共查询到20条相似文献，搜索用时 765 毫秒
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河北省张家口蔡家营铅锌矿区南外围,在原普查区的深边部继续开展综合物探工作,通过大功率激电测量及CSAMT可控源音频大地电磁法测深工作,圈定出综合异常,提出了以深边部为空间,以热液构造带、接触带为目标思路。根据本次综合物探方法的应用效果,通过钻探验证发现了伴生硫化物的隐伏铅锌矿体,对扩大矿区远景起到了一定作用。 相似文献
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直流激电是寻找金属硫化物矿床的一种较为有效方法。本文对某地区铅锌矿的激电资料进行了综合整理和研究,分析了该地区铅锌矿的激电异常特征,简要介绍激电中梯和激电测深概念、测量装置、激发激化法原理、工作仪器,并在激电中梯扫面异常体上,进行了激电测深工作,确定了异常体的空间形态,并进行工程验证。为直流激电方法研究提供了一个可以参考的例子。 相似文献
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我国激发极化法的研究和推广开始于20世纪50年代末与60年代初。最初是主要是时间域激发极化法,剖面装置大部分为中间梯度装置,而测深装置则大多数是对称四极。中间梯度装置具有工作效率高的优点,并且异常形态相对其他方法较为简单,并易于解释。本论文分析了岩矿石的激发极化的物理化学机制,与直流电场下的面极化特征和体极化特征,讨论了各种直流激电装置的激电异常。在这次勘查工作中,在勘查区展开了激电扫面工作,并在有异常的区域加设纵轴五极激电测深剖面。 相似文献
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基于产业链的全球铜贸易网络结构研究 总被引：4，自引：2，他引：2
基于产业链视角研究铜贸易网络,构建了2017年铜矿石、粗铜、精炼铜、铜材和废杂铜5类含铜产品的全球贸易网络,对比产业链上各环节产品的贸易网络的拓扑结构,以全面刻画铜资源的全球流动以及国家（地区）之间的铜贸易关系。主要结论如下：① 2001年以来,全球含铜产品贸易重量稳定增长,其中铜矿石贸易重量最大,精炼铜次之。② 5类含铜产品贸易网络的拓扑结构存在明显差异,根据社区发现算法可划分为4~8个组团,模块度在0.216~0.482之间。由于资源禀赋和工业体系发展程度不同,大部分国家（地区）在5类贸易网络中分属于不同的组团。③ 中国对铜资源的需求巨大,围绕着中国的需求产生的贸易关系在铜矿石、粗铜、精炼铜、废杂铜4类贸易网络中都构成第一大组团,分别包含47、102、120、135个国家（地区）,表明中国在全球铜贸易中占有重要地位,但也反映了中国铜资源自给率低、对外依存度大等问题。 相似文献
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Geophysical Models for the Cu-Dominated VHMS Mineralization in Katta District, Western Ethiopia 总被引：1，自引：0，他引：1
Tilahun Mammo 《Natural Resources Research》2013,22(1):5-18
Volcanic hosted massive sulfides (VHMS) have been recognized for many years within the Arabian–Nubian Shield of western Ethiopia. The Shield is a collision belt formed when East and West Gondwana collided during the Neoproterozoic time. It covers NE Africa and the Middle East and is known to have hosted several economic mineral deposits. Situated within the Shield, the Katta VHMS mineralization is primarily made up of chalcopyrite, sphalerite, pyrite, pyrrhotite, and magnetite. These minerals are known to have contrasting values in resistivity, chargeability, and magnetic susceptibility with the enclosing host rocks. These physical attributes make resistivity, IP, and magnetic methods ideal to study and detect the mineralization and possibly delineate the ore body. Dipole–dipole DC resistivity and induced polarization data collected along parallel profiles are inverted to generate both 2D and 3D models of resistivity and chargeability. The chargeability model successfully delineates the zone of sulfide mineralization and the resistivity model gives information on the stratigraphic horizons and the structures. Magnetic data collected along more closely spaced profiles were also inverted to recover the 3D magnetic susceptibility model. The recovered model shows a linear magnetic anomaly that could be associated with the sulfides. This anomaly shows good spatial continuity and is in good agreement with the result obtained in the chargeability model. The geophysical inversion results indicate a NNW oriented mineralized zone of considerable strike length and extending to a depth of about 380 m. This study suggests the presence of exploitable VHMS presence in Katta district and that the inversion methodology is an important interpretation tool in guiding the exploration and exploitation of sulfide mineralization. 相似文献
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摘要：土壤水分是全球水循环的重要组成成分,对研究土壤水分的空间分布、农作物长势和产量 、气候变化、水资源时空分布等有着重要意义 。本文利用Sentinel（哨兵）系列主动微波雷达卫星SAR（Sentinel-1）结合光学卫星（Sentinel-2）对格尔木中下游低矮植被覆盖下的地表土壤水分进行反演研究, 探讨不同极化组合方式和水云模型前后的土壤水分含量反演方法的适用性。结果表明：其中VV (VV Polarization) 极化对比VH (VH Polarization) 极化更加适用该区域,VV极化结合归一化水指数 (NDWI）反演地表土壤水分精度达到42.6%,拟合精度最高,VH极化仅为22.6%;利用水云模型去除植被覆盖后对地表土壤水分的反演精度有所提升,其中,VV极化精度提高约3.5%,VH极化提高1.5%;Sentinel系列卫星影像对于干旱区的土壤水分的反演具有较好的适用性。本文旨在探索一种适用于该研究区乃至柴达木盆地土壤水分实现大面积实时监测的可靠依据和手段。 相似文献
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This study examines how extreme weather influences regional inequality and polarization within Mozambique in the context of on-going economic shocks. Utilizing satellite-based estimates of rainfall spatially analyzed within a GIS, we establish a 16-year rainfall climatology and calculate monthly rainfall anomalies for 665 villages. We approximate storm-total rainfall from all tropical cyclones entering the Mozambique Channel, as well as the extent of damaging winds for those making landfall, between 2005 and 2008. We group villages according to tropical cyclone impacts and use hierarchical cluster analysis to group the remaining villages according to shared patterns of monthly rainfall anomalies. Using economic data from the 2005 and 2008 National Agricultural Surveys of Mozambique, we relate weather patterns associated with near normal rainfall, tropical cyclones, flooding, and drought to changes in inequality and polarization by conducting decomposition analyses of the Gini index and Duclos-Esteban-Ray (DER) polarization index. Our findings mainly correspond to the generally accepted view that weather shocks exacerbate existing income and power disparities within societies. However, in some cases we find evidence that inequality and polarization can decline in the aftermath of an extreme event, and increase even where the weather is relatively good. By identifying varying effects of extreme events on inequality and polarization at subnational level, our study enables a more detailed understanding of weather-related effects on socio-economic outcomes in rural societies rapidly integrating into the global economy. 相似文献
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桂林-漓江-阳朔旅游地系统空间演化模式及机制研究 总被引：6，自引：3，他引：3
通过构建旅游地空间演化基本模式,阐释了以漓江为主导的桂林-漓江-阳朔旅游地系统演化过程,归纳其经历了萌芽期、极化期和优化期,3个阶段分别体现出均质发展、极化发展、扩散发展的特征,并有向板块发展阶段演化的趋势。20世纪70年代以前,旅游地处于均质发展为特征的萌芽期,原赋景观为旅游发展提供了良好的基础,但是这一时期的旅游地在空间结构上处于低位的均质无序状态,各景区点未得到有效地开发;20世纪70年代末至2000年代中期,旅游地进入极化期,其中又分为以桂林城区旅游增长极形成为标志的初期极化发展阶段和以桂林城区-漓江-阳朔县城旅游地系统形成为标志的后期极化增长阶段;初期极化发展阶段,在旅游需求的推动下,桂林城区作为旅游增长极得到较快发展,为漓江旅游提供良好的基础设施和服务设施,对区域旅游发展起到组织作用。后期极化增长阶段,阳朔县城作为新的增长极发展起来,桂林城区旅游功能进一步强化,漓江作为旅游廊道功能也日益强化,桂林-漓江-阳朔旅游地空间系统基本形成;"十一五"期间为扩散发展时期。在此期间旅游影响对外扩散,区域旅游板块逐渐形成,并推动旅游地转型发展。桂林-漓江-阳朔旅游系统的旅游城镇、景区点间相互联系日益紧密,功能上更加协调,推动了更高一级的旅游地空间系统的形成和发展,因此可称其为桂北旅游地空间系统,或桂北旅游板块。探讨了旅游地系统演化机制,认为在不同时期,起主导的机制不同:在萌芽期,资源禀赋起着决定性作用;在极化发展期,受循环积累因果效应的推动,不同类型的需求成为建构的主要动力;在扩散发展期,对综合效益的追求成为主导力量。 相似文献
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2000年以来广东省经济极化时空演变 总被引：1，自引：0，他引：1
谢正峰 《云南地理环境研究》2014,(3):51-55
选择崔-王指数、变异系数和空间自相关等3种方法,以地级市为基本评价单元,对2000年以来广东省的经济极化的时空演变进行了分析。研究表明：（1）广东省经济极化程度呈上升趋势;（2）2000以来,广东省极化现象明显,但是经济总量的极化现象大于人均经济总量;（3）广东省人均GDP和GDP的Moran＇s I均为正值且呈现增大趋势,经济空间集聚程度呈增大趋势,但是人均GDP的空间集聚程度大于GDP;（4）从局部空间自相关关系来看,广东省经济极化格局2000年以来处于稳定状态。 相似文献
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W. Zürn J. Exß H. Steffen C. Kroner T. Jahr M. Westerhaus 《Geophysical Journal International》2007,171(2):780-796
Tilt from atmospheric loading has long been known to be the major source of long-period horizontal seismic noise. We try to quantify these effects for seismic data from the Black Forest Observatory (BFO), which is known to be a very quiet station. Experimental transfer functions between local barometric pressure and horizontal seismic noise are estimated for two long time-series by standard methods. Two simple analytical physical models are developed: the local deformation model (LDM) and the acoustic-gravity wave model (TWM). Subsequently these models, with only two free parameters are fit using least squares to the observed seismic noise for time-series of widely differing lengths. The results are variable, sometimes rather dramatic variance reductions are obtained and sometimes the reduction is hardly significant. The method produces the best results when barometrically induced noise is high. The resulting admittances for the LDM are compared to finite element calculations. Since the methods are simple and can result in conspicuous reductions in noise we provide one more reason for installing barometers at even the best broad-band seismic stations. 相似文献