群的遗传根性和强半单根性

本文利用群的根性的性质,解决了Szasz在环的根性理论中提出的公开问题在群论中的对应问题.同时我们研究了群的遗传根性和强半单根性的一些性质,并介绍了群的根类的交运算和并运算,由此得到了一些很好的结果.     

环的半单算子与半单类

设M是任意环类,u,ψ分别表示上根算子及半单算子。W.G.Leavitt在[1]中研究了uM成为遗传根的充要条件。本文将讨论ψM成为半单类,本质闭类,同态闭类或具有其它环类性质的一些等价条件。作为推论,最后给     

代数正规类中的遗传根与强半单根

Puczylowski建立了一般代数对象类的根理论.本文在代数正规类中,用格论方法刻划一般遗传根和强半单根类,探究它们的一些性质,推广了已知各类代数系统的某些根论研究.     

半单算子与半单类

1981年,W.G.Leavitt 深入地讨论了上根算子与根环类之间的关系(文〔1〕).但对于半单算子尚未见文献论述。本文考察了任一环类在半单算子作用下的状况。文中引进的(?)-可半单类在某种意义下可认为是〔1〕中 r-类的对偶;给出了(?)可半单类的刻划并利用上正则类考察了下根 L(M)的半单类。文中还给出半单算子作用下的环类 (?)M 成为遗传根和超幂零根的半单类的充要条件;得到了 U(?)M 是超幂零根的一个充分条件。     

半局部环的一个特征

给出了可换半局部环的一个外部特征，证明了Ｒ为半局部环当且仅当存在可逆Ｒ－模，其Ｔｏｐ为Ａｒｔｉｎ模．     

幂交半格上的交同余及其性质

给出了幂交半格上几个具体的交同余,证明了任意多个交同余的并是交同余,并指出幂交半格的交同余类是子交半格,介绍了幂交半格上由θ诱导的交同余具有保并性和保序性。     

σ-根与σ-半单类的构造

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．     

根偶与某些正则根的补根

本文讨论在什么条件下(α∶β)是根环类的问题,在假定α为优(Superior)根的条件下分别得出(α∶β)为根类,为遗传根类的充要条件,作为应用具体地给出双正则根,强正则根的补根.     

Distributive and Semihereditary Rings

Let A be a right and left distributive ring. For a positive integer n, we obtain a criterion of projectivity of all n-generated right ideals of the ring A and a criterion of the right semi-heredity of the ring A.__________Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 9, No. 1, pp. 253–258, 2003.     

On Semihereditary Maximal Orders

Let A be an order integral over a valuation ring V in a centralsimple F-algebra, where F is the fraction field of V. We showthat (a) if (V^h, F^h) is the Henselization of (V, F), then Ais a semihereditary maximal order if and only if A_VV^h is a semihereditarymaximal order, generalizing the result by Haile, Morandi andWadsworth, and (b) if J(V) is a principal ideal of V, then asemihereditary V-order is an intersection of finitely many conjugatesemihereditary maximal orders; if not, then there is only onemaximal order containing the V-order. 1991 Mathematics SubjectClassification 16H05.     

Finitely Presented Modules Over Semihereditary Rings

We prove that each almost local-global semihereditary ring R has the stacked bases property and is almost Bézout. More precisely, if M is a finitely presented module, its torsion part tM is a direct sum of cyclic modules where the family of annihilators is an ascending chain of invertible ideals. These ideals are invariants of M. Moreover, M/tM is a projective module which is isomorphic to a direct sum of finitely generated ideals. These ideals allow us to define a finitely generated ideal whose isomorphism class is an invariant of M. The idempotents and the positive integers defined by the rank of M/tM are invariants of M too. It follows that each semihereditary ring of Krull-dimension one or of finite character, in particular each hereditary ring, has the stacked base property. These results were already proved for Prüfer domains by Brewer, Katz, Klinger, Levy, and Ullery. It is also shown that every semihereditary Bézout ring of countable character is an elementary divisor ring.     

形式三角矩阵的PP和半遗传环(英文)

In this paper the sufficient and necessary conditions are given for a formal triangular matrix ring to be right PP, generalized right PP, or semihereditary, respectively.     

Rings of the Morita Contexts and Semihereditary Maximal V-Orders

Some necessary and sufficient conditions are given for rings of the Morita contexts to be semihereditary maximal V-orders, Prüfer rings and Dubrovin valuation rings.     

On Semihereditary and p.p. Monoid Rings

No Abstract. June 30, 1998     

A Note on Supplementing Radicals

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