SPH compressible turbulence   总被引：3，自引：0，他引：3  

J. J. Monaghan 《Monthly notices of the Royal Astronomical Society》2002,335(3):843-852

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Diagnostics of Near-Solar Plasma Turbulence Parameters Using the Radio Sounding Technique at Small Heliocentric Distances     

A. N. Afanasiev  N. T. Afanasiev 《Solar physics》2007,245(2):355-367

We investigate the temporal correlation function and the mean intensity of monochromatic radio emission in the neighborhood of a regular caustic produced by radio sounding of near-solar plasma. Using asymptotic analysis and numerical simulation, we determine conditions under which the temporal correlation function is related to the temporal structure function by a relation similar to that used for the solar wind diagnostics (Coles and Harmon, Astrophys. J. 337, 1023, 1989) in the case of weak refraction of radio waves. Information on the correlation function and on the mean intensity in the caustic shadow region can be used to determine the parameters of the electron density fluctuation spectrum at small heliocentric distances.  相似文献   

秦岭群裂谷岩浆建造地球化学型式及其成因探讨     

张泽军 《地球科学与环境学报》1993,(4)

秦岭群形成于早元古宙华北南缘裂谷化环境中。其下部有一套岩浆岩建造,包括基性和酸性的火山岩或侵入岩。地球化学资料表明,基性岩具有OIB型和CNB型两种地球化学型式,酸性岩具有壳幔混合型地球化学型式。这些变化起因于不同的源区和岩石成因过程,但本质上取决于岩石圈拉张程度和地幔流能量。  相似文献   

The formation of star clusters – I. Three-dimensional simulations of hydrodynamic turbulence     

David A. Tilley  Ralph E. Pudritz 《Monthly notices of the Royal Astronomical Society》2004,353(3):769-788

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秦岭中段板沙地区富钠质岩初探     

王锐  付春晓  付伟 《地球科学与环境学报》2002,24(1):1-4

板沙地区山凤断裂以北分布一类富钠质岩石 ,以往的研究较少。对该类岩石分布、产状作了详细描述 ,通过宏观微观特征及岩石化学、稀土元素地球化学特征的分析进一步确认其为一套热水沉积岩 ,是热水溶液喷出海底后与海水介质和陆源沉积物混合形成的  相似文献   

Turbulent amplification of magnetic field and diffusive shock acceleration of cosmic rays     

A. R. Bell 《Monthly notices of the Royal Astronomical Society》2004,353(2):550-558

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M. Y. Totagi 《大气科学进展》1994,11(4):491-498

The study of large-scale atmospheric turbulence and transport processes is of vital importance in the general circulation of the atmosphere. The governing equations of the power and cross—spectra for the atmospheric motion and transports in the domain of wave number frequency space have been derived. The contributions of the nonlinear interactions of the atmospheric waves in velocity and temperature fields to the conversion of kinetic and potential energies and to the meridional transports of angular momentum and sensible heat in the atmosphere have been discussed.  相似文献   

试论冀西北金银多金属矿产富集区地幔热柱及其成矿制约   总被引：8，自引：1，他引：7  

李红阳  闰升好  王金锁  牛树银  张建珍  杨秋荣 《地球学报》1996,17(4):401-412

本文以冀西北金、银多金属矿产富集区为例,讨论了超越在不同历史大地构造单元之上的中生代地幔热柱构造,论述了地幔热柱构造的地质、地球物理等标志特征,探讨了地幔热柱构造的变质作用、岩浆作用与成矿制约,并初步建立了壳幔成矿体系。  相似文献   

Tsunami bore runup     

Harry H. Yeh 《Natural Hazards》1991,4(2-3):209-220

Nearshore behaviors of tsunamis, specifically those formed as a single uniform bore, are investigated experimentally in a laboratory environment. The transition process from tsunami bore to runup is described by the momentum exchange process between the bore and the small wedge-shaped water body along the shore: the bore front itself does not reach the shoreline directly, but the large bore mass pushes the small, initially quiescent water in front of it. The fluid motions near the runup water line appear to be complex. The complex flow pattern must be caused by irregularities involved in the driving bore and turbulence advected into the runup flow. Those experimental results suggest that the tsunami actions at the shoreline involve significant mean kinetic energy together with violent turbulence. Even though the behaviors of bore motion were found to be different from those predicted by the shallow-water wave theory, the maximum runup height appears to be predictable by the theory if the value of the initial runup velocity is modified (reduced). Besides the friction effect, this reduction of the initial runup velocity must be related to the transition process as well as the highly interacting three-dimensional runup motion.  相似文献   

Some Basic Properties of the Surrogate Subgrid-Scale Heat Flux in the Atmospheric Boundary Layer   总被引：3，自引：3，他引：0  

Fernando Porté-Agel  Charles Meneveau  Marc B. Parlange 《Boundary-Layer Meteorology》1998,88(3):425-444

The development of improved subgrid-scale (SGS) models for large-eddy simulation of scalar transport in the atmospheric boundary layer requires an improved understanding of basic properties of the SGS fluxes. High frequency atmospheric wind speed and temperature data sampled at a height of 1.7 m are used to measure SGS heat fluxes and dissipation of temperature variance, by means of one-dimensional filtering and invoking Taylor's hypothesis. Conditional averaging is used to isolate interesting features of the SGS signals, and to relate them to the large-scale characteristics of the flow, such as the presence of coherent structures. Both mean and conditionally averaged SGS quantities are compared with those obtained using a standard eddy-diffusivity model. Within the limitations imposed by the one-dimensional data analysis, we observe that the model appears unable to reproduce important features of the real signals, such as the negative dissipation of temperature variance associated with strong negative resolved temperature gradients due to the ejection of warm air under unstable atmospheric stability conditions.  相似文献