全文获取类型
收费全文 | 25060篇 |
免费 | 1053篇 |
国内免费 | 1302篇 |
专业分类
化学 | 9613篇 |
晶体学 | 204篇 |
力学 | 440篇 |
综合类 | 67篇 |
数学 | 13214篇 |
物理学 | 3877篇 |
出版年
2024年 | 36篇 |
2023年 | 369篇 |
2022年 | 278篇 |
2021年 | 292篇 |
2020年 | 457篇 |
2019年 | 639篇 |
2018年 | 564篇 |
2017年 | 422篇 |
2016年 | 489篇 |
2015年 | 582篇 |
2014年 | 895篇 |
2013年 | 1532篇 |
2012年 | 1002篇 |
2011年 | 1820篇 |
2010年 | 1411篇 |
2009年 | 1751篇 |
2008年 | 1936篇 |
2007年 | 1737篇 |
2006年 | 1377篇 |
2005年 | 1036篇 |
2004年 | 928篇 |
2003年 | 832篇 |
2002年 | 1102篇 |
2001年 | 586篇 |
2000年 | 529篇 |
1999年 | 583篇 |
1998年 | 448篇 |
1997年 | 358篇 |
1996年 | 439篇 |
1995年 | 406篇 |
1994年 | 357篇 |
1993年 | 297篇 |
1992年 | 245篇 |
1991年 | 189篇 |
1990年 | 160篇 |
1989年 | 167篇 |
1988年 | 113篇 |
1987年 | 120篇 |
1986年 | 105篇 |
1985年 | 143篇 |
1984年 | 116篇 |
1983年 | 69篇 |
1982年 | 107篇 |
1981年 | 102篇 |
1980年 | 51篇 |
1979年 | 42篇 |
1978年 | 37篇 |
1977年 | 45篇 |
1976年 | 33篇 |
1971年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
We investigate several versions of a cardinal characteristic defined by Frankiewicz. Vojtáš showed , and Blass showed . We show that all the versions coincide and that is greater than or equal to the splitting number. We prove the consistency of and of .
Received: 2 October 1996 / Revised version: 22 May 1997 相似文献
42.
J. Schropp 《Numerische Mathematik》1997,78(1):87-101
Summary. We use the qualitative properties of the solution flow of the gradient equation to compute a local minimum of a real-valued function . Under the regularity assumption of all equilibria we show a convergence result for bounded trajectories of a consistent,
strictly stable linear multistep method applied to the gradient equation. Moreover, we compare the asymptotic features of
the numerical and the exact solutions as done by Humphries, Stuart (1994) and Schropp (1995) for one-step methods. In the
case of -stable formulae this leads to an efficient solver for stiff minimization problems.
Received July 10, 1995 / Revised version received June 27, 1996 相似文献
43.
The purpose of this paper is to give the Reid ``Roundabout Theorem' for quadratic functionals with general boundary conditions.
In particular, we describe the so-called coupled point and regularity condition introduced in [16] in terms of Riccati equation
solutions.
Accepted 27 February 1996 相似文献
44.
45.
46.
47.
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
48.
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
49.
S. A. Denisov 《Integral Equations and Operator Theory》2002,42(2):166-173
We consider the Krein systems. For the set of Stummel class coefficients, we establish the criterion in terms of these coefficients for the system to satisfy the Szegö-type estimate on the spectral measure. 相似文献
50.
Oleg Borodin 《Combinatorica》1993,13(1):121-125
The weight of an edge in a graph is the sum of the degrees of its end-vertices. It is proved that in each 3-polytope there exists either an edge of weight at most 13 for which both incident faces are triangles, or an edge of weight at most 10 which is incident with a triangle, or else an edge of weight at most 8. All the bounds 13, 10, and 8 are sharp and attained independently of each other. 相似文献