全文获取类型
收费全文 | 5282篇 |
免费 | 38篇 |
国内免费 | 10篇 |
专业分类
化学 | 2501篇 |
晶体学 | 125篇 |
力学 | 165篇 |
综合类 | 3篇 |
数学 | 648篇 |
物理学 | 1888篇 |
出版年
2019年 | 46篇 |
2018年 | 66篇 |
2017年 | 68篇 |
2016年 | 74篇 |
2015年 | 53篇 |
2014年 | 83篇 |
2013年 | 216篇 |
2012年 | 157篇 |
2011年 | 185篇 |
2010年 | 106篇 |
2009年 | 143篇 |
2008年 | 174篇 |
2007年 | 180篇 |
2006年 | 148篇 |
2005年 | 132篇 |
2004年 | 139篇 |
2003年 | 119篇 |
2002年 | 119篇 |
2001年 | 107篇 |
2000年 | 100篇 |
1999年 | 88篇 |
1998年 | 53篇 |
1997年 | 57篇 |
1996年 | 67篇 |
1995年 | 62篇 |
1994年 | 70篇 |
1993年 | 54篇 |
1992年 | 74篇 |
1991年 | 76篇 |
1990年 | 79篇 |
1989年 | 62篇 |
1988年 | 47篇 |
1987年 | 60篇 |
1986年 | 63篇 |
1985年 | 71篇 |
1984年 | 101篇 |
1983年 | 97篇 |
1982年 | 87篇 |
1981年 | 100篇 |
1980年 | 103篇 |
1979年 | 80篇 |
1978年 | 101篇 |
1977年 | 103篇 |
1976年 | 76篇 |
1975年 | 62篇 |
1974年 | 52篇 |
1973年 | 46篇 |
1972年 | 38篇 |
1969年 | 36篇 |
1966年 | 35篇 |
排序方式: 共有5330条查询结果,搜索用时 15 毫秒
1.
2.
3.
G. Ch. Shushkevich 《Technical Physics》1998,43(7):743-748
The electrostatic problem for a thin, unclosed spherical shell and a torus is reduced to paired summation equations in the
Legendre polynomials by means of formulas relating the spherical and toroidal harmonic functions. The paired equations are
transformed to a Fredholm integral equation of the second kind. Formulas are obtained for computing the charges of the conductors
in the form of a series in a small parameter. The capacitance is computed for certain geometrical parameters of the conductors.
Zh. Tekh. Fiz. 68, 1–6 (July 1998) 相似文献
4.
Two methods for multi-element preconcentration from copper by reductive matrix precipitation are presented. In systematic investigations on the coprecipitation behaviour of Ag, Al, Au, Bi, Cd, Co, Cr, Fe, Ga, In, Mn, Mo, NJ, Pb, Sb, Se, Sn, Te and Zn during precipitation of the copper matrix as Cu2O or CuSCN, the separation parameters were optimized. By combination with a hexamethyleneammonium hexamethylenedithiocarbamate collector precipitation, a concentration of 8 elements (Cu2O precipitation) or 13 elements (CuSCN precipitation) in a small volume was achieved. The limits of detection of the procedures are, depending on the element, 0.1–5 μg g?1 for flame atomic absorption spectrometry (AAS) and 0.01–0.1 μg g?1 for graphite furnace AAS. The relative standard deviations are about 3%. The analytical performance of the procedures is compared with that of an electrolytic copper separation. 相似文献
5.
6.
7.
The norm kernel of the A=12 system composed of two 6He clusters, and the L=0 basis functions (in the SU(3) and angular momentum-coupled schemes) are analytically obtained in the Fock-Bargmann space. The norm kernel has a diagonal form in the former basis, but the asymptotic conditions are naturally defined in the latter one. The system is a good illustration for the method of projection of the norm kernel to the basis functions in the presence of SU(3) degeneracy that was proposed by the authors. The coupled-channel problem is considered in the algebraic version of the resonating-group method, with the multiple decay thresholds being properly accounted for. The structure of the ground state of 12Be obtained in the approximation of zero-range nuclear force is compared with the shell-model predictions. In the continuum part of the spectrum, the S-matrix is constructed, the asymptotic normalization coefficients are deduced and their energy dependence is analyzed. 相似文献
8.
O. A. Sadygov Kh. M. Alimardanov Ch. A. Chalabiev 《Russian Journal of Applied Chemistry》2006,79(6):949-956
The features of induced bromination of aromatic hydrocarbons in the NaBr(KBr)-HX-H2O2(NaOCl) system were studied. 相似文献
9.
10.
K. K. Kadyrzhanov S. Khazhekber S. N. Lukashenko V. P. Solodukhin I. V. Kazachevskiy V. L. Poznyak B. B. Knyazev Ch. Rofer 《Czechoslovak Journal of Physics》2003,53(1):A39-A44
Data on the spatial distribution of radionuclides (241Am, 239Pu, 137Cs and 152Eu) formed during nuclear explosions of different types near P2 SNTS test site are presented. Radionuclide contamination induced by the explosions varies in the concentrations of individual radionuclides, their proportions and species. Examination of the variations is a crucial task to plan remediation activities as well as those aimed at decrease of radiation risk for population and prevention of repeated contamination. Concentrations of 241Am and 239+240Pu that are the most toxic radionuclides in the area lie in hundred thousands of Bqkg?1. The most contaminated areas are classified by the radionuclide concentration, ratio and form present in soil. 相似文献