共查询到19条相似文献,搜索用时 375 毫秒
1.
陈焕艮 《数学物理学报(A辑)》2009,29(2)
环R是强可分的,如果对任意有限生成投射R-模A,B,A⊕A ≌B⊕B,则A≌B.该文证明了置换环上的强可分性在亚直积下是不变量.作为应用,证明了R/(IJ)是强可分的当且仅当R/(I∩J)是强可分的. 相似文献
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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
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设Q是有限置换右R模,则EndR(Q)是可分环当且仅当对所有A,B∈FP(Q),A A≌A B≌B B A≤ B或B≤ A.作为应用得到了EndR(P Q)是可分环当且仅当EndRP和EndRQ为可分环,其中P,Q为有限置换右R模. 相似文献
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陈焕艮 《数学年刊A辑(中文版)》2003,(4)
设Q是有限置换右R模,则End_R(Q)是可分环当且仅当对所有A,B∈FP(Q),A AA B B B A≤ B或 B≤A,作为应用得到了 End_R(P Q)是可分环当且仅当End_R P和End_R Q为可分环,其中P,Q为有限置换右R模。 相似文献
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von-Neumann正则环与左SF-环 总被引:6,自引:0,他引:6
环R称为左SF-环,如果每个单左R-模是平坦的.众所周知,Von-Neumann正则环是SF-环,但SF-环是否是正则环至今仍是公开问题,本文主要研究左SF-环是正则环的条件,证明了:如果R是左SF-环且R的每个极大左(右)理想是广义弱理想,那么R是强正则环.并且推广了Rege[3]中的相应结果. 相似文献
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环R称为N-环,如果R的素根N(R)={r∈R|存在自然数n使rn=0}.本文不仅对N-环进行了刻划,而且还研究了N-环的VonNeumann正则性.特别证明了:对于N-环R,如下条件是等价的:(1)R是强正则环;(2)R是正则环;(3)R是左SP-环;(4)R是右SF-环;(5)R是MELT,左p-V-环;(6)R是MERT,右p-V-环.因此推广了文献[4]中几乎所有的重要结果,同时也改进或推广了其它某些有关正则环的有用结果. 相似文献
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模的弱消去问题与qu-正则环 总被引:4,自引:1,他引:3
本文考虑模的弱消去问题与正则环的Stablerange条件,引进了qu-正则环的概念,并用它刻划了一类满足弱消去条件的模,刻划了qu-正则环,指出一切满足比较公理的正则环均为qu-正则环.文中还考虑这些结果的应用.例如,刻划了满足弱消去律的拟内射模;证明了素的正则右自内射环上的任意非奇异内射右R-模可以从直和项中弱消去. 相似文献
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模的弱消去问题与qu-正则环 总被引:1,自引:0,他引:1
本文考虑模的弱消去问题与正则环的Stablerange条件,引进了qu-正则环的概念,并用它刻划了一类满足弱消去条件的模,刻划了qu-正则环,指出一切满足比较公理的正则环均为qu-正则环.文中还考虑这些结果的应用.例如,刻划了满足弱消去律的拟内射模;证明了素的正则右自内射环上的任意非奇异内射右R-模可以从直和项中弱消去. 相似文献
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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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研究范畴与半群通过幂等元双序建立的一种自然联系.对每个有幂等元的半群S,其幂等元生成的左、右主理想之集通过双序ω~e,ω~r自然确定两个有子对象、有像且每个包含都右可裂的范畴L(S),R(S),其中态射的性质与S中元素的富足性、正则性有自然对应.利用这个联系,我们定义了"平衡(富足、正规)范畴"概念.对任一平衡(富足、正规)范畴■,我们构造其"锥半群"■,证明■左富足(富足、正则),且每个平衡(富足、正规)范畴■都与某左富足(富足、正则)半群S的左主理想范畴L(S)(作为有子对象的范畴)同构. 相似文献
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陈焕艮 《数学年刊A辑(中文版)》2012,33(1):123-132
研究了正则理想是B-稳定的充分和必要条件,并且证明环R的正则理想I是B-稳定的当且仅当对任意的有限生成投射右R-模A,如果A1和A2是A的有限生成子模且满足A1≌A2,A1=A1I以及A2=A2I,则存在一个有限生成子模B,使得A=A1(?)B=A2(?)B;当且仅当对任意的幂等元e,f∈I,eR≌fR蕴含eR/(eR∩fR)≌fR/(eR∩fR);当且仅当对任意的a∈1+I,存在一个幂等元e∈I,使得a-e∈∪(R)并且aR∩eR=0.进而构造了相关的例子. 相似文献
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On Decompositions of Quasi-Regular Rings 总被引:1,自引:0,他引:1
Hu Xianhui 《东北数学》1994,(2)
OnDecompositionsofQuasi-RegularRings¥HuXianhui(胡先惠)(DepartmntofMathematics,theCentralInstituteofNationalities,Beijing,100081)... 相似文献
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It is proved that for matrices A,B in the n by n upper triangular matrix ring Tn(R) over a domain R,if AB is nonzero and central in Tn(R) then AB =BA.The n by n full matrix rings over right Noetherian domains are also shown to have this property.In this article we treat a ring property that is a generalization of this result,and a ring with such a property is said to be weakly reversible-over-center.The class of weakly reversible-over-center rings contains both full matrix rings over right Noetherian domains and upper triangular matrix rings over domains.The structure of various sorts of weakly reversible-over-center rings is studied in relation to the questions raised in the process naturally.We also consider the connection between the property of being weakly reversible-over-center and the related ring properties. 相似文献
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《Quaestiones Mathematicae》2013,36(1):79-81
Abstract Let R be an associative ring with 1. It is well known (see [1], [2]) that if R is commutative, then R is Yon Neumann regular (VNR) <=> the polynomial ring S = R[x] is semihereditary. While one of these implications is true in the general case, it is known that a polynomial ring over a regular ring need not be semihereditary (see [3]). In [4] we showed that a ring R is VNR <=> aS + xS is projective for each a ε R. In this note we sharpen this result and use it to show that if c is the ring epimorphism from R[x] to R that maps each polynomial onto its constant term, then R is Yon Neumann regular <=> the inverse image (under c) of each principal (right, left) ideal of R. is a principal (right. left) ideal of R[x] generated by a regular element. (Here an element is regular if and only if it is a non zero-divisor). 相似文献
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本文对非结合非分配环(以下简称两非环)引进Jacobson根概念,同时证明了它是文中意义下的极大合格正则右理想之交,并且通过一系列概念及结果,主要来建立两非环的结构定理,任何满足右理想极小条件的半单纯两非环R只有有限多个单纯理想,并且R是这些单纯理想之直和,这些单纯理想都是满足右理想极小条件的单纯半单纯两非环,它们中的每一个都可分解成有限多个极小右理想之直和,特别两非环取为通常结合环时,本文的结果包含通常结合环所熟知的结果。 相似文献
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von Neumann Regular Rings and Right SF-rings 总被引:2,自引:0,他引:2
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 paper, we study the regularity of right SF-rings and prove that if R is a right SF-ring whose all maximal (essential) right ideals are GW-ideals, then R is regular. 相似文献