Coarsening of three-dimensional structured and unstructured grids for subsurface flow

We present a generic, semi-automated algorithm for generating non-uniform coarse grids for modeling subsurface flow. The method is applicable to arbitrary grids and does not impose smoothness constraints on the coarse grid. One therefore avoids conventional smoothing procedures that are commonly used to ensure that the grids obtained with standard coarsening procedures are not too rough. The coarsening algorithm is very simple and essentially involves only two parameters that specify the level of coarsening. Consequently the algorithm allows the user to specify the simulation grid dynamically to fit available computer resources, and, e.g., use the original geomodel as input for flow simulations. This is of great importance since coarse grid-generation is normally the most time-consuming part of an upscaling phase, and therefore the main obstacle that has prevented simulation workflows with user-defined resolution. We apply the coarsening algorithm to a series of two-phase flow problems on both structured (Cartesian) and unstructured grids. The numerical results demonstrate that one consistently obtains significantly more accurate results using the proposed non-uniform coarsening strategy than with corresponding uniform coarse grids with roughly the same number of cells.     

湛江港邻近海域台风浪的模拟研究

对第三代近岸海浪数值模式SWAN及包含的物理过程进行了简要介绍，利用该模式对影响南海湛江港海域的二次台风浪过程进行了模拟研究：由藤田台风风场模型同化相应时刻的台风要素、NCAR/NCEP网格点资料、单站观测资料后，提供模式所需风场；利用自嵌套的方式，提供模式波谱边界条件；两次模拟结果与实际海浪观测资料相符较好，可以为该海域台风浪的模拟预报提供较为重要的参考。     

关于GPS应用的理论研究

文章主要从GPS应用坐标网的建立和GPS在产生机理上的应用两个方面 ,论述了关于GPS应用理论问题。     

RUNOFF GENERATION CHARACTERISTICS IN TYPICAL EROSION REGIONS ON THE LOESS PLATEAU

1 mTRODUCT1ONThe Loess Plateau in the central and westem China with an area of 430,(X)0 lQn2 is well known for itsancient cultUre and serious soil and water loss. About 287,(X)0 km2 of area in this region has an annualerosion be greatC than 1(XX) tlkIn2. The eroded soil totally amounts to more than 2.2 X l0' tons, amongwhich about l.6X 10' tons, on average, is delivered into the Yellow kiver mdeng the river one of thehighest sediment-laden rivers in the word. The serious soil erosion …     

洁净煤技术应用现状综述

我国是煤炭生产和消费大国 ,大力开发应用适合我国国情的煤炭地下气化技术、工业型煤技术、水煤浆气化技术、煤液化技术、洁净煤联合循环发电技术、煤系废弃物的综合利用技术等洁净煤技术 ,对提高煤炭利用率 ,改善环境状况 ,实现能源工业 (也包括化工及其它相关行业 )的可持续发展 ,有重要意义并具有广阔的发展前景。     

氢化物发生—原子荧光光谱法测定煤样中的硒

采用氢化物发生原子荧光光谱法测定了煤样中的总Se。煤样选用高压闷罐强酸消解的方法进行处理，所得消解液经6mol/L HCl将Se（Ⅵ）还原为Se（Ⅳ），然后进行测定。标准工作曲线的线性范围为0－400μg/L Se，检测限为0.4μg/L Se。用标准参考物质煤飞灰对方法进行了验证，所得总Se含量与标准值相符，对ω为10^-6级Se的4次测定，RSD≤4.5％。     

Sustainable landscape management in Slovenia: Environmental improvements for the Velenje coal mining community 1991–2000

The Velenje area (almost 200 km² with over 31,000 inhabitants) is based on the Šalek Valley, which became a leading area of industrialisation and urbanisation after the Second World War, with consequent pollution problems. Various industrial plants polluted the river Paka while more serious hazards arose through the coal mine which is a still causing landscape subsidence and the thermal power station in the neighbourhood of Šoštanj which is a major source of sulphur dioxide and nitrogen oxide pollution. In 1987 there was an ecological protest which marked the beginning of a sustainable development strategy for the community. During the past decade programmes have dealt with the degradation of air, soil and water to achieve cleaner air, a transformation in landuse and enhancement the river's formerly weak self-purifying capabilities. This article examines the changes in the valley since the attention of the authorities was drawn to the deterioration of living conditions. Despite the pressures of transition which have seen unemployment rising to over ten percent, significant environmental improvements have been made and the area stands as a model for the rest of the country. This revised version was published online in July 2006 with corrections to the Cover Date.     

Generation of Deccan Trap magmas

Deccan Trap magmas may have erupted through multiple centers, the most prominent of which may have been a shield volcano-like structure in the Western Ghats area. The lavas are predominantly tholeiitic; alkalic mafic lavas and carbonatites are rare. Radioisotope dating, magnetic chronology, and age constraints from paleontology indicate that although the eruption started some 68 Ma, the bulk of lavas erupted at around 65–66 Ma. Paleomagnetic constraints indicate an uncertainty of ± 500,000 years for peak volcanic activity at 65 m.y. in the type section of the Western Ghats. Maximum magma residence times were calculated in this study based on growth rates of “giant plagioclase” crystals in lavas that marked the end phase of volcanic activity of different magma chambers. These calculations suggest that the > 1.7 km thick Western Ghats section might have erupted within a much shorter time interval of ∼ 55,000 years, implying phenomenal eruption rates that are orders of magnitude larger than any present-day eruption rate from any tectonic environment. Other significant observations/conclusions are as follows: (1) Deccan lavas can be grouped into stratigraphic subdivisions based on their geochemistry; (2) While some formations are relatively uncontaminated others are strongly contaminated by the continental crust; (3) Deccan magmas were produced by 15–30% melting of a Fe-rich lherzolitic source at ∼ 3–2 GPa; (4) Parent magmas of the relatively uncontaminated Ambenali formation had a primitive composition with 16%MgO, 47%SiO₂; (5) Deccan magmas were generated much deeper and by significantly more melting than other continental flood basalt provinces; (6) The erupted Deccan tholeiitic lavas underwent fractionation and magma mixing at ∼ 0.2 GPa. The composition and origin of the crust and crust/mantle boundary beneath the Deccan are discussed with respect to the influence of Deccan magmatic episode.