全文获取类型
收费全文 | 5290篇 |
免费 | 224篇 |
国内免费 | 16篇 |
专业分类
化学 | 3567篇 |
晶体学 | 20篇 |
力学 | 139篇 |
数学 | 815篇 |
物理学 | 989篇 |
出版年
2023年 | 36篇 |
2022年 | 43篇 |
2021年 | 85篇 |
2020年 | 77篇 |
2019年 | 63篇 |
2018年 | 96篇 |
2017年 | 55篇 |
2016年 | 150篇 |
2015年 | 146篇 |
2014年 | 163篇 |
2013年 | 289篇 |
2012年 | 367篇 |
2011年 | 400篇 |
2010年 | 185篇 |
2009年 | 176篇 |
2008年 | 279篇 |
2007年 | 319篇 |
2006年 | 269篇 |
2005年 | 237篇 |
2004年 | 210篇 |
2003年 | 177篇 |
2002年 | 150篇 |
2001年 | 87篇 |
2000年 | 49篇 |
1999年 | 38篇 |
1998年 | 32篇 |
1997年 | 29篇 |
1996年 | 38篇 |
1995年 | 30篇 |
1994年 | 34篇 |
1993年 | 27篇 |
1992年 | 24篇 |
1991年 | 26篇 |
1990年 | 25篇 |
1989年 | 23篇 |
1988年 | 24篇 |
1985年 | 24篇 |
1984年 | 24篇 |
1983年 | 22篇 |
1982年 | 26篇 |
1981年 | 26篇 |
1980年 | 21篇 |
1977年 | 21篇 |
1934年 | 26篇 |
1933年 | 24篇 |
1932年 | 29篇 |
1930年 | 24篇 |
1929年 | 24篇 |
1927年 | 28篇 |
1924年 | 20篇 |
排序方式: 共有5530条查询结果,搜索用时 15 毫秒
11.
Various physical systems of dispersive waves admit solutions in the form of generalized solitary waves. Such waves result from the resonance between a long localized wave and short periodic oscillations. Many estimates (rigorous and numerical) have been given for the amplitude of the ripples in the tail of the generalized solitary wave when its central part has a sech2 shape. This Note provides estimates (not yet rigorous) for the ripple amplitude when the central part is flat and wide. To cite this article: C. Fochesato, F. Dias, C. R. Acad. Sci. Paris, Ser. I 337 (2003). 相似文献
12.
L. Bugliaro J. Fröhlich G.M. Graf J. Stubbe C. Fefferman 《Communications in Mathematical Physics》1997,187(3):567-582
A Lieb-Thirring-Sobolev type inequality for Pauli Hamiltonians with magnetic fields is derived. The bound is in terms of an
effective field, whose energy is comparable to that of the magnetic field itself. An application to the stability of matter
in magnetic fields is given.
Received: 19 September 1996 / Accepted: 3 January 1997 相似文献
13.
This Note deals with optimal control problems with only one control variable and one state constraint, of arbitrary order. We consider the case of finitely many boundary arcs and touch times. We obtain a no-gap theory of second-order conditions, allowing us to characterize second-order quadratic growth. To cite this article: J.F. Bonnans, A. Hermant, C. R. Acad. Sci. Paris, Ser. I 343 (2006). 相似文献
14.
Fr. Hernler R. Pfeningberger F. Pregl K. Fuchs C. Mai H. Hurts 《Analytical and bioanalytical chemistry》1938,112(11-12):421-425
15.
We study the asymptotic distribution of the fill‐up level in a binary trie built over n independent strings generated by a biased memoryless source. The fill‐up level is the number of full levels in a tree. A level is full if it contains the maximum allowable number of nodes (e.g., in a binary tree level k can have up to 2k nodes). The fill‐up level finds many interesting applications, e.g., in the internet IP lookup problem and in the analysis of level compressed tries (LC tries). In this paper, we present a complete asymptotic characterization of the fill‐up distribution. In particular, we prove that this distribution concentrates on one or two points around the most probably value k = ?log1/qn ? log log log n + 1 + log log(p/q)?, where p > q = 1 ? p is the probability of generating the more likely symbol (while q = 1 ? p is the probability of the less likely symbol). We derive our results by analytic methods such as generating functions, Mellin transform, the saddle point method, and analytic depoissonization. We also present some numerical verification of our results. © 2004 Wiley Periodicals, Inc. Random Struct. Alg., 2004 相似文献
16.
17.
We consider noncommutative line bundles associated with the Hopf fibrations of SUq(2) over all Podle? spheres and with a locally trivial Hopf fibration of S3pq. These bundles are given as finitely generated projective modules associated via 1-dimensional representations of U(1) with Galois-type extensions encoding the principal fibrations of SUq(2) and S3pq. We show that the Chern numbers of these modules coincide with the winding numbers of representations defining them. To cite this article: P.M. Hajac et al., C. R. Acad. Sci. Paris, Ser. I 336 (2003). 相似文献
18.
We study general relativity in the framework of non-commutative differential geometry. As a prerequisite we develop the basic notions of non-commutative Riemannian geometry, including analogues of Riemannian metric, curvature and scalar curvature. This enables us to introduce a generalized Einstein-Hilbert action for non-commutative Riemannian spaces. As an example we study a space-time which is the product of a four dimensional manifold by a two-point space, using the tools of non-commutative Riemannian geometry, and derive its generalized Einstein-Hilbert action. In the simplest situation, where the Riemannian metric is taken to be the same on the two copies of the manifold, one obtains a model of a scalar field coupled to Einstein gravity. This field is geometrically interpreted as describing the distance between the two points in the internal space.Dedicated to H. ArakiSupported in part by the Swiss National Foundation (SNF) 相似文献
19.
The computation of long wave propagation through the ocean obviously depends on the initial condition. When the waves are generated by a moving bottom, a traditional approach consists in translating the ‘frozen’ sea bed deformation to the free surface and propagating it. The present study shows the differences between the classical approach (passive generation) and the active generation where the bottom motion is included. The analytical solutions presented here exhibit some of the drawbacks of passive generation. The linearized solutions seem to be sufficient to consider the generation of water waves by a moving bottom. To cite this article: D. Dutykh et al., C. R. Acad. Sci. Paris, Ser. I 343 (2006). 相似文献
20.