全文获取类型
收费全文 | 528071篇 |
免费 | 4751篇 |
国内免费 | 1281篇 |
专业分类
化学 | 269084篇 |
晶体学 | 7648篇 |
力学 | 25991篇 |
综合类 | 17篇 |
数学 | 67784篇 |
物理学 | 163579篇 |
出版年
2021年 | 5029篇 |
2020年 | 5480篇 |
2019年 | 6223篇 |
2018年 | 8414篇 |
2017年 | 8561篇 |
2016年 | 11628篇 |
2015年 | 6179篇 |
2014年 | 10442篇 |
2013年 | 23487篇 |
2012年 | 18335篇 |
2011年 | 21788篇 |
2010年 | 16424篇 |
2009年 | 16281篇 |
2008年 | 20658篇 |
2007年 | 20509篇 |
2006年 | 18617篇 |
2005年 | 16624篇 |
2004年 | 15469篇 |
2003年 | 13955篇 |
2002年 | 13848篇 |
2001年 | 14729篇 |
2000年 | 11343篇 |
1999年 | 8753篇 |
1998年 | 7601篇 |
1997年 | 7471篇 |
1996年 | 6928篇 |
1995年 | 6257篇 |
1994年 | 6265篇 |
1993年 | 6018篇 |
1992年 | 6375篇 |
1991年 | 6866篇 |
1990年 | 6578篇 |
1989年 | 6488篇 |
1988年 | 6322篇 |
1987年 | 6133篇 |
1986年 | 5871篇 |
1985年 | 7409篇 |
1984年 | 7769篇 |
1983年 | 6532篇 |
1982年 | 6818篇 |
1981年 | 6326篇 |
1980年 | 6003篇 |
1979年 | 6504篇 |
1978年 | 6742篇 |
1977年 | 6632篇 |
1976年 | 6586篇 |
1975年 | 6303篇 |
1974年 | 6129篇 |
1973年 | 6425篇 |
1972年 | 4706篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
901.
Oksengendler B. L. Karimov M. Yunusov M. C. Karakhodzhaev A. K. 《Russian Physics Journal》2004,47(7):790-791
Russian Physics Journal - 相似文献
902.
A semiempirical model is proposed for the calculation of electrical, magnetic and thermal parameters of the plasma of a high-frequency induction discharge. The model is based on solving a system of two-dimensional Maxwell equations written for a cylindrical coordinate system. 相似文献
903.
Based on particular solutions of a system of wave equations which describe electromagnetic processes in an unbounded biisotropic medium and are represented in the form of generalized power series, a dispersion equation is obtained for a two-layer circular waveguide with a chiral and a dielectric layer. The solution of the dispersion equation is analyzed for some types of natural waves. 相似文献
904.
V. S. Gorelik P. P. Sverbil' A. B. Fadyushin V. V. Vasil'ev 《Journal of Russian Laser Research》2004,25(1):54-63
A possibility of application of semiconductor lasers of the visible range as exciting sources for Raman spectroscopy is studied. An experimental set-up for measuring Raman spectra of polycrystalline dielectrics and broad-gap semiconductors excited by a semiconductor laser with a wavelength of 640 nm was created. The conditions under which the spectral width of the lasing line of a semiconductor laser was within 10-3 cm-1 in the continuous mode with a power of 10 mW are realized. The characteristics of various types of exciting sources used in Raman spectroscopy are compared. The results of studies of the characteristic Raman spectra excited with a semiconductor laser in polycrystalline sulfur are presented. 相似文献
905.
A. N. Logunov 《Journal of Russian Laser Research》2004,25(4):331-348
A physical multidimensional local model of the propagation process of a laser pulse in air having no analogy to famous models in laser physics is constructed. It is based on the representations of classical wave mechanics characteristic of the theory of scalar wave fields. 相似文献
906.
907.
908.
The study of the effect of a perfectly conducting plane placed at a certain distance from the surface of a potassium niobate crystal on the characteristics of the generalized Rayleigh and Gulyaev-Bleustein surface waves is continued. In addition, the effect of an infinitely thin conducting layer applied to the surface of the piezoelectric on the characteristics of these waves is analyzed. It is found that a variation in the conductance of this layer can produce a result that completely differs from the result obtained when a perfectly conducting plane is moved toward the surface, although the extreme states of these actions (electrically open and short-circuited surfaces) are identical. A possible physical explanation of this difference is proposed. 相似文献
909.
910.
E. V. Aksenova A. Yu. Val’kov A. A. Karetnikov A. P. Kovshik V. P. Romanov E. I. Ryumtsev 《Journal of Experimental and Theoretical Physics》2004,99(5):965-977
The phenomenon of extraordinary ray refraction in a helical liquid crystal with large (compared to the light wavelength) pitch has been studied by theoretical and experimental methods. At a sufficiently large angle of incidence relative to the pitch axis, the extraordinary ray exhibits reflection (reversal) from a certain layer of the medium. The ordinary ray, for which the system is optically isotropic, exhibits no such reflection. The experimental dependences of the transmitted and reflected (reversed) rays are described using the geometrical optics approximation taking into account the optical losses for scattering inside the liquid crystal. 相似文献