全文获取类型
收费全文 | 57339篇 |
免费 | 7716篇 |
国内免费 | 14806篇 |
专业分类
化学 | 37651篇 |
晶体学 | 1832篇 |
力学 | 4598篇 |
综合类 | 1633篇 |
数学 | 9264篇 |
物理学 | 24883篇 |
出版年
2023年 | 393篇 |
2022年 | 1587篇 |
2021年 | 1567篇 |
2020年 | 1584篇 |
2019年 | 1669篇 |
2018年 | 1651篇 |
2017年 | 2251篇 |
2016年 | 1811篇 |
2015年 | 2267篇 |
2014年 | 2806篇 |
2013年 | 3757篇 |
2012年 | 3573篇 |
2011年 | 3905篇 |
2010年 | 4017篇 |
2009年 | 4056篇 |
2008年 | 4467篇 |
2007年 | 4006篇 |
2006年 | 3926篇 |
2005年 | 3303篇 |
2004年 | 2749篇 |
2003年 | 2111篇 |
2002年 | 2358篇 |
2001年 | 2303篇 |
2000年 | 2284篇 |
1999年 | 1405篇 |
1998年 | 823篇 |
1997年 | 673篇 |
1996年 | 632篇 |
1995年 | 518篇 |
1994年 | 501篇 |
1993年 | 563篇 |
1992年 | 502篇 |
1991年 | 465篇 |
1990年 | 460篇 |
1989年 | 444篇 |
1988年 | 395篇 |
1987年 | 399篇 |
1986年 | 347篇 |
1985年 | 356篇 |
1984年 | 384篇 |
1983年 | 349篇 |
1979年 | 347篇 |
1978年 | 351篇 |
1977年 | 334篇 |
1976年 | 415篇 |
1975年 | 373篇 |
1974年 | 392篇 |
1973年 | 400篇 |
1972年 | 369篇 |
1971年 | 343篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Ya. V. Fattakhov M. F. Galyautdinov T. N. L’vova I. B. Khaibullin 《Technical Physics》1997,42(12):1457-1459
The first results regarding the formation of a two-dimensional periodic structure of local melting regions on a silicon surface
upon pulsed light irradiation are presented. The conditions are established, and the mechanism of the formation of such structures
is discussed.
Zh. Tekh. Fiz. 67, 97–99 (December 1997) 相似文献
3.
4.
5.
6.
7.
LIU Jixue ZHANG Sanguo & CHEN Xiru Department of Statistics Finance University of Science Technology of China Hefei China Department of Mathematics Graduate School of Chinese Academy of Sciences Beijing China 《中国科学A辑(英文版)》2006,49(6):752-769
This paper studies the linear EV model when replicate observations are made only on independent variables. We construct the estimates of regression coefficients and prove the consistency and asymptotic normality under some proper conditions. Results obtained reveal the difference between the case where the independent and dependent variables are observed repeatedly and simultaneously and the case studied in this article. 相似文献
8.
An algorithm is proposed which allows one to construct higher symmetries of arbitrary order for some special classes of hyperbolic
systems possessing integrals. The Pohlmeyer-Lund-Regge system and the open two-dimensional Toda lattices are shown to belong
to the class of systems where our algorithm is applicable.
__________
Translated from Fundamental’naya i Prikladnaya Matematika (Fundamental and Applied Mathematics), Vol. 10, No. 1, Geometry
of Integrable Models, 2004. 相似文献
9.
A. I. Magunov A. Ya. Faenov I. Yu. Skobelev T. A. Pikuz E. Biémont P. Quinet F. Blasco C. Bonte F. Dorchies T. Caillaud F. Salin C. Stenz 《Journal of Experimental and Theoretical Physics》2002,95(6):998-1005
The satellite structure of 1s2p 1,3 P 1-1s 21 S 0 lines of the He-like argon ion in plasma produced by a 45-fs laser pulse in a gas-jet cluster target is measured with a high spectral resolution. Radiation transitions 2p → 1s from autoionizing states (AISs) are detected for ions ranging from Li-like to F-like. The spectrum observed is theoretically simulated with the use of the spectroscopic data for the AISs of multicharged ions obtained within the multiconfiguration relativistic Hartree-Fock method. Good agreement with experimental data is obtained when the main population channels of these states are taken into account for typical values of cluster-target plasma parameters. 相似文献
10.
Theoretical and experimental investigations on the performance of micro-perforated -panel absorbers are reviewed in this paper. By reviewing recent research work, this paper reveals a relationship between the maximum absorption coefficient and the limit of the absorption frequency bandwidth. It has been demonstrated that the absorption frequency bandwidth can be extended up to 3 or 4 octaves as the diameters of the micro-holes decrease. This has become possible with the development of the technologies for manufacturing micro-perforated panels, such as laser drilling, powder metallurgy, welded meshing and electro-etching to form micrometer order holes. In this paper, absorption characteristics of such absorbers in random fields and in high sound intensity are discussed both theoretically and experimentally. A new absorbing structure based on micro-perforated-panel absorbers demonstrate experimentally high sound absorption capability. This review shows that the micro-perforated-panel absorber has potentials to be one of ideal absorbing materials in the 21st century. 相似文献