全文获取类型
收费全文 | 1456235篇 |
免费 | 45921篇 |
国内免费 | 22269篇 |
专业分类
化学 | 705381篇 |
晶体学 | 20966篇 |
力学 | 79288篇 |
综合类 | 762篇 |
数学 | 249886篇 |
物理学 | 394895篇 |
综合类 | 73247篇 |
出版年
2022年 | 13726篇 |
2021年 | 17858篇 |
2020年 | 19700篇 |
2019年 | 19712篇 |
2018年 | 15183篇 |
2016年 | 32039篇 |
2015年 | 25917篇 |
2014年 | 37517篇 |
2013年 | 82653篇 |
2012年 | 46476篇 |
2011年 | 42706篇 |
2010年 | 43783篇 |
2009年 | 46559篇 |
2008年 | 40380篇 |
2007年 | 35232篇 |
2006年 | 41790篇 |
2005年 | 32857篇 |
2004年 | 34243篇 |
2003年 | 31967篇 |
2002年 | 33124篇 |
2001年 | 30841篇 |
2000年 | 27241篇 |
1999年 | 26705篇 |
1998年 | 24837篇 |
1997年 | 24795篇 |
1996年 | 24639篇 |
1995年 | 22141篇 |
1994年 | 21528篇 |
1993年 | 20532篇 |
1992年 | 20014篇 |
1991年 | 20201篇 |
1990年 | 19135篇 |
1989年 | 18925篇 |
1988年 | 18139篇 |
1987年 | 17858篇 |
1986年 | 16503篇 |
1985年 | 22717篇 |
1984年 | 23855篇 |
1983年 | 20077篇 |
1982年 | 21688篇 |
1981年 | 20909篇 |
1980年 | 20223篇 |
1979年 | 20382篇 |
1978年 | 21695篇 |
1977年 | 21247篇 |
1976年 | 20927篇 |
1975年 | 19623篇 |
1974年 | 19300篇 |
1973年 | 19708篇 |
1972年 | 14218篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
K. Batra V. Prasad M. Mohan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,20(2):191-198
The scattering of heavy ion with a multilevel Rydberg atom in the presence of an electromagnetic field is studied. The interaction
of Rydberg atom and the e.m field is explored using non-perturbative quasi-energy technique. Although the results are presented
for selected excitations but in actual calculations we have included many levels of the atom. The effect of various parameters
are shown on collisional excitation process. As an illustration detailed calculations are performed for the inelastic proton-Na
Rydberg atom collision accompanied by the transfer of photons and the effects of dressing due to the field are considered.
The emphasis of the present work is on collision induced transitions especially the case that involves change of orbital as
well as principal quantum number.
Received 26 December 2001 / Received in final form 8 April 2002 Published online 19 July 2002 相似文献
952.
A. Bozkurt 《Journal of Physics and Chemistry of Solids》2002,63(4):685-690
Ionic conductivity of dry quaternary ammonium polymer, polydiallyldimethylammonium with Cl− and H2PO4− counter ions was studied in a wide range of frequencies (10−2-107 Hz) and temperatures (300-470 K). The data were analysed within the formalism of permittivity. WAXS, and thermal properties of this polymer were investigated prior to conductivity measurements. 相似文献
953.
A. E. Angervaks S. A. Dimakov S. I. Kliment’ev A. I. Ryskin A. S. Shcheulin 《Optics and Spectroscopy》2002,93(2):307-314
The diffraction efficiency and the recording and relaxation times of dynamic reflection holograms, recorded in CdF2 crystals with bistable centers are studied experimentally in the temperature range 20–100°C. In the model experiments which measured the quality of the wave reflected from the hologram, the dynamic wavefront distortions are demonstrated to be efficiently compensated using a holographic corrector based on these crystals. CdF2 crystals with bistable centers are likely to be useful in solving problems of correction of laser light wavefront and image correction in observation telescopes with nonideal primary mirrors. 相似文献
954.
F. Iachello S. Oss 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(3):307-314
We present a brief review of algebraic techniques developed and applied in molecular spectroscopy in the last five years.
We also outline perspectives for new applications of the Lie algebraic method in the first decade of the new century.
Received 21 November 2001 相似文献
955.
956.
C. J. S. Clarke 《Israel Journal of Mathematics》1983,45(1):9-16
It is shown that any finite dimensionalC 0 manifold (connected and Hausdorff but otherwise unrestricted) has an atlas of cardinality not greater than that of the continuum; while if it has a Hölder continuous pseudo-Riemannian metric then there is a countable atlas. 相似文献
957.
The adsorption of hydrogen on a clean Cu10%/Ni90% (110) alloy single crystal was studied using flash desorption spectroscopy (FDS), Auger electron spectroscopy (AES), and work function measurements. Surface compositions were varied from 100% Ni to 35% Ni. The hydrogen chemisorption on a-surface of 100% nickel revealed strong attractive interactions between the hydrogen atoms in accordance with previous work on Ni(100). Three desorption states (β1, β2 and α) appeared in the desorption spectra. The highest temperature (α) state was occupied only after the initial population of the β2-state. As the amount of copper was increased in the nickel substrate, desorption from the higher energy binding α-state was reduced, indicating a decrease in the attractive interactions among hydrogen atoms. The hydrogen coverage at saturation was not affected by the addition of copper to the nickel substrate until the copper concentration was greater than 25% at which a sharp reduction in saturation coverage occurred. This phenomenon was apparently due to the adsorption of hydrogen on Ni atoms followed by occupation of NiNi and CuNi bridged adsorption sites, while occupation of CuCu sites was restricted due to an energy barrier to migration. 相似文献
958.
E. V. Morozov 《Journal of Mathematical Sciences》1991,57(4):3302-3305
Translated fromProblemy Ustoichivosti Stokhasticheskikh Modelei. Trudy Seminara, 1988, pp. 115–120. 相似文献
959.
A. V. Ponosov 《Journal of Mathematical Sciences》1991,56(3):2492-2496
We study properties of some linear and nonlinear operators which occur in the theory of stochastic differential and integral equations.Translated from Statisticheskie Metody Otsenivaniya i Proverki Gipotez, pp. 148–154, 1988. 相似文献
960.
A. I. Bril' V. P. Kabashnikov N. V. Kuz'mina Yu. V. Khodyko 《Journal of Applied Spectroscopy》1991,55(3):934-939
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 55, No. 3, pp. 478–484, September, 1991. 相似文献