华北地区强震前后的 h 值及“震情窗口”变化

邢台、渤海、海城以及唐山大地震前1年内,围绕震中甚至距离震中500多公里的地区发生的某些震群,出现衰减系数异常(h≤1)。同时发生在林县、太原、长岛地区的小震群,其月频度几乎同步出现峰值。称林县、太原、长岛地区为“震情窗口”。强震前区域震情h值异常和“震情窗口”变化呼应,对判断未来强震三要素是有益的。     

Some remarks on cumulus parameterization

A simple parameterization of cumulonimbus convective heating is presented. The model is primarily based on preserving a moisture budget and on detraining cloud air at levels corresponding to the neutral buoyancy of the air converged at low levels. Results are compared with data from the western Pacific and GATE. Agreement is good. Suggestions are offered for improving the model and extending it to other regions.     

镇江石马杂岩体中岩石包体的成因研究

石马杂岩体,为南京—镇江地区出露面积较大的燕山期花岗质杂岩体,具大量暗色、细粒辉石闪长质-石英闪长质岩石包体,岩浆动力学理论的应用和详细的岩相学,岩石地球化学研究表明,该杂岩体中的岩石包体是不同成分岩浆大规模对流、不均一混合机制驱动下形成的,在成因类型上属淬冷包体.     

Numerical Modelling of Melting Processes and Induced Diapirism In the Lower Crust

The processes of partial melting and magmatic diapirism within the lower crust are evaluated using a numerical underplating model. Fully molten basalt ( T = 1200°C) is emplaced at the Moho beneath a solid granite ( T = 750°C) in order that a melt front grows into the granite. If diapirism does not occur, this melt front in the granite reaches a minimal depth in the crust before (like in the molten basalt) crystallization takes place. the density contrast between the partially molten granite layer and the overlying solid granite can lead to a Rayleigh-Taylor instability (RTI) which results in diapiric rise of the partially molten granite. Assuming a binary eutectic system for both the granite and the underplating basalt and a temperature- and stress-dependent rheology for the granite, we numerically solve the governing equations and find (a) that diapirism occurs only within a certain but possibly realistic range of parameters, and (b) that if diapirs occur, they do not rise to levels shallower than 15 or perhaps 12km. the growth rate depends on the degree of melting and the thickness of the partially molten layer, as well as the viscosity of the solid and the partially molten granite. From a comparison of the growth rate with the velocity of a Stefan front it is possible to predict whether a melt front will become unstable and result in diapiric ascent or whether a partially molten layer is created, which remains at depth. We carry out such a comparison using our thermodynamically and thermomechanically consistent model of melting and diapirism.     

一种新的水面蒸发计算方法

本文应用相似理论,提出一个考虑自由对流和强迫对流相结合的水面蒸发模式,并用实测资料对蒸发模式作了检验。