共查询到18条相似文献,搜索用时 109 毫秒
1.
设S是幺半群.本文介绍并研究了正则右系的一个推广.一个右S-系A称为C(P)系,如果A的所有循环子系满足条件(P).本文证明了右C(P)系形成了右S-系的一个新的类,同时,C(P)性质为幺半群同调分类研究提供了新思路. 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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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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正则左S-系是von neumann正则半群的自然推广,逆左S-系是逆半群的自然扩广,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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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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认为S的每个元素都诱导了S-系上的一个一元运算,因此S-系是有限代数,泛代数中的所有概念都是适用的.定义了S-系的可半格化子集和S-系的子集的面,构建了逆半群上的S一系的内射壳.推广了有关文献中的结果. 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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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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设S,R是可分解半群.记US-FAct={sM∈S-Act|SM=M且SHoms(S,M)≌M],给出了范畴US-FAct与UR-FAct等价的刻划;S分别强Morita等价于一个夹层半群、局部单位半群、幺半群和群的条件;S是完全单半群当且仅当S强Morita等价于一个群且对任何指标集I,S SHoms(S,i∈I S)→i∈I S,s t·f→(st)f,是同构. 相似文献
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Let S be a semigroup with zero and an S-act be a centered left S-act. This paper is devoted to the study of chain conditions on PS-acts. We prove that a PS-act having finite decomposition has ACC (DCC) on all subacts if it has ACC (DCC) on essential subacts. Moreover, a PS-act with ACC (DCC) on essential subacts has ACC (DCC) on all subacts if and only if it has finite decomposition. We characterize the structure of a PS-act and generalize some results of the Goldie dimension and semisimple S-acts. 相似文献
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Haiyan Zhou 《代数通讯》2013,41(12):3842-3850
A ring R is called a left (right) SF-ring if all simple left (right) R-modules are flat. It is known that von Neumann regular rings are left and right SF-rings. In this article, we study the regularity of left SF-rings and we prove the following: 1) if R is a left SF-ring whose all complement left (right) ideals are W-ideals, then R is strongly regular; 2) if R is a left SF-ring whose all maximal essential right ideals are GW-ideals, then R is regular. 相似文献
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A Generalization of Regular Left Acts 总被引:1,自引:0,他引:1
Liu Zhongkui 《东北数学》1997,(2)
AGeneralizationofRegularLeftActs*)LiuZhongkui(刘仲奎)(DepartmentofMathematics,NorthwestNormalUniversity,Lanzhou,730070)J.Ahsan(D... 相似文献
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We characterize the ordered semigroups which are decomposable into simple and regular components. We prove that each ordered semigroup which is both regular and intra-regular is decomposable into simple and regular semigroups, and the converse statement also holds. We also prove that an ordered semigroup S is both regular and intra-regular if and only if every bi-ideal of S is an intra-regular (resp. semisimple) subsemigroup of S. An ordered semigroup S is both regular and intra-regular if and only if the left (resp. right) ideals of S are right (resp. left) quasi-regular subsemigroups of S. We characterize the chains of simple and regular semigroups, and we prove that S is a complete semilattice of simple and regular semigroups if and only if S is a semilattice of simple and regular semigroups. While a semigroup which is both π-regular and intra-regular is a semilattice of simple and regular semigroups, this does not hold in ordered semigroups, in general. 相似文献