2002年11月一次深秋暴雨浅析

深秋暴雨是小概率事件 ,本文对发生于 2 0 0 2年 11月 15日的一次深秋暴雨天气过程进行了分析 ,分析表明 ,中低层的切变线的存在与稳定少动 ,强度的不断增强是本次暴雨发生的直接原因 ;而南支强于北支 ,低槽北抬 ,北抬后维持在 30°N附近 ,并形成了强烈的风向和风速切变。     

内蒙扎鲁特旗富裕屯萤石矿可选性试验研究

对内蒙扎鲁特旗富裕屯萤石矿的可选性进行了试验研究，工作中采用了浮选和手选－浮选两种方法，而以浮选为主，在浮选中进行了粗选条件试验，精选试验和最终精矿的质量检查，其结果最终精矿ＣａＦ２的品位，杂质含量与精度均符合化工２级标准，并可作为矿床地质评价的依据。     

Long-term changes in ground water chemistry at a phytoremediation demonstration site

A field-scale demonstration project was conducted to evaluate the capability of eastern cottonwood trees (Populus deltoides) to attenuate trichloroethene (TCE) contamination of ground water. By the middle of the sixth growing season, trees planted where depth to water was <3 m delivered enough dissolved organic carbon to the underlying aquifer to lower dissolved oxygen concentrations, to create iron-reducing conditions along the plume centerline and sulfate-reducing or methanogenic conditions in localized areas, and to initiate in situ reductive dechlorination of TCE. Apparent biodegradation rate constants for TCE along the centerline of the plume beneath the phytoremediation system increased from 0.0002/d to 0.02/d during the first six growing seasons. The corresponding increase in natural attenuation capacity of the aquifer along the plume centerline, from 0.0004/m to 0.024/m, is associated with a potential decrease in plume-stabilization distance from 9680 to 160 m. Demonstration results provide insight into the amount of vegetation and time that may be needed to achieve cleanup objectives at the field scale.