关于型为L_2(p)的单K_4-群的一个新刻画（英文）

设G是型为L_2(p)的单K_4-群,其中p是不等于2~n-1的素数,σ_1(G)表示群G的最高阶元素的阶.本文证明了该类单K_4-群能被其阶|G|和最高阶元素的阶σ_1(G)唯一确定.所谓K_4-群指的是阶刚好含4个不同素因子的群.     

K_(1,4)-受限图的最长路

图G中同构于K_(1,p)的子图叫G的p-爪(p≥3).如果G中任意一个p-爪中1度顶点之间边(在G中的边)的数目≥p-2,则称G为K(1,p-)-受限图,它是无爪图(p=3)时的推广.本文证明了:连通的K_(1,4-)受限图G,若|G|≥7,则G有Hamilton路或有长至少为2δ+2的路.     

一些集的基数(Ⅸ)

Let X be an infinite set, C={G:G is a group defined on the X}, Define {H:H is isomorphic to G}, C_2={C & G js not commutative},then |C_2|=2 If K={F:F is a division ring defined on the X},K_1={K & F is not com mutative}, K_2={K & F is commutative},then |K_1| [ = IK2t --2:s~. Suppose T(X) {X~X & qψis bijective},S={G:G is a subgroup of T(X)},S_1={S & G is commutative}, S_2={S & G is not commutative},then |S_1|=|S_2|=2~(2~(|x|)).     

含p^n—2阶元的P^n阶p—群的自同构群

一个有限p-群G称为一个LA-群,如果当G是非循环的且|G|>p~2时有|G|/|Aut(G)|,本文证明了一个含有p~(n-2)阶元的p~n阶p-群是一LA-群。     

单K_3-群的新刻画（英文）

本文研究了sn(G)对单K_3-群的影响.通过对有限群G的子群和主因子的分析,给出了单K_3-群的一个刻画,结果如下:如果|G|=p~2qr且sn(G)={r,,pr,pq},这里pqr为不同素数,那么G≌A_5.类似的结论对其它单K_3-群都成立.     

图类αK_(α,α)UβCP(b)中的一类特殊整谱图

图G是一个简单,图G的补图记为G,如果G的谱完全由整数组成,就称G是整谱图,鸡尾酒会图CP (n)=K_(2n)-nK_2(K_(2n)是完全图)和完全二部图K_(a,a)都是整谱图.u_1表示图类αK_(α,α)UβCP(b)的一个主特征值,本文确图了当u_1=2b 1时,图类αK_(α,α)UβCP(b)中的所有的整谱图.     

无$K_{1,4}$子图的图的路覆盖

For a graph G, a path cover is a set of vertex disjoint paths covering all the vertices of G, and a path cover number of G, denoted by p(G), is the minimum number of paths in a path cover among all the path covers of G. In this paper, we prove that if G is a K_(1,4)-free graph of order n and σ_(k+1)(G) ≥ n-k, then p(G) ≤ k, where σ_(k+1)(G) = min{∑v∈S d(v) : S is an independent set of G with |S| = k + 1}.     

偶图Kn,r-A(|A|≤3)的圈长分布唯一性

阶为n的图G的圈长分布是序列(c_1,c_2,…,c_n),其中c_i是图G中长为i的圈数。设A(?)E(K_(n,r))。本文得到如下结果：若|A|=2,且n≤r≤min{n 6,2n-5),则G=K_(n,r)-A是由它的圈长分布确定的；若|A|=3,且n≤r≤min{n 6,2n-7),则G=K_(n,r)-A也是由它的圈长分布确定的。     

不含三角形的某些禁用子图的色数（英文）

Gyarfas曾猜想:对于一个给定的森林F,存在一个整数函数f(F,ω(G)),满足对任何一个不含F的图G有x(G)≤f(F,ω(G)),其中x(G)和ω(G)分别表示图G的色数和团数.令扫帚图B(m,n)表示将路P_m中的一个度为1的顶点和星K_(1,n)的中心点重合在一块所得到的阶为m+n的树.本文证明了:如果G是一个不含三角形且不含B(m,n)作为导出子图的图,则有x(G)≤m+n-1;对于一个给定的树T,证明了如果G是一个不含三角形且不含C_4和T作为导出子图的图,则有x(G)≤|T|-1.     

一类p-群的自同构群的阶

设 P 为奇素数,P~4阶群 G(121)=,a~p=b~p=c~p=d~p=1,[b,d]=a,[c,d]=b.本文给出了 G/Z(G)≌G_(121),Z(G)循环的群 G 的完全分类,并给出其中一些群的自同构群的阶,它们是自同构群的阶为 p~n 的p~(n-1)阶群,n≥6.从而完整地得到了:对一切奇素数 p,存在群 G 使|A(G)|=p~n 的最小 n 是6.     

$p$-子群具有$p$-超可解正规化子的有限群

在已有研究中,对于$p$-子群的正规化子而言,它的$p$-幂零性质对有限$p$-幂零群的结构具有重要的影响. 本文中, 设$P$是群$G$的西罗$p$-子群, $1\leq p^d<|P|$, 对于$P$的每个阶为$p^d$的正规子群$H$H,将$N_G(H)$的$p$-幂零性质减弱为$p$-超可解性质,结合$H$的弱$M$-可补充性质,探究$p$-超可解群的结构.同时,在$N_G(P)$是$p$-幂零的条件下,利用子群$K$的弱$M$-可补充条件研究群的$p$-幂零性质,其中$K_p\leq K$且$P''\leq K_p\leq \Phi(P)$. $K_p$是$K$的西罗$p$-子群.在一定程度上,主要结果推广了Frobenius定理.     

On Centralizer Subalgebras of Group Algebras

Let $G$ be a finite group, $H ≤ G$ and $R$ be a commutative ring with an identity $1_R$. Let $C_{RG}(H) = \{ α ∈ RG|αh= hα$ for all $h ∈ H \}$, which is called the centralizer subalgebra of $H$ in $RG$. Obviously, if $H = G$ then $C_{RG}(H)$ is just the central subalgebra $Z(RG)$ of $RG$. In this note, we show that the set of all $H$-conjugacy class sums of $G$ forms an $R$-basis of $C_{RG}(H)$. Furthermore, let $N$ be a normal subgroup of $G$ and $γ$ the natural epimorphism from $G$ to $\overline{G}= G/N$. Then $γ$ induces an epimorphism from $RG$ to $R\overline{G}$, also denoted by $γ$. We also show that if $R$ is a field of characteristic zero, then $γ$ induces an epimorphism from $C_{RG}(H)$ to $C_{R\overline{G}}(\overline{H})$, that is, $γ(C_{RG}(H)) = C_{R\overline{G}}(\overline{H})$.     

由圈长分布确定的二部图~$K_{n,n r}-A\ (|A|\leq 3)$

The cycle length distribution of a graph G of order n is a sequence （c1 （G）,…, cn （G））, where ci （G） is the number of cycles of length i in G. In general, the graphs with cycle length distribution （c1（G） ,…,cn（G）） are not unique. A graph G is determined by its cycle length distribution if the graph with cycle length distribution （c1 （G）,…, cn （G）） is unique. Let Kn,n＋r be a complete bipartite graph and A lohtaib in E（Kn,n＋r）. In this paper, we obtain： Let s 〉 1 be an integer. （1） If r = 2s, n 〉 s（s - 1） ＋ 2｜A｜, then Kn,n＋r - A （A lohtain in E（Kn,n＋r）,｜A｜ ≤ 3） is determined by its cycle length distribution; （2） If r = 2s ＋ 1,n 〉 s^2 ＋ 2｜A｜, Kn,n＋r - A （A lohtain in E（Kn,n＋r）, ｜A｜ ≤3） is determined by its cycle length distribution.     

环状硅酸盐图的友好指数集

Let G be a graph with vertex set V(G) and edge set E(G). A labeling f : V(G) →Z2 induces an edge labeling f*: E(G) → Z2 defined by f*(xy) = f(x) + f(y), for each edge xy ∈ E(G). For i ∈ Z2, let vf(i) = |{v ∈ V(G) : f(v) = i}| and ef(i) = |{e ∈ E(G) : f*(e) =i}|. A labeling f of a graph G is said to be friendly if |vf(0)- vf(1)| ≤ 1. The friendly index set of the graph G, denoted FI(G), is defined as {|ef(0)- ef(1)|: the vertex labeling f is friendly}. This is a generalization of graph cordiality. We investigate the friendly index sets of cyclic silicates CS(n, m).     

关于完全二部图$K_{4, n}$和$K_{n, n}$的点可区别 $IE$-全染色的一些注记

Let G be a simple graph.An IE-total coloring f of G refers to a coloring of the vertices and edges of G so that no two adjacent vertices receive the same color.Let C(u) be the set of colors of vertex u and edges incident to u under f.For an IE-total coloring f of G using k colors,if C(u)=C(v) for any two different vertices u and v of V(G),then f is called a k-vertex-distinguishing IE-total-coloring of G,or a k-VDIET coloring of G for short.The minimum number of colors required for a VDIET coloring of G is denoted by χ ie vt (G),and it is called the VDIET chromatic number of G.We will give VDIET chromatic numbers for complete bipartite graph K4,n (n≥4),K n,n (5≤ n ≤ 21) in this article.     

L7（3）与GL7（3）的OD-刻画

对于任意一个有限群G,令π（G）表示由它的阶的所有素因子构成的集合.构建一种与之相关的简单图,称之为素图,记作Γ（G）.该图的顶点集合是π（G）,图中两顶点p,g相连（记作p～q）的充要条件是群G恰有pq阶元.设π（G）={P₁,p2,…,p_x}.对于任意给定的p∈π（G）,令deg（p）:=|{q∈π（G）|在素图Γ（G）中,p～q}|,并称之为顶点p的度数.同时,定义D（G）:=（deg（p₁）,deg（p₂）,…,deg（p_s））,其中p₁2<…相似文献   

子群的S-条件置换性对有限群结构的影响

Let G be a finite group. Fix a prime divisor p of IGI and a Sylow p-subgroup P of G, let d be the smallest generator number of P and Ma（P） denote a family of maximal subgroups P1, P2 , Pd of P satisfying ∩^di=1 Pi = Ф（P）, the Frattini subgroup of P. In this paper, we shall investigate the influence of s-conditional permutability of the members of some fixed .Md（P） on the structure of finite groups. Some new results are obtained and some known results are generalized.     

关于有限群的S-半置换子群

Let d be the smallest generator number of a finite p-group P and let Md（P） = {P1,...,Pd} be a set of maximal subgroups of P such that ∩di=1 Pi = Φ（P）. In this paper, we study the structure of a finite group G under the assumption that every member in Md（Gp） is S-semipermutable in G for each prime divisor p of ｜G｜ and a Sylow p-subgroup Gp of G.     

一个关于平面图的K-(2,1)-全可选性的结果

设图$G$的一个列表分配为映射$L: V(G)\bigcup E(G)\rightarrow2^{N}$. 如果存在函数$c$使得对任意$x\in V(G)\cup E(G)$有$c(x)\in L(x)$满足当$uv\in E(G)$时, $|c(u)-c(v)|\geq1$, 当边$e_{1}$和$e_{2}$相邻时, $|c(e_{1})-c(e_{2})|\geq1$, 当点$v$和边$e$相关联时, $|c(v)-c(e)|\geq 2$, 则称图$G$为$L$-$(p,1)$-全可标号的. 如果对于任意一个满足$|L(x)|=k,x\in V(G)\cup E(G)$的列表分配$L$来说, $G$都是$L$-$(2,1)$-全可标号的, 则称$G$是 $k$-(2,1)-全可选的. 我们称使得$G$为$k$-$(2,1)$-全可选的最小的$k$为$G$的$(2,1)$-全选择数, 记作$C_{2,1}^{T}(G)$. 本文, 我们证明了若$G$是一个$\Delta(G)\geq 11$的平面图, 则$C_{2,1}^{T}(G)\leq\Delta+4$.