The High Agri Valley (southern Italy) is one of the largest intermontane basin southern Apennines affected by intensive agricultural and industrial activities. study groundwater chemical features provides much important information useful in water resource management. In this study, hydrogeochemical investigations coupled with multivariate statistics, saturation indices, stable isotope composit...

以安徽淮南采煤沉陷积水为研究对象，通过样品采集与测试，研究不同沉陷年限及类型积水水文地球化学和氢氧稳定同位素组成特征及影响因素.结果表明：（1）研究区水化学类型主要为Cl-Na、HCO3·Cl-Na型，沉陷积水中常量离子主要来源于蒸发岩溶解和硅酸盐风化，受蒸发作用和人为活动的影响明显，水化学组成随沉陷时间和类型变化不大.（2）淮南大气降水线方程为：δD=8.85δ18O+18.73，沉陷区积水氢氧稳定同位素值在淮南大气降水线右下方依次分布并接近降水线，表明沉陷积水主要来源于大气降水.（3）在降水稀释、水体蒸发及地下水补给的作用下，随着沉陷年限的增加，积水中重同位素越来越贫化，同一年限不同类型的积水同位素值变化较小.;Taking the coal mining subsidence water in Huainan, Anhui Provi...

introduction: appropriate definition of the distance measure between diffusion tensors has a deep impact on diffusion tensor image (dti) segmentation results. the geodesic metric is the best distance measure since it yields high-quality segmentation results. however, the important problem with the geodesic metric is a high computational cost of the algorithms based on it. the main goal of this ...

introduction: the selection of suitable beam angles and weights in external-beam radiotherapy is at present generally based upon the experience of the planner. therefore, automated selection of beam angles and weights in forward-planned radiotherapy will be beneficial. material and methods: in this work, an efficient method is presented within the matlab environment to investigate how to improv...