全文获取类型
收费全文 | 215654篇 |
免费 | 1567篇 |
国内免费 | 628篇 |
专业分类
化学 | 117994篇 |
晶体学 | 3270篇 |
力学 | 8371篇 |
综合类 | 6篇 |
数学 | 23365篇 |
物理学 | 64843篇 |
出版年
2020年 | 1970篇 |
2019年 | 2263篇 |
2018年 | 3206篇 |
2017年 | 3114篇 |
2016年 | 4271篇 |
2015年 | 2377篇 |
2014年 | 3821篇 |
2013年 | 9275篇 |
2012年 | 6897篇 |
2011年 | 8438篇 |
2010年 | 6073篇 |
2009年 | 5926篇 |
2008年 | 8138篇 |
2007年 | 8211篇 |
2006年 | 7632篇 |
2005年 | 6947篇 |
2004年 | 6176篇 |
2003年 | 5644篇 |
2002年 | 5501篇 |
2001年 | 5944篇 |
2000年 | 4687篇 |
1999年 | 3472篇 |
1998年 | 3008篇 |
1997年 | 3035篇 |
1996年 | 2825篇 |
1995年 | 2324篇 |
1994年 | 2424篇 |
1993年 | 2456篇 |
1992年 | 2602篇 |
1991年 | 2663篇 |
1990年 | 2567篇 |
1989年 | 2536篇 |
1988年 | 2467篇 |
1987年 | 2437篇 |
1986年 | 2359篇 |
1985年 | 3042篇 |
1984年 | 3200篇 |
1983年 | 2560篇 |
1982年 | 2830篇 |
1981年 | 2708篇 |
1980年 | 2507篇 |
1979年 | 2722篇 |
1978年 | 2836篇 |
1977年 | 2859篇 |
1976年 | 2835篇 |
1975年 | 2691篇 |
1974年 | 2668篇 |
1973年 | 2811篇 |
1972年 | 1876篇 |
1967年 | 1830篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
61.
Glezer A.M. Blinova E.N. Pozdnyakov V.A. Shelyakov A.V. 《Journal of nanoparticle research》2003,5(5-6):551-560
Journal of Nanoparticle Research - It was shown that the thermoelastic martensite transformation B2 ? B19 inside nanoparticles surrounded by amorphous matrix in Ni–Ti–Cu alloys as... 相似文献
62.
E. A. Sopkina 《Journal of Mathematical Sciences》2004,124(1):4832-4836
An invariant of a closed set that is equal to the sum of roots is introduced. For a closed subset in a root system, we describe symmetric and special parts and its stabilizer in the Weyl group by means of the sum of roots. We determine associated bases with respect to which the closed set has the simplest form. All possible values of the root sum are found. Bibliography: 9 titles. 相似文献
63.
E. Sh. Gutshabash 《JETP Letters》2003,78(11):740-744
The integration procedure based on the generalized Darboux transform is suggested for the Ishimori magnet model. Exact solutions are constructed for the model on the background of spiral structures. The possibility of phase transition in the system is hypothesized. 相似文献
64.
The results of optical study and quantum-chemical simulation of a conjugated organic system, 2-cyclooctylamino-5-nitropyridine (COANP)-fullerene, performed to determine its potential for application as a limiter of visible and near-IR laser radiation and as a material for diffraction elements in systems for reversible recording of optical information, are presented. Complexation between a COANP molecule and fullerene is considered as one of the main mechanisms responsible for the corresponding properties of this system. For the first time, nonlinear optical characteristics of COANP-C60 and COANP-C70 systems are comparatively studied and the intermolecular interaction between a COANP molecule and fullerene is analyzed on the quantum-chemical level. 相似文献
65.
The kinetics of decay of a phase hologram in a semiconductor CdF2 crystal with bistable In centers is studied. Kinetic constants of the hologram decay are found, and the potential relief of the bistable center is plotted. The resolving power of the crystal is evaluated and recording of a transparency is demonstrated. 相似文献
66.
Maria G. Semenova Larisa E. Belyakova Anna S. Antipova Yu. N. Polikarpov Lida Klouda Anna Markovic Michael M. Il'in 《Colloids and surfaces. B, Biointerfaces》2003,31(1-4):47-54
We report on the effect of commercially important polysaccharides (maltodextrins with variable dextrose equivalent (Paselli SA-2, MD-6 and MD-10) on the surface activity at the air–water interface of small-molecule surfactants (sms), possessing different hydrophobic–lipophilic balance ((SSL (Na+), the main component is a sodium salt of stearol–lactoyl lactic acid, and PGE (080), polyglycerol ester of C18 fatty acid), and widely used in food products. A marked change of the surface activity of sms was found in the presence of maltodextrins by tensiometry. The combined data of laser multiangle light scattering and mixing calorimetry have suggested that this result is governed by specific complex formation between maltodextrins and sms in aqueous medium. Measurements have been made of the molar mass, the second virial coefficient and the enthalpy of intermolecular interactions in aqueous solutions. The implication of a degree of polymerization of maltodextrins in this phenomenon was shown. The interrelation between the molecular parameters of the formed complexes and their surface activity at the air–water interface has been revealed and discussed. 相似文献
67.
Makarov V. L. Khlobystov V. V. Kashpur E. F. Mikhal'chuk B. R. 《Ukrainian Mathematical Journal》2003,55(6):942-955
We construct an integral Newton-type interpolation polynomial with a continual set of nodes. This interpolant is unique and preserves an operator polynomial of the corresponding degree. 相似文献
68.
69.
70.
N. B. Voznesensky E. V. Gavrilov A. P. Zhevlakov V. K. Kirillovskiĭ P. V. Orlov 《Technical Physics》2007,52(2):271-275
Methods and schemes to inspect the EUV mirror shape are developed on the basis of a point diffraction interferometer with computer processing of interferograms. A measurement accuracy to within 0.001 of a wavelength in the visual range is achieved. 相似文献