Stellar wind/ISM shocks in gravitational potentials     

A. Hubbard 《Monthly notices of the Royal Astronomical Society》2007,374(3):1045-1050

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The jet-powered optical nebula of Cygnus X–1     

D. M. Russell  R. P. Fender  E. Gallo †  C. R. Kaiser 《Monthly notices of the Royal Astronomical Society》2007,376(3):1341-1349

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Diffusion in momentum space as a picture of second-order Fermi acceleration     

M. Ostrowski  G. Siemieniec-Ozi b o 《Astroparticle Physics》1997,6(3-4):271-277

Energetic particles in a turbulent medium can be subject to second-order Fermi acceleration due to scattering on moving plasma waves. This mechanism leads to growing particle momentum dispersion and, at the same time, increases the mean particle energy. In the most frequently met situations both processes can be represented by a single momentum diffusion term in the particle kinetic equation. In the present paper we discuss the conditions allowing the additional term for regular acceleration to arise. For forward-backward asymmetric scattering centres, besides the diffusive term one should explicitly consider the regular acceleration term in momentum space, which can consist of the first-order (∝ V), as well as the second-order (∝ V²) part in the wave velocity V. We derive the condition for the scattering probability in the wave rest frame requied for vanishing the regular acceleration term and provide a simple mechanical example illustrating the theoretical concepts. Finally, we address its possible role in cosmic ray acceleration processes.  相似文献   

Peculiarities of surface wave fields in laterally inhomogeneous media in the framework of ray theory     

T. B. Yanovskaya  Yu. V. Roslov 《Geophysical Journal International》1989,99(2):297-303

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Synthetic seismograms in laterally heterogeneous, anelastic media by modal summation of P-SV-waves     

F. Vaccari  S. Gregersen  M. Furlan  G. F. Panza 《Geophysical Journal International》1989,99(2):285-295

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ANALYSES OF THE DYNAMIC EFFECTS ON WINTER CIRCULATION OF THE TWO MAIN MOUNTAINS IN THE NORTHERN HEMISPHERE——Ⅱ.VERTICAL PROPAGATION OF PLANETARY WAVES          下载免费PDF全文

邹晓蕾  吴国雄  叶笃正 《Acta Meteorologica Sinica》1992,(4)

A linear,hemispheric and stationary spectral model with multilayers in the vertical was employed to simulate thevertical propagation of waves triggered by mountains.Results show that,in cooperation with the East Asia zonal meanflow,Tibetan Plateau can excite a strong wavenumber 1 perturbation in the stratosphere with its ridge and trough lo-cated over the Pacific and Atlantic Oceans respectively.On the other hand,the stratospheric wavenumber 1 perturbationcaused by the mechanical forcing of the Rocky Mountains in cooperation with the North America zonal mean flow isvery weak.Calculations from observational data of the vertical profile of critical wavenumber for vertically propagatingwaves imply that the tropospheric wavenumber 1 perturbation can hardly penetrate the North America tropopause up-wards,whereas it can freely propagate through the East Asia tropopause into the stratosphere.Two-dimensional E-Pcross-sections obtained from both observational data and simulated results also demonstrate that waves excited by theRocky Mountains are refracted towards low latitudes in the troposphere during their upward propagation:whereas,inaddition to the above mentioned equatorward leaning branch,the wavenumber 1 and 2 planetary waves excited by theTibetan Plateau possess another branch which is refracted to high latitudes during upward propagation and penetratesthe tropopause into the stratosphere.It is therefore concluded that the difference in the horizontal and vertical wavepropagations in the two hemispheres is a result of the different dynamical forcing induced by the two main mountains inthe Northern Hemisphere.  相似文献   

Finite element modelling of surface wave transmission across regions of subduction     

Lawrence A. Drake  Bruce A. Bolt 《Geophysical Journal International》1989,98(2):271-279

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VLF waves in the magnetosphere     

A. R. W. Hughes 《Astrophysics and Space Science》1995,230(1-2):431-438

The study of VLF waves at ground based stations is an important source of information on particles trapped in the magnetosphere. By various techniques it is also possible to measure plasma densities, electric fields and monitor energetic particle injection. By studying the propagation of waves beneath the ionosphere it is possible to study particle precipitation from the magnetosphere. In this paper we summarise some of the techniques and results obtained from the study of VLF waves at the South African research station in Antarctica.  相似文献   

宇宙常数Λ≠0的平面引力波     

陆惠卿 《中国天文和天体物理学报》1988,(2)

本文讨论了宇宙常数Λ≠0时的平面引力波问题。在弱场近似下,得到了平面引力波传播方程及色散方程。通过对Kretschmann曲率标量的讨论发现,不同于Λ=0时h_(μv)仅有横场这一众所周知的结果,Λ<0时不存在一个坐标系,使h_(μv)的标量场、纵场、混合场分量全为零。最后讨论引力波辐射,结论是与Λ=0时无偶极辐射这一结果不同,Λ<0时,混合场的辐射有偶极辐射。  相似文献   

Traveltimes for global earthquake location and phase identification   总被引：68，自引：2，他引：66  

B. L. N. Kennett  E. R. Engdahl 《Geophysical Journal International》1991,105(2):429-465

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