全文获取类型
收费全文 | 30502篇 |
免费 | 952篇 |
国内免费 | 1178篇 |
专业分类
化学 | 15077篇 |
晶体学 | 477篇 |
力学 | 1361篇 |
综合类 | 105篇 |
数学 | 4377篇 |
物理学 | 11235篇 |
出版年
2024年 | 19篇 |
2023年 | 113篇 |
2022年 | 369篇 |
2021年 | 588篇 |
2020年 | 600篇 |
2019年 | 806篇 |
2018年 | 1211篇 |
2017年 | 1333篇 |
2016年 | 1610篇 |
2015年 | 839篇 |
2014年 | 1437篇 |
2013年 | 2171篇 |
2012年 | 2004篇 |
2011年 | 2126篇 |
2010年 | 2246篇 |
2009年 | 2132篇 |
2008年 | 2137篇 |
2007年 | 2021篇 |
2006年 | 1763篇 |
2005年 | 1202篇 |
2004年 | 834篇 |
2003年 | 520篇 |
2002年 | 617篇 |
2001年 | 566篇 |
2000年 | 799篇 |
1999年 | 507篇 |
1998年 | 571篇 |
1997年 | 525篇 |
1996年 | 173篇 |
1995年 | 97篇 |
1994年 | 102篇 |
1993年 | 60篇 |
1992年 | 72篇 |
1991年 | 73篇 |
1990年 | 53篇 |
1989年 | 33篇 |
1988年 | 29篇 |
1987年 | 21篇 |
1986年 | 23篇 |
1985年 | 22篇 |
1984年 | 15篇 |
1983年 | 30篇 |
1982年 | 15篇 |
1981年 | 20篇 |
1980年 | 12篇 |
1978年 | 10篇 |
1977年 | 12篇 |
1974年 | 8篇 |
1968年 | 10篇 |
1964年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
V. T. Bublik S. Yu. Matsnev K. D. Shcherbachev M. V. Mezhennyi M. G. Mil’vidskii V. Ya. Reznik 《Physics of the Solid State》2003,45(10):1918-1925
Diffuse x-ray scattering (DXS) is used to study the formation of microdefects (MDs) in heat-treated dislocation-free large-diameter silicon wafers with vacancies. The DXS method is shown to be efficient for investigating MDs in silicon single crystals. Specific defects, such as impurity clouds, are found to form in the silicon wafers during low-temperature annealing at 450°C. These defects are oxygen-rich regions in the solid solution with diffuse coherent interfaces. In the following stages of decomposition of the supersaturated solid solution, oxide precipitates form inside these regions and the impurity clouds disappear. As a result of the decomposition of the supersaturated solid solution of oxygen, interstitial MDs form in the silicon wafers during multistep heat treatment. These MDs lie in the {110} planes and have nonspherical displacement fields. The volume density and size of MDs forming in the silicon wafers at various stages of the decomposition are determined. 相似文献
92.
V. F. Shkar’ V. P. Denisenkov A. M. Grishin A. A. Yalali S. I. Khartsev E. I. Nikolaev V. N. Sayapin 《Physics of the Solid State》2003,45(12):2334-2337
Bismuth iron garnet films prepared through electron-beam and laser-induced evaporation on (001)-oriented substrates of scandium gallium gadolinium garnet are investigated using ferromagnetic resonance. It is assumed that the additional minima observed in the angular dependence of the resonance field can be associated with the magnetic moment of bismuth ions. 相似文献
93.
94.
M. S. Nikol’skii 《Computational Mathematics and Modeling》2007,18(4):420-431
We consider the behavior of bundles of optimal controls when the initial state of the system goes to some given vector. We
investigate three types of optimization problems: problems with fixed process length and a free right endpoint; problems with
fixed process length and a fixed right endpoint; time-optimal problems. The article is a review of recent results obtained
by the author.
__________
Translated from Nelineinaya Dinamika i Upravlenie, No. 4, pp. 301–314, 2004. 相似文献
95.
A. V. Porfir’eva G. A. Evtyugin E. Yu. Podshivalina L. I. Anchikova G. K. Budnikov 《Journal of Analytical Chemistry》2007,62(12):1180-1186
A new technique is proposed for detecting interactions between DNA and DNA autoimmune antibodies using a potentiometric sensor based on a glassy-carbon electrode modified with polyaniline and native DNA from chicken erythrocytes. It is shown that the DNA-antibody interaction changes the rate of polyaniline doping in transferring the DNA sensor from an alkaline (pH 7.5) solution, which is optimum for the immunochemical reaction, to an acidic (pH 3.0) solution. The dynamics of the variation of the DNA sensor potential depends on the titer of antibodies and their origin. The dependence of the DNA sensor signal on the dilution of the blood sera from systemic lupus erythematosus and autoimmune thyroiditis patients shows that DNA antibodies can be diagnosed by the characteristic maximum in the dilution curve found in the range of serum dilutions from 1: 20 to 1: 50. 相似文献
96.
D. A. Kosmodem’yanskii 《Moscow University Mathematics Bulletin》2007,62(2):56-60
Spectral properties of the following three homogenized problems in the mechanics of strongly nonhomogeneous media are considered: the “double porosity” problem, the oscillation problem for a mixture of two viscous compressible liquids, and the oscillation of a medium consisting of an elastic frame and a viscous liquid. For all three cases results on the structure of the spectrum and on the existence of so-called “spectral gaps” are obtained. 相似文献
97.
O. V. Il’in 《Journal of Mathematical Sciences》2007,141(1):1041-1047
We describe W-geometry of two-dimensional Toda systems associated with the Lie algebra C
n
.
__________
Translated from Fundamental’naya i Prikladnaya Matematika (Fundamental and Applied Mathematics), Vol. 11, No. 1, Geometry,
2005. 相似文献
98.
S. A. Andronati A. A. Krys’ko B. M. Chugunov T. A. Kabanova A. G. Artemenko 《Russian Journal of Organic Chemistry》2006,42(8):1174-1182
A new series of RGDF mimetics, derivatives of 4-(isoindolin-5-yl)amino-4-oxobutanoic acid, was synthesized. The compounds obtained inhibit efficiently the thrombocytes aggregation in experiments in vitro; their biological targets are fibrinogen receptors. The antiaggregatory activity and the affinity correlate with the hydrophobicity of the compounds. 相似文献
99.
Role of readily hydrolyzable polysaccharides of larch wood in production of board materials is studied. 相似文献
100.
S. V. Dil’man 《Mathematical Notes》2006,79(5-6):625-631
In 1996, D. Deng established an analog of the Baum—Katz theorem on the convergence rate in the law of large numbers for multi-indexed random variables. The series describing the convergence rate depends, in a natural way, on the parameter characterizing the excess of the normalized sums over some level. In this paper, we find the precise asymptotics of the sum of this series with respect to the above-mentioned parameter. Thus, a generalization of a recent result due to A. Gut and A. Spataru is obtained. 相似文献