全文获取类型
收费全文 | 199009篇 |
免费 | 3284篇 |
国内免费 | 493篇 |
专业分类
化学 | 112477篇 |
晶体学 | 2683篇 |
力学 | 7048篇 |
综合类 | 5篇 |
数学 | 23718篇 |
物理学 | 56855篇 |
出版年
2021年 | 1634篇 |
2020年 | 1994篇 |
2019年 | 2044篇 |
2018年 | 2675篇 |
2017年 | 2636篇 |
2016年 | 4448篇 |
2015年 | 3138篇 |
2014年 | 3902篇 |
2013年 | 9423篇 |
2012年 | 8044篇 |
2011年 | 8985篇 |
2010年 | 6224篇 |
2009年 | 5964篇 |
2008年 | 8440篇 |
2007年 | 8076篇 |
2006年 | 7613篇 |
2005年 | 7233篇 |
2004年 | 6425篇 |
2003年 | 5759篇 |
2002年 | 5464篇 |
2001年 | 6529篇 |
2000年 | 4946篇 |
1999年 | 3759篇 |
1998年 | 2687篇 |
1997年 | 2706篇 |
1996年 | 2709篇 |
1995年 | 2381篇 |
1994年 | 2441篇 |
1993年 | 2230篇 |
1992年 | 2725篇 |
1991年 | 2745篇 |
1990年 | 2591篇 |
1989年 | 2493篇 |
1988年 | 2458篇 |
1987年 | 2432篇 |
1986年 | 2267篇 |
1985年 | 2868篇 |
1984年 | 2860篇 |
1983年 | 2283篇 |
1982年 | 2273篇 |
1981年 | 2133篇 |
1980年 | 2063篇 |
1979年 | 2335篇 |
1978年 | 2412篇 |
1977年 | 2328篇 |
1976年 | 2269篇 |
1975年 | 2131篇 |
1974年 | 2123篇 |
1973年 | 2157篇 |
1972年 | 1399篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Lebedev V. T. Serebrov A. P. 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2020,14(1):1-5
Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques - A method for studying the magnetic dynamics of endofullerenes M@C2n (2n = 60, 70, …) and their derivatives,... 相似文献
102.
103.
104.
T. Noiri 《Acta Mathematica Hungarica》1998,80(1-2):105-113
In this paper the notion of pre gs-closed functions is introduced and investigated. Presemiclosed functions are pre gs-closed but not conversely. It is shown that s-normality is preserved under continuous pre gs-closed surjections. 相似文献
105.
P. Seelig A. Dax S. Faber M. Gerlach G. Huber T. Kühl D. Marx P. Merz W. Quint F. Schmitt H. Winter M. Würtz 《Hyperfine Interactions》1998,114(1-4):135-139
The investigation of the 1s HFS provides a good possibility for testing QED effects in a combination of a strong electric
and magnetic field. Here, we report about the laserspectroscopic measurements of the ground state hyperfine splitting in 207Pb81+. To handle this M1-transition in the infrared optical regime with its long lifetime, we developed a new detection technique
using a bunched ion beam. For the observation of fluorescence light, a new mirror system is adapted to the emission characteristics
from an ion beam at relativistic velocities.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
106.
107.
108.
In this Note we give a necessary and sufficient condition for the spectral controllability from one simple node of a general network of strings that undergoes transversal vibrations in a sufficiently large time. This condition asserts that no eigenfunction vanishes identically on the string that contains the controlled node. The proof combines the Beurling–Malliavin's theorem and an asymptotic formula for the eigenvalues of the network. The optimal control time may be characterized as twice the sum of the lengths of all the strings of the network. To cite this article: R. Dáger, E. Zuazua, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 545–550. 相似文献
109.
We study spectral properties of discrete Schrödinger operators with potentials obtained via dimerization of a class of aperiodic sequences. It is shown that both the nature of the autocorrelation measure of a regular sequence and the presence of generic (full probability) singular continuous spectrum in the hull of primitive and palindromic (four block substitution) potentials are robust under dimerization. Generic results also hold for circle potentials. We illustrate these results with numerical studies of the quantum mean square displacement as a function of time. The numerical techniques provide a very fast algorithm for the time evolution of wave packets. 相似文献
110.