全文获取类型
收费全文 | 171篇 |
免费 | 3篇 |
专业分类
化学 | 84篇 |
数学 | 9篇 |
物理学 | 81篇 |
出版年
2019年 | 3篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 11篇 |
2007年 | 12篇 |
2006年 | 3篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 7篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 9篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1958年 | 1篇 |
1935年 | 2篇 |
1932年 | 1篇 |
1928年 | 1篇 |
1924年 | 1篇 |
排序方式: 共有174条查询结果,搜索用时 15 毫秒
61.
D.T. Ling J.N. Miller D.L. Weissman P. Pianetta P.M. Stefan I. Lindau W.E. Spicer 《Surface science》1980,95(1):89-106
Starting with the three-step direct-transition model of ARPES for bulk materials, which was examined in the preceding paper, we propose a framework for describing changes in the photoemission spectra due to chemisorption. Normal emission ARPES data for Cu(100) with a c(2 × 2)O overlayer were obtained in the photon energy range hv = 11 to 34 eV. These spectra have been compared within the proposed framework with those obtained from clean Cu(100). Changes were found in the Cu emission features which could be explained by the relaxation of momentum conservation perpendicular to the surface in the optical excitation step and by the relaxation of momentum conservation parallel to the surface in the escape step. These changes include a photon energy dependent broadening of the d-band peak and the preferential attenuation of the sharp direct-transition feature associated with the sp-band. Some evidence for a surface resonance at the top of the d-bands has been obtained. Changes in the spectrum of scattered electrons were related to modifications of evanescent final states. A 1.3 eV wide band derived from the oxygen px,y-orbitals was deduced from spectra obtained at normal emission and along the and lines of the surface Brillouin zone. On the other hand, no emission was clearly detected from the oxygen pz-orbitals. Oxygen induced emission above the Cu d-bands was observed and attributed to antibonding states. This emission was directed towards the bulk [011] directions. 相似文献
62.
A photoemission investigation of Tm metal has been carried out using photon energies in the 100–200 eV range. Electron energy distribution curves and the photon absorption coefficient has been measured and the results are compared to earlier XPS and absorption measurements. No evidence of a valence change at the surface of Tm metal was found, a posibility proposed earlier. 相似文献
63.
64.
Soft X-ray photoemission experiments have led to the unambiguous observation of a metal surface core level () shift, due to an adsorbate (CO), to a binding energy larger than the bulk binding energy. The clean (110) surface component, with a binding energy 0.35 ± 0.02 eV lower than the bulk, is shifted by 1.06 ± 0.04 eV towards higher binding energy upon CO chemisorption. The lack of significant changes in the bulk component indicates the localized nature of the CO-Pt surface bonding. 相似文献
65.
We found, by correlating band bending, ultraviolet photoemission spectroscopy, and partial yield spectroscopy measurements, that Fermi level pinning at midgap of n-type GaAs(110) is caused by extrinsic states. The exact nature of these states is not yet clear, but the surfaces with Fermi level pinning were strained as evidence by a smeared valence band emission. This smearing was removed by as little as one oxygen per 104 to 105 surface atoms. This implies that the oxygen has very long range effects in causing spontanesous but small rearrangement of the surface lattice and removing surface strains. When about 5% of a monolayer of oxygen is adsorbed, a major change in the electronic structure takes place. Again, the oxygen coverage is very small, which suggests long range effects now leading to a fairly large rearrrangement of the surface lattice. Finally, from comparing the oxygen induced emission for exposures greater than 107 L O2, with the spectra from gas photoemission measurements on molecular oxygen, we suggest that the oxygen is chemisorbed as a molecule on the (110) surface of GaAs. 相似文献
66.
67.
68.
69.
Ingolf Hertel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,16(1):5-5
With this volume The European Physical Journal D (EPJ D) continues its tradition of publishing a selection of papers drawn from the bi-annual main conference in the field of cluster
physics. The readers should be aware that this is not a conference proceeding in the normal sense of the word, i.e. it is not a collection of all posters and papers presented at this conference. Rather, the guest-editors for this volume
of EPJ D have selected only such papers from this conference which comply with the normal high quality standards of a refereed
international scientific journal -- in terms of novelty, soundness and scientific quality. The guest-editors have made sure
that all papers have been subject to a standard refereeing process which ensures these high standards as expected by the readers
of EPJ D. We trust that the specific collection of papers published in this volume will contribute to the future attractiveness
of EPJ D especially in the ever growing field of cluster physics. 相似文献
70.
Textile reinforced concrete (TRC) is a composite of textile structures made of multi-filament yarns (rovings) within a cementitious matrix. Experimental investigations of textile reinforced concrete specimen show very complex failure mechanisms on different length scales. Therefore mechanical models on the micro, meso and macro scale are introduced. The paper presents a hierarchical material model of TRC on three scales. While on the micro scale the individual filaments of the fiber bundles are distinguished to determine an effective roving behavior, models on the meso scale are used to predict the macroscopic response of the composite material. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献