全文获取类型
收费全文 | 3607篇 |
免费 | 209篇 |
国内免费 | 17篇 |
专业分类
化学 | 2602篇 |
晶体学 | 49篇 |
力学 | 116篇 |
数学 | 430篇 |
物理学 | 636篇 |
出版年
2024年 | 10篇 |
2023年 | 36篇 |
2022年 | 153篇 |
2021年 | 120篇 |
2020年 | 98篇 |
2019年 | 169篇 |
2018年 | 124篇 |
2017年 | 84篇 |
2016年 | 194篇 |
2015年 | 121篇 |
2014年 | 130篇 |
2013年 | 266篇 |
2012年 | 233篇 |
2011年 | 198篇 |
2010年 | 165篇 |
2009年 | 153篇 |
2008年 | 158篇 |
2007年 | 169篇 |
2006年 | 144篇 |
2005年 | 113篇 |
2004年 | 115篇 |
2003年 | 87篇 |
2002年 | 92篇 |
2001年 | 63篇 |
2000年 | 52篇 |
1999年 | 39篇 |
1998年 | 16篇 |
1997年 | 24篇 |
1996年 | 29篇 |
1995年 | 24篇 |
1994年 | 18篇 |
1993年 | 23篇 |
1992年 | 20篇 |
1991年 | 19篇 |
1990年 | 16篇 |
1989年 | 11篇 |
1988年 | 14篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1985年 | 18篇 |
1984年 | 32篇 |
1983年 | 17篇 |
1982年 | 18篇 |
1981年 | 16篇 |
1980年 | 25篇 |
1979年 | 16篇 |
1978年 | 16篇 |
1977年 | 10篇 |
1976年 | 12篇 |
1973年 | 14篇 |
排序方式: 共有3833条查询结果,搜索用时 0 毫秒
1.
2.
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
3.
5‐Amino‐4‐methyl‐2‐phenyl‐6‐substitutedfuro[2,3‐d]pyrimidines ( 2a‐c ) were reacted with 2,5‐dimethoxytetrahydrfuran to afford the pyrrolyl derivatives 3a‐c . Compound 3a was chosen as intermediate for the synthesis of poly fused heterocycles incorporated furopyrimidines moiety 4–11 . Some of the synthesized compounds were screened for their antibacterial and antifungal activities. 相似文献
4.
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
5.
6.
LetP(z) be a polynomial of degreen which does not vanish in |z|<1. In this paper, we estimate the maximum and minimum moduli of thekth polar derivative ofP(z) on |z|=1 and thereby obtain compact generalizations of some known results, which among other results, yields interesting refinements of Erdos-Lax theorem and a theorem of Ankeny and Rivlin. 相似文献
7.
We consider the isothermal flow through a cylindrical flat chamber, a model of some particular heat exchanger, for which LDV measurements and a numerical simulation have been performed. Experimental results show the establishment of an important vortex zone, the secondary flow extending all along the chamber radius. This observation leads to an expected significant increase of the fluid mixing. Results issued from the numerical simulation appear to be in close agreement with experimental data. Nevertheless, the k–ε model used here must be improved to obtain a better approach near the vortex centre. To cite this article: S. Petitot et al., C. R. Mecanique 330 (2002) 593–599. 相似文献
8.
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
9.
10.
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