最高阶元素个数为2p~2的有限群是可解群

本文讨论了最高阶元素个数 ｜Ｍ（Ｇ）｜＝ ２Ｐ２ （为素数）的有限群，证明了群 Ｇ是可解群     

关于一类自同构群

本文给出了所有Ｐ＾３阶（ｐ为素数）群的自同构群的结构。     

一类不能作为自同构群的奇阶群

本文考虑如下问题：怎样的有限群可以作为另一个有限群的全自同构群？我们首先证明，若有限群Ｋ有一个正规Ｓｙｌｏｗｐ－子群使得｜Ｋ：Ｚ（Ｋ）｜ｐ＝ｐ２，那么Ｋ有２阶自同构．利用这个结果，我们证明了，若奇阶群Ｇ具有阶Ｐｓｍ（１≤ｓ≤３），ｐ为｜Ｇ｜的最小素因子，ｐｍ，ｍ无立方因子，则Ｇ不可能作为全自同构群．     

自同构群是循环群被交换群扩张的有限群

设Ｃ是有限群，ＡｕｔＧ＝ＡＢ，，Ａ是交换群且每Ｓｙｌｏｗ子群的秩≤２，Ｂ是循环群，本文得出了Ｇ的结构，特别地，证明了ＡｕｔＧ是秩≤２的交换群时，Ｇ循环。     

非幂零极大子群指数为素数幂的有限群

本文证明了如下结果，１．设ｐ是一个素数，如果有限群Ｇ的每一非幂零的极大子群的指数都为ｐ的方幂，则Ｇ为可解群．２．如果有限群Ｇ的每一非幂零的极大子群的指数为素数幂，则Ｇ／Ｓ（Ｇ）１或ＰＳＬ（２，７），其中Ｓ（Ｇ）表示Ｇ的最大可解正规子群．     

内-FI群和外-FI群

若群Ｇ的同构子群类均是有限的，则称群Ｇ为ＦＩ群，本文分别研究了所谓的内－ＦＩ群和外－ＦＩ群的性质，给出了这两类无限群的令人满意的结构描述。     

自同构群

设Ｇ是有限群，ＡｕｔＧ＝ＡＢ，Ｂ△ＡｕｔＧ，（｜Ａ｜，｜Ｂ｜）＝１，Ａ是交换群且每Ｓｙｏｗ子群的秩≤２，Ｂ是循环群。本文得出了Ｇ的结构，特别地，证明了ＡｕｔＧ是秩≤的交换群时，Ｇ循环。     

关于n—可解群与n—幂零群的两个结果

本文证明了下面主要结果：设Ｇ是ｎ－可解群，π是一些素数之集，若对任意ｐ∈∩π（Ｇ），（ｐ，ｎ（１－ｎ））＝１，则Ｇ的π－Ｈａｌｌ子群的个数ｒ＝ｋ１ｋ２．．．ｋｔ，每ｋｉ≡１（ｍｏｄｐ），某Ｐ∈π，且每ｋｉ整除Ｇ的一个主因子。     

具有给定Sylow子群正规化子性质的有限群

本文首先给出了非正规Ｓｙｌｏｗ子群的正规化子完全可分的有限群上根的结构，然后对于完全可分群系和Ｈａｌｌπ－子群为幂零的可解群系Ｃπ，得到了：一个群Ｇ属于这种群系的充要条件是它的Ｓｙｌｏｗ子群的正规化子属于该群系．此外，还得到了一个有趣的定理：如果一局部群系具有这种Ｓｙｌｏｗ子群正规化子性质（即，若一个群Ｇ的所有Ｓｙｌｏｗ子群的正规化寻属于，则群Ｇ属于），那么对于任意素数ｐ，的极大内局部屏ｆ所对应的群系ｆ（Ｐ）也都一定具有这种性质．     

模糊群的模糊同态

引进模糊群的模糊同态概念，给出模糊同态下子模糊群(正规子模糊群)间的对应关系’建立模糊群的模糊同态基本定理，同时讨论模糊群的若干性质，得到一系列等价条件。     

一类不能作为自同构群的有限群

本文证明了阶小于ｐ９的有限交换ｐ－群不能作为有限群的自同构群，从而推进了ＭａｃＨａｌｅ的结果．     

On the Automorphism Groups of Affine-Invariant Codes.

Using the classification of finite simple groups, we obtain a condition for a permutation group on a finite field GF(pm) to have the affine group AGL(1,pm) as a subgroup. Applying this result to the automorphism groups of non trivial affine-invariant codes, we prove that these automorphism groups are always subgroups of the general affine group AGL(m,p).     

若干家族p-群的自同构群的阶

本文确定了Rodney James文章中P．Hall isoclinism族第一家族到第十家族所有群的自同构群的阶,并纠正了Rodney James文章里的某些错误．     

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.     

子群为拟正规或自正规的有限群

本文研究了每个子群为拟正规或自正规的有限群，给出了这类群的完全分类，主要结果为定理Ｇ的每个子群为拟正规或自正规当且仅当Ｇ为下列情形之一：Ⅰ）Ｇ为拟Ｈａｍｉｌｔｏｎ群，Ⅱ）Ｇ＝ＨＰ，其中Ｈ为Ｇ的正规ａｂｅｌｉａｎｐ＇－Ｈａｌｌ子群．Ｐ＝〈ｘ〉∈Ｓｙｌ＿ｐ（Ｇ）。〈ｘ￣ｐ〉＝Ｏ＿ｐ（Ｇ）＝Ｚ（Ｇ），ｘ在Ｈ上诱导Ｈ的一个ｐ阶无不动点的幂自同构．ｐ为｜Ｇ｜的最小素因子。由此定理可得文［１］所获得的定理。     

幂群与它的生成群

设г是G上的幂群,即以G的非空子集为元素,在G的子集的运算之下所成的群.P_1,P_2是这样的两个性质 P_1:对任意g∈G,存g∈G,存在A∈г,使得g∈A. P_2:对任意A,B∈г,如果A≠B,则A∩B=φ. 本文得出了群G上的幂群г分别具有性质P_1或P_2的充要条件.     

自同构群阶为prq~2的有限群

本文给出满足|Aut(G)|=prq~2,q>2的有限群 G的完全分类。     

On Some Groups with Finite Involution Saturated with Finite Simple Groups

In the paper, on the basis of the notion of saturation introduced in [1], we give a characterization of locally finite simple groups with an Abelian Sylow 2-subgroup in the classes of mixed and periodic groups. A part of the main results was announced in [2]. Theorem 2 of the paper generalizes results of [3, 4].     

Expansive Convergence Groups are Relatively Hyperbolic

Let a discrete group G act by homeomorphisms of a compactum in a way that the action is properly discontinuous on triples and cocompact on pairs. We prove that such an action is geometrically finite. The converse statement was proved by P. Tukia [T3]. So, we have another topological characterisation of geometrically finite convergence groups and, by the result of A. Yaman [Y2], of relatively hyperbolic groups. Further, if G is finitely generated then the parabolic subgroups are finitely generated and undistorted. This answer to a question of B. Bowditch and eliminates restrictions in some known theorems about relatively hyperbolic groups. Received: April 2007, Revision: May 2008, Accepted: August 2008