全文获取类型
收费全文 | 741478篇 |
免费 | 5968篇 |
国内免费 | 2332篇 |
专业分类
化学 | 361280篇 |
晶体学 | 10668篇 |
力学 | 39569篇 |
综合类 | 18篇 |
数学 | 117346篇 |
物理学 | 220897篇 |
出版年
2021年 | 5849篇 |
2020年 | 6409篇 |
2019年 | 7286篇 |
2018年 | 19233篇 |
2017年 | 19026篇 |
2016年 | 19132篇 |
2015年 | 8378篇 |
2014年 | 12948篇 |
2013年 | 30241篇 |
2012年 | 26229篇 |
2011年 | 36832篇 |
2010年 | 25299篇 |
2009年 | 25676篇 |
2008年 | 31534篇 |
2007年 | 33399篇 |
2006年 | 23683篇 |
2005年 | 22231篇 |
2004年 | 20915篇 |
2003年 | 19355篇 |
2002年 | 18365篇 |
2001年 | 19033篇 |
2000年 | 14806篇 |
1999年 | 11530篇 |
1998年 | 9939篇 |
1997年 | 9692篇 |
1996年 | 9231篇 |
1995年 | 8320篇 |
1994年 | 8246篇 |
1993年 | 8072篇 |
1992年 | 8514篇 |
1991年 | 8990篇 |
1990年 | 8562篇 |
1989年 | 8438篇 |
1988年 | 8313篇 |
1987年 | 8073篇 |
1986年 | 7666篇 |
1985年 | 9983篇 |
1984年 | 10437篇 |
1983年 | 8646篇 |
1982年 | 9051篇 |
1981年 | 8637篇 |
1980年 | 8252篇 |
1979年 | 8770篇 |
1978年 | 9021篇 |
1977年 | 8886篇 |
1976年 | 8863篇 |
1975年 | 8379篇 |
1974年 | 8263篇 |
1973年 | 8577篇 |
1972年 | 6221篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
The present paper analyzes the properties of structural phase transitions under the extremal conditions of high pressures. In the context of the theory of density functional (TDF), the pressures of the B1–B2 transitions are calculated for small alkali-halide crystals as functions of the crystal size. The size effect of the B1–B2 transition – an increase in the transition pressure with the decreasing crystal grain radius – has been established for all investigated halides except lithium fluoride for which the dependence is reverse. 相似文献
62.
We calculate the leading and next-to-leading logarithmic resummed distribution for the jet broadening in deep inelastic scattering,
as well as the power correction for both the distribution and mean value. A truncation of the answer at NLL accuracy, as is
standard, leads to unphysical divergences. We discuss their origin and show how the problem can be resolved. We then examine
DIS specific procedures for matching to fixed order calculations and compare our results to the data. One of the tools developed
for the comparison is an NLO parton distribution evolution code. When compared to PDF sets from MRST and CTEQ it reveals limited
discrepancies in both.
Received: 16 October 2001 / Published online: 12 April 2002 相似文献
63.
Sanzharov N. A. Yarovoi A. T. Bekhtereva E. S. Ulenikov O. N. 《Russian Physics Journal》2002,45(10):1024-1031
Analytical formulas are derived that describe the dependences of the transition probabilities in vibrational-rotational spectra of XY3-type molecules with C
3v
symmetry on the rotational quantum numbers. 相似文献
64.
Electrical resistivity of U3Tein4, U2Te3 (cubic) and UTe3 has been measured over temperature range 4.2–300 K. The two former compounds appear to be semimetallic conductors while the last one has semiconducting character. The results are discussed in the terms of available magnetic data. 相似文献
65.
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
66.
A. Mielke 《Journal of statistical physics》1991,62(3-4):509-528
The magnetic properties of the one-dimensional Hubbard model with a hardcore interaction on a ring (periodic boundary conditions) are investigated. At finite temperatures it is shown to behave up to exponentially small corrections as a pure paramagnet. An explicit expression for the ground-state degeneracies is derived. The eigenstates of this model are used to perform a perlurbational treatment for large but finite interactions. In first order inU
1 an effective Hamiltonian for the one-dimensional Hubbard model is derived. It is the Hamiltonian of the one-dimensional Hcisenberg model with antiferromagnetic couplings between nearest neighbor spins. An asymptotic expansion for the ground-state energy is given. The results are valid for arbitrary densities of electrons. 相似文献
67.
68.
69.
70.
Results of an experiment on investigating the fluctuations of a sound signal with a frequency of 295 Hz on a stationary 32-km-long acoustic path in a shallow sea are presented. Hydrological conditions on the path were characterized by the presence of a weak thermocline and a frequent occurrence of intense internal wave trains. The space-time characteristics of these internal waves were measured in detail. Experimental evidence of the repetition of the forms of internal solitons in the variations of the amplitude and phase of an acoustic signal was obtained. 相似文献