全文获取类型
收费全文 | 2205篇 |
免费 | 162篇 |
国内免费 | 9篇 |
专业分类
化学 | 1526篇 |
晶体学 | 25篇 |
力学 | 68篇 |
数学 | 270篇 |
物理学 | 487篇 |
出版年
2023年 | 14篇 |
2022年 | 61篇 |
2021年 | 76篇 |
2020年 | 56篇 |
2019年 | 88篇 |
2018年 | 68篇 |
2017年 | 49篇 |
2016年 | 115篇 |
2015年 | 76篇 |
2014年 | 83篇 |
2013年 | 168篇 |
2012年 | 139篇 |
2011年 | 129篇 |
2010年 | 96篇 |
2009年 | 93篇 |
2008年 | 109篇 |
2007年 | 122篇 |
2006年 | 107篇 |
2005年 | 80篇 |
2004年 | 69篇 |
2003年 | 56篇 |
2002年 | 55篇 |
2001年 | 51篇 |
2000年 | 37篇 |
1999年 | 30篇 |
1998年 | 16篇 |
1997年 | 16篇 |
1996年 | 16篇 |
1995年 | 15篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1988年 | 7篇 |
1987年 | 11篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 23篇 |
1983年 | 14篇 |
1982年 | 7篇 |
1981年 | 12篇 |
1980年 | 18篇 |
1979年 | 10篇 |
1978年 | 14篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1975年 | 10篇 |
1973年 | 8篇 |
1862年 | 8篇 |
排序方式: 共有2376条查询结果,搜索用时 15 毫秒
1.
2.
3.
The main result of the paper is a theorem, using which a new proof of Roth’s theorem is obtained, a new solvability criterion
for the matrix equation AX-YB = C is proved, a formula for a particular solution of the latter is derived, and the least of
the orders of square nonsingular matrices containing a given rectangular matrix as a submatrix is determined. Bibliography:
5 titles.
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 323, 2005, pp. 15–23. 相似文献
4.
Jun-tao Chang Joerg Evers Marian O. Scully M. Suhail Zubairy 《量子光学学报》2006,12(B08):77-77
We propose a scheme to obtain the distance of two identical atoms placed inside the standing wave field by monitoring the collective resonance fluorescence spectrum emitted by the two particles. We find three different parameter ranges, depending on the distance of the atoms as compared to the transition wavelength. For large interparticle distances, dipole-dipole coupling is negligible, and the main system evolution arises from the interaction with the standing wave field. In the small-distance limit, the dynamics is dominated by the dipole-dipole interaction. Finally, in the intermediate region, a rich interplay of the various couplings arises, which however is lifted for strong driving laser fields. The present measurement procedure allows us to distinguish the three cases. In each of the cases, we show how to determine the distance of the two particles and their respective positions relative to the nodes of the standing wave field with fractional-wavelength precision. 相似文献
5.
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
6.
Al.Th. Kermanidis D.G. Stamatelos G.N. Labeas Sp.G. Pantelakis 《Theoretical and Applied Fracture Mechanics》2006,45(2):148-158
The synergetic effect of corrosion and corrosion induced hydrogen embrittlement damage processes which occur at local scale has been found to result in a dramatic macroscopic tensile ductility loss of the 2024 aluminum alloy. In the present work, the tensile behaviour of corroded 2024 T351 specimens has been estimated on the basis of FE analysis by taking into account the local material properties in the damaged areas. A parametric study is involved to account for the effect of thickness in the results. Calculated tensile properties obtained with the analysis agree well with experimental data. 相似文献
7.
L. V. Giurgiu M. N. Grecu X. Filip O. Raita Al. Darabont D. Gavre J. Blasco 《Applied magnetic resonance》2003,24(3-4):351-360
We report an electron paramagnetic resonance (EPR) investigation of the spin dynamics in the paramagnetic regime of the colossal magnetoresistive manganites La2/3Ca1/3Mn1?x Me x O3 (Me=Al, In;x≤0.05). The temperature dependences of the EPR linewidth and integral intensity have been analyzed in terms of the bottleneck spin relaxation and small-polaron hopping models. The exchange coupling integral between Mn3+ and Mn4+ ions and the polaron activation energy decrease with increasing doping level. A discussion is given concerning the factors which could explain the observed changes. 相似文献
8.
9.
Summary Transfer chemical potentials have been determined from measured solubilities for four uncharged encapsulated iron(II) complexes containing three diimine ligating moieties and O3BOBu-n and O3BF capping groups, in H2O–MeOH andt-BuOH–H2O solvent mixtures, The trends in transfer chemical potentials are discussed in terms of the natures of the encapsulating ligands, and are compared with those for a selection of other iron(II)-diimine complexes. 相似文献
10.