关于l－群的半单结构

令Ｇ是一个ｌ－群，Ｇ的一个凸ｌ－子群Ａ叫做多余的，如果对Ｇ的任－凸ｌ－子群Ｗ，只要Ａ∨Ｗ＝Ｇ，就有Ｗ＝Ｇ．复令Ｒ（Ｇ）为Ｇ的所有多余凸ｌ－子群的集合并生成的凸ｌ－子群．我们证明了Ｒ（Ｇ）是ｌ－群Ｇ的一种报并且是在Ａｍｉｔｓｕｒ－Ｋｕｒｏｓｈ意义下的根．进一步我们得到了有限值ｌ－群的半单结构定理即Ｒ（Ｇ）＝０当且仅当Ｇｌ－同构于具有半单性的单ｌ－群的亚直积，同时我们还得到了一系列有意义的推论．     

关于l－群的半单结构

令Ｇ是一个ｌ－群，Ｇ的一个凸ｌ－子群Ａ叫做多余的，如果对Ｇ的任－凸ｌ－子群Ｗ，只要Ａ∨Ｗ＝Ｇ，就有Ｗ＝Ｇ．复令Ｒ（Ｇ）为Ｇ的所有多余凸ｌ－子群的集合并生成的凸ｌ－子群．我们证明了Ｒ（Ｇ）是ｌ－群Ｇ的一种报并且是在Ａｍｉｔｓｕｒ－Ｋｕｒｏｓｈ意义下的根．进一步我们得到了有限值ｌ－群的半单结构定理即Ｒ（Ｇ）＝０当且仅当Ｇｌ－同构于具有半单性的单ｌ－群的亚直积，同时我们还得到了一系列有意义的推论．     

格群的扭自由根式

格群的扭自由根式仝道荣（河海大学，南京２１００２４）我们利用［１，２］中的术语及符号。设Ｔ及Ｔ′分别为所有扭类自和所有扭自由类的集￣［３．４］．一个扭自由称作是遗传的，如果对任意的ｌ－，群Ｇ，蕴含着Ｇ／ＨＥ令Ｔ′为所有拟遗传扭自由类的集。定理１假定那...     

格序群的C-根类和K-根类

本文研究了Ｃ-根类（即凸ｌ－子群格可分辨根类）和Ｋ－根类．证明了：投射ｌ－群、强投射ｌ－群、两两分裂ｌ－群、Ｆ－群等许多ｌ－群类都是ｌ－子群格可分辨的,但Ｈａｍｉｌｔｏｎｌ－群不是;Ｃ－根类格是根类格的一个有伪补的闭子格,而且是根类半群的一个子半群．每个凸Ｏ一子群都是闭的,而且给出了由一簇Ｋ一根类及一个根类所生成的Ｋ－根类的形式．     

一个与G－分次环和G－集的Smash积有关的Maschke－Type定理

对任意群Ｇ，［１］研究了有单位元１的Ｇ－分次环与有限可迁Ｇ－集的Ｓｍａｓｈ积．在本文中，我们对任意可迁Ｇ－集Ａ讨论了具有局部单位元的Ｇ－分次环与Ｇ－集Ａ的Ｓｍａｓｈ积，证明了有关的一个Ｍａｓｃｈｋｅ－ｔｙＰｅ定理．推广了［２］［３］中的一些重要结果．     

有限群的内射子

设Ｆ为一个Ｆｉｔｔｉｎｇ类，Ｇ为一个有限群．本文证明了：如果Ｇ／ＧＦ为π（Ｆ）可解，则在Ｇ中有唯一的Ｆ内射子共轭类．     

Nest代数的Jacobson根的μ-核值保持映射

设算子代数Ａ　Ｂ（Ｈ），μ（Ａ）表示Ａ中的部分等距算子全体，若ｐ是Ａ到Ｂ（Ｈ）的线性映射，且对任意的ＵＥｕ（Ａ），有叫Ｕ）（ｋｅｃＵ）Ｇｒ“ｈＣｒ，则称　是Ａ上的μ－核值保持映射。本文将证明：Ｎｅｓｔ代数的Ｊａｃｏｂｓｏｎ根上的范数拓扑连续的μ－核值保持映射是广义内导子。     

一个与G—分次环和G—集的Smash积有关的Maschke—Type定理

对任意群Ｇ，〔１〕研究了有单位元１的Ｇ－分次环与有限可迁Ｇ－集的Ｓｍａｓｈ积，在本文中，我们对任意可迁Ｇ－集Ａ讨论了具有局部单元元的Ｇ－分次环与Ｇ－集Ａ的Ｓｍａｓｈ积，证明了有关的一个Ｍａｈｃｈｋｅ－ｔｙｐｅ定理，推广了〔２〕〔３〕中的一些重要结果。     

G-集分次模与Morita Context

对任意群Ｇ， Ｈ≤Ｇ，［１］研究了Ｇ－分次环Ｒ与有限可迁Ｇ－集的ｓｍａｓｈ积.在本文中我们对任意可迁Ｇ－集，讨论了一个关于Ｒ（Ｈ）与ｓｍａｓｈ积Ｒ＃Ｇ／Ｈ的Ｍｏｒｉｔａ ｃｏｎｔｅｘｔ，从而推广了［２］，［３］，［４］给出的关于Ｇ－分次环及其与群Ｇ的ｓｍａｓｈ积的一些重要结果．     

一类泛连通无爪图

本文证明了如果Ｇ是３连通无爪图，且Ｇ的每个导出子图Ａ，Ａ＋都满足（ａ１，ａ２），则Ｇ是泛连通图（除了当ｕ，ｖ∈Ｖ（Ｇ），ｄ（ｕ，ｖ）＝１时，Ｇ中可能不存在（ｕ，ｖ）－ｋ路外，这里２≤ｋ≤４）．     

某些中间图的邻点可区别E-全色数

设G（V,E）是简单连通图,T（G）为图G的所有顶点和边构成的集合,并设C是k-色集（k是正整数）,若T（G）到C的映射f满足：对任意uv∈E（G）,有f（u）≠f（v）,f（u）≠f（uv）,f（v）≠f（uv）,并且C（u）≠C（v）,其中C（u）={f（u）}∪{f（uv）｜uv∈E（G）}.那么称f为图G的邻点可区别E-全染色（简记为k-AVDETC）,并称χ_（at）~e（G）=min{k｜图G有k-邻点可区别E-全染色}为G的邻点可区别E-全色数.图G的中间图M（G）就是在G的每一个边上插入一个新的顶点,再把G上相邻边上的新的顶点相联得到的.探讨了路、圈、扇、星及轮的中间图的邻点可区别E-全染色,并给出了这些中间图的邻点可区别E-全色数.     

List Injective Coloring of Planar Graphs

Acta Mathematicae Applicatae Sinica, English Series - A k-coloring of a graph G is a mapping c: V(G) → {1, 2, ?, k}. The coloring c is called injective if any two vertices have a common...     

Factorization of mappings of topological spaces and homomorphisms of topological groups in accordance with weight and dimension ind

Symbols w(X), nw(X), and hl(X) denote the weight, the network weight, and the hereditary Lindelöf number of a space X, respectively. We prove the following factorization theorems.

1. Let X and Y be Tychonoff spaces, φ: X→Y a continuous mapping, hl(X)≤τ, and w(Y)≤τ. Then there exist a Tychonoff space Z and continuous mappings ψ: X→Z, χ: Z→Y such that φ=χ o ψ, Z=ψ(X), w(Z)≤τ andind Z≤ind X. Moreover, if nw(X)≤τ, then mapping ψ is one-to-one.
2. Let π: G→H be a continuous homomorphism of a Hausdorff topological group G to a Hausdorff topological group H, hl(G)≤τ and w(H)≤τ. Then there are a Hausdorff topological group G^* and continuous homomorphisms g: G→G^*, h: G^*→H so that π=h o g, G^*=g(G), w(G^*)≤τ andind G^*≤ind G. If nw(G)≤τ, then g is one-to-one.
3. For every continuous mapping φ: X→Y of a regular Lindelöf space X to a Tychonoff space Y one can find a Tychonoff space Z and continuous mappings ψ: X→Z, χ: Z→Y such that φ=χ o ψ, Z=ψ(X), w(Z)≤w(Y),dim Z≤dim X, andind ₀ Z≤ind ₀ X, whereind ₀ is the dimension function defined by V.V.Filippov with the help of G_δ-partitions. If we additionally suppose that X has a countable network, then ψ can be chosen to be one-to-one. The analogous result also holds for topological groups.
4. For each continuous homomorphism π: G→H of a Hausdorff Lindelöf Σ-group G (in particular, of a σ-compact group G) to a Hausdorff group H there exist a Hausdorff group G^* and continuous homomorphisms g: G→G^*, h:G^*→H so that π=h o g, G^*=g(G), w(G^*)≤w(H),dimG^*≤dimG, andind G^*≤ind G. Bibliography: 25 titles.

     

Unit and proper bitolerance digraphs

In this paper we prove that the following statements about a directed graph G→ are equivalent. (1) G→ is a unit bitolerance digraph, (2) G→ is a proper bitolerance digraph, and (3) the digraph obtained by reversing all arc directions of G→ is an interval catch digraph (also known as a point-core digraph). This result combined with known algorithms for recognizing interval catch digraphs, gives the first known polynomial-time algorithm for recognizing a class of (bi)tolerance digraphs. © 1997 John Wiley & Sons, Inc.     

On interior regularity and Liouville's theorem for harmonic mappings

It is well known that the weakly harmonic mapping U∶M→N (M,N: Riemannian manifolds) is regular if the image U(M) is contained in some sufficiently small ball and for this case Liouville's theorem is valid. In this paper we show that the smallness condition for U(M) can be released if U minimizes the energy functional and the sectional curvatures of the target manifold N are bounded by some suitable function of the distance from some fixed point of N.     

On the boundedness of topological categories

Let K be a complete and cocomplete category with a given proper (E,M)-factorization. K is called well-bounded if K is moreover bounded with a generator and cowellpowered with respect to the given factorization. Freyd-Kelly proved the following theorem about well-bounded categories: Let K be a well-bounded category and let Γ be a class of cylinders in the small category C¹, and let all but a set of these cylinders be cones. Then Γ(C,K) is a reflective subcategory of [C,K]. The main results of this paper are: (I) If F: K→L is a Top-functor and L is well-bounded, then K is well-bounded. (II) If U is an E-reflective subcategory of a well-bounded category,then U is again wellbounded. As a corollary one obtains for instance that all coreflective and all epireflective subcategories of the category of topological spaces are well-bounded.     

一类多重联图的邻点可区别E-全染色

设G（V,E）是一个简单图,k是一个正整数,f是一个V（G）∪E（G）到{1,2,…,k]．的映射．如果Au,v∈E（G）,则f（u）≠f（v）,f（u）≠f（uv）,f（v）≠f（uv）,C（u）≠C（v）,其中C（u）={f（u））U{f（uv）｜uv∈E（G））．称f是图G的邻点可区别E-全染色,称最小的数k为图G的邻点可区别B全色数．本文给出了星、路、圈间的多重联图的邻点可区别E-全色数．     

星扇轮联图的邻点可约边染色

对简单图G(V,E),若存在自然数κ(1≤κ≤Δ(G))和映射f:E(G)→{1,2,…,κ}使得对任意相邻两点u,v∈V(G),uv∈E(G),当d(u)=d(v)时,有C(u)=C(u),则f为G的κ-邻点可约边染色(简记为κ-AVREC of G),而x′_(aur)(G)=max{κ|κ-AVREC of G}称为G的邻点可约边染色数.其中C(u)={f(uv)|uv∈E(G)}.证明了联图在若干情况下的邻点可约边染色定理,得到了S_n+S_n,F_n+F_n,W_n+W_n,S_n+F_n,S_n+W_n和F_n+W_n的邻点可约边色数.