全文获取类型
收费全文 | 2558篇 |
免费 | 74篇 |
国内免费 | 243篇 |
专业分类
化学 | 161篇 |
晶体学 | 2篇 |
力学 | 15篇 |
综合类 | 23篇 |
数学 | 2071篇 |
物理学 | 603篇 |
出版年
2024年 | 11篇 |
2023年 | 34篇 |
2022年 | 33篇 |
2021年 | 42篇 |
2020年 | 63篇 |
2019年 | 89篇 |
2018年 | 87篇 |
2017年 | 93篇 |
2016年 | 49篇 |
2015年 | 43篇 |
2014年 | 74篇 |
2013年 | 502篇 |
2012年 | 50篇 |
2011年 | 96篇 |
2010年 | 108篇 |
2009年 | 118篇 |
2008年 | 162篇 |
2007年 | 157篇 |
2006年 | 116篇 |
2005年 | 122篇 |
2004年 | 111篇 |
2003年 | 92篇 |
2002年 | 87篇 |
2001年 | 71篇 |
2000年 | 72篇 |
1999年 | 74篇 |
1998年 | 95篇 |
1997年 | 65篇 |
1996年 | 20篇 |
1995年 | 20篇 |
1994年 | 17篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1973年 | 3篇 |
1936年 | 1篇 |
排序方式: 共有2875条查询结果,搜索用时 15 毫秒
11.
Takehiko Yamanouchi 《Journal of Functional Analysis》2003,201(2):522-560
In this paper, we generalize the notion of the canonical extension of automorphisms of von Neumann algebras to the case of actions of locally compact quantum groups (in the sense of Kustermans and Vaes). Various expected properties will be shown to hold for this new canonical extension. As an application, we describe the flow of weights of the crossed product of a type III factor by some special action of a discrete Kac algebra. 相似文献
12.
A. Aizpuru F.J. Pérez-Fernández 《Journal of Mathematical Analysis and Applications》2003,284(1):89-96
Several classical results on uniform convergence of unconditionally Cauchy series are generalized to weakly unconditionally Cauchy series. This uniform convergence is characterized through subalgebras and subfamilies of . A generalization of the Orlicz-Pettis theorem is also proved by mean of subalgebras of . 相似文献
13.
In this paper we continue to study the spectral norms and their completions ([4]) in the case of the algebraic closure $ \overline {\mathbb Q} $ of ? in ?. Let $ \widetilde{\overline{\mathbb{Q}}} $ be the completion of $ \overline {\mathbb Q} $ relative to the spectral norm. We prove that $ \widetilde{\overline{\mathbb{Q}}} $ can be identified with the R‐subalgebra of all symmetric functions of C(G), where C(G) denotes the ?‐Banach algebra of all continuous functions defined on the absolute Galois group G = Gal$ {\overline {\mathbb Q}} / {\mathbb Q} $. We prove that any compact, closed to conjugation subset of ? is the pseudo‐orbit of a suitable element of $ \widetilde{\overline{\mathbb{Q}}} $. We also prove that the topological closure of any algebraic number field in $ \widetilde{\overline{\mathbb{Q}}} $ is of the form $\widetilde{\mathbb{Q}[x]}$ with x in $ \widetilde{\overline{\mathbb{Q}}} $. 相似文献
14.
Shuang Zhang 《K-Theory》1992,6(1):1-27
We first determine the homotopy classes of nontrivial projections in a purely infinite simpleC*-algebraA, in the associated multiplier algebraM(A) and the corona algebraM
A/A in terms ofK
*(A). Then we describe the generalized Fredholm indices as the group of homotopy classes of non-trivial projections ofA; consequently, we determine theK
*-groups of all hereditaryC*-subalgebras of certain corona algebras. Secondly, we consider a group structure of *-isomorphism classes of hereditaryC*-subalgebras of purely infinite simpleC*-algebras. In addition, we prove that ifA is aC*-algebra of real rank zero, then each unitary ofA, in caseA it unital, each unitary ofM(A) and ofM(A)/A, in caseA is nonunital but -unital, can be factored into a product of a unitary homotopic to the identity and a unitary matrix whose entries are all partial isometries (with respect to a decomposition of the identity).Partially supported by a grant from the National Science Foundation. 相似文献
15.
A. Daele 《K-Theory》1992,6(5):465-485
LetA be a real or complex Banach algebra and assume that is an action of a finite groupG onA by means of continuous automorphisms. To such a finite covariant system (A, G, ), we associate an Abelian groupK(A, G, ). We obtain some classical exact sequences for an algebraA and a closed invariant idealI. We also compute the group in a few important special cases. Doing so, we relate our new invariant to the classicalK
0 andK
1 of a Banach algebra and to theK-theory of 2-graded Banach algebras. Finally, we obtain a result that gives a close relationship of our groupK(A, G, ) with theK-theory of the crossed productA
G. In particular, we prove a six-term exact sequence involving our groupK(A, G, ) and theK-groups ofA
G. In this way, we hope to contribute to the well-known problem of finding theK-theory of the crossed productA
G in the case of an action of a finite group. 相似文献
16.
Let A be a finite-dimensional algebra over arbitrary base field k. We prove: if the unbounded derived module category D-(Mod-A) admits symmetric recollement relative to unbounded derived module categories of two finite-dimensional k-algebras B and C:D- (Mod - B) D-(Mod - A) D-(Mod - C),then the unbounded derived module category D-(Mod - T(A)) admits symmetric recollement relative to the unbounded derived module categories of T(B) and T(C):D-(Mod - T(B)) D-(Mod - T(A)) D-(Mod -T(C)). 相似文献
17.
建立了齐次群上伴随于Herz空间和Beurling代数的Hardy空间的分子分解理论.作为其应用.研究了中心强奇异Calderon-Zygmund算子在这些空间上的有界性. 相似文献
18.
弱闭T(N)-模的预零化子的等距映射 总被引:1,自引:0,他引:1
本文刻划了弱闭T(N)-模的预零化子间的等距映射.设u,W分别为由左连续序同态N→~N和N→~N所确定的弱闭T(N)-模, u(?),W(?)分别为u,W的预零化子,Φ为由u(?)到W(?)上的线性等距映射.若(0)*=(0)#=(0),dim(0)+≠1且min{dim(H(?)~H),dim(He(?)^H)}≥2,则存在酉算子Ui,Vi(i=1,2),使得Φ(A)=U1AV*1或Φ(A)=U2A*V2*. 相似文献
19.
Nazih Nahlus 《Proceedings of the American Mathematical Society》2003,131(5):1321-1327
Let be an algebraically closed field of arbitrary characteristic, and let be a surjective morphism of connected pro-affine algebraic groups over . We show that if is bijective and separable, then is an isomorphism of pro-affine algebraic groups. Moreover, is separable if and only if (its differential) is surjective. Furthermore, if is separable, then .
20.
We show the existence of a rank function on finitely generated modules over group algebras , where is an arbitrary field and is a finitely generated amenable group. This extends a result of W. Lück (1998).