全文获取类型
收费全文 | 3857篇 |
免费 | 61篇 |
国内免费 | 4篇 |
专业分类
化学 | 1674篇 |
晶体学 | 48篇 |
力学 | 116篇 |
数学 | 436篇 |
物理学 | 1648篇 |
出版年
2022年 | 44篇 |
2021年 | 83篇 |
2020年 | 74篇 |
2019年 | 86篇 |
2018年 | 131篇 |
2017年 | 102篇 |
2016年 | 148篇 |
2015年 | 86篇 |
2014年 | 113篇 |
2013年 | 178篇 |
2012年 | 162篇 |
2011年 | 163篇 |
2010年 | 162篇 |
2009年 | 132篇 |
2008年 | 192篇 |
2007年 | 170篇 |
2006年 | 152篇 |
2005年 | 155篇 |
2004年 | 111篇 |
2003年 | 115篇 |
2002年 | 99篇 |
2001年 | 99篇 |
2000年 | 88篇 |
1999年 | 50篇 |
1998年 | 49篇 |
1997年 | 50篇 |
1996年 | 44篇 |
1995年 | 24篇 |
1994年 | 28篇 |
1993年 | 39篇 |
1992年 | 39篇 |
1991年 | 46篇 |
1990年 | 34篇 |
1989年 | 39篇 |
1988年 | 33篇 |
1987年 | 28篇 |
1985年 | 31篇 |
1984年 | 32篇 |
1983年 | 28篇 |
1982年 | 26篇 |
1981年 | 28篇 |
1979年 | 34篇 |
1978年 | 31篇 |
1977年 | 43篇 |
1976年 | 34篇 |
1975年 | 28篇 |
1974年 | 29篇 |
1973年 | 34篇 |
1972年 | 29篇 |
1971年 | 28篇 |
排序方式: 共有3922条查询结果,搜索用时 15 毫秒
1.
A. D. Smirnov 《Journal of Applied Spectroscopy》1991,54(1):33-38
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 54, No. 1, pp. 46–50, January, 1991. 相似文献
2.
Yu. M. Smirnov 《Journal of Applied Spectroscopy》2006,73(6):785-791
Dissociative excitation of the lead atom in e-PbI2 collisions has been studied experimentally. 27 excitation cross sections were measured for an energy of the exciting electrons
equal to 100 eV. Nine optical excitation functions were recorded with variation of the electron energy in the range 0–100
eV. The most probable reaction channels for low electron energies are discussed, as well as the ratio of the dissociative
excitation cross sections for the lead atom in e-PbI2 and e-PbCl2 collisions.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 701–706, November–December, 2006. 相似文献
3.
A method for stabilizing frequency based on using the soliton state of the Bose-Einstein condensate of alkali metal atoms as an atomic source was suggested. The critical total number of lithium condensate particles at which the existence of a quasi-one-dimensional soliton in the condensate was possible and the lifetime of such a soliton were estimated. The attainable accuracy of measuring reference transition frequencies in the suggested standard was shown to be substantially higher than with the known quantum frequency standards. 相似文献
4.
Yu. A. Kumzerov L. S. Parfen’eva I. A. Smirnov H. Misiorek J. Mucha A. Jezowski 《Physics of the Solid State》2003,45(1):57-60
The thermal conductivity of crystalline chrysotile asbestos made up of hollow tubular Mg3Si2O5(OH)4 filaments is measured in the range 5–300 K. The paper discusses the possibility of using this material in studies of the thermal conductivity of thin filaments of metals and semiconductors incorporated into the channels of crystalline chrysotile asbestos tubes. 相似文献
5.
6.
Russian Physics Journal - 相似文献
7.
8.
V. V. Alexandrov E. V. Grabovsky M. V. Zurin I. V. Krasovsky K. N. Mitrofanov S. L. Nedoseev G. M. Oleinik I. Yu. Porofeev A. A. Samokhin P. V. Sasorov V. P. Smirnov M. V. Fedulov I. N. Frolov 《Journal of Experimental and Theoretical Physics》2004,99(6):1150-1172
A qualitative model of the dynamics of a multiterawatt radiating Z-pinch with cold start and high rate of current rise is proposed. The model is used to analyze discharges with currents I ~ 2–5 MA (with dI/dt > 1013 A/s) through uniform or structured plasma-producing loads, including wire arrays. The most important consequence of cold start is that spatially nonuniform plasma production is prolonged to almost the entire current rise time. Under these conditions, the Ampére force begins to play a dominant role in the plasma dynamics before the plasma-producing load is completely transformed into an accelerated plasma. The results of computations of wire-array vaporization are presented. A formula is proposed for estimating the highest attainable velocity of plasma flow into a heterogeneous liner driven by the Ampére force. It is shown that local imbalance between radial motion of the produced plasma and supply of the plasma-producing substance to be ionized leads to axially nonuniform breakthrough of magnetic flux into the liner, which precedes plasma collapse. The magnetic-flux breakthrough gives rise to a chaotic azimuthal-axial plasma structure consisting of radial plasma jets of relatively small diameter, which is called a radial plasma rainstorm. The breaking-through azimuthal magnetic flux obstructs further current flow in the breakthrough region. Analyses of Z-pinch implosion based on the theory of Rayleigh-Taylor instability or the snowplow model are incorrect under the plasma-rainstorm conditions. The processes taking place in a stagnant Z-pinch include conversion of the energy carried by the current-generated magnetic field into turbulent MHD flow of the ion component of the plasma, its convective mixing with magnetic field, heating, energy transfer from ions to electrons, and emission from the plasma. Under typical experimental conditions, emission plays a key role in the energy balance in an imploding pinch. Z-pinch is modeled by an electric-circuit component that has a time-dependent nonlinear impedance and consumes the magnetic energy supplied by a generator through a magnetically insulated transmission line (MITL). The peak power reached in the circuit is comparable to the peak soft X-ray power output emitted by the pinch in terms of magnitude and timing. Optimum matching conditions are formulated for the generator-MITL-pinch circuit. 相似文献
9.
S. P. Savin L. M. Zelenyi E. Amata J. Buechner J. Blecki S. I. Klimov B. Nikutowski J. L. Rauch S. A. Romanov A. A. Skalsky V. N. Smirnov P. Song K. Stasiewicz 《JETP Letters》2004,79(8):368-371
The study of the interaction between collisionless plasma flow and stagnant plasma revealed the presence of an outer boundary layer at the border of a geomagnetic trap, where the super-Alfvén subsonic laminar flow changes over to the dynamic regime characterized by the formation of accelerated magnetosonic jets and decelerated Alfvén flows with characteristic relaxation times of 10–20 min. The nonlinear interaction of fluctuations in the initial flow with the waves reflected from an obstacle explains the observed flow chaotization. The Cherenkov resonance of the magnetosonic jet with the fluctuation beats between the boundary layer and the incoming flow is the possible mechanism of its formation. In the flow reference system, the incoming particles are accelerated by the electric fields at the border of boundary layer that arise self-consistently as a result of the preceding wave-particle interactions; the inertial drift of the incoming ions in a transverse electric field increasing toward the border explains quantitatively the observed ion acceleration. The magnetosonic jets may carry away downstream up to a half of the unperturbed flow momentum, and their dynamic pressure is an order of magnitude higher than the magnetic pressure at the obstacle border. The appearance of nonequilibrium jets and the boundary-layer fluctuations are synchronized by the magnetosonic oscillations of the incoming flow at frequencies of 1–2 mHz. 相似文献
10.