全文获取类型
收费全文 | 65209篇 |
免费 | 3527篇 |
国内免费 | 8179篇 |
专业分类
化学 | 44311篇 |
晶体学 | 1225篇 |
力学 | 1012篇 |
综合类 | 435篇 |
数学 | 18713篇 |
物理学 | 11219篇 |
出版年
2024年 | 91篇 |
2023年 | 514篇 |
2022年 | 1045篇 |
2021年 | 1029篇 |
2020年 | 1395篇 |
2019年 | 1598篇 |
2018年 | 1418篇 |
2017年 | 1875篇 |
2016年 | 1809篇 |
2015年 | 1567篇 |
2014年 | 2255篇 |
2013年 | 5003篇 |
2012年 | 4097篇 |
2011年 | 3544篇 |
2010年 | 2856篇 |
2009年 | 3943篇 |
2008年 | 4231篇 |
2007年 | 4384篇 |
2006年 | 3861篇 |
2005年 | 3268篇 |
2004年 | 3120篇 |
2003年 | 2579篇 |
2002年 | 3309篇 |
2001年 | 2139篇 |
2000年 | 1916篇 |
1999年 | 1914篇 |
1998年 | 1604篇 |
1997年 | 1235篇 |
1996年 | 1175篇 |
1995年 | 1118篇 |
1994年 | 997篇 |
1993年 | 813篇 |
1992年 | 803篇 |
1991年 | 512篇 |
1990年 | 465篇 |
1989年 | 438篇 |
1988年 | 305篇 |
1987年 | 271篇 |
1986年 | 282篇 |
1985年 | 274篇 |
1984年 | 242篇 |
1983年 | 144篇 |
1982年 | 223篇 |
1981年 | 197篇 |
1980年 | 218篇 |
1979年 | 189篇 |
1978年 | 185篇 |
1977年 | 135篇 |
1976年 | 128篇 |
1974年 | 53篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
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
82.
本文首先提出逆(反)对策这一新问题,给出了数学模型;探讨了“奇门遁甲”预测理论(术)中的数学问题;通过系统分析“专门遁甲”预测过程,可知它的预测过程隐含着一个特殊的逆(反)对策问题;最后指出逆(反)对策问题的广泛存在并给出案例分析. 相似文献
83.
Summary. We study a diffusion model of an interacting particles system with general drift and diffusion coefficients, and electrostatic
inter-particles repulsion. More precisely, the finite particle system is shown to be well defined thanks to recent results
on multivalued stochastic differential equations (see [2]), and then we consider the behaviour of this system when the number
of particles goes to infinity (through the empirical measure process). In the particular case of affine drift and constant diffusion coefficient,
we prove that a limiting measure-valued process exists and is the unique solution of a deterministic PDE. Our treatment of
the convergence problem (as ) is partly similar to that of T. Chan [3] and L.C.G. Rogers - Z. Shi [5], except we consider here a more general case allowing
collisions between particles, which leads to a second-order limiting PDE.
Received: 5 August 1996 / In revised form: 17 October 1996 相似文献
84.
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
85.
Dorina Mitrea Marius Mitrea Jill Pipher 《Journal of Fourier Analysis and Applications》1997,3(2):131-192
We study boundary value problems for the time-harmonic form of the Maxwell equations, as well as for other related systems
of equations, on arbitrary Lipschitz domains in the three-dimensional Euclidean space. The main goal is to develop the corresponding
theory for Lp-integrable bounday data for optimal values of p's. We also discuss a number of relevant applications in electromagnetic scattering. 相似文献
86.
87.
88.
89.
90.
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