全文获取类型
收费全文 | 3872篇 |
免费 | 154篇 |
国内免费 | 34篇 |
专业分类
化学 | 2510篇 |
晶体学 | 14篇 |
力学 | 92篇 |
数学 | 516篇 |
物理学 | 928篇 |
出版年
2024年 | 6篇 |
2023年 | 27篇 |
2022年 | 115篇 |
2021年 | 149篇 |
2020年 | 101篇 |
2019年 | 159篇 |
2018年 | 134篇 |
2017年 | 123篇 |
2016年 | 175篇 |
2015年 | 131篇 |
2014年 | 168篇 |
2013年 | 220篇 |
2012年 | 306篇 |
2011年 | 334篇 |
2010年 | 173篇 |
2009年 | 183篇 |
2008年 | 276篇 |
2007年 | 244篇 |
2006年 | 230篇 |
2005年 | 194篇 |
2004年 | 156篇 |
2003年 | 104篇 |
2002年 | 105篇 |
2001年 | 38篇 |
2000年 | 32篇 |
1999年 | 32篇 |
1998年 | 28篇 |
1997年 | 30篇 |
1996年 | 24篇 |
1995年 | 16篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有4060条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Alexey Yurasov Alexander Granovsky Sergey Tarapov Jean-Pierre Clerc 《Journal of magnetism and magnetic materials》2006
The transmission of millimeter-range electromagnetic waves (30–50 GHz) through a magnetic nanocomposite thin film exhibiting tunnel magnetoresistance (TMR) is calculated. The relative change of transmission coefficient in an applied magnetic field due to the magnetorefractive effect is approximately linear with TMR and strongly depends on nanocomposite resistivity and film thickness. The obtained results are in a good agreement with experiment. 相似文献
6.
Sergey Chervon 《General Relativity and Gravitation》2004,36(7):1547-1553
A new strategy of exact solutions construction in inflationary cosmology within the self-interacting scalar field theory is proposed. It is shown that inflationary models have no restrictions dictated by the slow-roll approximation on the self-interacting potential. The suggested approach makes it possible to compute precisely the e-folds numbers in inflationary scenarios. The scalar field with a logarithmic evolution in time is analyzed in details. Other possible types of scalar field evolution are discussed. 相似文献
7.
An analytic solution of the problem concerning the frequencies and shapes of free axially symmetric oscillations of a truncated spherical sector filled with an ideal compressible fluid is constructed. A spherical wall of smaller radius and the radial wall of the sector are absolutely rigid. A thin elastic shell whose edge is clamped in the radial wall is located on a spherical boundary of larger radius. The outer surface of the shell borders vacuum. The phenomenon of an anomalous decrease in the fundamental frequency as the spherical walls approach each other is discovered. An approximate formula for determination of the lowest fundamental frequencies, which are approximately proportional to the square root of the difference of the radii of spherical walls for small values of this difference, is constructed and tested numerically. Bibliography: 13 titles. 相似文献
8.
Viktor A. Nikolaenko Yurii Z. Kovdrya Sergey P. Gladchenko 《Journal of Molecular Liquids》2005,120(1-3):171-174
The magnetotransport in a nondegenerate quasi-one-dimensional (Q1D) electron system over superfluid helium has been investigated experimentally. The measurements are performed in the presence of a perpendicular magnetic field B up to 2.6 T in the temperature range T=0.48–2.05 K in the system of conducting channels of 100–400 nm width. It is shown that the value of longitudinal magnetoresistance ρxx increases with B. In the electron-gas scattering region (T>0.9 ), the behaviour of ρxx agrees with classical Drude law. In the quantum transport regime, the self-consistent Born approximation (SCBA) theory for a 2D electron system over liquid helium describes the experimental data qualitatively. The deviation due to the difference of the experimentally studied Q1D system of the electrons in a parabolic potential well differs from theoretically analysed one. The experimental data agree with the theoretical calculation for the Q1D electron system at the weak magnetic field and the low temperature.
The negative magnetoresistance of the conducting channels has been observed in both the gas- and the ripplon-scattering region. These effects have been explained by weak carrier localization on the gas atoms at high temperature and by display of the quantum magnetotransport features in a mesoscopic system at low temperature. 相似文献
9.
10.
Sergey A. Ponomarenko 《Optics Communications》2006,261(1):1-4
We describe a class of spatio-temporal optical pulses that spread neither spatially nor temporarily in linear dispersive media over long propagation distances. These new spatio-temporal pulses, referred to as linear optical bullets, can have any spatio-temporal profile and temporal width, and they carry a finite amount of energy. We also discuss in detail a technique for the experimental realization of linear optical bullets. 相似文献