摘要
A ring R is called semicommutative if for every α∈ R, rR （α） is an ideal of R. It is well-known that the n by n upper triangular matrix ring is not semicommutative for any ring R with identity when n ≥ 2. We show that a special subring of upper triangular matrix ring over a reduced ring is semicommutative.
称环R是半交换的,如果对任意a∈R,rR(a)是R的理想．若n≥2,则任意具有单位元的环R上的n阶上三角矩阵环不是半交换环．我们证明了reduced环上的上三角矩阵环的一类特殊子环是半交换环．
基金
the National Natural Science Foundation of China (10171082), TRAPOYT, and NWNUKJCXGC212
