给出Abel环的如下几个新刻画:1)R为Abel环当且仅当每个幂等元可唯一地表示为一个可逆元与一个幂等元之和;2)R为Abel环当且仅当对每个x∈R,存在正整数n=n(x)>1,使得x-x^n∈ZR()R;3)R为Abel环当且仅当对每个e∈E(R),x∈R,存在n=n(e,x)>1,使得xe-ex=(xe-ex)^n;4)R为Abel环当且仅当对每个x∈E(R),存在唯一的g∈N2(R),使得e=g+x,其中N2(R)={a∈R|a^2=0}.
In this paper, some new characterizations of Abelian rings are given. 1) A ring R is Abel if and only if every idempotent can be written uniquely as the sum of an unit and an idempotent 2) R is an Abelian ring if and only if for each xER, there exists an integer n=n(x)〉1 such that x-xn∈ ZE(R) 3) R is an Abelian ring if and only if for each e E∈(R) and each x ∈ R, there exists an integer n=n(e, x)〉1 such that xe-ex= (xe-ex)n 4) R is an Abelian ring if and only if for eacheEE(R) there exists a unique gEE(R) and unique x∈N2(R) such that e=g+x, where N2 (R)= {a∈R|a2 =0 }.