全文获取类型
收费全文 | 317篇 |
免费 | 9篇 |
专业分类
化学 | 148篇 |
晶体学 | 1篇 |
力学 | 14篇 |
数学 | 14篇 |
物理学 | 149篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2014年 | 6篇 |
2013年 | 14篇 |
2012年 | 14篇 |
2011年 | 22篇 |
2010年 | 10篇 |
2009年 | 16篇 |
2008年 | 13篇 |
2007年 | 16篇 |
2006年 | 13篇 |
2005年 | 6篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1973年 | 3篇 |
1967年 | 1篇 |
排序方式: 共有326条查询结果,搜索用时 16 毫秒
41.
42.
G.D. Alkhazov R. Beurtey A. Boudard G. Bruge H. Catz A. Chaumeaux P. Couvert J.L. Escudié J.M. Fontaine M. Garçon J. Guyot D. Legrand J.C. Lugol R.M. Lombard M. Matoba Y. Terrien 《Physics letters. [Part B]》1977,67(4):402-404
Elastic scattering of 1.047 GeV protons is studied on the isotopically enriched 58,60,62,64Ni isotopes. A spin independent Glauber theory analysis allowed the extraction of nuclear matter densities for these targets. 相似文献
43.
E. Aprile-Giboni J. Bystricky J. Deregel PH. Drompt C. Eisenegger J.M. Fontaine E. Heer R. Hess S. Jaccard F. Lehar W.R. Leo S. Mango S. Morenzoni Y. Onel F. Perrot D. Rapin J. Vrzal J. Yonnet 《Nuclear Physics A》1984,431(4):637-668
The main structure around m = 2.15 GeV first observed by the Argonne group in the spin-dependent total cross section ΔσL is confirmed in the energy range available at SIN. A simultaneous study of the scattered particles at small angles has been carried out with success and gave the spin-correlation parameter A00kk for the pp elastic scattering and for the reaction pp → π+d. The contribution of the 3-body reactions to this spin-dependent total cross section has been deduced and found to be lower than the contribution of the π+d reaction even at 583 MeV. 相似文献
44.
The trajectory of a charged test particle under a Lorentz force is obtained as the geodesic of a riemannian four dimensional manifold. Originally, the geodesic equation is nonlinear in some vector field A′μ. The nonlinearity is traded in for the correct characteristic of the test particle through a gauge condition, imposed upon A′μ, which turns the geodesic into the fully covariant linear and gauge invariant Lorentz equation. Fitting the ratio inside the gauge leaves F′μν independent of and allows its identification with the E.-M. tensor Fμν. This four dimensional approach allows the identification of the fifth coordinate used in Kaluza's geometrization |1,2|. The gauge function appears as the sum of Hamilton-Jacobi function plus an additional term, related to the “length” of the trajectory. It is this latter term which guarantees the correct “normalisation” of the ratio. 相似文献
45.
M. Della Negra D. Drijard H.G. Fischer G. Fontaine H. Frehse P. Frenkiel G. Ghesquière R. Gokieli P. Hanke P.G. Innocenti W. Isenbeck E.E. Kluge V. Korbel S. Krzywdzinski D. Linglin A. Minten D.R.O. Morrison A. Putzer D. Wegener 《Physics letters. [Part B]》1975,59(4):401-404
Events with a positive particle of large transverse momentum emitted at medium angles have been studied using the split field magnet spectrometer at the CERN-ISR at a c.m. energy of √s = 52.5 GeV. Positive particles with large longitudinal momentum, |x| > 0.5, i.e., leading particles, associated to large pT events, are analysed. 相似文献
46.
Michle Fontaine Joseph Delhalle Mireille Defranceschi Grard Lcayon Jacques Boissel 《International journal of quantum chemistry》1993,46(1):171-181
3-21G RHF calculations on (CF3)2O and (CF3)2OH+ molecules are carried out to assess the changes induced in the molecular properties of ether links in poly (perfluoro ethers) interacting with acid sites at contact surfaces. Geometry of the species, vibrational frequencies, proton affinity, and energetics of the (CF3)2OH+ fragmentation provide a preliminary basis to understand problems raised by lubricant degradation. © 1993 John Wiley & Sons, Inc. 相似文献
47.
Aharonian F Akhperjanian AG Barres de Almeida U Bazer-Bachi AR Becherini Y Behera B Beilicke M Benbow W Bernlöhr K Boisson C Bochow A Borrel V Braun I Brion E Brucker J Brun P Bühler R Bulik T Büsching I Boutelier T Carrigan S Chadwick PM Charbonnier A Chaves RC Chounet LM Clapson AC Coignet G Costamante L Dalton M Degrange B Deil C Dickinson HJ Djannati-Ataï A Domainko W Drury LO Dubois F Dubus G Dyks J Egberts K Emmanoulopoulos D Espigat P Farnier C Feinstein F Fiasson A Förster A Fontaine G 《Physical review letters》2008,101(17):170402
In the past few decades, several models have predicted an energy dependence of the speed of light in the context of quantum gravity. For cosmological sources such as active galaxies, this minuscule effect can add up to measurable photon-energy dependent time lags. In this Letter a search for such time lags during the High Energy Stereoscopic System observations of the exceptional very high energy flare of the active galaxy PKS 2155-304 on 28 July 2006 is presented. Since no significant time lag is found, lower limits on the energy scale of speed of light modifications are derived. 相似文献
48.
Henri-Joël Sedjame Rachid Brahmi Gwendoline Lafaye Jacques Barbier Céline Fontaine 《Comptes Rendus Chimie》2018,21(3-4):182-193
Monolithic catalysts are prepared by washcoating cordierite monoliths with different sols (Pt/Al2O3, Pt/CeO2, Pt/ZrO2, Pt/Al2O3CeO2, Pt/Al2O3ZrO2, and Pt/CeO2ZrO2). These sols are prepared by a sol–gel process and characterized by specific surface area (SBET), inductively coupled plasma, hydrogen chemisorption, high-resolution transmission electron microscopy, field emission scanning electron microscopy, oxygen storage capacity, X-ray diffraction, temperature-programmed reduction, CO2 chemisorption, and the model reaction of 3,3-dimethylbutene isomerization. The catalytic performances of the monolithic catalysts are then evaluated for the acetic acid oxidation. The nature of catalyst coating has been found to influence the adherence with the cordierite monolith and the presence of cerium in the catalyst appears to increase the adherence of the latter. Pt/CeO2, Pt/Al2O3CeO2, and Pt/CeO2ZrO2 are found to be the most reducible catalysts (oxygen storage capacity and temperature-programmed reduction) and to have the lowest acidities (3,3-dimethylbutene isomerization). CO2 chemisorption shows that these catalysts possess a good basicity. From the relation established between the catalytic activity and the redox and acid–base properties it has been concluded that the reducibility is the key factor for a good catalytic activity although the basicity has a significant influence on the catalytic performance. 相似文献
49.
50.