全文获取类型
收费全文 | 581篇 |
免费 | 11篇 |
国内免费 | 4篇 |
专业分类
化学 | 288篇 |
晶体学 | 2篇 |
力学 | 27篇 |
数学 | 85篇 |
物理学 | 194篇 |
出版年
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2016年 | 8篇 |
2015年 | 15篇 |
2014年 | 11篇 |
2013年 | 26篇 |
2012年 | 32篇 |
2011年 | 23篇 |
2010年 | 18篇 |
2009年 | 20篇 |
2008年 | 20篇 |
2007年 | 22篇 |
2006年 | 31篇 |
2005年 | 22篇 |
2004年 | 18篇 |
2003年 | 14篇 |
2002年 | 23篇 |
2001年 | 12篇 |
2000年 | 13篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1994年 | 20篇 |
1993年 | 21篇 |
1992年 | 25篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1972年 | 5篇 |
1968年 | 3篇 |
1890年 | 2篇 |
1888年 | 4篇 |
排序方式: 共有596条查询结果,搜索用时 15 毫秒
81.
Several experiments relating to the volume dependence of crystal field interactions in rare earth pnictides have been carried out. These experiments include measurements of 1) the temperature dependence of the susceptibility of PrN, 2) the room temperature compressibilities of PrN and PrAs, 3) the NMR frequency shifts for 141Pr in PrN and PrSb, and 4) the low-temperature pressure dependence of the 141Pr frequency shift in PrN and PrSb. Although electrostatic screening effects on crystal field interactions in PrN are smaller than in the heavier Pr- pnictides, the anomalous volume dependence of the 141Pr NMR shift is essentially the same in all these compounds. 相似文献
82.
D. M. Poirier J. H. Weaver Koichi Kikuchi Yohji Achiba 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,26(1):79-83
X ray photoemission spectra show ~10 valence band features in C60 and C84 films, although they are less distinct in C84 because of the increased number of valence electrons and the decreased molecular symmetry. The presence of inequivalent carbon atoms in C84 is reflected by the fact that the C 1s main line is ~0.2 eV wider than in C60. The C 1s satellite region of C84 exhibits four features within 15 eV of the main line and shows that the HOMO-LUMO π-π* excitation energy of C84 is ~0.5 eV smaller than in C60. Potassium 2p spectra for K-doped C84 films suggest the formation of a phase with composition K3C84 with two spectroscopically-distinguishable K sites. A new spectral feature emerges when the K content is increased beyond K3C84, suggesting a phase transition and a saturated composition of K6C84, as for KxC60. These similarities are intriguing since KxC84 is insulating for all x while K3C60 is metallic and superconducting. 相似文献
83.
84.
85.
86.
Felix Barz Joseph G. Gordon Michael R. Philpott Michael J. Weaver 《Chemical physics letters》1982,91(4):291-295
The intensity of surface-enhanced Raman scattering (SERS) from thiocyanate and chloride adsorbed on silver electrodes is shown to depend critically on whether the electrode is illuminated during the oxidation-reduction cycle used to pretreat the electrode. The value and magnitude of the photoeffect is dependent upon the type of surface vibrational mode, the adsorbate and the wavelength of the radiation during the ORC. The effects are attributed to the production of SERS active clusters of Ag atoms by photoreduction of the Ag(I) phase films during the ORC. 相似文献
87.
The theory of linear collective motion is developed by the method of canonical transformations, recovering, as special cases, the earlier results of Casimir, Bohr-Mottelson, and Villars. In the approximation of constant Eckart-frame vectors, the kinetic energy Hamiltonian is shown to commute with the invariant operators of the collective motion symmetry group CM(3). The collective motion approach of Tomonaga, and the symmetry approach of Gell-Mann, are discussed and shown to be essentially equivalent, and to be properly contained in the CM(3) structure. The invariant operators of CM(3) are determined and shown to imply two invariants for nuclear collective motion: the volume Λ and the vortex-spin v. Representations of CM(3) are obtained and related to wavefunctions of the generator-coordinate form. 相似文献
88.
Abstract. For k ≥ 2, we exhibit complete k-curvature homogeneous neutral signature pseudo-Riemannian manifolds which are not locally affine homogeneous (and hence not
locally homogeneous). All the local scalarWeyl invariants of these manifolds vanish. These manifolds are Ricci flat, Osserman,
and Ivanov-Petrova.
Mathematics Subject Classification (2000): 53B20 相似文献
89.
90.