全文获取类型
收费全文 | 13875篇 |
免费 | 316篇 |
国内免费 | 315篇 |
专业分类
化学 | 1653篇 |
晶体学 | 30篇 |
力学 | 170篇 |
综合类 | 14篇 |
数学 | 11556篇 |
物理学 | 1083篇 |
出版年
2023年 | 28篇 |
2022年 | 55篇 |
2021年 | 39篇 |
2020年 | 71篇 |
2019年 | 334篇 |
2018年 | 374篇 |
2017年 | 204篇 |
2016年 | 139篇 |
2015年 | 182篇 |
2014年 | 383篇 |
2013年 | 1157篇 |
2012年 | 427篇 |
2011年 | 958篇 |
2010年 | 825篇 |
2009年 | 856篇 |
2008年 | 1105篇 |
2007年 | 1094篇 |
2006年 | 815篇 |
2005年 | 503篇 |
2004年 | 426篇 |
2003年 | 363篇 |
2002年 | 293篇 |
2001年 | 289篇 |
2000年 | 261篇 |
1999年 | 314篇 |
1998年 | 243篇 |
1997年 | 223篇 |
1996年 | 230篇 |
1995年 | 321篇 |
1994年 | 286篇 |
1993年 | 208篇 |
1992年 | 175篇 |
1991年 | 134篇 |
1990年 | 119篇 |
1989年 | 93篇 |
1988年 | 74篇 |
1987年 | 77篇 |
1986年 | 82篇 |
1985年 | 112篇 |
1984年 | 93篇 |
1983年 | 47篇 |
1982年 | 83篇 |
1981年 | 74篇 |
1980年 | 72篇 |
1979年 | 53篇 |
1978年 | 68篇 |
1977年 | 43篇 |
1976年 | 43篇 |
1975年 | 18篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Extending to r > 1 a formula of the authors, we compute the expected reflection distance of a product of t random reflections in the complex reflection group G(r, 1, n). The result relies on an explicit decomposition of the reflection distance function into irreducible G(r, 1, n)-characters and on the eigenvalues of certain adjacency matrices.Received December 8, 2003 相似文献
12.
We give a criterion to decide if a given w-homogeneous derivation on A?k[X1,X2,X3] is locally nilpotent. We deduce an algorithm which decides if a k-subalgebra of A, which is finitely generated by w-homogeneous elements, is the kernel of some locally nilpotent derivation. 相似文献
13.
We prove the existence of solutions to nonlinear free boundary problem with singularities at given points. 相似文献
14.
C. Sparber J. A. Carrillo J. Dolbeault P. A. Markowich 《Monatshefte für Mathematik》2004,141(3):237-257
We analyze the long-time behavior of transport equations for a class of dissipative quantum systems with Fokker-planck type diffusion operator, subject to confining potentials of harmonic oscillator type. We establish the existence and uniqueness of a non-equilibrium steady state for the corresponding dynamics. Further, using a (classical) convex Sobolev inequality, we prove an optimal exponential rate of decay towards this state and additionally give precise dispersion estimates in those cases, where no stationary state exists. 相似文献
15.
16.
Modifying complex plane rotations, we derive a new Jacobi-type algorithm for the Hermitian eigendecomposition, which uses only real arithmetic. When the fast-scaled rotations are incorporated, the new algorithm brings a substantial reduction in computational costs. The new method has the same convergence properties and parallelism as the symmetric Jacobi algorithm. Computational test results show that it produces accurate eigenvalues and eigenvectors and achieves great reduction in computational time.The work of this author was supported in part by the National Science Foundation grant CCR-8813493 and by the University of Minnesota Army High Performance Computing Research Center contract DAAL 03-89-C-0038.The work of this author was supported in part by the University of Minnesota Army High Performance Computing Research Center contract DAAL 03-89-C-0038. 相似文献
17.
18.
Summary. We present a simple proof, based on modified logarithmic Sobolev inequalities, of Talagrand’s concentration inequality for
the exponential distribution. We actually observe that every measure satisfying a Poincaré inequality shares the same concentration
phenomenon. We also discuss exponential integrability under Poincaré inequalities and its consequence to sharp diameter upper
bounds on spectral gaps.
Received: 10 June 1996 / In revised form: 9 August 1996 相似文献
19.
Hiromichi Kurosu Mizuyo Kikuchi Isao Ando 《Journal of Polymer Science.Polymer Physics》1995,33(5):769-775
The solid-state 15N CP/MAS NMR spectra and 15N spin-lattice relaxation times (T1) of doped and dedoped 15N-labeled polypyrroles prepared by electrochemical polymerization, have been measured by means of high-resolution solid-state 15N NMR. The 15N signal of polypyrrole consists of four peaks decomposed by line shape analysis. The four peaks obtained have been assigned to the various structures of polypyrrole. Further, the half-width of the 15N NMR spectra of polypyrroles is discussed as related to the electrical conductivity. © 1995 John Wiley & Sons, Inc. 相似文献
20.
Robert L. Jerrard Halil Mete Soner 《Calculus of Variations and Partial Differential Equations》2002,14(2):151-191
We study the Ginzburg-Landau functional
for , where U is a bounded, open subset of . We show that if a sequence of functions satisfies , then their Jacobians are precompact in the dual of for every . Moreover, any limiting measure is a sum of point masses. We also characterize the -limit of the functionals , in terms of the function space B2V introduced by the authors in [16,17]: we show that I(u) is finite if and only if , and for is equal to the total variation of the Jacobian measure Ju. When the domain U has dimension greater than two, we prove if then the Jacobians are again precompact in for all , and moreover we show that any limiting measure must be integer multiplicity rectifiable. We also show that the total variation
of the Jacobian measure is a lower bound for the limit of the Ginzburg-Landau functional.
Received: 15 December 2000 / Accepted: 23 January 2001 / Published online: 25 June 2001 相似文献