全文获取类型
收费全文 | 10810篇 |
免费 | 2503篇 |
国内免费 | 650篇 |
专业分类
化学 | 1435篇 |
晶体学 | 48篇 |
力学 | 2949篇 |
综合类 | 129篇 |
数学 | 2397篇 |
物理学 | 7005篇 |
出版年
2024年 | 29篇 |
2023年 | 117篇 |
2022年 | 187篇 |
2021年 | 219篇 |
2020年 | 331篇 |
2019年 | 302篇 |
2018年 | 297篇 |
2017年 | 350篇 |
2016年 | 370篇 |
2015年 | 311篇 |
2014年 | 602篇 |
2013年 | 701篇 |
2012年 | 645篇 |
2011年 | 790篇 |
2010年 | 647篇 |
2009年 | 651篇 |
2008年 | 722篇 |
2007年 | 726篇 |
2006年 | 682篇 |
2005年 | 675篇 |
2004年 | 612篇 |
2003年 | 570篇 |
2002年 | 443篇 |
2001年 | 427篇 |
2000年 | 362篇 |
1999年 | 298篇 |
1998年 | 282篇 |
1997年 | 227篇 |
1996年 | 196篇 |
1995年 | 186篇 |
1994年 | 137篇 |
1993年 | 144篇 |
1992年 | 124篇 |
1991年 | 120篇 |
1990年 | 85篇 |
1989年 | 85篇 |
1988年 | 71篇 |
1987年 | 53篇 |
1986年 | 28篇 |
1985年 | 29篇 |
1984年 | 26篇 |
1983年 | 14篇 |
1982年 | 25篇 |
1981年 | 17篇 |
1980年 | 11篇 |
1979年 | 11篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1973年 | 6篇 |
1971年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 27 毫秒
1.
2.
Tsuguo SUNAMURA 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2015,91(9):481-500
Substantial progress in research on the recession of coastal cliffs composed of soft materials has been made in recent years and data with higher accuracy have been accumulated. This paper provides the state of the art review in the recession studies and highlights two new findings obtained from the reanalysis of existing data. The review topics are: episodic and localized nature of cliff recession; the development of cliffline; the relationship between cliff height and recession rate; mechanisms of cliff toe erosion by waves; a fundamental equation for wave-induced toe erosion; factors controlling toe erosion; and slope instabilities and mass movements. The findings are presented on (1) the temporal change in cliffline recession mode and (2) the effect of beach sediment at the cliff base on the cliff erosion. 相似文献
3.
4.
Bobby Wilson 《偏微分方程通讯》2015,40(8):1521-1542
This article explores the questions of long time orbital stability in high order Sobolev norms of plane wave solutions to the NLSE in the defocusing case. 相似文献
5.
The zero dissipation limit of the one-dimensional non-isentropic micropolar equations is studied in this paper. If the given rarefaction wave which connects to vacuum at one side, a sequence of solution to the micropolar equations can be constructed which converge to the above rarefaction wave with vacuum as the viscosity and the heat conduction coefficient tend to zero. Moreover, the uniform convergence rate is obtained. The key point in our analysis is how to control the degeneracies in the vacuum region in the zero dissipation limit process. 相似文献
6.
《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2020,37(2):417-456
We study the energy-critical nonlinear wave equation in the presence of an inverse-square potential in dimensions three and four. In the defocussing case, we prove that arbitrary initial data in the energy space lead to global solutions that scatter. In the focusing case, we prove scattering below the ground state threshold. 相似文献
7.
In this paper, we consider a viscoelastic wave equation of variable coefficients in the presence of past history with nonlinear damping and delay in the internal feedback and dynamic boundary conditions. Under suitable assumptions, we establish an explicit and general decay rate result without imposing restrictive assumption on the behavior of the relaxation function at infinity by Riemannian geometry method and Lyapunov functional method. 相似文献
8.
9.
10.
Second-order random wave solutions for interfacial internal waves in N-layer density-stratified fluid 下载免费PDF全文
This paper studies the random internal wave equations describing the density interface displacements and the velocity potentials of N-layer stratified fluid contained between two rigid walls at the top and bottom. The density interface displacements and the velocity potentials were solved to the second-order by an expansion approach used by Longuet-Higgins (1963) and Dean (1979) in the study of random surface waves and by Song (2004) in the study of second- order random wave solutions for internal waves in a two-layer fluid. The obtained results indicate that the first-order solutions are a linear superposition of many wave components with different amplitudes, wave numbers and frequencies, and that the amplitudes of first-order wave components with the same wave numbers and frequencies between the adjacent density interfaces are modulated by each other. They also show that the second-order solutions consist of two parts: the first one is the first-order solutions, and the second one is the solutions of the second-order asymptotic equations, which describe the second-order nonlinear modification and the second-order wave-wave interactions not only among the wave components on same density interfaces but also among the wave components between the adjacent density interfaces. Both the first-order and second-order solutions depend on the density and depth of each layer. It is also deduced that the results of the present work include those derived by Song (2004) for second-order random wave solutions for internal waves in a two-layer fluid as a particular case. 相似文献