共查询到17条相似文献,搜索用时 140 毫秒
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本论文考虑了所有强平坦右S-系是正则系的幺半群的刻画,证明了所有强平坦右S-系是正则S-系当且仅当S是右PSF幺半群并且S的每一个左coilpasible子幺半群包含左零元.该结果对Kilp和Knauer在文献[7]中的问题给出了一个新的回答. 相似文献
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本文引入了条件(wp),研究了其性质,建立了它与弱平坦性之间的联系,并利用其给出了某些幺半群的S-系范畴特征。 相似文献
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右消去幺半群、左正则带和左正则型A幺半群 总被引:2,自引:0,他引:2
本文利用右消去幺半群,左正则带建立了真左正则型A幺半群.在证明了任一左正则型A幺半群均有P-覆盖后,给出P-覆盖的结构. 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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本文引入了条件(PW),讨论了条件(PW)与条件(P)、条件(PE)之间的关系,刻画了幺半群上S-系的平坦性. 相似文献
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本文讨论所有循环平坦系满足条件(P)的幺半群的“元素--理想”特征问题,该问题至今仍未获解决,在S是左PSF幺半群的条件下,本文证明了所有循环平坦右S-系满足条件(P)当且仅当S的任意元x或者是右可消元,或者是右零元,当且仅当对S的任意真右理想I,或存在a∈I-Ia,或I中的所有元素均为右零元,该结果改进并推广了「4」、「7」、「8」、「15」中的部分结果。 相似文献
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正则左S-系是von Neumann正则半群的自然推广,逆左S-系是逆半群的自然推广.作为左逆半群的自然推广,本文引入了L-逆左系的概念,并用来刻画了几类幺半群,如左逆幺半群,逆幺半群,adequate幺半群等. 相似文献
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R. KHOSRAVI 《数学研究与评论》2012,32(4):392-398
In this paper we introduce a class of right S-acts called retractable S-acts which are right S-acts with homomorphisms into their all subacts. We also give some classifications of monoids by comparing such acts with flatness properties. 相似文献
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本文考虑拟内射、伪内射、核内射以及支内射S-系的性质,重点讨论这些广义内射S-系的上的线性方程组的性质.例如,A是核内射S-系当且仅当A的任意收缩核B上的任意A-相容线性方程组在B上是可解的;A是支内射S-系当且仅当同构于A的任一分支的S-系B上的任意A-相容线性方程组在B上是可解的.进而讨论了伪内射、核内射以及支内射S-系的融合余积的性质.最后给出了一个充分条件,基于此条件核内射和支内射S-系是等价的. 相似文献
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In this article we characterize monoids over which every right S-act has a strongly flat (condition (P)) cover. Similar to the perfect monoids, such monoids are characterized by condition (A) and having strongly flat (condition (P)) cover for each cyclic right S-act. We also give a new characterization for perfect monoids as monoids over which every strongly flat right S-act has a projective cover. 相似文献
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Richard Wiegandt 《Semigroup Forum》2006,72(2):312-328
After recapitulating the rudiments of the Kurosh-Amitsur
radical theory of S-acts, hereditary radicals are discussed.
The hereditary Hoehnke radical assignments r which designate a
Rees congruence r(A) to each S-act A, are the hereditary
Kurosh-Amitsur radical assignments.
Then the corresponding radical as well as semisimple classes are
characterized.
Equivalence classes of injective S-acts determine hereditary
torsion assignments t, these are just the hereditary Hoehnke
radicals, but the congruence t(A) of A need not be a Rees
congruence.
Torsion and torsionfree classes are characterized; several
hereditary torsion assignments may determine the same torsion
class which is always a radical class closed under taking subacts.
Examples show that a hereditary torsion assignment need not be a
hereditary radical. 相似文献
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GongZengtai 《数学研究》1994,27(1):77-82
In this paper, We give a varlational-type definition of (CnP) integrals. It is equivalent to the original definition of Perron-type and to the definition of Riemann-type, in this way the problem on definition of(CnP)′s Riemann-type has been solved completely. 相似文献