R,L(R)是强二和环当且仅当R是强二和环当且仅当■(R)是强二和环.同时还证明了对一交换局部环R,它是强二和环当且仅当T_n(R)(n=2,3)的每个角环都是强二和环.