给出了ZP-内射维数以及ZP-平坦维数的定义,揭示了左ZP-内射维数l.zp.ID(R)=0及右ZP-平坦维数r.zp.FD(R)=0的环,即它们为非奇异环,并给出等价描述.讨论了环R的左ZP-内射维数l.zp.ID(R)≤n以及环R的右ZP-平坦维数r.zp.FD(R)≤n的等价刻画,证明了环R上的模类ZPI若满足单同态的上核封闭且l.zp.ID(R)
The notions of the ZP-injective dimensions and the ZP-flat dimensions are defined. It is shown that a ring R is left nonsingular if and only if l. zp. ID( R) = 0 if and only if r. zp. FD( R) = 0. Then the equivalent statements of l. zp. ID( R) ≤n and r. zp. FD( R) ≤n are studied. If ZPI is closed under cokernel of any monomorphism and l. zp. ID( R) 〈∞,then l. zp. ID( R) = r. zp. FD( R) = l. zp-id(_RR). Finally,it is proved that every quotient module of a ZP-injective left R-module is ZP-injective if and only if ZPI is closed under cokernel of any monomorphisms and l. zp. ID( R) ≤1.