全文获取类型
收费全文 | 425篇 |
免费 | 6篇 |
专业分类
化学 | 196篇 |
晶体学 | 5篇 |
力学 | 14篇 |
数学 | 43篇 |
物理学 | 173篇 |
出版年
2020年 | 7篇 |
2019年 | 4篇 |
2014年 | 8篇 |
2013年 | 14篇 |
2012年 | 11篇 |
2011年 | 16篇 |
2010年 | 12篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 10篇 |
2006年 | 13篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1998年 | 3篇 |
1997年 | 11篇 |
1996年 | 13篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 5篇 |
1992年 | 10篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 13篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 11篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1971年 | 4篇 |
1968年 | 4篇 |
1967年 | 4篇 |
1966年 | 3篇 |
1934年 | 3篇 |
1915年 | 6篇 |
1890年 | 4篇 |
1886年 | 4篇 |
1884年 | 3篇 |
排序方式: 共有431条查询结果,搜索用时 15 毫秒
131.
C. Reinhardt R. Kiyan S. Passinger A.L. Stepanov A. Ostendorf B.N. Chichkov 《Applied Physics A: Materials Science & Processing》2007,89(2):321-325
Renewed and growing interest in the field of surface plasmon polaritons (SPPs) comes from a rapid advance of nanostructuring
technologies. In this paper, we will report on the application of two-photon polymerization (2PP) technique for the fabrication
of dielectric SPP-structures, which can be used for localization, guiding, and manipulation of SPPs on a subwavelength scale.
This technology is based on nonlinear absorption of near-infrared femtosecond laser pulses. Resolutions down to 100 nm (and
even better) are already achievable. Characterization of these structures is performed by leakage radiation microscopy. 2PP
allows the fabrication of dielectric waveguides, splitters, and couplers directly on metal surfaces. The dielectric structures
on metal films are demonstrated to be very efficient for the excitation of SPPs. Using these structures, one can achieve excitation
and focusing of the resulting plasmon field.
PACS 42.70.Gi; 42.70.Jk; 42.82.Cr; 71.36.+c; 78.20.-e 相似文献
132.
We report on the 3-D modelling of periodic arrays of capacitive micromachined ultrasonic transducers (cMUTs) operating in fluid. Specific developments have been performed to model biperiodic transducer arrays and to take into account radiation into any stratified media at the front-side as well as the back-side of the device. The model is based on a periodic finite-element-analysis/boundary-element-method (FEA/BEM). It is applied to micromachined ultrasonic transducers (MUTs), based on silicon-nitride-circular-membrane arrays on a silicon substrate, and operating in water. The spectrum characteristics of MUTs excited in phase are investigated, showing that very-large-band emission is achievable as previously demonstrated by many authors. However, other contributions are also found, depending on the excitation conditions, that do not radiate in the fluid. These contributions are identified as guided modes that could generate significant cross-talk effects. The origin and the nature of these modes is analyzed to gain insight in the actual operation of MUTs. 相似文献
133.
J. Reinhardt U. Müller B. Müller W. Greiner 《Zeitschrift für Physik A Hadrons and Nuclei》1981,303(3):173-188
In the strong Coulomb field of a nucleus or quasimolecule withZ?172 a change of the QED vacuum has been predicted, signalled by the spontaneous emission of positrons if holes in theK-shell are available. The dynamical semiclassical theory of positron excitation in heavy ion scattering is presented and extended to collisions with nuclear contact. Interference patterns in the energy spectrum of the emitted positrons and, for sufficiently long reaction timeT, the emerging of a characteristic line at the position of the 1sσ-resonance is predicted. The position and width of the 1sσ-resonance is calculated in dependence on the nuclear configuration, the effect of electron screening is taken into account. Recent experimental indications [1, 2] for structures in the spectra of positrons emitted in U-U collisions at energies close to the Coulomb barrier are discussed in terms of spontaneous positron creation. The observed spectra could be explained under the assumption of long lasting nuclear reactions (T?4·10?20 s) with a cross section in the millibarn region. Various consequences of this interpretation are discussed. 相似文献
134.
Reinhardt Kiehl 《Inventiones Mathematicae》1972,16(1-2):40-112
Ohne ZusammenfassungHerrn Professor Dr. K. Stein zu seinem 60. Geburtstag gewidmet. 相似文献
135.
136.
137.
138.
The recently developed semiclassical theory of large amplitude collective excitations and fission is applied to the so-called Suzuki model, which is exactly soluble within this theory. In particular we study the leading order quantum corrections to the time-dependent mean-field approximation in the fission problem. 相似文献
139.
140.
Reinhardt Kiehl 《Inventiones Mathematicae》1967,4(2):139-141
Ohne Zusammenfassung 相似文献