全文获取类型
收费全文 | 9741篇 |
免费 | 302篇 |
国内免费 | 3篇 |
专业分类
化学 | 4983篇 |
晶体学 | 56篇 |
力学 | 184篇 |
数学 | 1972篇 |
物理学 | 2851篇 |
出版年
2021年 | 112篇 |
2020年 | 134篇 |
2019年 | 115篇 |
2018年 | 182篇 |
2017年 | 196篇 |
2016年 | 470篇 |
2015年 | 342篇 |
2014年 | 390篇 |
2013年 | 884篇 |
2012年 | 423篇 |
2011年 | 506篇 |
2010年 | 322篇 |
2009年 | 271篇 |
2008年 | 277篇 |
2007年 | 198篇 |
2006年 | 199篇 |
2005年 | 100篇 |
2004年 | 114篇 |
2003年 | 126篇 |
2002年 | 153篇 |
2001年 | 127篇 |
2000年 | 136篇 |
1999年 | 126篇 |
1998年 | 124篇 |
1997年 | 122篇 |
1996年 | 115篇 |
1995年 | 120篇 |
1994年 | 101篇 |
1993年 | 102篇 |
1992年 | 93篇 |
1991年 | 94篇 |
1990年 | 85篇 |
1989年 | 83篇 |
1988年 | 115篇 |
1987年 | 101篇 |
1986年 | 96篇 |
1985年 | 140篇 |
1984年 | 129篇 |
1983年 | 110篇 |
1982年 | 94篇 |
1981年 | 97篇 |
1980年 | 115篇 |
1979年 | 110篇 |
1978年 | 112篇 |
1977年 | 128篇 |
1976年 | 110篇 |
1975年 | 89篇 |
1974年 | 119篇 |
1973年 | 105篇 |
1966年 | 81篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
On‐line coupling of LC and ICP‐MS has been used for fractionation and detection of species of Cu, Fe, I, Se and Zn in human serum. It has been shown that anion exchange chromatography provided better separation capability (both intra‐ and inter‐element) than size‐exclusion chromatography. The mobile phases for ion exchange chromatography consisted of Tris–HNO3 buffer and ammonium salt (nitrate, acetate or formate). Formate was found to be the best mobile phase counter ion, enabling good chromatographic separation, and is acceptable for mass spectrometry too. The quantitative evaluation of element concentrations adhering to individual fractions was performed by the peak area normalization method. The repeatability of results ranged from 3 to 15% (depending on the element concentration level) and represented the main part of the result uncertainty. The accuracy of Cu and Zn fraction determinations was confirmed by comparison with the isotope dilution technique. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
2.
The complete set of self-consistent parameters of nominally undoped LiNbO3 crystals of congruent composition that describe the electro-optic, piezoelectric, elasto-optic, elastic, and dielectric response
has been determined by numerically evaluating available measurements. The parameters were determined at room temperature and
consist of the low-frequency clamped dielectric constants εS
ij, elastic stiffness constants at constant electric field CE
ijkl, piezoelectric stress coefficients eijk, elasto-optic constants at constant electric field pE
ijkl, and clamped electro-optic coefficients rS
ijk. It is shown that the complete set is required for calculating the effective electro-optic coefficients and dielectric constants
in photorefractive applications of LiNbO3.
Received: 4 January 2002 / Revised version: 1 February 2002 / Published online: 14 March 2002 相似文献
3.
4.
Petr Šeba 《Letters in Mathematical Physics》1988,16(1):51-59
The method of complex scaling, usually used in atomic and molecular resonance calculations, is generalized to the Dirac equation. It is shown that Dirac resonances are associated with nonreal eigenvalues of the scaled Dirac Hamiltonian. The perturbation theory for the resonance parameters is also discussed. 相似文献
5.
6.
7.
8.
9.
Sodium hexafluoromanganate(III) has been synthesized by heating equimolecular quantities of Na2MnF5 and NaF in argon atmosphere. The compound is monoclinic witha=5.56 (1) Å,b=5.84 (1) Å,c=8.10 (2) Å, =90.7 (2) andZ=2. It is a high spin complex with
eff
and the deformation of the octahedra is evident from its IR-spectra. Two enantiotropic transitions (at 562 and 653°C) and the melting point at 800°C have been observed.
8. Mitt.: Mh. Chem.106, 483 (1975). 相似文献
8. Mitt.: Mh. Chem.106, 483 (1975). 相似文献
10.
L. Avanov N. Borodkova Z. NĚmeček A. Omeltchenko J. Šafránková A. Skalski Yu. Yermolaev G. Zastenker 《Czechoslovak Journal of Physics》1987,37(6):759-774
The paper describes the results of investigations of the solar wind ions, carried out on board the high apogee Prognoz 7 and Prognoz 8 Earth's satellites with the aid of an SKS instrument (USSR) and a Monitor instrument (USSR-SSR). Behaviour of proton and that of components on the front of Earth's bow and interplanetary shock waves were compared by means of the energoanalysis and energy-mass analysis techniques. In several long-term periods of observation the solar wind heavy ions — oxygen, silicon and iron were determined. It enabled us to estimate the solar corona chemical composition and electron temperature.Presented at the 5th General Assembly IAGA/IAMAP August 5–17, 1985, Prague, Czechoslovakia. 相似文献