全文获取类型
收费全文 | 233184篇 |
免费 | 1999篇 |
国内免费 | 801篇 |
专业分类
化学 | 116917篇 |
晶体学 | 3997篇 |
力学 | 10766篇 |
综合类 | 1篇 |
数学 | 25534篇 |
物理学 | 78769篇 |
出版年
2020年 | 1787篇 |
2019年 | 2046篇 |
2018年 | 2720篇 |
2017年 | 2652篇 |
2016年 | 3916篇 |
2015年 | 2392篇 |
2014年 | 3974篇 |
2013年 | 10086篇 |
2012年 | 7535篇 |
2011年 | 9408篇 |
2010年 | 6688篇 |
2009年 | 6631篇 |
2008年 | 8710篇 |
2007年 | 8742篇 |
2006年 | 8276篇 |
2005年 | 7495篇 |
2004年 | 6924篇 |
2003年 | 6112篇 |
2002年 | 6060篇 |
2001年 | 7091篇 |
2000年 | 5376篇 |
1999年 | 4239篇 |
1998年 | 3566篇 |
1997年 | 3472篇 |
1996年 | 3293篇 |
1995年 | 3010篇 |
1994年 | 2954篇 |
1993年 | 3046篇 |
1992年 | 3158篇 |
1991年 | 3333篇 |
1990年 | 3084篇 |
1989年 | 3029篇 |
1988年 | 3069篇 |
1987年 | 2958篇 |
1986年 | 2803篇 |
1985年 | 3810篇 |
1984年 | 4008篇 |
1983年 | 3199篇 |
1982年 | 3412篇 |
1981年 | 3343篇 |
1980年 | 3232篇 |
1979年 | 3336篇 |
1978年 | 3424篇 |
1977年 | 3350篇 |
1976年 | 3449篇 |
1975年 | 3142篇 |
1974年 | 3152篇 |
1973年 | 3194篇 |
1972年 | 2236篇 |
1971年 | 1849篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
221.
An assumption that the most probable fragments of spontaneous low-energy fission inherit the quantum structure of initial nuclei is discussed. The energies Q of spontaneous decay into two fragments of nuclei with 2 < Z < 102 are estimated. The transition from negative to positive values of Q occurs near Z = 40. 相似文献
222.
Russian Physics Journal - 相似文献
223.
224.
225.
Acoustical Physics - A method for calculating the resulting field of an opaque radiator and the field scattered by an inhomogeneous inclusion in a planar layered waveguide is described. The... 相似文献
226.
M. E. Kompan V. P. Kuznetsov V. V. Rozanov A. V. Yakubovich 《Physics of the Solid State》2004,46(6):1110-1112
The size of an ionistor capacitor structure is found to change during its charging and discharging. The specific feature of this effect that distinguishes it from other known effects of changing sizes under electric and magnetic fields (the piezoelectric effect and striction) is the complete hysteresis; i.e., the size reached under the exposure remains unchanged after the field is turned off. 相似文献
227.
P. A. Vityaz 《Physics of the Solid State》2004,46(4):606-610
Technological features of the commercial production of detonation-synthesis nanodiamonds at the SINTA Joint-Stock Company and the characteristics of the nanodiamonds and diamond-containing mixtures produced are considered. Nanodiamond applications in the production of composite electrolytic coatings that are based on chromium, nickel, gold, and silver, exhibit good service properties, and save on the use of noble metals and electric power are exemplified. Nanodiamond applications for the modification of plastics, antifriction lubricants, and oxide coatings grown by microarc oxidation of aluminum alloys are also considered. The prospective application of nanodiamonds as a raw material in the synthesis of diamond powders and superhard composites by static and shock-wave loading is demonstrated. 相似文献
228.
Aerodynamic interaction of two bodies in a supersonic flow 总被引:1,自引:0,他引:1
229.
In the present paper, the Shubnikov–de Haas oscillation frequencies arising in laminated charge-ordered crystals with a monotonic negative reluctance due to scattering of current carriers on charged impurities with a short-range potential are calculated and classified. It is demonstrated that non-semiclassical oscillation frequencies can be a measure of charge ordering. 相似文献
230.
S. P. Gavva 《Optics and Spectroscopy》2003,95(2):208-212
In the context of the theory of molecular vibrations, by applying the direct product operation of matrices, an equation for the vibrations of vibrationally excited molecules at combination and difference frequencies is obtained. From the solution of this equation, elements of vibration patterns and expressions that can be used for the study of changes in the molecular structural parameters and the coefficients of kinematic interactions are determined. The formulas obtained are applied to the calculation of the anharmonic electro-optical parameters of the molecules of water H2O and its two isotopes H2 17O and H2 18O. These calculations are performed in terms of the semiempirical quantum-chemical CNDO/2 method and by numerical differentiation of dipole moment functions by employing a cubic spline approximation. 相似文献