On $ \sigma $ -Subnormality of Sylow Subgroups in a Finite Group

Siberian Mathematical Journal - Given an arbitrary partition  $ \sigma $ of the set of primes, we give some criteria for the $ \sigma $ -subnormality of a Sylow subgroup of...     

A New Characterization of Finite $ \sigma $ -Soluble $ P\sigma T $ -Groups

Siberian Mathematical Journal - We prove that  $ G $ is a finite $ \sigma $ -soluble group with transitive $ \sigma $ -permutability if and only if the following hold: (i) $ G $ possesses...     

Separated Lattices of Multiply $ \sigma $ -Local Formations

Siberian Mathematical Journal - Let $ n>0 $ and let $ \sigma=\{\sigma_{i}\mid i\in I\} $ be a partition of the set of all primes $ {��} $ . We prove that the lattice of all $ n...     

Intersections of Three Nilpotent Subgroups in a Finite Group

Siberian Mathematical Journal - We complete the proof of the theorem that any nilpotent subgroups  $ A $ , $ B $ , and  $ C $ of a finite group  $ G $ satisfy...     

有限群的$\Phi$-$\tau$-可补子群

假设$\tau$是一个子群算子, $H$是有限群$G$的一个$p$-子群. 令 $\bar{G}=G/H_{G}$且$\bar{H}=H/H_{G}$, 如果$\bar{G}$有一个次正规子群$\bar{T}$ 和一个包含于$\bar{H}$ 的$\tau$-子群$\bar{S}$满足$\bar{G}=\bar{H}\bar{T}$且$\bar{H}\cap\bar{T}\leq \bar{S}\Phi(\bar{H})$, 就称$H$是$G$的一个$\Phi$-$\tau$- 可补子群. 文章通过讨论群$G$的准素数子群的$\Phi$-$\tau$-可补性给出了超循环嵌入和$p$-幂零性的一些新的特征.     

关于数论函数$\sigma(n)$的一个注记

对于两个不相同的正整数$m$和$n$, 如果满足$\sigma(m)=\sigma(n)=m+n$, 则称之为一对亲和数, 这里$\sigma(n)=\sum_{d|n}d$.本文给出了$f(x,y)=x^{2^{x}}+y^{2^{x}}(x>y\geq{1},(x,y)=1)$不与任何正整数构成亲和数对的结论, 这里$x$,$y$具有不同的奇偶性, 即, 关于$z$的方程$\sigma(f(x,y))=\sigma(z)=f(x,y)+z$不存在正整数解.     

Periodic structure of $ \sigma $-permutations maps on In

Summary. We present a result concerning the periodic structure of certain maps on Iⁿ = [0,1]ⁿ which are called s \sigma -permutation maps. This structure resembles that given by the xarkovskii's ordering for continuous interval maps.     

On Intersections of $ \pi $ -Hall Subgroups in Finite $ D_{\pi} $ -Groups

Siberian Mathematical Journal - We give an example of a series of finite $ D_{\pi} $ -groups where for each group $ G $ in the series and its $ \pi $ -Hall subgroup $ H $ , the inequality $ H\cap...     

关于同余式$\sigma(n)\equiv 1\pmod n$

Let k ≥ 2 be an integer, and let σ(n) denote the sum of the positive divisors of an integer n. We call n a quasi-multiperfect number if σ(n) = kn + 1. In this paper, we give some necessary properties of them.     

Finite Groups with Prescribed $ \Phi $ -Simple Maximal Subgroups

Siberian Mathematical Journal - Given $ r\in\{2,3,5\} $ , we study the structure of finite non- $ r $ -decomposable groups whose every non- $ r $ -decomposable maximal subgroup is a  $...     

关于同余式$\sigma(n)\equiv 1\pmod n$, II

Let k ≥ 2 be an integer, and let a（n） denote the sum of the positive divisors of an integer n. We call n a quasi-multiperfect number if a（n） = kn ＋ 1. In this paper, we give some necessary properties of quasi-multiperfect numbers with four different prime divisors.     

Finite Groups with Solvable or $ \Phi $ -Simple Maximal Subgroups

Siberian Mathematical Journal - We study the structure of nonsolvable finite groups whose every nonsolvable maximal subgroup is $ \Phi $ -simple.     

无条件C的广义$\alpha \eta $}-单调性的判别标准

用$\alpha $和 $\eta $关于第一分量是仿射的且是斜对称的条件代替条件C, 得到如下结论: (1)如果一个函数的梯度是(严格)$\alpha \eta $-伪单调的,则该函数是(严格)伪$\alpha \eta $-不变凸的; (2)如果一个函数的梯度是拟$\alpha \eta $-单调的,则该函数是拟$\alpha \eta $-不变凸的.     

On $\mathfrak{F}_\tau$-$s$-Supplemented Subgroups of Finite Groups

Let $\mathfrak{F}$ be a non-empty formation of groups, $\tau$ a subgroup functor and $H$ a $p$-subgroup of a finite group $G.$ Let $\overline{G}=G/H_G$ and $\overline{H} =H/H_G.$ We say that $H$ is $\mathfrak{F}_\tau$-$s$-supplemented in $G$ if for some subgroup $\overline{T}$ and some $\tau$-subgroup $\overline{S}$ of $\overline{G}$ contained in $\overline{H},$ $\overline{H}\overline{T}$ is subnormal in $\overline{G}$ and $\overline{H} ∩ \overline{T} ≤ \overline{S}Z_{\mathfrak{F}}(\overline{G}).$ In this paper, we investigate the influence of $\mathfrak{F}_\tau$-$s$-supplemented subgroups on the structure of finite groups. Some new characterizations about solubility of finite groups are obtained.     

四阶整数辛群中扭元的共轭类

本文给出四阶整数辛群中扭元的全部共轭等价类.总共有55个不同的扭元等价类,它们的阶数分别是2, 3, 4, 5, 6, 8, 10, 12.没有其它阶的扭元.