全文获取类型
收费全文 | 298356篇 |
免费 | 2256篇 |
国内免费 | 522篇 |
专业分类
化学 | 142671篇 |
晶体学 | 5008篇 |
力学 | 14788篇 |
综合类 | 11篇 |
数学 | 43274篇 |
物理学 | 95382篇 |
出版年
2020年 | 1724篇 |
2019年 | 1918篇 |
2018年 | 10842篇 |
2017年 | 11727篇 |
2016年 | 7480篇 |
2015年 | 3042篇 |
2014年 | 3673篇 |
2013年 | 9200篇 |
2012年 | 10767篇 |
2011年 | 20318篇 |
2010年 | 12680篇 |
2009年 | 12768篇 |
2008年 | 17528篇 |
2007年 | 21026篇 |
2006年 | 6886篇 |
2005年 | 12779篇 |
2004年 | 8901篇 |
2003年 | 8440篇 |
2002年 | 6266篇 |
2001年 | 6298篇 |
2000年 | 4933篇 |
1999年 | 3559篇 |
1998年 | 2791篇 |
1997年 | 2720篇 |
1996年 | 2755篇 |
1995年 | 2533篇 |
1994年 | 2415篇 |
1993年 | 2239篇 |
1992年 | 2894篇 |
1991年 | 2798篇 |
1990年 | 2743篇 |
1989年 | 2769篇 |
1988年 | 2798篇 |
1987年 | 2802篇 |
1986年 | 2665篇 |
1985年 | 3387篇 |
1984年 | 3413篇 |
1983年 | 2693篇 |
1982年 | 2794篇 |
1981年 | 2851篇 |
1980年 | 2620篇 |
1979年 | 2976篇 |
1978年 | 2976篇 |
1977年 | 3009篇 |
1976年 | 2878篇 |
1975年 | 2605篇 |
1974年 | 2559篇 |
1973年 | 2552篇 |
1972年 | 1740篇 |
1968年 | 1800篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Journal of Experimental and Theoretical Physics - A systematic nonperturbative scheme for calculating the ground state energy is adapted for studying systems of strongly correlated electrons on a... 相似文献
92.
93.
94.
95.
96.
Pan Huang Dawen Xu Robert M. Reich Felix Kaiser Boping Liu Fritz E. Kühn 《Tetrahedron letters》2019,60(24):1574-1577
A first example of an Et2Zn mediated silylation of 1-aklynes is reported. A series of functional groups are tolerated in this reaction. Mechanistic studies support Zn alkynilides as intermediates in the reaction. This reaction protocol provides a practical method for the preparation of alkynylsilanes and expands the application of organometallic zinc in organic synthesis. 相似文献
97.
The structure, chemical composition, and magnetic properties of electrochemically deposited nanocrystalline Co-Ni-Fe films
were investigated using a number of techniques. A high saturation magnetic induction up to B
s
= 21 kG was attained. An enhancement of the saturation magnetization compared to the ideal anticipated one was revealed,
which correlated with the nonlinear behavior of the structural phase composition and lattice parameters with the change of
the composition.
The text was submitted by the authors in English. 相似文献
98.
N. I. Golovina G. N. Nechiporenko G. G. Nemtsev G. P. Dolganova V. P. Roshchupkin D. B. Lempert G. B. Manelis 《Russian Journal of Applied Chemistry》2007,80(1):24-30
Methods for phase stabilization of ammonium nitrate were sought for in order to considerably expand the application area of this oxidizing agent in various-purpose self-combustible formulations, including that in a new generation of gas-generating formulations for automobile air bags. New methods for stabilization of ammonium nitrate were studied and, in particular, a search was made for organic compounds that can stabilize ammonium nitrate even at their low content. The mechanism of phase state stabilization of ammonium nitrate by compounds of this kind was examined. 相似文献
99.
Yu. V. Pokonova 《Russian Journal of Applied Chemistry》2007,80(12):2163-2164
Kinetic, sorption and selectivity properties of commercial adsorbents are improved by adding petroleum residues (tar asphaltene concentrates) 13% of whole mass. Obtained adsorbents can be used for selective extraction of nobel metals from multicomponent polymetallic solutions of heavy metals and fro sewages purification for removing arsenic. 相似文献
100.
The possibility of realizing SASE Free Election Laser in x-ray waveband with EM-wave wiggler is studied in this paper. SASE effect including saturation length, saturation power and nonlinear process is explored through a 3-D simulation code. A utilization of seed light from laser plasma x-ray is also analyzed, which demonstrates the feature of shortening the interaction length for saturation. The results show that sizeable output power of x-ray laser would be generated with a middle energy electron beam. 相似文献