共查询到16条相似文献,搜索用时 124 毫秒
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本文研究了n维复形上(m,n)-树的判定性质,并对(m,n)-树的-个充分必要条件进行了推广. 相似文献
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设R是一个环,M是一个R-双边模,m和n是两个非负整数满足m+n≠0,如果δ是一个从R到M的可加映射满足对任意A∈R,(m+n)δ(A~2)=2mAδ(A)+2nδ(A)A,则称δ是一个(m,n)-Jordan导子.本文证明了,如果R是一个单位环,M是一个单位R-双边模含有一个由R中幂等元代数生成的左(右)分离集,那么,当m,n0且m≠n时,每一个从R到M的(m,n)-Jordan导子恒等于零.还证明了,如果A和B是两个单位环,M是一个忠实的单位(A,B)-双边模(N是一个忠实的单位(B,A)-双边模),m,n0且m≠n,U=[A N M B]是一个|mn(m-n)(m+n)|-无挠的广义矩阵环,那么每一个从U到自身的(m,n)-Jordan导子恒等于零. 相似文献
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引入了(I,K)-(m,n)-内射环的概念,给出了(I,K)-(m,n)-内射环的等价刻划.讨论了(I,K)-(m,n)-内射环与(I,K)-(m,1)-内射环之间的关系及左(I,K)-(m,n)-内射环和右(I,K)-(m,n)-内射环的关系.证明了R是右(I,K)-(m,n)-内射环当且仅当如果z=(m1,m2,…,mn)∈Kn且A∈Im×n,rR(A)∈rRn(z),则存在y∈Km,使得z=yA推广了已知的相关结论. 相似文献
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(m,n)—树的计数公式 总被引:1,自引:1,他引:0
Beineke和 Pippert[1,2 ] 将树的概念推广到高维空间 ,后来 Dewdney[3] 又进一步把它推广到 n维复形上 ,得到了 (m,n) —树的概念 .本文在 n维复形领域 ,利用 (m,n) —树的图论特征和组合的方法 ,独立地得出了顶点标号的 (m,n)—树的计数公式 . 相似文献
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设G是一个图.
设g和f是两个定义在V(G)上的整值函数使得对V(G)所有的顶点x有g(x)f(x).
图G被称为(g,f,n)-临界图,如果删去G的任意n个顶点后的子图都含有G的(g,f)-因子.
本文给出了图是(a,b,n)-临界图几个充分条件.
进一步指出这些条件是最佳的. 例如,如果对V(G)所有的顶点x和y都有g(x)<f(x),
n+g(x)dG(x)和g(x)/(dG(x)-n)f(y)/dG(y),则G是(g,f,n)-临界图. 相似文献
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Characterizations of ( m,n )-Jordan Derivations and ( m,n )-Jordan Derivable Mappings on Some Algebras 下载免费PDF全文
Let R be a ring, M be a R-bimodule and m, n be two fixed nonnegative integers with m + n = 0. An additive mapping δ from R into M is called an(m, n)-Jordan derivation if(m +n)δ(A~2) = 2 mAδ(A) + 2nδ(A)A for every A in R. In this paper, we prove that every(m, n)-Jordan derivation with m = n from a C*-algebra into its Banach bimodule is zero. An additive mappingδ from R into M is called a(m, n)-Jordan derivable mapping at W in R if(m + n)δ(AB + BA) =2mδ(A)B + 2 mδ(B)A + 2 nAδ(B) + 2 nBδ(A) for each A and B in R with AB = BA = W. We prove that if M is a unital A-bimodule with a left(right) separating set generated algebraically by all idempotents in A, then every(m, n)-Jordan derivable mapping at zero from A into M is identical with zero. We also show that if A and B are two unital algebras, M is a faithful unital(A, B)-bimodule and U = [A M N B] is a generalized matrix algebra, then every(m, n)-Jordan derivable mapping at zero from U into itself is equal to zero. 相似文献
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In this paper, let m, n be two fixed positive integers and M be a right R-module, we define (m, n)-M-flat modules and (m, n)-coherent modules. A right R-module F is called (m, n)-M-flat if every homomorphism from an (n, m)-presented right R-module into F factors through a module in addM. A left S-module M is called an (m, n)-coherent module if MR is finitely presented, and for any (n, m)-presented right R-module K, Hom(K, M) is a finitely generated left S-module, where S = End(MR). We mainly characterize (m, n)-coherent modules in terms of preenvelopes (which are monomorphism or epimorphism) of modules. Some properties of (m, n)-coherent rings and coherent rings are obtained as corollaries. 相似文献
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1引言 记Pn为次数不超过n的一元多项式函数类,约定零多项式的次数为-∞,即deg(0)=一∞;记Rm,n为分子属于Pm,分母属于Pn\{0}的一元有理函数类.在[1-5]的基础上,文[6]引进了有理插值问题的(m-n)f方程组,其为经典(m/n)f方程组的一种等价变换.由于变换之后,使得参数之间地位相同,并且在个数上也与空间自由度一致,因此成为分析有理插值的一个有力工具.文[7]利用(m-n)f方程组,讨论了有理插值的基本特征,给出并证明了关于基本特征的基本关系定理.文[8]则在此基础上解决了有理插值的适定性问题. 相似文献
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In this paper,let m,n be two fixed positive integers and M be a right R-module,we define (m,n)-M-flat modules and (m,n)-coherent modules.A right R-module F is called (m,n) M-flat if every homomorphism from an (n,m)-presented right R-module into F factors through a module in addM.A left S-module M is called an (m,n)-coherent module if MR is finitely presented,and for any (n,m)-presented right R-module K,Horn(K,M) is a finitely generated left S-module,where S = End(MR).We mainly characterize (m,n)-coherent modules in terms of preenvelopes (which are monomorphism or epimorphism) of modules.Some properties of (m,n)-coherent rings and coherent rings are obtained as corollaries. 相似文献
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Walid Al-Kawarit 《代数通讯》2013,41(10):3879-3896
In this article, we compare (n, m)-purities for different pairs of positive integers (n, m). When R is a commutative ring, these purities are not equivalent if R does not satisfy the following property: there exists a positive integer p such that, for each maximal ideal P, every finitely generated ideal of R P is p-generated. When this property holds, then the (n, m)-purity and the (n, m′)-purity are equivalent if m and m′ are integers ≥np. These results are obtained by a generalization of Warfield's methods. There are also some interesting results when R is a semiperfect strongly π-regular ring. We also compare (n, m)-flatnesses and (n, m)-injectivities for different pairs of positive integers (n, m). In particular, if R is right perfect and right self (?0, 1)-injective, then each (1, 1)-flat right R-module is projective. In several cases, for each positive integer p, all (n, p)-flatnesses are equivalent. But there are some examples where the (1, p)-flatness is not equivalent to the (1, p + 1)-flatness. 相似文献