有限可解群的几个充分条件

该文首先讨论某些具有广义产ρ-幂零子群的有限群的可解性，推广了[1]，[2]的主要结果，然后讨论具有极小非ρ-幂零群作为其极大子群的有限群的可解性．     

关于可分群的若干结果

两个正规可解子群的乘积可解,但两个(超)可解子群(幂零子群)的乘积不一定是(超)可解(幂零)的。本文引入半正规与S—半正规的概念。讨论了两个(超)可解(幂零)子群的乘积的(超)可解(幂零)性。本文提到的群均为有限群。     

On the group with the same orders of Sylow normalizers as the finite projective special unitary group

In this paper we prove that a finite group G is isomorphic to the finite projective special unitary group Un(q) if and only if they have the same order of Sylow r-normalizer for every prime r.     

On Weakly Factorizable Groups

Groups with complemented subgroups, which are also called completely factorizable groups, were studied by P. Hall, S. N. Chernikov, and N. V. Chernikova (Baeva). For complete factorizability, it is sufficient (Theorem 1) that each proper subgroup have a normal complement in some larger subgroup. A group is said to be weakly factorizable if each of its proper subgroups is complemented in some larger subgroup; the problem of describing finite groups with this property is posed (Question 8.31) in the Kourovka Notebook. Some properties of these groups are considered. The question is studied for Sylow p-subgroups of Chevalley-type groups of characteristic p. The main theorem, Theorem 2, establishes the weak factorizability of the Sylow p-subgroups in the symmetric and alternative groups and in the classical linear groups over fields of characteristic p> 0, excluding the unitary groups of odd dimension > p.     

有限群可解的两个充要条件

利用Sylow 2-子群和Sylow 3-子群的c-可补性得到有限群成为可解的两个充要条件，推广了几个已知的定理．     

关于正规P—补

本短文得到的主要结果为:(1)设G为p-可解群,P∈Syl_p G,P循环,则G有正规p-补或GL有正规p-补.(2)设p为|G|的最小素因子,P∈Syl_pG,P正则或为Hamilton 2-群,则G有正规p-补的充要条件是对任意P的含Φ(P)且阶为p|φ(P)|的子群均在N_G(P)中类正规.     

弱C-正规子群与p-幂零群

称群G的一个子群H为弱C-正规的,如果存在G的次正规子群K,使得G=HK且H∩K≤HG,其中HG表示G包含在H中的最大的正规子群.利用子群的弱C-正规性得到有限群成为p-幂零群的一些充分条件.     

<Emphasis Type="Italic">c</Emphasis>-Semipermutable subgroups of finite groups

A subgroup is called c-semipermutable in G if A has a minimal supplement T in G such that for every subgroup T ₁ of T there is an element x ∈ T satisfying AT ₁ ^x = T ₁ ^x A. We obtain a few results about the c-semipermutable subgroups and use them to determine the structures of some finite groups.