Stimulated scattering induced by the longitudinal electric field of a pump wave is studied theoretically for the case of dense, relativistic electron beams traveling in cylindrical metal waveguides, Two processes are examined. In one, the pump wave decays parametrically into a slow and a fast space charge wave. In the other, it decays into a slow space charge wave and a TM wave of the guide. Th...

We have performed atomic simulations of crack propagation along a weak interface joining two harmonic crystals. The simulations show that a mode II shear dominated crack can accelerate to the Rayleigh wave speed and then nucleate an intersonic daughter that travels at the longitudinal wave speed. This contradicts the general belief that a crack can travel no faster than the Rayleigh speed.

To Professor Arnulf Schlüter on his 60th Birthday A study is made of the nonlinear damping of parallel propagating Alfven waves in a high ß plasma. Two circularly polarized parallel propagating waves give rise to a beat wave, which in general contains both a longitudinal electric field component and a longitudinal gradient in the magnetic field strength. The wave damping is due to the interacti...

In this paper, we report on surface-plasmon-resonance enhancement of the time-dependent reflection changes caused by laser-induced acoustic waves. We measure an induced several acoustical modes, such as longitudinal, quasi-normal, and surface waves, a factor 10–20. show that longitudinal quasi-normal modes are enhanced in wings plasmon polariton resonance. The wave-induced peak attribute to wav...

The propagation of both fast and slow longitudinal waves in bovine cancellous bone in vitro was experimentally examined by the pulse transmission technique in relation to the bone density. Experimental results show that the propagation speed and the amplitude of the fast wave increase greatly with the bone density and those of the slow wave decrease reversely with the bone density.

The matrix variational Padé approximant and its generalization to elastic wave scattering are discussed. Predictions of the method for the scattering of a longitudinal plane wave are compared with the exact scattering from spherical voids and inclusions. Its predictions are also compared to those of the first and second Born approximations and to the standard matrix Padé approximant based on th...

We investigate a linearized tensor-tensor theory of gravity with torsion and a perturbed torsion wave solution is discovered in background Minkowski spacetime with zero torsion. Furthermore, gauge transformations of any perturbed tensor field are derived in general background non-Riemannian geometries. By calculating autoparallel deviations, both longitudinal and transverse polarizations of the...

Nonlinear relations among frequencies and phases in modulational instability of circularly polarized Alfvén waves are discussed, within the context of one dimensional, dissipation-less, unforced fluid system. We show that generation of phase coherence is a natural consequence of the modulational instability of Alfvén waves. Furthermore, we quantitatively evaluate intensity of wave-wave interact...

This thesis describes recent developments of theoretical and experimental techniques for longitudinal atom optics and interferometry, in which time-dependent interactions are used to create coherences in the longitudinal momentum of a matter wave. We present a fully quantum mechanical treatment of the classic molecular beams resonance experiment, a beam of two state particles interacting with t...

The controlled presplitting blasting technique is widely used in mining engineering to improve the permeability and gas extraction efficiency of coal seams. One of the key factors is the appropriate arrangement of the blasting and drainage holes, which can help improve the gas drainage quantity. To optimize the drilling layout to enhance gas-drainage efficiency, a series of controlled presplitt...