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1.
引进了(K,L)-内射性和(K,L)-伪内射性,这里K和L分别是模范畴上短正合列类的子类和模范畴态射类的子类。然后对这样定义的广义内射性进行了不依赖于预根理论的讨论,并对伪内射性与伪投射性之间的关系作了讨论。  相似文献   

2.
将(m,n)-内射环的概念推广到(J,K)-(m,n)-内射环,给出(J,K)-(m,n)-内射环的等价刻划.并借助(m,n)-内射环的某些性质研究(J,K)-(m,n)-内射环.  相似文献   

3.
设I,K是环R的右理想,讨论了环R的平凡扩张R∝R具有右(I0,K0)-(m,n)-内射性(特别地,右(I0,K0)-n-内射性、右(I0,K0)-P-内射性、右(I0,K0)-FP-内射性)的充分条件,其中I0=I∝I,K0=K∝K.此外,本文还讨论了环R[A,B]具有强正则性、弱正则性的充要条件.  相似文献   

4.
设R是一个环.一个右R-模N叫做M-(m,n)-内射的,如果每一个从Rm的n-生成子模到N的右R-模单同态都能扩展到Rm到N的R-模同态.如果RR是M-(m,n)-内射的,则称R是右M-(m,n)-内射的.M-(m,n)-内射性是MP-内射性的推广.本文首先给出了一个右R-模N是M-(m,n)-内射模的刻画,其次通过MP-内射性给出了N是M-(m,n)-内射的一个充分条件,最后给出了可裂零扩张是M-(m,n)-内射的一个性质,从而推广了MP-内射性的性质.  相似文献   

5.
作为文献[4]的主要结果的推广,在这篇文章中我们证明了扭曲模范畴MAC(Ψ)中任何对象都存在内射包和此范畴存在余生成子和生成子.  相似文献   

6.
交换环上的极大性内射模   总被引:3,自引:2,他引:1  
设R是交换环,■表示R的极大理想生成的乘法系,M是R-模.若对R的任何极大理想m,有ExtR1(R/m,M)=0,则M称为极大性内射模.若R自身为极大性内射模,则R称自极大性内射环.若对J∈■,x∈M,由Jx=0能推出x=0,则M称为■-无挠模.证明了在Dedekind整环上,M是极大性内射模当且仅当M是内射模.指出若R的极大理想都是有限生成的,则每个■-无挠模存在极大性内射包络.还证明了若R是■-无挠的自极大性内射模,则自反模是极大性内射模,且非极大素理想都是极大性内射模;若还有R的每个极大理想是有限生成的,则自由模与投射模是极大性内射模.最后,证明了在MFG整环上,平坦模是极大性内射模.  相似文献   

7.
×R-双代数L的左模范畴与左L*-模范畴是等价的.左(L,A)-Hopf模范畴同构于左A#L*-模范畴.在引入了对极的概念之后并将基本结构定理推广到×R-Hopf代数上的Hopf模上.  相似文献   

8.
引入了一种广义Gorenstein内射模定义,即n-Gorenstein内射模,证明了这种模类在一定条件下为扩张封闭的当且仅当它是内射预解的,也给出了强n-Gorenstein内射模的内射等价性及其上合冲性质.  相似文献   

9.
(e,M)-内射模     
本文引入了(e,M)-内射模的概念.设M是任意一个固定的右R-模.称右R-模X是(e,M)-内射模,如果对任意的基本单同态f:K→M,从K到X的任意同态都能扩张到M.本文给出了(e,M)-内射模的一些性质和刻画.  相似文献   

10.
针对模论中两类重要的模子范畴:投射模范畴与内射模范畴,以及模论中两个重要的概念:small模和self-small模,对偶地引入了co-small模和co-self-small模的概念,给出了这两类范畴间对偶的等价刻画,特别地,给出了在Noether情形下余-*-模的刻画.  相似文献   

11.
有限群G被称为是一个ST-群,若对于子群H≤K≤L使得H在KS-中半正规,K在L中s-半正规,则有H在L中s-半正规.证明了对于含有素数幂阶的abnormal子群的有限群而言,可解ST-群类同可解T-群类和可解PT-群类是同一群类.  相似文献   

12.
For any abelian function field K (i.e. any subfield of a cyclotomic function field L=k(ΛP) over the rational function field k) with conductor being an irreducible polynomial over a finite field of odd characteristic, by studying the Carlitz-module structure and the character group of K, an explicit upper bound and a calculating formula of the relative divisor class number h-(K) of K are given. Our calculated results of K develop Rosen's recent results of L.  相似文献   

13.
邹辉文 《江西科学》2000,18(2):63-67
设P(G,λ)表示简单图G的色多项式。简单图H称为与G是色等价的(记作H ̄G),如果P(H,λ)=P(G,λ)。简单图类L称为色正规图类,若对任意H,G∈L使H ̄G都有H与G同构。  相似文献   

14.
Let K 6 be a real cyclic sextic number fields, and K 2, K 3 be its quadratic and cubic subfields. Let h(L) denote the ideal class number of field L. Seven congruences for h -=h(K 6)/h(K 2)h(K 3) are obtained. In particular, when conductor f\-6 of K 6 is prime p, then Ch -≡B p-16B 5(p-1)6 (mod p), where C is an explicitly given constant, and B n is the Bernoulli number. These results for real cyclic sextic fields are an extension of results for quadratic and cyclic quartic fields obtained by Ankeny_Artin_Chowla, Kiselev, Carlitz, Lu Hongwen, Zhang Xianke from 1948 to 1988.  相似文献   

15.
本文研究了一类高阶半线性边值问题ε~2y~(n)=f(x,y,y′,…,y~(n-2),ε),00是小参数。在适当的假设下,作者证明了解的存在性,并得到了解的一致有效的渐近展开式。  相似文献   

16.
In microbial fuel cell (MFC), the rate of electron transfer to anode electrode is a key intrinsic limiting factor on the power output of MFCs. Using Klebsiella pneumoniae (K. pneumoniae) strain L17 as biocatalyst, we studied the mechanism of electron shuttle via self-producing mediator in a cubic air-chamber MFC. To eliminate the influence of biofilm mechanism, the anode electrode was coated with microfiltration membrane (0.22 μm). Data showed that the microfiltration membrane coated and uncoated MFCs achie...  相似文献   

17.
在本文中,作者研究了一类一阶线性泛函微分方程的振动性质,获得了一些使方程的所有解振动的充分条件。  相似文献   

18.
研究控制幅值受限下定常离散线性系统在某类扰动作用下的能控性问题。给出了这类系统的初始状态有了发拍能控的条件;给出了系统完全的能控时,状态矩阵的特征值所要满足的必要条件,最后,对一类特殊系统给出了完全能控的充分条件。  相似文献   

19.
MHC antigens in urine as olfactory recognition cues   总被引:10,自引:0,他引:10  
P B Singh  R E Brown  B Roser 《Nature》1987,327(6118):161-164
The classical class I antigens of the major histocompatibility complex (MHC) are cell-surface glycoproteins which were originally discovered because they cause rapid rejection of cells or tissues grafted between unrelated individuals. These molecules are encoded by the K, D and L loci of the mouse MHC (and analogous loci in other species) which show extreme species polymorphism and a large number of alleles. In an outbreeding population 3.6 X 10(9) unique MHC class I phenotypes can be encoded by the 100 alleles at each of the K and D loci and the 6 alleles at the L locus. This level of polymorphism ensures that the cells and tissues of each unrelated individual are uniquely identified by their class I membrane-bound antigens. Like other membrane bound proteins, these class I molecules are anchored in the lipid bilayer by a hydrophobic domain encoded by exon 5. However, there have been reports of the occurrence of classical class I molecules in true solution in the blood of humans, mice, and rats. We report here that classical polymorphic class I molecules in normal rats are constitutively excreted in the urine and that untrained rats can distinguish the smell of urine samples taken from normal donors that differ only at the class I MHC locus and therefore excrete different allelomorphs of class I molecules in their urine.  相似文献   

20.
分析了多级安全关系数据库系统中客体安全级的不同定义方法;描述了基于数据项级的多级关系模式;对利用多示例和分级存储的方法防止高安全级数据的泄漏,多级关系的分解和恢复进行了详细的讨论.  相似文献   

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