Predictive GIS model for potential mapping of Cu, Pb, Zn mineralization

IntroductionChina is the third richest country in the world ofmineral resources with a total potential value of 11trillion USdollars. Yunnan Provincce is one of theimportant metallogenic belts for nonferrous and pre-cious metal deposits[1].Mineral source …     

涡度相关仪倾斜订正方法的比较及应用

利用973暴雨项目2002年在安徽肥西观测的涡度相关资料,针对目前涡度相关法中存在的仪器倾斜误差问题,采用两种倾斜订正方法计算湍流参数并进行对比分析.结果表明,三次坐标轴旋转倾斜订正方法和平面拟合方法均可以对仪器倾斜引起的误差进行坐标旋转订正,有效剔除仪器倾斜引起的侧向应力的影响,以及仪彝倾斜时水平方向风速引起的虚假湍流通量,提高了湍流通量的计算精度.两种倾斜订正方法各有一定适用条倬,平面拟合方法优于三次坐标轴旋转倾斜订正方法.     

非定常过程对大气边界层的内参数与风廓线的影响(二)

本文用大气边界层运动方程的数值积分研究了当边界层顶风向不变但风速变化时对大气边界层的内参数u_*/A(u_*为摩擦速度,A为上界风速)和α角(地面风与上界风向的交角)的影响。设上界处风速随时间指数增加及减少,最后趋于定常。在大气正、斜压时,u_*/A及α角的时间变化均是振幅衰减的振荡,最后趋于定常时相应的值。在时间变化过程中的任一时刻,内参数值与当上界条件取该时刻上界风时的定常解结果有一定的差别,严格说,定常时的内参数值并不能直接用于当上界风非定常时。本文还考虑了上界风速非定常对风廓线的影响。     

东明县节约集约利用土地的几点做法

在国家土地宏观调控政策趋紧的新形势下，如何破解土地制约瓶颈，缓解项目用地矛盾，确保经济又好又快发展，成为摆在各级政府面前亟待研究解决的一个难题。对此，东明县立足实际，经过反复论证和积极探索，坚持以政策“杠杆”为支点，找准土地政策和项目建设的最佳结合点，合理规划建设用地，确保了全县土地利用的总体平衡，走出了一条符合东明特点的科学合理利用土地之路。     

临沂市城区岩溶地下水流模拟

地下水动力条件变化是导致临沂市城区岩溶塌陷的诱因和动因，通过分析岩溶区地质及水文地质条件，建立了临沂市城区岩溶地下水流数值模型，预测了2007年6月至2019年6月地下水水位时空变化过程。从流场拟合情况看，所建模型拟合效果良好，客观反映了地下水系统演化规律，可以用于岩溶塌陷预警预报，为岩溶塌陷地质灾害防治提供技术依据。     

The Cretaceous volcanic succession around the Songliao Basin,NE China: relationship between volcanism and sedimentation

With volume ratio of 8:1:1.5 amongst acidic, intermediate and basaltic rocks, the Cretaceous volcanics around the Songliao Basin are a series of high‐K or medium‐K, peraluminous or metaluminous, calc‐alkaline rocks, lacking typical basalts and peralkaline members of typical rift‐related types. Their eruption ages range between 133 and 127 Ma, 124 and 122 Ma and 117 and 113 Ma respectively. They are high in total (Rare earth element) REE contents (96.1–326 ppm), enriched in LREE and depleted in HREE (LREE/HREE = 4.6–13.8), with negative Eu and Ce anomalies (Eu/Eu* = 0.04–0.88; Ce/Ce* = 0.60–0.97). They have enriched large‐ion lithophile elements (e.g. K, Ba, Th) and depleted high field strength elements (e.g. Nb, Ti and Y), suggesting a subduction‐related tectonic setting. The volcanic activities migrated from south to north, forming a successively northward‐stepping volcanic series and showing a feature significantly different from the overlying sedimentary sequence striking northeast. Thus, an overlap basin model was proposed. Accompanied by opening of the basin, the volcanogenic succession was formed at the block‐faulting stage (131–113 Ma) owing to the closure of the Mongolia–Okhotsk ocean in the Jurassic and early Cretaceous, while the overlying sedimentary sequence was unconformably deposited at the spreading stage (Albian–Maastrichtian) owing to the oblique subduction of the Pacific plate under the Eurasian plate. The volcanic succession constitutes the lower unit of basin filling and is the forerunner of further basin spreading. Copyright © 2002 John Wiley & Sons, Ltd.