全文获取类型
收费全文 | 74784篇 |
免费 | 1734篇 |
国内免费 | 269篇 |
专业分类
化学 | 38202篇 |
晶体学 | 870篇 |
力学 | 2661篇 |
综合类 | 7篇 |
数学 | 10063篇 |
物理学 | 24984篇 |
出版年
2022年 | 482篇 |
2021年 | 650篇 |
2020年 | 791篇 |
2019年 | 673篇 |
2018年 | 1018篇 |
2017年 | 941篇 |
2016年 | 1734篇 |
2015年 | 1188篇 |
2014年 | 1607篇 |
2013年 | 3456篇 |
2012年 | 3209篇 |
2011年 | 3718篇 |
2010年 | 2587篇 |
2009年 | 2377篇 |
2008年 | 3265篇 |
2007年 | 3149篇 |
2006年 | 2957篇 |
2005年 | 2605篇 |
2004年 | 2352篇 |
2003年 | 1966篇 |
2002年 | 1821篇 |
2001年 | 2158篇 |
2000年 | 1635篇 |
1999年 | 1271篇 |
1998年 | 1019篇 |
1997年 | 981篇 |
1996年 | 1014篇 |
1995年 | 916篇 |
1994年 | 925篇 |
1993年 | 882篇 |
1992年 | 1011篇 |
1991年 | 834篇 |
1990年 | 836篇 |
1989年 | 764篇 |
1988年 | 764篇 |
1987年 | 764篇 |
1986年 | 672篇 |
1985年 | 923篇 |
1984年 | 940篇 |
1983年 | 734篇 |
1982年 | 801篇 |
1981年 | 790篇 |
1980年 | 735篇 |
1979年 | 799篇 |
1978年 | 763篇 |
1977年 | 780篇 |
1976年 | 751篇 |
1975年 | 693篇 |
1974年 | 666篇 |
1973年 | 627篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Keller Teichmann Hans Pfeiffer W. Langenbeck A. Reid Heinrich Menzel Th. Höpner W. Mühlsteph M. Ulmann Geib R. E. Liesegang 《Colloid and polymer science》1939,87(1):100-104
Ohne Zusammenfassung 相似文献
102.
103.
V. Balek T. Mitsuhashi I.M. Bountseva H. Haneda Z. Malek J. Šubrt 《Journal of Sol-Gel Science and Technology》2003,26(1-3):185-189
The diffusion structural analysis (DSA) was used to characterize microstructure changes of hydrous titania gel films under in situ conditions of heating. TG and DTA were used in order to elucidate the processes controlling the formation of anatase film during heating of hydrous titania gel film. The annealing of porosity and near surface structure defects of the dehydrated titania films was indicated by DSA in the temperature range 255–700°C as the decrease of radon release rate. It was demonstrated that the annealing was enhanced on heating in oxygen in comparison with heating in argon. The DSA experimental results were compared with model curves describing the radon diffusion mobility and the annealing of radon diffusion paths. 相似文献
104.
105.
J. Song H. Jiang Z.J. Liu D.Y. Khang Y. Huang J.A. Rogers C. Lu C.G. Koh 《International Journal of Solids and Structures》2008,45(10):3107-3121
A finite-deformation theory is developed to study the mechanics of thin buckled films on compliant substrates. Perturbation analysis is performed for this highly nonlinear system to obtain the analytical solution. The results agree well with experiments and finite element analysis in wavelength and amplitude. In particular, it is found that the wavelength depends on the strain. Based on the accurate wavelength and amplitude, the membrane and peak strains in thin films, and stretchability and compressibility of the system are also obtained analytically. 相似文献
106.
We present some algorithms related to rings of Ore polynomials (or, briefly, Ore rings) and describe a computer algebra library
for basic operations in an arbitrary Ore ring. The library can be used as a basis for various algorithms in Ore rings, in
particular, in differential, shift, and q-shift rings.
__________
Translated from Sovremennaya Matematika i Ee Prilozheniya (Contemporary Mathematics and Its Applications), Vol. 13, Algebra,
2004. 相似文献
107.
108.
Z.J. Yang T.H. Johansen H. Bratsberg G. Helgesen A.T. Skjeltorp 《Physica C: Superconductivity and its Applications》1989,160(5-6):461-465
Based on a dipole-dipole interaction model, we discuss the levitation force and related vibration problems to understand the effects of flux pinning in type-II superconductors, and the applications of levitation in superconducting systems. 相似文献
109.
A Raney-Ag catalyst was prepared by leaching out aluminium from a Raney Ag-Al alloy with NaOH solution. The kinetics of leaching
has been investigated in a stirred-batch-reactor at various temperatures by using alloy particles of different sizes. The
kinetic model best fitting the experimental results has been determined.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
110.
Thermodynamic fluctuations in systems that are in nonequilibrium steady states are always spatially long ranged, in contrast to fluctuations in thermodynamic equilibrium. In the present paper we consider a fluid subjected to a stationary temperature gradient. Two different physical mechanisms have been identified by which the temperature gradient causes long-ranged fluctuations. One cause is the presence of couplings between fluctuating fields. Secondly, spatial variation of the strength of random forces, resulting from the local version of the fluctuation-dissipation theorem, has also been shown to generate long-ranged fluctuations. We evaluate the contributions to the long-ranged temperature fluctuations due to both mechanisms. While the inhomogeneously correlated Langevin noise does lead to long-ranged fluctuations, in practice, they turn out to be negligible as compared to nonequilibrium temperature fluctuations resulting from the coupling between temperature and velocity fluctuations. 相似文献