On p-Cover-Avoid and S-Quasinormally Embedded Subgroups in Finite Groups

Let G be a finite group, p the smallest prime dividing the order of G and P a Sylow p-subgroup of G. If d is the smallest generator number of P, then there exist maximal subgroups P1, P2,..., Pd of P, denoted by Md（P） = {P1,...,Pd}, such that di=1 Pi = Φ（P）, the Frattini subgroup of P. In this paper, we will show that if each member of some fixed Md（P） is either p-cover-avoid or S-quasinormally embedded in G, then G is p-nilpotent. As applications, some further results are obtained.

A Note on s-quasinormally Embedded and c-supplemented Subgroups of Finite Groups

In this paper the influence of s-quasinormally embedded and c-supplemented subgroups on the p-nilpotency of finite groups is investigate and some recent results are generalized.

Some Generalized Normal Subgroups and p-nilpotency of Finite Groups

In this paper, the influence of s-semipermutable, c~#-normal, subnormally embedded and ss-quasinormal subgroups on the p-nilpotency of finite groups is investigated and some recent results are generalized.

On Nearly SS-Embedded Subgroups of Finite Groups

Abstract Let H be a subgroup of a finite group G. H is nearly SS-embedded in G if there exists an S-quasinormal subgroup K of G, such that HK is S-quasinormal in G and H∩ K≤HseG, where HseG is the subgroup of H, generated by all those subgroups of H which are S-quasinormally embedded in G. In this paper, the authors investigate the influence of nearly SS-embedded subgroups on the structure of finite groups.

c^＊-Quasinormally embedded subgroups of finite groups

Suppose that G is a finite group and H is a subgroup of G. H is said to be s-quasinormally embedded in G if for each prime p dividing │H│, a Sylow p-subgroup of H is also a Sylow p-subgroup of some s-quasinormal subgroup of G; H is called c^＊-quasinormally embedded in G if there is a subgroup T of G such that G = HT and HCqT is s-quasinormally embedded in G. We investigate the influence of c^＊-quasinormally embedded subgroups on the structure of finite groups. Some recent results are generalized.

有限群超可解性的新刻画

研究了-嵌入子群对有限群结构的影响。特别地,得到了有限群超可解性的一些新刻画,发展和推广了许多已知结论。

On weakly s-permutably embedded subgroups of finite groups （II）

Suppose that G is a finite group and H is a subgroup of G. H is said to be s-permutably embedded in G if for each prime p dividing ｜H｜, a Sylow p-subgroup of H is also a Sylow p-subgroup of some s-permutable subgroup of G; H is called weakly s-permutably embedded in G if there are a subnormal subgroup T of G and an s-permutably embedded subgroup Hse of G contained in H such that G = HT and H n T ≤ Hse. In this paper, we continue the work of [Comm. Algebra, 2009, 37： 1086-1097] to study the influence of the weakly s-permutably embedded subgroups on the structure of finite groups, and we extend some recent results.

On Nearly σ-Embedded Subgroups of Finite Groups

Let G be a finite group,σ={σi|i∈ I}be some partition of the set of all primes and σ(G)={(σi|σi∩ π(G)≠0}.We say that a subgroup H of G is nearly cr-cmbcdded in G if there exists a cr-permutable subgroup T of G such that H∩T is a<r-permutable subgroup of G and H C\T<HaeG^where Haec is the subgroup of H generated by all those subgroups of H which are cr-permutably embedded in G.In this paper,we study the structure of G under the condition that some given subgroups of G are nearly cr-embedded in G.Some known results are generalized.

s-Permutably embedded subgroups and p-supersolvable groups

Let G be a finite group,and H a subgroup of G.H is called s-permutably embedded in G if each Sylow subgroup of H is a Sylow subgroup of some s-permutable subgroup of G.In this paper,we use s-permutably embedding property of subgroups to characterize the p-supersolvability of finite groups,and obtain some interesting results which improve some recent results.

On s-Quasinormal and c-Normal Subgroups of a Finite Group

Let F be a saturated formation containing the class of supersolvable groups and let G be a finite group. The following theorems are shown： （1） G ∈ F if and only if there is a normal subgroup H such that G/H ∈ F and every maximal subgroup of all Sylow subgroups of H is either c-normal or s-quasinormally embedded in G; （2） G ∈F if and only if there is a soluble normal subgroup H such that G/H∈F and every maximal subgroup of all Sylow subgroups of F（H）, the Fitting subgroup of H, is either e-normally or s-quasinormally embedded in G.

次正规嵌入子群与有限群的p-幂零性

在P是群G的Sylowp-子群,其中p是|G|的一个素因子的条件下,证明G为p-幂零群当且仅当NG(P)为p-幂零群且下列条件之一成立:P的每个极大子群都在G中次正规嵌入;P的每个2-极大子群都在G中次正规嵌入.

有限群的C-正规子群

本文利用Ｃ＿正规子群对有限群的超可解性进行了研究，推广了已有的结果．

含有C＊-正规子群的有限群

设G为有限群,H是G的子群。称H是G的S-拟正规子群,如果对G的任意Sylow子群P,有HP=PH;称H是G的S-拟正规嵌入子群,若H的Sylow子群为G的某个S-拟正规子群的Sylow子群;称H是G的C*-正规子群,如果G有正规子群K使得G=HK且满足H∩K在G中是S-拟正规嵌入的。设d是p-群P的最小生成元个数。考虑P的d个极大子群构成的集合Μd(P)=P1,…,Pd且使得它们的交是P的Frattini子群Φ(P)。对Μd(P)中的群在满足C*-正规假设条件下群的结构进行了研究,并推广了最近的一些结论。

关于有限群的π-拟正规嵌入子群

设G是有限群,称G的子群H在G中π-拟正规嵌入,如果对于│H│的每个素因子p,H的Sylow p-子群也是G的某个π-拟正规子群的Sylow p-子群。利用极大(小)子群的π-拟正规嵌入性,得到了如下包含超可解群类和幂零群系的饱和群系的充分条件。1)设是包含超可解群类的一个饱和群系,且N是有限群G的一个正规子群使得G/N∈F。如果F*(N)的任意奇阶Sylow子群Q的所有极大子群均在NG(Q)中π-拟正规嵌入,F*(N)的Sylow2-子群的极大子群在G中π-拟正规嵌入,则G∈F。2)设是包含的一饱和群系,且H是有限群G的一个正规子群使得G/H∈。如果H的极小子群或4阶循环子群均在G中π-拟正规嵌入,则G∈F。推广并加深了一些已知结果。

某些极大子群对有限群结构的影响

利用某些极大子群的π-拟正规性,得到了包含超可解群类的饱和群系的一个充分条件:设F是包含超可解群U类的一个饱和群系,且N是有限群G的一个正规子群使得G/N∈F.如果F*(N)的任意奇阶Sylow子群Q的所有极大子群均在NG(Q)中π-拟正规嵌入,F*(N)的Sylow2-子群的极大子群在G中π-拟正规嵌入,则G∈F.

有限群的素数幂阶S-拟正规嵌入子群

设G为有限p-可解群,其中p为|G|的奇素因子.若P为G的Sylow p-子群且最小生成系含d个元素.考虑集合M_d(P)={P_1,…,P_d},其中P_1,…,P_d是P的极大子群且满足(?)P_i=φ(P).证明了若M_d(P)中每个元在G中是S-拟正规嵌入的,则G为p-超可解群.作为应用,还得到了一些进一步的结论.

弱S-嵌入子群与有限群的超可解

群G的子群H被称为G的弱S-嵌入子群,是指存在G的正规子群T使得HT为G的S-可换子群且H∩T≤Hse,其中Hse是群G含于H的一个S-可换嵌入子群。研究了群G的某些素数幂阶弱S-嵌入子群对其超可解性的影响,同时也得到了关于饱和群系的几个新的刻画。

弱s~＊-拟正规嵌入子群对p-幂零群的影响

引入了弱s*-拟正规嵌入子群的概念,并利用弱s*-拟正规嵌入子群研究p-幂零群的构造,推广了最近的一些结果.

弱S-嵌入子群与有限群的p-幂零性

研究了群G的某些弱S-嵌入子群对其p-幂零性的影响,得到了几个新结果,同时也推广了原有的一些众所周知的结论.

顺序集合套与反模糊子群

本文利用顺序集合套给出了反Fuzzy子群的定义，并讨论了其基本性质。