外FO-群

如果群G的所有真商群都是FO-群,但是群G本身不是FO-群,则称G为外FO-群,本文将给出外FO-群完全的结构描述.     

其真商群为满足极小条件的FO-群的群

本文利用外FA-群(JNFA-groups)的结果,给出了其真商群为满足极小条件的FO-群但它本身不具备这种性质的群的结构的满意的描述。     

真商群为s-自对偶群的有限p-群

如果有限群G的每个子群与G的某个商群同构,则称群G为s-自对偶群.如果s-自对偶群G的每个商群与G的某个子群同构,则称群G为自对偶群.本文分类了每个真商群均为s-自对偶群的有限p-群.作为推论,本文还分类了每个真截段均为s-自对偶群的有限p-群,每个真商群均为自对偶群的有限p-群,以及每个真截段均为自对偶群的有限p-群...     

拟极小外p-自同构不动点子群为p阶的p-群

阶为某素数p的方幂的自同构如果不是内自同构,则称其为外p-自同构.如果φ是群G的外p-自同构且o(φ)=p,其中φ是φ在Out(G)=Aut(G)/Inn(G)中的自然同态像,则称φ为群G的拟极小外p-自同构.设φ是有限p-群G的任意拟极小外p-自同构,给出了|C_G(φ)|≤p时G的结构.     

关于广义Dedekind群

如果群G的任意循环子群H满足|HG:H|≤p,其中p是素数,那么称G是C*(p)-群.若群G是有限C*(p)-p-群,则当p＞3时,该群的幂零类至多为2;若p=3,该群的幂零类至多为3,而且当cl(G)=3时,exp(G)=9;同时,若G与任意有限C*(p)-p群G × K直积是C*(p)-P-群G×K,则G是初等阿贝尔p-群.最后还对局部幂零的C*(p)-群进行了探讨.     

|A(G)|=26p2(p为奇素数)的有限Abel群G

本文根据有限Abel群G的自同构群A(G)的阶研究了群G的构造.利用有限交换群的一些性质,经过详细的理论推导,获得了|A(G)|=26p2(p为奇素数)的有限Abel群G的全部类型.     

一类可解T-群

有限群 G 叫作 T-群,如果在 G 中正规关系是传递的.有限群 G 叫作 Et-群,如果 G 的各个子群在 G 中是正规的或自我正规化的.Et-群是可解 T-群.本文分为四节.第一节,考察 Et-群的结构和性质,并给出 Et-群的两个判定定理.第二节,确定一切极小非 Et-群.第三节,确定二极大子群都是 Et-群的有限非可解群.最后一节,给出 PN-群的一个类似.PN-群是指每个极小子群都正规的有限群.     

子群的核平凡或正规闭包极大的有限p群

称有限p群G为ACT群,如果对每个交换子群H,其正规核HG=1或HG=H.又称p群G是CC群,如果对每个非正规交换子群H,有HG=1或HG在G中的指数为p.本文分类了ACT群和CC群.     

特征与可解性

本文研究了具有不可约特征x使得x(1)²=|G:Z(G)|成立的群G的可解性,并证明了:对于这样的群G,当|Irr(G)|≤4时,G是可解群;当4<|Irr(G)|≤6时,在某些条件下,G是有解群.     

最高阶元素个数不同的有限群

本文首先讨论了当群G的某r阶元素的集合M_(?)(G)只含两个元素时G的性质,然后给出了当群G的最高阶元素的集合M(G)只含两个元素时群G的一个刻划,最后得到了当|M(G)|为奇数或不大于4时,群G为超可解;当|M(G)|=2p,p为素数,G为可解群。     

幂零Hall π-子群的存在性

本文首先将Ｈａｌ定理推广为：设Ｎ为Ｇ的正规子群，若Ｎ为Ｅｎπ群，Ｇ／Ｎ为Ｄπ群，则Ｇ为Ｄπ群．在此基础上得到了群Ｇ为Ｅｎπ群的充要条件为：（１）Ｇ存在正规子群Ｎ，满足Ｎ及Ｇ／Ｎ为Ｅｎπ群；（２）对任意ｐ∈π，任意ｑ∈π ｛ｐ｝及任意ｐ 元素ｘ，ＣＧ（ｘ）含Ｇ的Ｓｙｌｏｗｑ 子群．另外，我们对非Ａｂｌｅ单群的情形也进行了一些讨论．     

U(4,Z)的自同构群(英文)

In this paper,the automorphism group of G is determined,where G is a 4 × 4 upper unitriangular matrix group over Z.Let K be the subgroup of AutG consisting of all elements of AutG which act trivially on G/G,G /ζG and ζG,then （i） InnG ■ K ■ AutG;（ii） AutG/K≌=G₁×D₈×Z₂,where G₁=(a,b,c|a⁴=b²=c²=1,a^b=a^-1,[a,c]= [b,c]=1 ;（iii） K/Inn G≌=Z×Z×Z.     

关于CAP-子群的一点注记（英文）

对于有限群G的每一主因子H/K来说,若G的子群L满足LH=LK或者L∩H=L∩K,则称L是G的CAP-子群.本文通过假设G的每个非循环Sylow子群P有一个子群D使得1〈｜D｜〈｜P｜,且P的所有阶为｜D｜和2｜D｜（若P是非交换2-群且｜P∶D｜〉2）的子群H是G的CAP-子群,得到G为p-幂零群的一个结果.     

On SS-quasinormal subgroups and the structure of finite groups

A subgroup H of a finite group G is said to be an SS-quasinormal subgroup of G if there is a subgroup B of G such that G = HB and H permutes with every Sylow subgroup of B. In this paper, we investigate the structure of a group under the assumption that every subgroup with order pm of a Sylow p-subgroup P of G is SS-quasinormal in G for a fixed positive integer m. Some interesting results related to the p-nilpotency and supersolvability of a finite group are obtained. For example, we prove that G is p-nilpo...     

p-Fitting子群的CAP-嵌入子群

群G的子群H称为G的CAP-嵌入子群,如果对于|H|的每个素因子p,存在G的某个CAP-子群K,使得H的某个Sylow p-子群也是K的一个Sylowp-子群.本文通过假定G的p-Fitting子群F_p(G)的某个Sylow p-子群的每个极大子群是G的CAP-嵌入子群,得到一些新的结果.     

Tamely uniform orders

The following two results are proven.

(i) Let G be a finitely generated torsion-free linear group. If every torsion-free section of G is an R-group, then G is soluble of finite rank. Conversely, if G has finite rank, then it has a subgroup of finite index, in which every torsion-free section is an R-group.

Let G be a finitely generated torsion-free soluble group. If in every torsion-free section of G the normalizer of each isolated subgroup is isolated, then G has finite rank. Conversely, if G has finite rank, then it has a subgroup K of finite index such that in every torsion-free section of K the normalizer of each isolated subgroup is isolated.     

The influence of X-semipermutability of subgroups on the structure of finite groups

Let A be a subgroup of a group G and X be a nonempty subset of G. A is said to be X-semipermutable in G if A has a supplement T in G such that A is X-permutable with every subgroup of T. In this paper, we investigate further the influence of X-semipermutability of some subgroups on the structure of finite groups. Some new criteria for a group G to be supersoluble or p-nilpotent are obtained.     

QUASI-PERMUTATION REPRESENTATIONS OF ALTERNATING AND SYMMETRIC GROUPS

The quantities c(G), q(G) and p(G) for finite groups were defined by H. Behravesh. In this article, these quantities for the alternating group An and the symmetric group Sn are calculated. It is shown that c(G) = q(G)=p(G) = n, when G = An or Sn.