关于半正规的几类群

利用子群的半正规性讨论了几类有限群的结构,得到如下主要结果:(l)极大子群超可解的有限群当其极大子群的极小子群半正规时,它不是超可解群就是如下三种群之一:(I)p~αq~β阶内-Abel群,p(?)q-1;(Ⅱ)p^(α+β)r(?)阶群,α≥2,β≥0,p~β=│φ(G)│,p^(α-1)||r—1,α^((?)~α+β)=c_1^(?)=c_2^(?)=…=c_(?)^(?)=1,c_ic_j=c_jc_i,i,j=1,2,…,p,c_(?)^(?)=c_(i+1),i=1,2,…,p-1,c_(?)^(?)=c_1^(?),t(mod r)指数p^(α-1);(Ⅲ)D_(2_q)型群;(2)极大子群可解的非Abel有限单群当其二次极大子群的极小子群半正规时,G恰为A_5.

P-kernel Normal Systems in Weakly P-inversive Semigroups

In this paper, we first give the concept of weakly P-inversive semigroup S（P）. Then we describe the strong P-congruences on S（P） in terms of their P-kernel normal systems. It is proved that there is a bijection between the strong P-congruences and the P-kernel normal systems. Finally, it is also prove that the lattice of strong P-congruences and the lattice of P-kernel normal systems on S（P） are isomorphic.