全文获取类型
收费全文 | 84篇 |
免费 | 1篇 |
专业分类
化学 | 20篇 |
力学 | 3篇 |
数学 | 4篇 |
物理学 | 58篇 |
出版年
2023年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 4篇 |
2011年 | 5篇 |
2010年 | 5篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 4篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 2篇 |
排序方式: 共有85条查询结果,搜索用时 46 毫秒
51.
Optimal dense wavelength-division multiplexed transmission is obtained based on high-order periodic dispersion-managed solitons in a dispersion-slope-compensated fiber link. 相似文献
52.
Using the equations of motion of pulse width and chirp, we present an analytical method for designing dispersion-managed (DM) fiber systems without optical losses. We show that the initial Gaussian pulse considered for the analytical design of periodically amplified DM fiber systems with losses will propagate as a proximity fixed point. Then averaging the DM soliton fields obtained from the slow dynamics of the proximity fixed point will yield the exact fixed point. 相似文献
53.
We derive a master equation for a mirror interacting with the vacuum field via radiation pressure. The dynamical Casimir effect leads to decoherence of a superposition state in a time scale that depends on the degree of "macroscopicity" of the state components, and which may be much shorter than the relaxation time scale. Coherent states are selected by the interaction as pointer states. 相似文献
54.
A. Degasperis M. Conforti F. Baronio S. Wabnitz 《The European physical journal. Special topics》2007,147(1):233-252
Boomerons are described as accelerated solitons for
special integrable systems of coupled wave equations. A general
formalism based on the Lax pair method is set up to introduce such
systems which look of Nonlinear Schr?dinger-type with linear,
quadratic and cubic coupling terms. The one-soliton solution of
such general systems is also briefly discussed. We display special
instances of wave systems which are of potential interest for
applications, including dispersion-less models of resonating
waves. Among these, special attention and details are given to the
celebrated equations describing the resonant interaction of three
waves, in view of their application to optical pulse propagation
in quadratic nonlinear media. For this particular case, we present
exact solutions of the three-wave resonant interaction system, in
the form of triplets moving with a common nonlinear velocity
(simultons). The simultons have nontrivial phase-fronts and exist
for different velocities and energy flows. We studied simulton
stability upon propagation, and found that solitons with a
velocity greater than a certain critical value are stable. We
explore a novel consequence of the particle-like nature of
three-wave simultons, namely their inelastic scattering with
particular linear waves. Such phenomenon is associated with the
excitation (decay) of stable (unstable) simultons by means of the
absorption (emission) of the energy carried by a particular
isolated pulse. Inelastic processes are exactly described in terms
of boomerons. We also briefly consider collisions between
different three-wave simultons. 相似文献
55.
Stability and optimization of dispersion-managed soliton control 总被引:1,自引:0,他引:1
Dispersion-managed solitons with in-line all-optical regeneration are shown to be subject to amplitude and timing-jitter instabilities. We identify and discuss the different natures of these instabilities by means of a linear stability analysis, which is in good agreement with the full numerical solutions of the governing equations. Stable pulse propagation can be achieved through appropriate choices of dispersion map and pulse energy. 相似文献
56.
Fluoropolymer blends have been widely used as binders for exterior coatings because of their excellent resistance to ultra-violet (UV) radiation as well as to many corrosive chemical agents.It is known that the fluorinated component usually has a lower glass transition temperature and easily crystallizes in the final structure depending upon the blend composition and sample annealing condition.We investigated the effect of blend composition and annealing process (slow and fast cooling) on the surface mor... 相似文献
57.
von Haeften K Laarmann T Wabnitz H Möller T Fink K 《The journal of physical chemistry. A》2011,115(25):7316-7326
We report a comprehensive investigation of the electronically excited states of helium clusters and droplets of sizes ranging from a few to several 10(7) atoms using time-resolved fluorescence excitation spectroscopy and quantum chemical ab initio calculations. We employ various approaches for our analysis considering the lifetime-dependence of the fluorescence intensity, spectral shifts, intensity scaling with cluster size, isotopic dependence, and density-dependence of the calculated electron wave function radii. A unique feature of helium clusters and droplets is their radially varying particle density. Our results show that short-lived fluorescence is sensitive to regions of increased density and probes excitations located in the bulk volume, whereas long-lived fluorescence is sensitive to regions of reduced density such as for small clusters or for the surface of large droplets. Spectra of (3)He droplets serve as a reference for low density, but are free from contributions of small clusters. This allows us to distinguish regions of reduced density as these can be due to both surface states or small clusters. Our analysis reveals a picture where spectral features are related to regions of different density due to isotopic composition, cluster size, and surface or bulk volume location of the excitations. The 2s and 2p related excitations appear as blue-shifted wings for small clusters or for excited atoms within the surface layer, whereas in the bulk-volume of large droplets, they appear as distinct bands with large intensities, dominating the entire spectrum. Excitations at energies higher than 23 eV are unambiguously assigned to regions of low and medium density location within the deeper parts of the surface layer but show no relation to the bulk volume. Our findings support the idea that in liquid helium high-lying states and, in particular, Rydberg states are quenched in favor of the 2s and 2p excitations. 相似文献
58.
We present a theoretical overview of soliton switching phenomena in two-mode nonlinear couplers. By complementing numerical studies with perturbative or exact solitary wave solutions, one finds that nonlinear Schrödinger or sine-Gordon solitons tend to maintain their identity in the coupled systems. Moreover, the coupling itself may originate novel vector solitary waves, such as gap solitons in periodic media. The switching dynamics in the presence of dissipative perturbations such as linear gain or intrapulse Raman scattering is also discussed. 相似文献
59.
We show that inducing modulation instability with a weak modulation whose frequency is such that its second harmonic falls within the band of instability may lead to asynchronous Fermi-Pasta-Ulam recurrence and efficient transfer of power from the pump into the second harmonic of the modulation, resulting in a periodic modulation at the second harmonic with extinction ratios in excess of 30 dB. 相似文献
60.
Laarmann T Rusek M Wabnitz H Schulz J de Castro AR Gürtler P Laasch W Möller T 《Physical review letters》2005,95(6):063402
The ionization dynamics of Ar and Xe clusters irradiated with intense vacuum ultraviolet light from a free-electron laser is investigated using photoelectron spectroscopy. Clusters comprising between 70 and 900 atoms were irradiated with femtosecond pulses at 95 nm wavelength (approximately 13 eV photon energy) and a peak intensity of approximately 4 x 10(12) W/cm2. A broad thermal distribution of emitted electrons from clusters with a maximum kinetic energy up to 30-40 eV is observed. The observation of relatively low-energy photoelectrons is in good agreement with calculations using a time-dependent Thomas-Fermi model and gives experimental evidence of an outer ionization process of the clusters, due to delayed thermoelectronic emission. 相似文献