全文获取类型
收费全文 | 223篇 |
免费 | 6篇 |
国内免费 | 33篇 |
专业分类
化学 | 1篇 |
力学 | 1篇 |
综合类 | 7篇 |
数学 | 253篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2018年 | 9篇 |
2017年 | 12篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 8篇 |
2013年 | 36篇 |
2012年 | 11篇 |
2011年 | 7篇 |
2010年 | 2篇 |
2009年 | 14篇 |
2008年 | 12篇 |
2007年 | 21篇 |
2006年 | 14篇 |
2005年 | 9篇 |
2004年 | 5篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 7篇 |
2000年 | 17篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 12篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有262条查询结果,搜索用时 15 毫秒
151.
Themonoidofendomorphismsofagraph ,inparticular,thatofstrongendomorphismsofagraph ,hasbeentheobjectofresearchesinthetheoryofsemigroupsforquitesometime(cf .[1 ]— [9]) .Asispointedoutinsomestandardbooksonsemigrouptheorysuchas[1 0 ],theideaofdeducingfactsaboutthesemi… 相似文献
152.
Marianne Akian 《Transactions of the American Mathematical Society》1999,351(11):4515-4543
Considering measure theory in which the semifield of positive real numbers is replaced by an idempotent semiring leads to the notion of idempotent measure introduced by Maslov. Then, idempotent measures or integrals with density correspond to supremums of functions for the partial order relation induced by the idempotent structure. In this paper, we give conditions under which an idempotent measure has a density and show by many examples that they are often satisfied. These conditions depend on the lattice structure of the semiring and on the Boolean algebra in which the measure is defined. As an application, we obtain a necessary and sufficient condition for a family of probabilities to satisfy the large deviation principle.
153.
154.
155.
Haonan Zhang 《代数通讯》2013,41(10):4095-4113
Sekine quantum groups are a family of finite quantum groups. The main result of this article is to compute all the idempotent states on Sekine quantum groups, which completes the work of Franz and Skalski. This is achieved by solving a complicated system of equations using linear algebra and basic number theory. From this, we discover a new class of non-Haar idempotent states. The order structure of the idempotent states on Sekine quantum groups is also discussed. Finally we give a sufficient condition for the convolution powers of states on Sekine quantum group to converge. 相似文献
156.
157.
M. Jayaraman 《代数通讯》2013,41(11):3331-3345
We study generalizations of regular modules by Ramamurthy and Mabuchi. These are also generalizations of fully right idempotent and fully left idempotent rings, respectively. We also define and study the properties of *-weakly regular modules, a generalization of fully idempotent rings. 相似文献
158.
R is any ring with identity. Let Spec r (R) (resp. Spec(R)) be the set of all prime right ideals (resp. all prime ideals) of R and let U r (eR) = {P ? Spec r (R) | e ? P}. In this article, we study the relationships among various ring-theoretic properties and topological conditions on Spec r (R) (with weak Zariski topology). A ring R is called Abelian if all idempotents in R are central (see Goodearl, 1991). A ring R is called 2-primal if every nilpotent element is in the prime radical of R (see Lam, 2001). It will be shown that for an Abelian ring R there is a bijection between the set of all idempotents in R and the clopen (i.e., closed and open) sets in Spec r (R). And the following results are obtained for any ring R: (1) For any clopen set U in Spec r (R), there is an idempotent e in R such that U = U r (eR). (2) If R is an Abelian ring or a 2-primal ring, then, for any idempotent e in R, U r (eR) is a clopen set in Spec r (R). (3) Spec r (R) is connected if and only if Spec(R) is connected. 相似文献
159.
Matej Brešar 《代数通讯》2013,41(1):154-163
Let 𝒜 be a ring, let ? be an 𝒜-bimodule, and let 𝒞 be the center of ?. A map F:𝒜 → ? is said to be range-inclusive if [F(x), 𝒜] ? [x, ?] for every x ∈ 𝒜. We show that if 𝒜 contains idempotents satisfying certain technical conditions (which we call wide idempotents), then every range-inclusive additive map F:𝒜 → ? is of the form F(x) = λx + μ(x) for some λ ∈ 𝒞 and μ:𝒜 → 𝒞. As a corollary we show that if 𝒜 is a prime ring containing an idempotent different from 0 and 1, then every range-inclusive additive map from 𝒜 into itself is commuting (i.e., [F(x), x] = 0 for every x ∈ 𝒜). 相似文献
160.
Mason introduced the reflexive property for ideals, and then this concept was generalized by Kim and Baik, defining idempotent reflexive right ideals and rings. In this article, we characterize aspects of the reflexive and one-sided idempotent reflexive properties, showing that the concept of idempotent reflexive ring is not left-right symmetric. It is proved that a (right idempotent) reflexive ring which is not semiprime (resp., reflexive), can always be constructed from any semiprime (resp., reflexive) ring. It is also proved that the reflexive condition is Morita invariant and that the right quotient ring of a reflexive ring is reflexive. It is shown that both the polynomial ring and the power series ring over a reflexive ring are idempotent reflexive. We obtain additionally that the semiprimeness, reflexive property and one-sided idempotent reflexive property of a ring coincide for right principally quasi-Baer rings. 相似文献