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1.
设R为环,t是左R-模范畴的一个遗传挠理论.文中证明了下述各点等价:(1)每个内射左R-模是t-平坦的;(2)每个t-有限表现左R-模的内射包络是t-平坦的;(3)每个t-有限表现左R-模是自由R-模的子模;(4)每个t-有限表现左R-模是自反的且其对偶模是H-有限生成的.  相似文献   

2.
F-V-环的广义内射性刻划   总被引:1,自引:0,他引:1  
刘仲奎 《数学学报》1995,38(2):200-206
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。  相似文献   

3.
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。  相似文献   

4.
T拟内射模与TQI环   总被引:2,自引:0,他引:2  
张顺华 《数学学报》1995,38(1):71-76
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  相似文献   

5.
李济凤 《工科数学》2000,16(1):21-24
献「1」中,Ming.R.Y.C引进了YJ-内射模的概念,且指出正则环上的每个模均是YJ-内射模,那么反之如何呢?「1」中做了一些结果,本拟就这个问题作进一步讨论。  相似文献   

6.
关于局部Noether模   总被引:2,自引:0,他引:2  
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.  相似文献   

7.
广义FP—内射模、广义平坦模与某些环   总被引:2,自引:0,他引:2  
左(右)R-模A称为GFP-内射模,如果ExtR(M,A)=0对任-2-表现R-模M成立;左(右)R-模称为G-平坦的,如果Tor1^R(M,A)=0(Tor1^R(AM)=0)对于任一2-表现右(左)R-模M成立;环R称左(右)R-半遗传环,如果投射左(右)R-模的有限表现子模是投射的,环R称为左(右)G-正而环,如果自由左(右)R-模的有限表现子模为其直和项,研究了GFP-内射模和G-平坦模的一些性质,给出了它们的一些等价刻划,并利用它们刻划了凝聚环,G-半遗传环和G-正则环。  相似文献   

8.
陈建龙 《数学季刊》1992,7(1):25-31
本文主要证明了:(1)适合右零化子升链条件的左A-内射环为QF环。(2)适合左零化子升链条件的左f-内射环为QF环。(3)若对环R的任意左理想A,B和右理想I满足r(A∩B)=r(A) r(B),rι(I)=I,则R为半完全环且有本质左基座,特别地,右CF的左A-内射环(或E(RR)为投射左R-模)为QF环。  相似文献   

9.
设 R是 G-分次,本文讨论了环 R的相关环 R,R# G*, Re, Q(R), RG, R*G及 R的正规化扩张S的非奇异性,右一致性,右基座之间的关系.当R是YJ-内射模时,证明了J(R)=Z(R)。  相似文献   

10.
本文给出了每个有限生成平坦模内射,既投射又内射的环类的刻划.给出了每个有限生成平坦模既投射又内射这一环类的分类  相似文献   

11.
Lixin Mao 《代数通讯》2013,41(5):1505-1516
In this article, we investigate when every simple module has a projective (pre)envelope. It is proven that (1) every simple right R-module has a projective preenvelope if and only if the left annihilator of every maximal right ideal of R is finitely generated; (2) every simple right R-module has an epic projective envelope if and only if R is a right PS ring; (3) Every simple right R-module has a monic projective preenvelope if and only if R is a right Kasch ring and the left annihilator of every maximal right ideal of R is finitely generated.  相似文献   

12.
Let R be a ring. A fight R-module M is called f-projective if Ext^1 (M, N) = 0 for any f-injective right R-module N. We prove that (F-proj,F-inj) is a complete cotorsion theory, where (F-proj (F-inj) denotes the class of all f-projective (f-injective) right R-modules. Semihereditary rings, von Neumann regular rings and coherent rings are characterized in terms of f-projective modules and f-injective modules.  相似文献   

13.
Characterizations of Strongly Regular Rings   总被引:9,自引:0,他引:9  
CharacterizationsofStronglyRegularRingsZhangJule(章聚乐)(DepartmentofMathematics,AnhuiNormalUniversity,Wuhu241000)Abstract:Inthi...  相似文献   

14.
Carl Faith 《代数通讯》2013,41(9):4223-4226
This paper is on the subject of residually finite (= RF) modules and rings introduced by Varadarajan [93] and [98/99]. Specifically there are several theorems that simplify proofs and generalize some results of Varadarajan, namely.

Theorem 1. An RF right R-module is finitely bedded (= has finite essential socle iff M is finite.

Corollay. If T is a right RF woth just finitely many simple ringht R-modules, them R is fimite.

Theorem 2. A commutative ring R is residually finite iff every local ring Rm at a maximal ideal m is finite.  相似文献   

15.
Faith Carl 《代数通讯》2013,41(6):559-571
For a ring R, the following two conditions are equivalent:.

(1) If E is an indecomposable injective right R-module, then End ER is a field (not necesarily commutative).

(2) Every co-irreducible rigtht ideal is critical.

Since (2) has been characterized ideal-theoretically, this amounts to an ideal-theoretical characterization of (1). These rings come up to the study of (QI) rings in which every quasi-injective module is injective.  相似文献   

16.
称左R-模M是ecg-扩张模,如果M的任意基本可数生成子模是M的直和因子的基本子模.在研究了ecg-扩张模的基本性质的基础上,本文证明了对于非奇异环R,所有左R-模是ecg-扩张模当且仅当所有左R-模是扩张模.同时我们还用ecg-拟连续模刻画了Noether环和Artin半单环.  相似文献   

17.
Zip模(英文)     
张翠萍  陈建龙 《东北数学》2008,24(3):233-249
A ring R is called right zip provided that if the annihilator τR(X) of a subset X of R is zero, then τR(Y) = 0 for some finite subset Y C X. Such rings have been studied in literature. For a right R-module M, we introduce the notion of a zip module, which is a generalization of the right zip ring. A number of properties of this sort of modules are established, and the equivalent conditions of the right zip ring R are given. Moreover, the zip properties of matrices and polynomials over a module M are studied.  相似文献   

18.
雷震 《大学数学》2008,24(1):29-32
通过单边理想是广义弱理想来刻画强正则环,证明了下列条件是等价的:①R是强正则环;②R是半素的左GP-V′-环,且每一个极大的左理想是广义弱理想;③R是半素的左GP-V′-环,且每一个极大的右理想是广义弱理想.  相似文献   

19.
W.D. Buigess 《代数通讯》2013,41(14):1729-1750
A right FPF ring is one over which every finitely generated faithful right module is a generator. The main purpose of the article is to givp the following cnaracterization of certain right FPF rings. TheoremLet R be semiprime and right semihereditary. Then R is right FPF iff (1) the right maximal ring of quotients Qr (R) = Q coincides with the left and right classical rings of quotients and is self-injective regular of bounded index, (ii) R and Q have the same central idem-potents, (iii) if I is an ideal of R generated by a ma­ximal ideal of the boolean algebra of central idempotent s5 R/I is such that each non-zero finitely generated right ideal is a generator (hence prime), and (iv) R is such that every essential right ideal contains an ideal which is essential as a right ideal

In case that R is semiprime and module finite over its centre C, then the above can be used to show that R is FPF (both sides) if and only if it is a semi-hereditary maximal C-order in a self-injective regular ring (of finite index)

In order to prove the above it is shown that for any semiprime right FPF ring R, Q lcl (R) exists and coincides with Qr(R) (Faith and Page have shown that the latter is self-injective regular of bounded index). It R is semiprime right FPF and satisfies a polynamical identity then the factor rings as in (iii) above are right FPF and R is the ring of sections of a sheaf of prime right FPF rings

The Proofs use many results of C. Faith and S Page as well as some of the techniques of Pierce sheaves  相似文献   

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