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1.
关于l-群的半单结构 总被引:3,自引:0,他引:3
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. 相似文献
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关于l-群的半单结构 总被引:4,自引:0,他引:4
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. 相似文献
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类比于一般环上模的内射类,定义了幺半群上的S-系的内射类和投射类,并利用它们刻画了几类特殊的幺半群.证明了完全内射幺半群和完全拟内射幺半群是等价的.并且证明了对于标致幺半群S,它是完全投射的当且仅当它是完全拟投射的当且仅当它上面的投射S-系构成了一个投射类. 相似文献
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关于BCI—代数伴随半群中的可逆元 总被引:4,自引:0,他引:4
给出了BCI-代数的伴随半群中可逆元的刻划,说明BCI-代数的p-半单闭理想与其伴随半群的子群之间有一一对应关系,并证明最大的p-半单闭理想是根理想。 相似文献
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F.A.Szasz在[1]中提出公开问题55:设K是Jacobson根为零的全体亚直既约环类,研究类K确定的上根.本文对此进行了研究,证明了Jacobson根为零的全体亚直既约环类K确定的上根R是特殊根,它介于Jacobson根与Brown-McCoy根之间.并给出任意结合环A为R-根环的充要条件. 相似文献
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有限交换环上线性群的Carter子群 总被引:2,自引:0,他引:2
令R为有限交换局部环,K为其剩余类域.本文研究了R上一般线性群GLnR的Carter子群的存在性及结构.得到的结果是:若charK为奇数或K=F2,GLnR中存在唯一的Carter子群的共轭类,即Sylow-2子群的正规化子;若charK=2且|K|>2,GLnR中不含Carter子群. 相似文献
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结合环根论中由具有单位元的单环类所确定的上根就是Brown-McCoy根.本文指出在Γ-环中,鉴于Γ-环单位元的复杂性质使得有幺单Γ-环类确定的上根演变成8个,进而研究了这些根之间及这些根与Γ-环其它根之间的大小关系. 相似文献
9.
具有给定Sylow子群正规化子性质的有限群 总被引:5,自引:0,他引:5
郭文彬 《数学年刊A辑(中文版)》1994,(6)
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. 相似文献
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σ-根与σ-半单类的构造 总被引:1,自引:0,他引:1
继[1~3]分别给出σ-根及其半单类的两个特征性质,研究了对于已知环类M,含于M的最大σ-根及σ-半单类和包含M的最小σ-半单类的构造,同时得到σ-半单闭包σ-遗传的一个充分条件. 相似文献
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H. France-Jackson 《Acta Mathematica Hungarica》2002,93(3):249-251
Two special classes are said to be similar if they determine the same upper radical. A necessary and sufficient condition for a special radical to be generated by distinct similar special classes is given and all similar special classes generating a given special radical are described. 相似文献
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Throughout,allringsconsideredhaveanidentity,modulesareunitalleftmodulesandE(M)standsfortheinjectivehullofM.Now,letSbeaclassofmodules,thatisacollectionofR-modulessuchthatifM∈SthenanyR-moduleisomorphictoMbelongstoS.Wewillfreelyusethenotation,terminologyandresultsof[2].Recently,thereareanumberofwellknowntheoremswhichcharacterizeringsintermsofinjectiveandprojectivemodules(cf.[1],[3]and[4]).In[5,6]injectivityclassesandprojec-tivityclassesareintroducedandsimilarresultsremaintruewheninjectivity(… 相似文献
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Let
be a class of groups. The elementary class with base
is defined as the minimal class of groups containing
and closed with respect to taking subgroups, quotient groups, group extensions, and direct limits. Properties of such classes are studied. Some applications to the theory of elementary amenable groups and a relation to the Kurosh--Chernikov classes of generalized solvable groups are considered. 相似文献
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Marc Levine 《K-Theory》2003,30(2):129-135
We recall our construction of fundamental classes in the algebraic cobordism of smooth quasi-projective varieties, and show by example that it is not possible to extent this to fundamental classes, functorial for local complete intersection morphisms, for Cohen–Macaulay varieties. 相似文献
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GuiQiaoXU YongPingLIU 《数学学报(英文版)》2004,20(1):81-92
This paper concerns the problem of average σ-width of Sobolev-Wiener classes W^rpq(R^d),W^rpq(M,R^d),and Besov-Wiener classes S^rpqθb(R^d).S^rpqθB(R^d),S^rpqθb(M,R^d),S^rpqθB(R^d)in the metric Lq(R^d) for 1≤q≤p≤∞.The weak asymptotic results concerning the average linear widths,the average Bernstein widths and the infinite-dimensional Gel‘fand widths are obtained,respectively. 相似文献
18.
Gioan showed that the number of cycle reversing classes of totally cyclic orientations of a given graph can be calculated
as an evaluation of the corresponding Tutte polynomial. We note that the concept of cycle reversing classes of orientations
coincides with that of Eulerian-equivalence classes considered by Chen and Stanley, and Kochol. Based on this coincidence,
we give a bijective proof of Gioan’s result. Precisely, the main result of the paper is an algorithmic bijection between the
set of Eulerian-equivalence classes of totally cyclic orientations and the set of spanning trees without internally active
edges.
相似文献
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Let P be a linear partial differential operator with coefficients in the Gevrey class Gs. We prove first that if P is s‐hypoelliptic then its transposed operator tP is s‐locally solvable, thus extending to the Gevrey classes the well‐known analogous result in the C∞class. We prove also that if P is s‐hypoelliptic then its null space is finite dimensional and its range is closed; this implies an index theorem for s‐hypoelliptic operators. Generalizations of these results to other classes of functions are also considered. 相似文献