露天铁矿禀赋优势等级划分和合理矿业税费的研究          下载免费PDF全文

刘保顺袁怀雨  李克庆 《地质与勘探》2003,39(4):69-72

利用自组织神经网络，对我国主要露天铁矿进行了禀赋优势等级划分。权利金大小的确定，应以铁矿资源的资产评估为基础，资产评估时合理成本的取值应是评估矿山所在同一等级矿山的平均成本。矿产资源的原有价值是权利金征收的对象。最后以歪头山为实例，计算了铁矿资源的原有价值和权利金。结果表明，目前对歪头山铁矿征收的税费仍然偏高。  相似文献   

The design of post‐mining landscapes using geomorphic principles     

G. R. Hancock  R. J. Loch  G. R. Willgoose 《地球表面变化过程与地形》2003,28(10):1097-1110

Nature can provide analogues for post‐mining landscapes in terms of landscape stability and also in terms of the rehabilitated structure ‘blending in’ with the surrounding undisturbed landscape. In soil‐mantled landscapes, hillslopes typically have a characteristic pro?le that has a convex upper hillslope pro?le with a concave pro?le lower down the slope. In this paper hillslope characteristic form is derived using the area–slope relationship from pre‐mining topography at two sites in Western Australia. Using this relationship, concave hillslope pro?les are constructed and compared to linear hillslopes in terms of sediment loss using the SIBERIA erosion model. It is found that concave hillslopes can reduce sediment loss by up to ?ve times that of linear slopes. Concave slopes can therefore provide an alternative method for the construction of post‐mining landscapes. An understanding of landscape geomorphological properties and the use of erosion models can greatly assist in the design of post‐mining landscapes. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

从激光扫描数据中进行建筑物特征提取研究   总被引：42，自引：4，他引：42  

李必军  方志祥  任娟 《武汉大学学报(信息科学版)》2003,28(1):65-70

提出了一套基于建筑物几何特征的信息挖掘方案，并具体介绍了研究中采用的一些原理、方法与实用算法，从而可以直接从激光扫描数据中提取建筑物的平面外轮廓信息。利用本方案对车载激光扫描系统获取的城市建筑物试验数据进行了具体的处理，并给出了三维建模和可视化表达结果。  相似文献   

Coal mining along the Warfield Fault, Mingo County, West Virginia: a tale of ups and downs     

J. Marc Coolen   《International Journal of Coal Geology》2003,54(3-4):193

Mine development along a 15-mile (24 km) section of the Warfield Fault in Mingo County, West Virginia has broadened the geological understanding of the fault and its related structures. The fault has been exposed in two new road cuts, one in the northeast-trending segment at Neely Branch and one in the eastern east-trending segment at the head of Marrowbone Creek. Both exposures show a well-defined normal fault with a 45° to 55° N dip, juxtaposing sandstone/shale packages from the roof and the floor of the Coalburg seam. The fault is associated with a thin gouge zone, some drag folding, and parallel jointing. Its trace tends to run parallel to the crest of the adjacent Warfield Anticline. Based on underground mine development and detailed core drilling, the vertical offset along the fault plane ranges from a maximum of 240 ft (73 m) in the central part of the area near the structural bend to less than 100 ft (30 m) in western and eastern directions. The fault is located along the relatively steeply dipping (locally in excess of 25%) southern limb of the Warfield Anticline, and appears related to a late phase of extension involving folded Pennsylvanian strata. On a regional scale, the lithological variations across the fault do not suggest any appreciable strike-slip component.Underground room and pillar mines in the Coalburg seam north and south of the fault have been greatly impacted by the Warfield structures. Due to the combined (and opposite) effects of the folding and faulting, the northern mines are located up to 400 ft (125 m) higher in elevation than the southern ones. Overland conveyor belts connect mining blocks separated by the fault. The practical mining limit along the steep slopes toward the fault is around 15%. Subsidiary normal faults with offsets in the 5- to 15-ft (1.5–4.5 m) range are fairly common and form major roof control and production hurdles. Overall, the Warfield structures pose an extra challenge to mine development in this part of the Appalachian Coalfields.  相似文献   

Mercury mobility at the Carson River Superfund Site, west-central Nevada, USA: Interpretation of mercury speciation data in mill tailings, soils, and sediments     

Paul J. Lechler  Jerry R. Miller  Liang-Chi Hsu  Mario O. Desilets 《Journal of Geochemical Exploration》1997,58(2-3)

The Carson River Superfund Site in west-central Nevada is an area of Hg-contaminated soil, sediment, water, air, and biola resulting from the amalgamation milling of Ag-Au ores of the Comstock lode worked approximately a century ago. In order to develop an understanding of the behavior, transport, and fate of Hg at this site, a technique was developed to estimate the proportions of total, elemental, exchangeable, organic, and sulfide Hg in soils, sediments, and tailings.Results of this analysis performed on active Carson River sediments indicate that Hg is selectively dissolved out of Hg-Au amalgam particles and subsequently adsorbed to fine-grained sediments which are then deposited in downstream, low-energy reaches of the Carson River and Labontan Reservoir. In the relatively more-reducing environment of the reservoir Hg appears to be converted, in large part, to relatively-insoluble HgS.The original elemental form of Hg released to the environment is the chemical form which is still dominant in most highly-contaminated soils, sediments, and tailings. Deeper, more-reducing soil horizons, however, appear to fix a significant portion of the Hg as HgS, analogous to the Lahontan Reservoir example described above. This fixation as HgS is documented to be largely limited to higher-sulfur areas where sulfide minerals from the Comstock ores increase the total sulfur concentrations of contaminated soils, sediments, and tailings.  相似文献   

边坡及其它类工程地质问题研究   总被引：2，自引：0，他引：2  

徐嘉谟 《水文地质工程地质》1997,24(2):35-38

本文提出有关边坡工程地质研究方面的一些新概念，看法和问题，并概述了属地这一专题的边坡及其它各类工程地质问题的研究成果。  相似文献   

科尔沁沙地巴克窑地区近150年的环境演变^*   总被引：3，自引：1，他引：3  

任国玉  肖平 《地理研究》1997,16(4):39-46

在沉积和花粉分析的基础上,对科尔沁沙地东南部巴克窑地区过去150年的植被和环境演变进行了重建。巴克窑等湖泡的诞生时间是在上个世纪前期,约1837年前后。这个时间也正是科尔沁沙地东南部地区首次大规模人口移入和垦荒年代。突然增加的人类活动导致了沙丘植被的迅速破坏,而植被减少和沙丘活化引起区域水文循环的重新调整,即原来通过植物蒸腾作用输出的水量明显减弱,致使地下潜水位上升,形成一系列湖泡。以后,沙地系统的演化主要是在人类活动、气候和系统内部反馈机制的共同作用下完成的。  相似文献   

山西离柳矿区奥陶系灰岩水环境质量分区及成因研究     

张玉良 《华北地质矿产杂志》1996,11(2):237-244

本文对离柳矿区奥陶系灰岩岩溶地下水的环境质量进行了评价和分区，结合地质条件简述了各区的特点；还用地质－水文地质学相结合的理论，对各环境质量区形成的原因，进行了分析和研究，进而从理论上证明环境质量分区和选用标准的合理性。  相似文献   

井筒及围岩应力,应变观测方法研究     

苏仲杰  隋惠全 《岩土力学》1997,18(3):82-87

采用最新研制的岩体应力、应变匹配传感器对西安立井煤柱开采引起的井筒附加应力特别是对井筒穿过断层附近产生的附加应力进行了较系统的观测，并对观测结果进行了分析和总结。  相似文献   

露天矿边坡的位移监测与滑坡预报   总被引：11，自引：0，他引：11  

李炼  陈从新 《岩土力学》1997,18(4):69-74

对湖北大冶铁矿滑坡区域的长期监测资料进行分析和总结，提出依据位移-时间曲线预报滑坡的方法。  相似文献