准平衡部分熔融过程中熔体的迁移以及与之有关的衰减作用

要想建立流体和熔体分凝的动力学模式就需要了解地球物质在部分熔融时的物理性质。在高温流变的情况下,稳定态的物理特性是由颗粒般大小的熔体相的准平衡分布决定的。熔融时流变相的影响主要是增加扩散变形(牛顿式)的动力;而且在所有的颗粒边界被熔体模式所取代而建立准平衡时影响最大。这种情形在实验室或天然硅酸盐部分熔融的样品中至今还未见到。所见到的“普通”熔体的形态是一种沿着三个颗粒交汇点和无熔体的颗     

地球的热演化及构造演化

构造模型与经过地幔传导的热对流模式密切相关。目前,主要的地幔对流模式是那些与板块和地幔柱有关的模式,相应地,主要的构造模型有板块构造及“地幔柱”构造。根据不断提高的对地幔对流演化的认识,可以评价这些构造模型或其它可能的构造模型的相对意义。     

Neutrino Event Rates from Gamma-Ray Bursts

We recalculate the diffuse flux of high-energy neutrinos produced by gamma-ray bursts in the relativistic fireball model. Although we confirm that the average single burst produces only approximately 10-2 high-energy neutrino events in a detector with a 1 km2 effective area, i.e., about 10 events yr-1, we show that the observed rate is dominated by burst-to-burst fluctuations that are very large. We find event rates that are expected to be larger by 1 order of magnitude, likely more, which are dominated by a few very bright bursts. This greatly simplifies their detection.     

直接解释地表地质构造的重力异常剖面的近似方法

前言关于求解引起重力异常的地质体形状的问题,在一般情况下还没有直接的解法.对这种问题.为了求得严格的解必须求助于尝试法(迭代法).对于二度地质体,博特(1960)、福尔尼埃和克鲁皮卡(1973)等人曾较详细地讨论过这一问题.对某些理想化的物体,斯基尔斯(1963)还提出了估计最大深度的方法.对于异常地质体的一般形状和密度差作     

Fast transport simulation with an adaptive grid refinement

One of the main difficulties in transport modeling and calibration is the extraordinarily long computing times necessary for simulation runs. Improved execution time is a prerequisite for calibration in transport modeling. In this paper we investigate the problem of code acceleration using an adaptive grid refinement, neglecting subdomains, and devising a method by which the Courant condition can be ignored while maintaining accurate solutions. Grid refinement is based on dividing selected cells into regular subcells and including the balance equations of subcells in the equation system. The connection of coarse and refined cells satisfies the mass balance with an interpolation scheme that is implicitly included in the equation system. The refined subdomain can move with the average transport velocity of the subdomain. Very small time steps are required on a fine or a refined grid, because of the combined effect of the Courant and Peclet conditions. Therefore, we have developed a special upwind technique in small grid cells with high velocities (velocity suppression). We have neglected grid subdomains with very small concentration gradients (zero suppression). The resulting software, MODCALIF, is a three-dimensional, modularly constructed FORTRAN code. For convenience, the package names used by the well-known MODFLOW and MT3D computer programs are adopted, and the same input file structure and format is used, but the program presented here is separate and independent. Also, MODCALIF includes algorithms for variable density modeling and model calibration. The method is tested by comparison with an analytical solution, and illustrated by means of a two-dimensional theoretical example and three-dimensional simulations of the variable-density Cape Cod and SALTPOOL experiments. Crossing from fine to coarse grid produces numerical dispersion when the whole subdomain of interest is refined; however, we show that accurate solutions can be obtained using a fraction of the execution time required by uniformly fine-grid solutions.