全文获取类型
收费全文 | 4400篇 |
免费 | 236篇 |
国内免费 | 377篇 |
专业分类
化学 | 1068篇 |
晶体学 | 19篇 |
力学 | 438篇 |
综合类 | 21篇 |
数学 | 1940篇 |
物理学 | 1527篇 |
出版年
2024年 | 8篇 |
2023年 | 91篇 |
2022年 | 86篇 |
2021年 | 110篇 |
2020年 | 136篇 |
2019年 | 101篇 |
2018年 | 91篇 |
2017年 | 121篇 |
2016年 | 116篇 |
2015年 | 107篇 |
2014年 | 180篇 |
2013年 | 394篇 |
2012年 | 134篇 |
2011年 | 241篇 |
2010年 | 182篇 |
2009年 | 265篇 |
2008年 | 289篇 |
2007年 | 275篇 |
2006年 | 246篇 |
2005年 | 197篇 |
2004年 | 189篇 |
2003年 | 158篇 |
2002年 | 172篇 |
2001年 | 132篇 |
2000年 | 136篇 |
1999年 | 111篇 |
1998年 | 112篇 |
1997年 | 92篇 |
1996年 | 55篇 |
1995年 | 33篇 |
1994年 | 61篇 |
1993年 | 63篇 |
1992年 | 47篇 |
1991年 | 40篇 |
1990年 | 24篇 |
1989年 | 29篇 |
1988年 | 24篇 |
1987年 | 26篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 24篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1970年 | 5篇 |
排序方式: 共有5013条查询结果,搜索用时 15 毫秒
131.
Luis A. Caffarelli 《偏微分方程通讯》2016,41(7):1149-1182
We study a free boundary problem arising from the theory of thermal insulation. The outstanding feature of this set optimization problem is that the boundary of the set being optimized is not a level surface of a harmonic function, but rather a hypersurface along which a harmonic function satisfies a Robin condition. We show that minimal sets exist, satisfy uniform density estimates, and, under some geometric conditions, have “locally flat” boundaries. 相似文献
132.
In this paper, a shape optimization problem, modelling a welding process, governed by a second order non coercive PDE is considered. The well posedness of the shape optimal design problem is showed using the degree of Leray–Schauder. Then the existence of an optimal solution is proved. 相似文献
133.
《Comptes Rendus Physique》2018,19(5):341-346
A specimen observed in high-resolution transmission electron microscopy is electron transparent and its thickness is often less than about 10 nm. When it contains a linear defect like a screw dislocation, the obtained image can exhibit more or less important perturbations due to elastic relaxation nearby both free surfaces. Therefore, the theoretical interpretation of an image should include this relaxation in the calculation model. In the present work, it is evaluated for screw misfit dislocations piercing normally an elastically heterogeneous bicristalline plate (thickness 2h) from the following assumptions: there is no applied force on the thin plate and any surface stress related to a possible nanometric structure along the two free surfaces is neglected. The solution is found from an appropriate combination of known elastic fields in an infinite medium, which enables total stresses applying on two planes distant of 2h to be cancelled. This solution generalizes for the first time that of Eshelby and Stroh (1951), who consider an isolated screw dislocation normal to a homogeneous plate. 相似文献
134.
135.
Alexander M. Toikka Alexandra Yu. Pulyalina Andrey V. Petrov 《Mendeleev Communications》2021,31(1):79-80
- Download : Download high-res image (172KB)
- Download : Download full-size image
136.
137.
138.
139.
This work is devoted to the study of tensor gauge fields on a string-like defect in six dimensions. This model is very successful in localizing fields of various spins only by gravitational interaction. Due to problems of field localization in membrane models we are motivated to investigate if a string-like defect localizes the Kalb–Ramond field. In contrast to what happens in Randall–Sundrum and thick brane scenarios we find a localized zero mode without the addition of other fields in the bulk. Considering the local string defect we obtain analytical solutions for the massive modes. Also, we take the equations of motion in a supersymmetric quantum mechanics scenario in order to analyze the massive modes. The influence of the mass as well as the angular quantum number in the solutions is described. An additional analysis on the massive modes is performed by the Kaluza–Klein decomposition, which provides new details about the KK masses. 相似文献
140.
In this paper, an accurate model of the spin-coating process is presented and investigated from the analytical point of view. More precisely, the spin-coating process is being described as a one-phase free boundary value problem for Newtonian fluids subject to surface tension and rotational effects. It is proved that for T > 0 there exists a unique, strong solution to this problem in (0, T) belonging to a certain regularity class provided the data and the speed of rotation are small enough in suitable norms. The strategy of the proof is based on a transformation of the free boundary value problem to a quasilinear evolution equation on a fixed domain. The keypoint for solving the latter equation is the so-called maximal regularity approach. In order to pursue in this direction one needs to determine the precise regularity classes for the associated inhomogeneous linearized equations. This is being achieved by applying the Newton polygon method to the boundary symbol. 相似文献