全文获取类型
收费全文 | 33845篇 |
免费 | 2679篇 |
国内免费 | 2908篇 |
专业分类
化学 | 21237篇 |
晶体学 | 448篇 |
力学 | 2408篇 |
综合类 | 260篇 |
数学 | 4467篇 |
物理学 | 10612篇 |
出版年
2022年 | 558篇 |
2021年 | 677篇 |
2020年 | 738篇 |
2019年 | 835篇 |
2018年 | 860篇 |
2017年 | 892篇 |
2016年 | 1170篇 |
2015年 | 986篇 |
2014年 | 1268篇 |
2013年 | 1697篇 |
2012年 | 1857篇 |
2011年 | 1883篇 |
2010年 | 1558篇 |
2009年 | 1630篇 |
2008年 | 1684篇 |
2007年 | 1620篇 |
2006年 | 1459篇 |
2005年 | 1220篇 |
2004年 | 1117篇 |
2003年 | 1037篇 |
2002年 | 1206篇 |
2001年 | 1099篇 |
2000年 | 782篇 |
1999年 | 605篇 |
1998年 | 460篇 |
1997年 | 376篇 |
1996年 | 359篇 |
1995年 | 321篇 |
1994年 | 284篇 |
1993年 | 330篇 |
1992年 | 293篇 |
1991年 | 293篇 |
1990年 | 313篇 |
1989年 | 311篇 |
1987年 | 268篇 |
1985年 | 290篇 |
1984年 | 291篇 |
1982年 | 279篇 |
1980年 | 265篇 |
1979年 | 304篇 |
1978年 | 330篇 |
1977年 | 320篇 |
1976年 | 404篇 |
1975年 | 360篇 |
1974年 | 388篇 |
1973年 | 396篇 |
1972年 | 369篇 |
1971年 | 331篇 |
1970年 | 314篇 |
1969年 | 298篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
The method of nonlinear moments, when used to solve the Boltzmann equation, necessitates the calculation of collision integral
matrix elements. The matrix elements are hard to calculate numerically, especially at large indices. The asymptotics of the
matrix elements are constructed. In terms of the model of pseudopower particle interaction, a formula free of summation is
derived. This makes it possible to find the asymptotic behavior of linear and nonlinear elements when two indices are large.
For an arbitrary interaction cross section, asymptotic expansions of linear and nonlinear matrix elements in one index are
obtained. For Maxwellian molecules, asymptotic formulas are derived for three large indices. 相似文献
22.
23.
24.
V. V. Dvorkin N. N. Dzbanovskii A. F. Pal’ N. V. Suetin A. Yu. Yur’ev P. Ya. Detkov 《Physics of the Solid State》2004,46(4):729-732
A suspension of ultrafine-dispersed nanodiamond was used for introducing (in particular, selectively) high-density centers of diamond nucleation on various substrates. High-quality doped diamond films to be used as electrochemistry electrodes were deposited from the gas phase in a microwave discharge on certain substrates treated using ultrafine-dispersed nanodiamond. A uniform distribution of nucleation centers with concentrations greater than 1010 cm-2 on silicon substrates was obtained. Electrochemical current-potential curves were measured for continuous films. Diamond meshes of different transparency were grown using selective nucleation. Successful production of high-quality doped diamond meshes gives grounds to consider them the most promising electrodes for use in electrochemistry. 相似文献
25.
26.
M. Ya. Izrailovich 《Acoustical Physics》2004,50(2):163-168
On the basis of the method of equivalent linearization combined with the method of moments, laws of self-oscillation excitation are obtained that provide the modes with maximum intensity of resonance (or quasi-resonance) oscillations in one-dimensional systems with distributed parameters. A restriction of a general type is imposed on the law of excitation. In the particular case of an integral quadratic restriction, the law of excitation leads to the generation of purely harmonic self-oscillations. The use of an extended (multiplicatively stabilizing) control provides the uniqueness and stability of the quasi-optimal mode of self-oscillation. 相似文献
27.
Jensen and Toft 8 conjectured that every 2‐edge‐connected graph without a K5‐minor has a nowhere zero 4‐flow. Walton and Welsh 19 proved that if a coloopless regular matroid M does not have a minor in {M(K3,3), M*(K5)}, then M admits a nowhere zero 4‐flow. In this note, we prove that if a coloopless regular matroid M does not have a minor in {M(K5), M*(K5)}, then M admits a nowhere zero 4‐flow. Our result implies the Jensen and Toft conjecture. © 2005 Wiley Periodicals, Inc. J Graph Theory 相似文献
28.
The nearest-neighbor two-point correlation function of the Z-invariant inhomogeneous eight-vertex model in the thermodynamic limit is computed using the free-field representation.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 3, 243–247 (10 August 1998)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
29.
30.