摘要:

AbstractThe annealing behaviour of quench condensed H2‐, HD‐ and D2‐films has been investigated using acoustic surface waves. Upon annealing at temperatures far below the triple point we observe drastic changes of sound velocity and attenuation which can be attributed to a considerable rearrangement of the film structure via surface diffusion. These findings are in good agreement with recent experiments using surface plasmons. From the temperature dependence of the speed of the structural changes we deduce the activation energies for surface self‐diffusion as 23 K, 35 K, and 47 K for H2, HD, and D2, respe

ISSN:0003-3804    

DOI:10.1002/andp.19955070102

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractA two‐dimensional diffraction grating for phonons is described. It scatters thermal phonons strongly when their dominant wavelength is equal to the grating's lattice constant. Through measurements of the Kapitza resistance between the silicon crystal carrying the grating and liquid helium, it is shown that the scattering by the grating is predominantly coherent, as expected for phonon diffractio

ISSN:0003-3804    

DOI:10.1002/andp.19955070103

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe collapse of laser‐induced bubbles in water is investigated by high speed photography at framing rates as high as 20 million frames per second. The case of a spherical bubble in an unbounded liquid is compared with the Gilmore model. Bubbles collapsing in front of a solid wall show a rich dynamics depending on their normalized distance. Unprecedented details are given of the generic sequence of events leading to multiple shock waves and bubble shape metamorphosis upon collaps

ISSN:0003-3804    

DOI:10.1002/andp.19955070104

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractA method to transfer secret information using chaotic dynamical systems is proposed. It is based on modulating a chaotic system with the message such that its time evolution contains the hidden information. Decryption of the cipher is achieved by chaos control. Operation of the scheme is demonstrated by en‐ and decoding a short german tex

ISSN:0003-3804    

DOI:10.1002/andp.19955070105

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractWe consider the formation and the Kondo effect of local magnetic moments in the Anderson‐Hubbard model with off‐diagonal disorder. The existence of moments at sites weakly coupled to the environment is deduced in effective medium approximation. The distribution of moments is calculated both deep in the metallic phase and near the metal‐insulator transition. We discuss the Kondo quenching of the moments and derive a distribution of local Kondo tempera

ISSN:0003-3804    

DOI:10.1002/andp.19955070106

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractWe review some basic notions and results of White Noise Analysis that are used in the construction of the Feynman integrand as a generalized White Noise functional. We show that the Feynman integrand for the harmonic oscillator in an external potential is a Hida distribution.

ISSN:0003-3804    

DOI:10.1002/andp.19955070107

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractWe analyze the quantum fluctuations of vacuum stress tensors and spacetime curvatures, using the framework of linear response theory which connects these fluctuations to dissipation mechanisms arising when stress tensors and spacetime metric are coupled. Vacuum fluctuations of spacetime curvatures are shown to be a sum of two contributions at lowest orders; the first one corresponds to vacuum gravitational waves and is restricted to light‐like wavevectors and vanishing Einstein curvature, while the second one arises from gravity of vacuum stress tensors. From these fluctuations, we deduce noise spectra for geodesic deviations registered by probe fields which determine ultimate limits in length or time measurements. In particular, a relation between noise spectra characterizing spacetime fluctuations and the number of massless neutrino fields is obtaine

ISSN:0003-3804    

DOI:10.1002/andp.19955070108

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

ISSN:0003-3804    

DOI:10.1002/andp.19955070109

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

ISSN:0003-3804    

DOI:10.1002/andp.19955070101

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY