使用相关内射性对拟连续模的一个刻划

近二十年，许多环与模工作对拟投射模与拟内射模作了各种推广与研究。连续模与拟连续模就是拟内射模的一种推广，拟连续模要比连续模弱。在[2]，作对连续模与拟连续模做了深入的研究。在这篇章中，利用相关内射性给出了拟连续模的一个刻划。     

T拟内射模与TQI环

本文定义并刻划了Ｔ拟内射模与Ｔ拟内射包，证明了ＷＧ－ｃｏｃｒｉｔｉｃａｌＴ拟内射模的自同态环为正则非奇异右自内射环．最后讨论了Ｔ拟内射模与Ｔ内射模一致的环，即ＴＱＩ环．还给出了Ｇａｂｒｉｅｌ拓扑Ｇ中每个右理想Ｔ拟内射的几个等价条件     

关于拟GP-内射模

在本文中,我们定义了拟GP-内射模,并且得到了关于它的一些结果.这些结果总结了GP-内射环和拟P-内射模的一些结果.     

伪内射模与主伪内射模

本文研究了伪内射模与主伪内射模,它们分别是拟内射模与PQ-内射模的推广．伪内射模是对偶于伪投射模的．我们讨论了伪内射模与主伪内射模的性质及其自同态环,并得到了自同态环的Jacobson根的若干性质．     

拟极小内射模

本文给出了拟极小内射模的概念、刻画和性质,推广了极小内射环和P-拟内射模的一些性质.     

关于局部Noether模

本文证明了如下结果：左 Ｒ－模 Ｍ是局部 Ｎｏｅｔｈｅｒ模当且仅当σ［Ｍ］中的任意Ｍ－内射左Ｒ－模的直和是一个有限余生成左Ｒ－模和一个拟连续（或连续,直内射）左Ｒ－模的直和．     

关于拟p-内射模的一些研究(英文)

得到了关于拟p-内射模的一些结果,这些结果总结并且推广了p-内射环的一些结果.     

Ni-内射半模及其性质

主要引进了Ni-内射半模的概念,并结合环中N-内射模与半环中内射半模的性质,得到了关于Ni-内射半模的一些性质,这些性质是内射模与内射半模性质的推广.     

拟遗传代数的特征模与张量积

本文研究零关系拟遗传代数A的模范畴与其正合Borel子代数B的模范畴之间的联系.证明了正合Borel子代数B的诱导模范畴完全含于A的好模范畴, 即好模诱导好模. 特别, 设A是具有纯粹强正合子代数B的零关系拟遗传代数,则A的特征模是B的特征模通过正合函子-_BA的诱导模当且仅当内射B-模的诱导A-模作为B-模仍是内射的. 本文还证明了基拟遗传单列代数的正合Borel子代数是右单列的, 并且其特征模恰是它的正合Borel子代数的特征模的诱导模.     

F－V－环的广义内射性刻划

设Ｆ是含单位元的结合环Ｒ上的左Ｇａｂｒｉｅｌ拓朴，称Ｒ是Ｆ－Ｖ－环，如果商范畴（Ｒ，Ｆ）－Ｍｏｄ中的所有单对象都是内射对象。本文我们利用左Ｒ－模的ｖＮ－内射性及拟内射性给出Ｆ－Ｖ－环的特征刻划。     

第n根性质与根环

令E为 (MR)的自同态环 ,本文首先证明了MR 有第n根性质的充要条件是EE 有第n根性质 ,由此引进了根环的概念 ,并研究了根环的性质。特别地我们证明了如nA nB且A拟内射 ,则A B .     

On QB Endomorphism Rings

We study, in this article, QB endomorphism rings of quasi-projective modules by means of completions of diagrams. The dual problems for quasi-injective modules are also investigated.     

Principally quasi-injective modules

An R-module M is called principally quasi-injective if each R-hornomorphism from a principal submodule of M to M can be extended to an endomorphism of M. Many properties of principally injective rings and quasi-injective modules are extended to these modules. As one application, we show that, for a finite-dimensional quasi-injective module M in which every maximal uniform submodule is fully invariant, there is a bijection between the set of indecomposable summands of M and the maximal left ideals of the endomorphism ring of M

Throughout this paper all rings R are associative with unity, and all modules are unital. We denote the Jacobson radical, the socle and the singular submodule of a module M by J(M), soc(M) and Z(M), respectively, and we write J(M) = J. The notation N ?^ess M means that N is an essential submodule of M.     

纯奇点范畴中的Buchweitz定理

我们定义纯奇点范畴D_(psg)~b(R)为有界纯导出范畴D_(pur)~b(R)与纯投射模构成的有界同伦范畴K~b(■)的Verdier商,得到了纯奇点范畴D_(psg)~b(R)三角等价于相对纯投射模的Gorenstein范畴的稳定范畴■的一个充分必要条件.同时,还给出三角等价D_(psg)~b(R)≌D_(psg)~b(S)的充分条件,这里R和S都是环.     

Absolutely Pure Covers

Absolutely pure modules act in ways similar to injective modules. There are conditions on a ring which guarantee that the class of injective modules will be covering. In this article, we define conditions on the ring R which guarantee that the class of absolutely pure modules will be covering. These include R being left coherent, which we show implies a number of other necessary properties.     

Quasi-injective dimension

Following our previous work about quasi-projective dimension [11], in this paper, we introduce quasi-injective dimension as a generalization of injective dimension. We recover several well-known results about injective and Gorenstein-injective dimensions in the context of quasi-injective dimension such as the following. (a) If the quasi-injective dimension of a finitely generated module M over a local ring R is finite, then it is equal to the depth of R. (b) If there exists a finitely generated module of finite quasi-injective dimension and maximal Krull dimension, then R is Cohen-Macaulay. (c) If there exists a nonzero finitely generated module with finite projective dimension and finite quasi-injective dimension, then R is Gorenstein. (d) Over a Gorenstein local ring, the quasi-injective dimension of a finitely generated module is finite if and only if its quasi-projective dimension is finite.     

幺半群的内射类及投射类刻画

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．     

Injectives containihg no proper quasi-injective submodules

Let Q be a uniform quasi-injective right R-module Then Q has no proper quasi-injective submodules ≠ 0 if and only if every cyclic submodule is strongly prime. For certain rings a stronger condition is shown to hold, namely that every cyclic submodule is compressible.