全文获取类型
收费全文 | 942篇 |
免费 | 14篇 |
专业分类
化学 | 522篇 |
晶体学 | 5篇 |
力学 | 24篇 |
数学 | 25篇 |
物理学 | 380篇 |
出版年
2021年 | 13篇 |
2020年 | 19篇 |
2019年 | 18篇 |
2018年 | 19篇 |
2017年 | 21篇 |
2016年 | 18篇 |
2015年 | 14篇 |
2014年 | 22篇 |
2013年 | 40篇 |
2012年 | 28篇 |
2011年 | 42篇 |
2010年 | 25篇 |
2009年 | 24篇 |
2008年 | 36篇 |
2007年 | 43篇 |
2006年 | 38篇 |
2005年 | 55篇 |
2004年 | 38篇 |
2003年 | 26篇 |
2002年 | 46篇 |
2001年 | 43篇 |
2000年 | 27篇 |
1999年 | 37篇 |
1998年 | 18篇 |
1997年 | 15篇 |
1994年 | 9篇 |
1993年 | 11篇 |
1992年 | 10篇 |
1991年 | 13篇 |
1990年 | 8篇 |
1989年 | 16篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 5篇 |
1984年 | 7篇 |
1983年 | 9篇 |
1981年 | 5篇 |
1979年 | 9篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 8篇 |
1973年 | 11篇 |
1972年 | 5篇 |
1971年 | 11篇 |
1970年 | 9篇 |
1969年 | 5篇 |
1968年 | 4篇 |
1967年 | 7篇 |
1965年 | 5篇 |
排序方式: 共有956条查询结果,搜索用时 15 毫秒
1.
Physics of Atomic Nuclei - The article presents the concept of a channel-type reactor with a combined cooled moderator. The moderator consists of ceramic beryllium oxide and a liquid... 相似文献
2.
3.
N. V. Vysotina A. S. Naumov N. N. Rozanov R. L. Sabirov V. E. Semenov V. A. Smirnov T. V. Starchikova S. V. Fedorov S. A. Chizhov V. E. Yashin 《Optics and Spectroscopy》2004,97(3):411-415
The final stage of self-focusing of 500-ps pulses of a neodymium laser in silicate and phosphate glasses and in the nonlinear liquids perfluorooctane, benzene, and toluene is studied theoretically and experimentally. The formation of spatial solitons, which are stable due to the nonlinearity saturation, is demonstrated. It is found that the intensity of the nonlinearity saturation is close to that of the threshold breakdown for glasses and the role of stimulated Raman scattering is significant for liquids. 相似文献
4.
CV Tomy D Pal SS Banerjee S Ramakrishnan AK Grover S Bhattacharya MJ Higgins G Balakrishnan McK Paul 《Pramana》2002,58(5-6):925-935
The weakly pinned single crystals of the hexagonal 2H-NbSe2 compound have emerged as prototypes for determining and characterizing the phase boundaries of the possible order-disorder
transformations in the vortex matter. We present here a status report based on the ac and dc magnetization measurements of
the peak effect phenomenon in three crystals of 2H-NbSe2, in which the critical current densities vary over two orders of magnitude. We sketch the generic vortex phase diagram of
a weakly pinned superconductor, which also utilizes theoretical proposals. We also establish the connection between the metastability
effects and pinning. 相似文献
5.
6.
A computer simulation of the kinetics of free-radical oxidation of lipids in the presence of tocopherol was performed. The induction periods and initial rates of oxidation as functions of initial tocopherol concentrations were found to exhibit extremums. The extended kinetic scheme used in this study describes all types of observed relationships and eliminates illusory contradictions between two groups of experiments in which the antioxidant and prooxidant effects of tocopherol were found. The model can form a basis for the prediction of the effects of tocopherol and its analogs under real conditions. 相似文献
7.
We estimate the possible influence of spectral line profile (Lorentz profile, Van Vleck–Weisskopf profile, and profile obtained by solving kinetic equation) on the rotation part of the dielectric permittivity of water-vapor monomers. Spectral regions corresponding to long-wavelength (static) and high-frequency (optical) limiting cases as well as regions in close proximity to resonances of various intensities are considered. The studied effects are compared with the corresponding effects on water-vapor absorption coefficient, which are related to factors determining the line-shape structure. 相似文献
8.
We describe equipment and a method for performing an experiment on a short meteor radio line of length 85 km. The feature of the experiment is monitoring of meteor-matter deposition to the atmosphere using a radar located at one point of the radio line with the simultaneous determination of the main radio-line characteristics. 相似文献
9.
The molecular structures of phenylphosphine and its analogs, aniline and phenylarsine, were studied by gas-phase electron diffraction and quantum-chemical methods. The geometry and force constants were calculated at the HF/6-31G and B3LYP/6-31G* levels of theory. Phenylphosphine and phenylarsine possess a bisector conformation with asymmetric phenyl rings. The main geometric parameters are as follows (r
a): P-C 1.833(6), C-Cav 1.397(1)Å. The structures of molecules like X2YPh (X = H, F, Cl; Y = N, P, As) were discussed. 相似文献
10.