全文获取类型
收费全文 | 250篇 |
免费 | 25篇 |
专业分类
化学 | 110篇 |
力学 | 2篇 |
数学 | 7篇 |
物理学 | 156篇 |
出版年
2021年 | 2篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 10篇 |
2014年 | 10篇 |
2013年 | 10篇 |
2012年 | 15篇 |
2011年 | 16篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 13篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 9篇 |
1992年 | 1篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1973年 | 1篇 |
1971年 | 4篇 |
1969年 | 1篇 |
1967年 | 3篇 |
1966年 | 2篇 |
1943年 | 2篇 |
1939年 | 1篇 |
排序方式: 共有275条查询结果,搜索用时 251 毫秒
31.
W. Hoheisel U. Schulte M. Vollmer F. Träger 《Applied Physics A: Materials Science & Processing》1990,51(4):271-280
Desorption induced by electronic excitation with laser light is discussed. Emphasis is placed on nonthermal desorption where surface plasma excitation in small particles precedes the rupture of the surface chemical bond. A scenario for the mechanism underlying such a process is proposed. In this context, calculations of the electronic spectra of small sodium particles are presented and the influence of different multipole orders of the collective electron oscillation, of different shapes of the clusters and of the substrate are outlined. Furthermore, manipulation of the size distribution of metal particles on supports is described as an application of the effect. This allows the preparation of very special surfaces with novel physical and chemical properties. Methods to characterize such adsorbate-substrate combinations, especially by use of the optical spectra of the particles, are also discussed. Finally, prospects for future experiments in this field are outlined. 相似文献
32.
33.
34.
35.
H. Knapp H. Risken H. D. Vollmer 《Applied Physics A: Materials Science & Processing》1978,15(3):265-270
For a homogeneously broadened two-level ring laser model the stability of the cw laser oscillation in the presence of a passive
medium is investigated. The passive material is treated similar to the active material, but without an external pumping mechanism.
Stable and unstable regions are shown for various parameters. The stability region of the cw solution becomes extremly small
for certain parameters. 相似文献
36.
J. Vollmer J. P. Nisius P. Hertel E. Krätzig 《Applied Physics A: Materials Science & Processing》1983,32(3):125-127
Eight LiNbO3: Ti waveguides have been fabricated under differing conditions. The effective refractive indices of guided modes have been measured and successfully fitted to Gaussian index profiles. The change of refractive index and titanium concentration are related by a power law, the exponents being different for the extraordinary and the ordinary beam. 相似文献
37.
The transient solution of the laser Fokker-Planck equation is investigated in the threshold region. Especially for the initial condition, that no photons are present att=0, the transient of the laser distribution function, of the mean intensity and of the mean squared deviation (variance) into the stationary values are shown. Finally we give a physical explanation of the effects involved and we discuss some features of the transient photon counting probability. 相似文献
38.
Evidence for temperature-dependent electron band dispersion in a pentacene thin film polymorph on graphite is provided by angle- and energy-dependent ultraviolet photoelectron spectroscopy. The bands derived from the highest occupied molecular orbital exhibit dispersion of approximately 190 meV at room temperature, and approximately 240 meV at 120 K. Intermolecular electronic coupling in pentacene thin films is thus confirmed to be dependent on temperature and possibly crystal structure, as suggested by additional infrared absorption measurements. 相似文献
39.
40.
Vollmer W 《Chemistry & biology》2008,15(2):93-94
FtsZ is a prokaryotic homolog of eukaryotic tubulin and forms the essential bacterial cell division ring (Z-ring). A new study in this issue of Chemistry & Biology, L?ppchen et al., provides further evidence that differences in nucleotide-binding properties of FtsZ and tubulin can be exploited to specifically target the bacterial Z-ring. 相似文献