全文获取类型
收费全文 | 629937篇 |
免费 | 5064篇 |
国内免费 | 1634篇 |
专业分类
化学 | 319252篇 |
晶体学 | 9241篇 |
力学 | 32039篇 |
综合类 | 27篇 |
数学 | 82999篇 |
物理学 | 193077篇 |
出版年
2021年 | 5833篇 |
2020年 | 6288篇 |
2019年 | 7173篇 |
2018年 | 9686篇 |
2017年 | 9813篇 |
2016年 | 13573篇 |
2015年 | 7284篇 |
2014年 | 12336篇 |
2013年 | 27943篇 |
2012年 | 21634篇 |
2011年 | 25750篇 |
2010年 | 19417篇 |
2009年 | 19376篇 |
2008年 | 24370篇 |
2007年 | 24127篇 |
2006年 | 21902篇 |
2005年 | 19563篇 |
2004年 | 18336篇 |
2003年 | 16515篇 |
2002年 | 16337篇 |
2001年 | 17517篇 |
2000年 | 13468篇 |
1999年 | 10444篇 |
1998年 | 8979篇 |
1997年 | 8900篇 |
1996年 | 8333篇 |
1995年 | 7468篇 |
1994年 | 7549篇 |
1993年 | 7270篇 |
1992年 | 7829篇 |
1991年 | 8221篇 |
1990年 | 7943篇 |
1989年 | 7856篇 |
1988年 | 7649篇 |
1987年 | 7385篇 |
1986年 | 7110篇 |
1985年 | 9109篇 |
1984年 | 9525篇 |
1983年 | 7959篇 |
1982年 | 8189篇 |
1981年 | 7749篇 |
1980年 | 7325篇 |
1979年 | 7957篇 |
1978年 | 8186篇 |
1977年 | 8163篇 |
1976年 | 8141篇 |
1975年 | 7776篇 |
1974年 | 7570篇 |
1973年 | 7931篇 |
1972年 | 5833篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
A. E. Zernov 《Ukrainian Mathematical Journal》1991,43(6):705-709
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 43, No. 6, pp. 755–760, June, 1991. 相似文献
212.
213.
214.
215.
V. D. Levchenko A. I. Morozov A. S. Sigov 《Journal of Experimental and Theoretical Physics》2002,94(5):985-991
Multilayer ferromagnet-layered antiferromagnet (Fe/Cr) structures frustrated because of roughness of interlayer boundaries were studied by mathematical modeling methods. The phase diagram of a three-layer system (plotted as film thickness versus the degree of roughness of the interfaces) was obtained, and the order parameter distributions in each phase were determined. The character of phase transitions in this system was studied. The applicability range of the Slonczewski magnetic proximity model was determined. 相似文献
216.
We generalize literature data and our own experimental data on using 1,3-dipolar cycloaddition reactions for synthesis of fullerene C60 derivatives containing annelated heterocyclic moieties.M. V. Lomonosov Moscow State University, Moscow 119899, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 291–297, March, 1998. 相似文献
217.
Summary Observation of fluorescence reactions on TLC plates is a valuable additional tool within the scope of screening procedures for many toxicologically relevant substances commonly encountered in clinical- and forensic-toxicological analysis. The reactions are based on native fluorescence without any treatment and on reactions obtained with an approved derivatization procedure. Due to the enormous sensitivity of the fluorescence detection, the method is also applicable to very low concentrations and small amounts of biological materials. The procedures described in this article have proven their high pragmatic usefulness in many practical cases.Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthday 相似文献
218.
On the basis of the invariant imbedding method the disturbance theory for complex constants of propagation is proposed. This approach allows us to consider the influence of layer and anisotropic fluctuations of refractive index on the beyond-the-horizon propagation in the adiabatic approximation with the existence of an evaporation duct. Finally, the authors consider some examples of the calculations and investigate stochastic effects connected with the interaction between fluctuating and regular waveguides. 相似文献
219.
220.