全文获取类型
收费全文 | 18109篇 |
免费 | 1194篇 |
国内免费 | 1875篇 |
专业分类
化学 | 726篇 |
晶体学 | 16篇 |
力学 | 638篇 |
综合类 | 283篇 |
数学 | 9358篇 |
物理学 | 2025篇 |
综合类 | 8132篇 |
出版年
2024年 | 31篇 |
2023年 | 162篇 |
2022年 | 205篇 |
2021年 | 272篇 |
2020年 | 301篇 |
2019年 | 331篇 |
2018年 | 321篇 |
2017年 | 384篇 |
2016年 | 410篇 |
2015年 | 396篇 |
2014年 | 791篇 |
2013年 | 950篇 |
2012年 | 805篇 |
2011年 | 995篇 |
2010年 | 905篇 |
2009年 | 1153篇 |
2008年 | 1200篇 |
2007年 | 1394篇 |
2006年 | 1187篇 |
2005年 | 1069篇 |
2004年 | 860篇 |
2003年 | 892篇 |
2002年 | 798篇 |
2001年 | 665篇 |
2000年 | 708篇 |
1999年 | 610篇 |
1998年 | 572篇 |
1997年 | 498篇 |
1996年 | 401篇 |
1995年 | 289篇 |
1994年 | 291篇 |
1993年 | 231篇 |
1992年 | 189篇 |
1991年 | 179篇 |
1990年 | 159篇 |
1989年 | 134篇 |
1988年 | 108篇 |
1987年 | 71篇 |
1986年 | 36篇 |
1985年 | 39篇 |
1984年 | 33篇 |
1983年 | 13篇 |
1982年 | 28篇 |
1981年 | 16篇 |
1980年 | 19篇 |
1979年 | 19篇 |
1978年 | 12篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1936年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Alexander P. Schuster 《Proceedings of the American Mathematical Society》1997,125(6):1717-1725
Properties of the unions of sampling and interpolation sets for Bergman spaces are discussed in conjunction with the examples given by Seip (1993). Their relationship to the classical interpolation sequences is explored. In addition, the role played by canonical divisors in the study of these sets is examined and an example of a sampling set is constructed in the disk.
42.
Alexander Afriat 《Foundations of Physics Letters》1995,8(5):467-480
We consider the question of factorizability in tensor product spaces, and argue that the correlations associated with entangled states are even more problematic in the general case involving any tensor product of Hilbert spaces, than in the Einstein, Podolsky, and Rosen case with only two [1]. 相似文献
43.
By constructing close-one-cochain density Ω^12n in the gauge group space we get the Wess-Zumino-Witten (WZW) effective Lagrangian on high-dimensional noncommutative space.Especially consistent anomalies derived from this WZW effective action in noncommutative four-dimensional space coincide with those obtained by L.Bonora etc.(het-th/0002210). 相似文献
44.
高智民 《纯粹数学与应用数学》1994,10(2):1-5
本文证明了:若X是K-半分层空间,f是闭映射,则f(X)是K-半分层空间,这一结果推广改进了Lutzer与高国士的有关结果。 相似文献
45.
The gedanken experiment of the clock paradox is solved exactly using the general relativistic equations for a static homogeneous gravitational
field. We demonstrate that the general and special relativistic clock paradox solutions are identical and in particular that
they are identical for finite acceleration. Practical expressions are obtained for proper time and coordinate time by using the destination distance as
the key observable parameter. This solution provides a formal demonstration of the identity between the special and general
relativistic clock paradox with finite acceleration and where proper time is assumed to be the same in both formalisms. By
solving the equations of motion for a freely falling clock in a static homogeneous field elapsed times are calculated for
realistic journeys to the stars.
1 Both authors contributed equally to this paper. 相似文献
46.
We study problems of interpolation of positive linear operators in couples of ordered Banach spaces. From this viewpoint, we study couples of noncommutative spaces L 1, L ∞ associated with weights and traces on von Neumann algebras. 相似文献
47.
当s∈ R,0,〈q, p〈∈∞,0,〈β≤∞且 max{-n/q,-nδ2/qδ1}〈a时,定义了加权Herz—type Triebel-Lizorkin空间kq^q,pF^s β(R^n,ω1,ω2)和Kq^a,pF^sβ(R^n,ω1,ω2),并给出这些空间的一些特征及在这些空间上的Hard—Littlewood极大算子不等式. 相似文献
48.
The estimation-valued property of B-valued asymptotic martingale 总被引:2,自引:0,他引:2
KONG Fanliang 《自然科学进展(英文版)》2006,16(7):773-776
In this paper, with the Doob decomposition of B-valued asymptotic martingale, we study the estimation-valued property of B-valued asymptotic martingale in Banach space B,which has the Radon-Nikodym Property and is dual-separable, and give a series of result and proof. 相似文献
49.
In this paper, we consider questions related to the structure of inverse matrices of linear bounded operators acting in infinite-dimensional complex Banach spaces. We obtain specific estimates of elements of inverse matrices for bounded operators whose matrices have a special structure. Matrices are introduced as special operator-valued functions on an index set. The matrix structure is described by the behavior of the given function on elements of a special partition of the index set. The method used for deriving the estimates is based on an analysis of Fourier series of strongly continuous periodic functions. 相似文献
50.
A. M. Chebotarev 《Mathematical Notes》2002,71(3-4):408-427
We prove that a quantum stochastic differential equation is the interaction representation of the Cauchy problem for the Schrödinger equation with Hamiltonian given by a certain operator restricted by a boundary condition. If the deficiency index of the boundary-value problem is trivial, then the corresponding quantum stochastic differential equation has a unique unitary solution. Therefore, by the deficiency index of a quantum stochastic differential equation we mean the deficiency index of the related symmetric boundary-value problem.In this paper, conditions sufficient for the essential self-adjointness of the symmetric boundary-value problem are obtained. These conditions are closely related to nonexplosion conditions for the pair of master Markov equations that we canonically assign to the quantum stochastic differential equation. 相似文献