全文获取类型
收费全文 | 557347篇 |
免费 | 4898篇 |
国内免费 | 1503篇 |
专业分类
化学 | 274615篇 |
晶体学 | 8498篇 |
力学 | 27514篇 |
综合类 | 11篇 |
数学 | 78233篇 |
物理学 | 174877篇 |
出版年
2021年 | 4281篇 |
2020年 | 4639篇 |
2019年 | 5225篇 |
2018年 | 12716篇 |
2017年 | 13263篇 |
2016年 | 12826篇 |
2015年 | 6371篇 |
2014年 | 9742篇 |
2013年 | 22884篇 |
2012年 | 20165篇 |
2011年 | 29140篇 |
2010年 | 20072篇 |
2009年 | 20044篇 |
2008年 | 26284篇 |
2007年 | 28696篇 |
2006年 | 17890篇 |
2005年 | 19979篇 |
2004年 | 16559篇 |
2003年 | 15203篇 |
2002年 | 13769篇 |
2001年 | 14686篇 |
2000年 | 11295篇 |
1999年 | 8593篇 |
1998年 | 7242篇 |
1997年 | 7126篇 |
1996年 | 6799篇 |
1995年 | 5774篇 |
1994年 | 5778篇 |
1993年 | 5705篇 |
1992年 | 6148篇 |
1991年 | 6424篇 |
1990年 | 6115篇 |
1989年 | 6017篇 |
1988年 | 5786篇 |
1987年 | 5846篇 |
1986年 | 5582篇 |
1985年 | 7146篇 |
1984年 | 7317篇 |
1983年 | 6052篇 |
1982年 | 6343篇 |
1981年 | 6005篇 |
1980年 | 5782篇 |
1979年 | 6251篇 |
1978年 | 6374篇 |
1977年 | 6279篇 |
1976年 | 6281篇 |
1975年 | 5919篇 |
1974年 | 5844篇 |
1973年 | 6065篇 |
1972年 | 4208篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
O. Perru F. Ibrahim O. Bajeat C. Bourgeois F. Clapier E. Cottereau C. Donzaud M. Ducourtieux S. Galès D. Guillemaud-Mueller C. Lau H. Lefort F. Le Blanc A. C. Mueller J. Obert N. Pauwels J. C. Potier F. Pougheon J. Proust B. Roussière J. Sauvage O. Sorlin D. Verney 《Physics of Atomic Nuclei》2003,66(8):1421-1427
The PARRNe facility has been used to produce neutron-rich isotopes 83,84Gaby the ISOL method. Their decay has been studied, and β-γ coincidence and γ-γ coincidence data were collected as a function of time. The first two excited levels in 83Ge and the first excited level in 84Ge have been measured for the first time. 相似文献
994.
Lobanovsky L. S. Troyanchuk I. O. 《Journal of Experimental and Theoretical Physics》2003,96(2):331-334
Journal of Experimental and Theoretical Physics - The magnetoresistance effect in the SmCu3Mn4O12 compound with a perovskite-like structure is investigated for the first time. It is found that an... 相似文献
995.
The steady motion of a spheroidal aerosol particle with inner nonuniformly distributed heat sources (sinks) that is placed
in an external temperature gradient is theoretically studied in the Stokes approximation. The mean temperature of the particle
surface is assumed to differ slightly from that of the gaseous environment. An analytic expression for the force and rate
of thermophoresis are found by solving the gas-dynamic equations in view of the motion of the environment. 相似文献
996.
Set-Valued and Variational Analysis - 相似文献
997.
In the present paper we give necessary and sufficient conditions for the subgroup separability of the fundamental group of a finite graph of groups with finitely generated abelian vertex groups.
998.
An experiment was designed to determine whether normally sighted human subjects would be able to adapt to the handicapping effects of sudden deprivation of visual cues on horizontal plane sound localization. Two groups of sighted normal-hearing young adults participated. One group was allowed the benefit of sight. The other group was blindfolded. Measurements of accuracy and the time to respond were made daily over the course of five consecutive days, in a semi-reverberant sound proof booth that modeled listening in a small office. Sound localization was assessed using an array of eight speakers that surrounded the subject in space. Each day, one block of 120 trials was presented for each of three stimuli, two one-third octave noise bands, centred at 0.5 and 4 kHz, and broadband noise, to assess the utilization of interaural temporal difference cues, interaural level difference cues and binaural and spectral cues in combination. Blindfolded subjects were relatively less accurate than sighted subjects. Both groups showed gains with practice, the blindfolded group to a greater degree, largely due to improvements in the use of spectral cues. The blindfolded group took longer to respond than the sighted group, but showed greater decrements in response time with practice. 相似文献
999.
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
1000.
A self-consistent, completely quantum calculation of the structure of the inner crust of neutron stars is carried out in the Wigner-Seitz approximation with a realistic phenomenological nuclear energy functional, where pair correlations of neutrons and protons are included in the explicit form. It has been shown that the superfluidity of neutrons and protons affects the structure of the ground state of the crust. 相似文献