全文获取类型
收费全文 | 257325篇 |
免费 | 3097篇 |
国内免费 | 898篇 |
专业分类
化学 | 122198篇 |
晶体学 | 3280篇 |
力学 | 13543篇 |
综合类 | 8篇 |
数学 | 50792篇 |
物理学 | 71499篇 |
出版年
2021年 | 1336篇 |
2020年 | 1644篇 |
2019年 | 1601篇 |
2018年 | 12221篇 |
2017年 | 12106篇 |
2016年 | 9383篇 |
2015年 | 3119篇 |
2014年 | 3489篇 |
2013年 | 8065篇 |
2012年 | 10024篇 |
2011年 | 17671篇 |
2010年 | 10730篇 |
2009年 | 10937篇 |
2008年 | 13592篇 |
2007年 | 15389篇 |
2006年 | 7040篇 |
2005年 | 7447篇 |
2004年 | 7023篇 |
2003年 | 6902篇 |
2002年 | 5760篇 |
2001年 | 6486篇 |
2000年 | 4814篇 |
1999年 | 3616篇 |
1998年 | 2658篇 |
1997年 | 2707篇 |
1996年 | 2718篇 |
1995年 | 2448篇 |
1994年 | 2440篇 |
1993年 | 2296篇 |
1992年 | 2762篇 |
1991年 | 2696篇 |
1990年 | 2545篇 |
1989年 | 2481篇 |
1988年 | 2427篇 |
1987年 | 2458篇 |
1986年 | 2254篇 |
1985年 | 2881篇 |
1984年 | 2869篇 |
1983年 | 2312篇 |
1982年 | 2341篇 |
1981年 | 2186篇 |
1980年 | 2183篇 |
1979年 | 2455篇 |
1978年 | 2506篇 |
1977年 | 2437篇 |
1976年 | 2333篇 |
1975年 | 2206篇 |
1974年 | 2188篇 |
1973年 | 2180篇 |
1972年 | 1405篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
G. Baldsiefen H. Hübel W. Korten U. J. van Severen J. A. Cizewski N. H. Medina D. R. Napoli C. Rossi Alvarez G. Lo Bianco S. Signorelli 《Zeitschrift für Physik A Hadrons and Nuclei》1996,355(1):337-338
High-spin states in196Pb have been populated using the reaction170Er(30Si,4n). The previously observed shears bands in this nucleus have been extended and some of their transitions have been reordered. They now form regular bands with band crossings. One of the bands splits into two pathways at high spin. 相似文献
942.
Yu. Dryagin N. Scalyga T. Geist 《International Journal of Infrared and Millimeter Waves》1996,17(7):1199-1204
The construction of a notch-filter for 140 GHz with very low passband insertion loss is described. It is based on a single-mode rectangular waveguide and cylindrical cavities matched to it. The typical transmission characteristic is also presented. 相似文献
943.
Minimax estimates for functionals of solutions of wave equations with time-periodic right-hand sides
L. T. Adzhubey O. G. Nakonechy Yu. K. Pidlypenko 《Journal of Mathematical Sciences》1995,77(5):3452-3457
Minimax mean-square estimates for the velocity potential in the steady regime, as well as for the intensities of harmonic
ponts sources, are obtained from the results of inaccurate measurements of the potential. Bibliography: 4 titles.
Translated fromObchyslyuval’na ta Prykladna Matematyka, No. 77, 1993, pp 87–96. 相似文献
944.
945.
S. E. Kubatkin A. Ya. Tzalenchuk Z. G. Ivanov P. Delsing R. I. Shekhter T. Claeson 《JETP Letters》1996,63(2):126-132
We report on a successful attempt to fabricate a Coulomb blockade electrometer consisting of an ultrasmall YBa2Cu3O7−δ (YBCO) island coupled to two gold electrodes through a high-resistance native surface tunnel barrier. A third electrode placed
near the island was used as an electrostatic gate. Spectra typical for tunneling into the YBCO superconductor were reproducibly
measured. At temperatures below 0.5 K the low-bias conductance was suppressed by the Coulomb blockade. The blockade could
be periodically varied by the gate potential. An external magnetic field of up to 5 T strongly influenced the transport via
the island but without any change in the period of the Coulomb oscillations.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 2, 112–117 (25 January 1996)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
946.
947.
Details are given of a new method allowing an exact calculation of the spontaneous magnetization in the corner as well as along the edge at an arbitrary distance of the corner for a rectangular planar Ising ferromagnet. 相似文献
948.
Veerasingam R. Campbell R.B. Mcgrath R.T. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1995,23(4):688-697
A one-dimensional multispecies model of a helium filled AC plasma display cell is described. The model includes a continuity equation for each species. Poisson's equation and a circuit equation. The fill gas is helium for which the cross sections for ionization and excitation for the various atomic states are well known. The reaction rates for the different species were parametrized as functions of E/N using a zero-dimensional spatial and two velocity multispecies Boltzmann kinetic code. Calculations are performed using address and sustain voltages operating at a frequency of 50 kHz to model the pulse behavior of a dielectric barrier discharge which occurs over a time scale on the order of 200 ns or less. The code simulates multipulse behavior and shows reasonably good agreement with experimental data. The simulations show that the circuit filters out the discharge dynamics and that the pulse width of the discharge current depends on the circuit RC time constant. Using a 123 V sustain voltage, the calculated discharge current is 0.4 A with a full width at half maximum (FWHM) of 28 ns. Experimental values using a 120 V sustain voltage are 0.32 A discharge current and 42 ns FWHM 相似文献
949.
950.
F. Grisch P. Bouchardy M. Péalat B. Chanetz T. Pot M. C. Coët 《Applied physics. B, Lasers and optics》1993,56(1):14-20
Rotational temperature and nitrogen number density are measured in the shock wave/boundary layer interaction region in the vicinity of a two-dimensional compression corner disposed in a low pressure, 55 K, Mach 10 hypersonic air flow. Spatially-resolved data are recorded using a nonlinear optical technique named dual-line coherent anti-Stokes Raman scattering (DLCARS). Averaged temperature and density profiles are compared with those predicted by a Navier-Stokes solver. Good agreement is found. 相似文献