模范畴上的包含性弱反射

本文在有单位元的结合环上,研究模范畴的完全子范畴上的弱反射,得出特殊模族上包含性弱反射存在的一个充分条件,从而对模性质的内在本质有着更深入的刻画.     

广义Frame与广义Frame的商

本文将frame、frame同态、商frame与核的概念在范畴意义下作推广,并且证明Frame范畴是广义Frame范畴的反射子范畴.进而讨论了一个广义frame A的商与A上核函子之间的关系.特别地,我们证明了A上全部核函子所构成的范畴N(A)是一个广义frame.     

p-除环上矩阵的幂的性质

该文讨论了Ａｂｅｌ范畴中态射的幂的性质。把这些性质用到ｐ－除环上的矩阵范畴,得到ｐ－除环上矩阵的幂的一些结论。     

左R-n模的范畴与Hom函子

正合列问题是同调代数的基本问题之一。在Abel范畴的同调代数中,先有核的概念再讨论正合列的概念。但,因n-予加法范畴不具有零对象,欲讨论正合列,对其引进拟核。本文对左R-n模的范畴_R~M_n~l讨论了与拟核相应的正合列;把Hom函子推广到_R~M_n~l上,讨论了它关于拟正合列、弱双积、正向系统的正向极限的不变性。至于对带终对象的范畴的正合列的讨论我们将在中进行。     

可除Quantale的一些范畴性质

证明了GL-幺半群范畴是可除单位Quantale范畴的满反射子范畴,并且可除单位Quantale范畴是可除Quantale范畴的满反射子范畴。进而可知,GL-幺半群范畴是可除Quantale范畴的满反射子范畴。     

L-fuzzy模范畴中的极限

本文给出了L-fuzzy模范畴中的极限有点式和无点式刻画,讨论了L-fuzzy模范畴中极限的存在性、唯一性和结构性定理,并得到了极限函子与常量系统函子的伴随性。     

关于加法范畴上的两个猜测

本文继文［１］在加法范畴上引进左Ｚｏｒｎ条件、Ｋ－商范畴等概念，讨论范畴上的Ｋｏｔｈｅ猜测与Ｈｅｒｅｔｅｉｎ猜测，得到两个猜测成立的充要条件，并同时得到环论上的一个新结果和两个猜测成立的条件．这个条件改进了文［３］中的条件．     

加权射影线上的tilting对象和cluster-tilting对象

本文在加权射影线相关的范畴中讨论tilting对象与cluster-tilting对象之间的关系,证明当亏格为1时,向量丛稳定范畴中的tilting对象与相应的cluster范畴中的cluster-tilting对象对应.特别地, cluster范畴中的cluster-tilting对象由加权射影线上凝聚层范畴中的tilting对象诱导.     

不分明化sp-拓扑空间及范畴FSPTop的拓扑性

基于连续逻辑值语义,研究了不分明化sp-拓扑空间,讨论了不分明化的sp-开集,sp-邻域,sp-闭包及sp-内部等性质,给出了不分明化sp-连续映射的概念,引入了范畴FSPTop,证明了范畴FSPTop是范畴Set上的拓扑范畴。     

Yoneda 范畴与线性拓扑空间

<正> 我们为了今后的需要想弄清拓扑代数上的拓扑模构成什么性质的范畴,以及在这种范畴上是否能建立同调代数的基本函子.[8]中讨论了在拓扑模范畴上建立 E_xt~n 与 Torn的问题,但他使用的是相对范畴,要求正合序列(?)-分裂,还有些数学工作者在讨论 Banach模时(例见[12],[13])也要加上类似的条件.但这种条件似乎不太自然.Palamodor 在[15]中引入了半 abel 范畴,但单靠半 abel 范畴本身的结构不足以得到 E_xt~n 函子,必须     

MORITA THEORY FOR ASSOCIATIVE RINGS

In this paper we develop a Morita theory for associative rings without identity using the categories CMod-R of modules M such that M ? Hom(R,M) and DMod-R of modules M such that M ? R ? M. This extends the main results of Morita theory to a wide class of rings, that properly includes the idempotent rings.     

矩阵环中的一类极大的广义的Armendariz子环

An associative ring with identity R is called Armendariz if, whenever （∑^m i=0^aix^i）（∑^n j=0^bjx^j）=0 in R[x],aibj=0 for all i and j. An associative ring with identity is called reduced if it has no non-zero nilpotent elements. In this paper, we define a general reduced ring （with or without identity） and a general Armendariz ring （with or without identity）, and identify a class of maximal general Armendariz subrings of matrix rings over general reduced rings.     

Latroids and their representation by codes over modules

It has been known for some time that there is a connection between linear codes over fields and matroids represented over fields. In fact a generator matrix for a linear code over a field is also a representation of a matroid over that field. There are intimately related operations of deletion, contraction, minors and duality on both the code and the matroid. The weight enumerator of the code is an evaluation of the Tutte polynomial of the matroid, and a standard identity relating the Tutte polynomials of dual matroids gives rise to a MacWilliams identity relating the weight enumerators of dual codes. More recently, codes over rings and modules have been considered, and MacWilliams type identities have been found in certain cases.

In this paper we consider codes over rings and modules with code duality based on a Morita duality of categories of modules. To these we associate latroids, defined here. We generalize notions of deletion, contraction, minors and duality, on both codes and latroids, and examine all natural relations among these.

We define generating functions associated with codes and latroids, and prove identities relating them, generalizing above-mentioned generating functions and identities.

     

Module categories with linearly ordered closed subcategories

In an earlier paper the first named authors investigated rings whose kernel functors are linearly ordered. The main tool for describing prop-erties of such rings was the filter of ideals associated to a kernel functor. In the present paper more generally closed module categories (i.e. closed under kernels, cokernels and direct sums) with linearly ordered closed sub-categories are studied. Properties of these categories are given and they are characterized by conditions on special objects, i.e. cogenerators or generators.     

模范畴Recollement的Koenig定理

Koenig定理描述了环的导出范畴允许recollement的一个充分必要条件.本文给出环的模范畴版本的Koenig定理及其应用.应用一是可以导出Morita等价定理,应用二是可以描述三角矩阵环与模范畴的recollement之间的密切联系.     

Non-Noetherian Cohen–Macaulay rings

In this paper we investigate a property for commutative rings with identity which is possessed by every coherent regular ring and is equivalent to Cohen–Macaulay for Noetherian rings. We study the behavior of this property in the context of ring extensions (of various types) and rings of invariants.     

四元数环与四元数函子

本文给出了交换环上的四元数环是除的两个充要条件，在环范畴的子范畴间定义子四元数函数子，并证明了它是一个正合函子，同时讨论了环类的遗传性，同态闭性在四元数函子下的变化情况。     

The prüfer rings that are endomorphism rings of artinian modules

In this paper we characterize the (commutative) Priifer rings that can be realized as endomorphism rings of artinian modules over arbitrary associative rings with identity (Theorem 4.7). This characterization is obtained by determining the structure of ∑-pure-injective modules over Prufer rings (Theorems 3.4 and 3.5)     

Arithmetical and semihereditary semigroup rings

In this paper conditions on the commutative ring R (with identity) and the commutative semigroup ring S (with identity) are found which characterize those semigroup rings R[S] which are reduced or have weak global dimension at most one. Likewise, those semigroup rings R[S] which are semihereditary are completely determined in terms of R and S.     

每一个元素都是左零因子之环

本文引进左(右)零因子环的概念,它们是一类无单位元的环.我们称一个环为左(右)零因子环,如果对于任何 $a \in R$,都有$r_R (a) \neq 0~(l_R(a)\neq 0)$,而称一个环为强左(右)零因子环,如果$r_R(R)\neq 0~(l_R(R)\neq 0)$.Camillo和Nielson称一个环$R$为右有限零化环(简称RFA-环),如果$R$的每一个有限子集都有非零的右零化子.本文给出左零因子环的一些基本例子,探讨强左零因子环和RFA-环的扩张,并给出它们的等价刻画.