设R是一个含1的连通交换环,且R上每个幂等阵都相似于对角阵,Mn(R)表示环R上n×n矩阵全体.刻画了当2为R中的单位时,从M2(R)到Mm(R)(m=2,3)的保幂等加法映射形式.
Suppose R is a connected commutative ring with the multiplicative identity 1, and every idempotent matrix over R is similar to a diagonal matrix. The authors denote by Mn (R) the ring of all n × n matrices. The additive preservers of idempotence from M2 (R) to Mm (R) (m =2,3 ) are characterized when R is a unit in R.