共查询到20条相似文献,搜索用时 140 毫秒
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肖艳艳 《纯粹数学与应用数学》2013,(6):615-620
在双扭Hopf代数上引入分次理想与分次子余代数的概念,研究局部有限的双扭Hopf代数的分次理想,给出局部有限的双扭Hopf代数的分次子空间是分次理想的一个充分必要条件. 相似文献
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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. 相似文献
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关于二元函数在一点的全微分存在的判别条件,一般教科书都是要求两个一阶偏导数在该点处连续(参见[1])。文献[2]削弱了这个条件,只要求其中一个一阶编导在该点处连续,文献[3]给出了全微分存在的另一个条件:要求两个一阶偏导数在该点的一个邻域内存在(但不要连续),及在邻域内至少存在一个有界的二阶混合偏导数。容易说明,〔2〕、〔3〕中判别条件的适用范围并不完全一样.从而〔2〕、〔3〕给出的都只是充分条件而非必要条件.讫今为止,尚未见到关于全微分存在的充分必要条件.本文将偏导数和全微分联系考虑,得到一个全微分存在的充分必要条件.作为这个充要条件的推论,可立即得出〔2〕、〔3〕中的判别条件. 相似文献
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阿贝尔群的完整子半群的若干结果 总被引:3,自引:0,他引:3
本文证明了无扭阿贝尔群G是唯一线性序的,当且仅当G的每一个完整子半群只含唯一的极小完整子半群。若群G的每一个完整子半群只含有限多个极小完整子半群,则G中所有完整子半群组成的集T(G)满足DCC。 相似文献
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Conjugacy classes in the free group on two generators which have the same trace for all two-dimensional representations form
a trace class. The number of classes in a trace class is called the stable multiplicity of the trace class. We prove a condition
for the stable multiplicity to be minimal, and suggest a necessary and sufficient condition. 相似文献
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《Quaestiones Mathematicae》2013,36(3):301-315
ABSTRACT In this paper we investigate the following two classes of left R-modules: N(P) ={A|A has no non-zero direct summand P ε P} and H(p) = {A} if B ? A with B ε N(P), then B = 0}, where P is a class of projective R-modules. We demonstrate that N(p) is, in general, not a torsion class but that H(P) is always a torsionfree class. We also investigate those classes P and rings R for which N(P) is the largest non-trivial torsion class of R-modules. 相似文献
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本文应用最小中心多项式给出了体上代数矩阵的素有理标准形与初等因子组的构造,由此得到体上代数矩阵相似的充要条件以及相似于一个对角矩阵的充要条件.本文还讨论了体上矩阵的左、右特征值的构造与性质. 相似文献
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In the study of symmetry classes of tensors, finding examples of symmetry classes of tensors that possess an o*-basis is of considerable interest. There are only few classes of groups that have been provided a necessary and sufficient condition for having such a basis. There is no general criterion for any finite group yet. In this note, we provide a necessary and sufficient condition for the existence of o*-basis of symmetry classes of tensors associated with semi-direct product of some finite abelian groups and, consequently, their wreath product. 相似文献
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Yao Musheng 《数学年刊B辑(英文版)》1994,15(1):1-8
HOMOLOGICAL PROPERTIES OF TORSION CLASSES UNDER CHANGE OF RINGS ¥YAOMUSHENGAbstract:LetRbearingwithidentity,xbeacentralelemen... 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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张无畏 《高校应用数学学报(A辑)》1999,14(1):2
本文研究了两类分段对称系统周期解的存在性,得到了系统相应的周期解存在的充分条件.作为应用,证明了一类具有分段对称性的时滞微分方程的周期解的存在性,推广了现有的相关结果. 相似文献
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Christophe Mourougane 《Mathematische Annalen》2006,335(1):221-247
Using different forms of the arithmetic Riemann-Roch theorem and the computations of Bott-Chern secondary classes, we compute
the analytic torsion and the height of Hirzebruch surfaces. 相似文献
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We study an invariant of a 3-manifold which consists of Reidemeister torsion for linear representations which pass through a finite group. We show a Dehn surgery formula on this invariant and compute that of a Seifert manifold over S2. As a consequence we obtain a necessary condition for a result of Dehn surgery along a knot to be Seifert fibered, which can be applied even in a case where abelian Reidemeister torsion gives no information. 相似文献
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本文研究有限群元素共轭类的平均长度问题.利用初等群论方法和有限群特征标理论,在共轭类平均长度为某一定数时,获得了对有限群结构的刻划,且对有限群数量性质的研究是有意义的. 相似文献