全文获取类型
收费全文 | 9713篇 |
免费 | 842篇 |
国内免费 | 1140篇 |
专业分类
化学 | 3264篇 |
晶体学 | 19篇 |
力学 | 811篇 |
综合类 | 124篇 |
数学 | 5609篇 |
物理学 | 1868篇 |
出版年
2024年 | 7篇 |
2023年 | 88篇 |
2022年 | 109篇 |
2021年 | 194篇 |
2020年 | 252篇 |
2019年 | 296篇 |
2018年 | 306篇 |
2017年 | 337篇 |
2016年 | 288篇 |
2015年 | 276篇 |
2014年 | 388篇 |
2013年 | 1443篇 |
2012年 | 430篇 |
2011年 | 509篇 |
2010年 | 431篇 |
2009年 | 504篇 |
2008年 | 596篇 |
2007年 | 593篇 |
2006年 | 552篇 |
2005年 | 497篇 |
2004年 | 461篇 |
2003年 | 481篇 |
2002年 | 415篇 |
2001年 | 315篇 |
2000年 | 283篇 |
1999年 | 232篇 |
1998年 | 250篇 |
1997年 | 236篇 |
1996年 | 159篇 |
1995年 | 128篇 |
1994年 | 98篇 |
1993年 | 89篇 |
1992年 | 71篇 |
1991年 | 66篇 |
1990年 | 55篇 |
1989年 | 39篇 |
1988年 | 21篇 |
1987年 | 27篇 |
1986年 | 21篇 |
1985年 | 27篇 |
1984年 | 16篇 |
1983年 | 8篇 |
1982年 | 21篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 11篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1972年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2021,38(5):1337-1371
In this paper we consider minimizers of the functional where is a bounded open set and where are the first k eigenvalues on Ω of an operator in divergence form with Dirichlet boundary condition and with Hölder continuous coefficients. We prove that the optimal sets have finite perimeter and that their free boundary is composed of a regular part, which is locally the graph of a -regular function, and a singular part, which is empty if , discrete if and of Hausdorff dimension at most if , for some . 相似文献
4.
In this article a coupled version of the improved divergence‐free‐condition compensated method will be proposed to simulate time‐varying geometries by direct forcing immersed boundary method. The proposed method can be seen as a quasi‐multi‐moment framework due to the fact that the momentum equations are discretized by both cell‐centered and cell‐face velocity. For simulating time‐varying geometries, a semi‐implicit iterative method is proposed for calculating the direct forcing terms. Treatments for suppressing spurious force oscillations, calculating drag/lift forces, and evaluating velocity and pressure for freshly cells will also be addressed. In order to show the applicability and accuracy, analytical as well as benchmark problems will be investigated by the present framework and compared with other numerical and experimental results. 相似文献
5.
6.
7.
8.
Guangtao Duan Takuya Matsunaga Akifumi Yamaji Seiichi Koshizuka Mikio Sakai 《国际流体数值方法杂志》2021,93(1):148-175
Corrective matrix that is derived to restore consistency of discretization schemes can significantly enhance accuracy for the inside particles in the Moving Particle Semi‐implicit method. In this situation, the error due to free surface and wall boundaries becomes dominant. Based on the recent study on Neumann boundary condition (Matsunaga et al, CMAME, 2020), the corrective matrix schemes in MPS are generalized to straightforwardly and accurately impose Neumann boundary condition. However, the new schemes can still easily trigger instability at free surface because of the biased error caused by the incomplete/biased neighbor support. Therefore, the existing stable schemes based on virtual particles and conservative gradient models are applied to free surface and nearby particles to produce a stable transitional layer at free surface. The new corrective matrix schemes are only applied to the particles under the stable transitional layer for improving the wall boundary conditions. Three numerical examples of free surface flows demonstrate that the proposed method can help to reduce the pressure/velocity fluctuations and hence enhance accuracy further. 相似文献
9.
10.