关于由J-半单的亚直不可约环类所确定的刻划

On some characters of the upper radical determined by the class of all J - semisimple subdirectly irreducible rings

[1]中定义由J-半单的亚直不可约环类所确定的上根R,并给出了一个环为R-根环的几个等价条件。另给出了一些刻划,最后证明了对任意环A,R（An）=[R（A）]n.

The upper radical R determined by the class of all J-semisimple subdirectly irreducible rings is defined and some equivilent conditins are gived in[l], the author gives some character conditions and proves that for everyring A, R(An) = (R(A))n