全文获取类型
收费全文 | 3923篇 |
免费 | 152篇 |
国内免费 | 16篇 |
专业分类
化学 | 2345篇 |
晶体学 | 14篇 |
力学 | 189篇 |
数学 | 816篇 |
物理学 | 727篇 |
出版年
2023年 | 29篇 |
2022年 | 29篇 |
2021年 | 52篇 |
2020年 | 57篇 |
2019年 | 53篇 |
2018年 | 63篇 |
2017年 | 29篇 |
2016年 | 99篇 |
2015年 | 113篇 |
2014年 | 110篇 |
2013年 | 261篇 |
2012年 | 243篇 |
2011年 | 252篇 |
2010年 | 152篇 |
2009年 | 159篇 |
2008年 | 173篇 |
2007年 | 198篇 |
2006年 | 190篇 |
2005年 | 153篇 |
2004年 | 132篇 |
2003年 | 99篇 |
2002年 | 121篇 |
2001年 | 52篇 |
2000年 | 42篇 |
1999年 | 34篇 |
1998年 | 42篇 |
1997年 | 40篇 |
1996年 | 44篇 |
1995年 | 32篇 |
1994年 | 38篇 |
1992年 | 27篇 |
1991年 | 34篇 |
1990年 | 28篇 |
1989年 | 29篇 |
1988年 | 37篇 |
1987年 | 26篇 |
1985年 | 28篇 |
1984年 | 31篇 |
1983年 | 31篇 |
1982年 | 31篇 |
1979年 | 32篇 |
1978年 | 31篇 |
1977年 | 34篇 |
1976年 | 48篇 |
1975年 | 42篇 |
1974年 | 50篇 |
1973年 | 60篇 |
1972年 | 38篇 |
1971年 | 39篇 |
1970年 | 29篇 |
排序方式: 共有4091条查询结果,搜索用时 46 毫秒
21.
S. B. Érenburg L. N. Mazalov N. V. Bausk M. K. Drozdova 《Journal of Structural Chemistry》1994,35(4):517-522
SKα, SKβ, ClKβ, ClKβ, and PdLβ2 X-ray fluorescent and PdK EXAFS spectra were obtained for some organic solutions of dialkyl sulfide complexes with palladium
chloride. Solvent effects on the electronic and spatial structure of complexes in solution are discussed. In the benzene solution
of [PdCl22(C6H13)2S], complex molecules interact with solvent molecules along a coordinate that is perpendicular to the plane of the complex
molecule.
Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurmal Strukturnoi Khimii, Vol. 35, No. 4, pp. 105c111, July–August, 1994.
Translated by L. Smolina 相似文献
22.
A. A. Afanas'ev V. M. Katarkevich A. N. Rubinov T. Sh. Éfendiev 《Journal of Applied Spectroscopy》2002,69(5):782-787
Spatial redistribution of microparticles in a suspension on exposure to the interference laser field depending on the parameters of the particles and the field characteristics has been analyzed theoretically. Results of experimental investigations are presented that illustrate the capture of an ensemble of polymeric small spheres and also of the lymphocytes of human blood and other microparticles in a liquid in the interference radiation bands of the He–Ne laser. 相似文献
23.
Frédéric Coquel Thierry Gallouët Jean-Marc Hérard Nicolas Seguin 《Comptes Rendus Mathematique》2002,334(10):927-932
Closure laws for interfacial pressure and interfacial velocity are proposed within the frame work of two-pressure two-phase flow models. These enable us to ensure positivity of void fractions, mass fractions and internal energies when investigating field by field waves in the Riemann problem. To cite this article: F. Coquel et al., C. R. Acad. Sci. Paris, Ser. I 334 (2002) 927–932. 相似文献
24.
Marie‐France Llauro Julien Loiseau Fernande Boisson Frdric Delolme Catherine Ladavire J. Claverie 《Journal of polymer science. Part A, Polymer chemistry》2004,42(21):5439-5462
Low‐molecular‐weight poly(acrylic acid) (PAA) was synthesized by reversible addition fragmentation chain transfer polymerization with a trithiocarbonate as chain‐transfer agent (CTA). With a combination of NMR spectroscopy and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, the PAA end‐groups of the polymer were analyzed before and after neutralization by sodium hydroxide. The polymer prior to neutralization is made up of the expected trithiocarbonate chain‐ends and of the H‐terminated chains issued from a reaction of transfer to solvent. After neutralization, the trithiocarbonates are transformed into thiols, disulfides, thiolactones, and additional H‐terminated chains. By quantifying the different end‐groups, it was possible to demonstrate that fragmentation is the rate limiting step in the transfer reaction. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5439–5462, 2004 相似文献
25.
F. F. Éfendiev 《Mathematical Notes》1992,51(2):204-207
Translated from Matematicheskie Zametki, Vol. 51, No. 2, pp. 139–143, February, 1992. 相似文献
26.
Institut des Hautes Études Scientifiques 《Publications Mathématiques de L'IHéS》2004,100(1):271-282
Sans résumé 相似文献
27.
We say that a vertexx of a graph is predominant if there exists another vertexy ofG such that either every maximum clique ofG containingy containsx or every maximum stable set containingx containsy. A graph is then called preperfect if every induced subgraph has a predominant vertex. We show that preperfect graphs are perfect, and that several well-known classes of perfect graphs are preperfect. We also derive a new characterization of perfect graphs. 相似文献
28.
A multiparameter boundary-value problem of fresh infiltration water seepage in a drained fringe above quiescent saline water is solved in the direct statement and studied in detail. 相似文献
29.
Yu. G. Abov D. S. Denisov N. O. Elyutin S. K. Matveev Yu. I. Smirnov A. O. Éidlin F. S. Dzheparov D. V. L’vov 《Journal of Experimental and Theoretical Physics》1998,87(6):1195-1200
The asymptotic behavior of the spectra for large values of the scattering vector for the case of elastic multiple small-angle
neutron scattering (SANS) is investigated theoretically and experimentally. An expansion of the spectrum in terms of the reciprocal
of the magnitude of the momentum transfer is obtained taking account of the influence of the instrumental line. It is shown
that, to within some factor, the leading term of the expansion is identical to the differential single-scattering cross section
averaged over a statistical ensemble of particles; several subsequent terms in the expansion are calculated and the range
of applicability of the resulting expressions is determined. The asymptotic behavior of the multiple SANS spectrum is measured,
using a two-crystal neutron spectrometer, for samples of an HTSC ceramic, the alloy Fe-Ni, and Al powder. The agreement between
the experimental results and the theoretical predictions is analyzed.
Zh. éksp. Teor. Fiz. 114, 2194–2203 (December 1998) 相似文献
30.
For a real Enriques surface Y we prove that every homology class in H1(Y (R), Z/2) can be represented by a real algebraic curve if and only if all connected components of Y(R) are orientable. Furthermore, we give a characterization of real Enriques surfaces which are Galois-Maximal and/or Z-Galois-Maximal and we determine the Brauer group of any real Enriques surface Y. 相似文献