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   

新产业区的形成机制及其与传统空间组织理论的关系   总被引：8，自引：1，他引：8  

田明  樊杰 《地理科学进展》2003,22(2):186-194

在新产业区概念和特征进行概括的基础上,归纳了产业区发展的一般过程,并重点对新产业区的形成机制及所具有的优势进行了探讨。地方化产业群及区域创新网络的形成是新产业区成熟的标志,知识外溢、经济外部性导致的收益递增,以及基于密切的内部联系引来交易成本的降低使新产业区获得了强大的经济竞争优势,新产业区的空间组织形式所具有的网络效应、创新效应和企业与地方文化的良好融合是经济竞争优势的根本。最后,对新产业区理论和传统的空间组织理论之间的关系进行了对比分析,总结了二者的之间的异同。  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   

贵州贵阳地区下三叠统凝缩段的遗迹化石特征   总被引：2，自引：0，他引：2  

王尚彦 《沉积与特提斯地质》1997,17(2):58-62

贵阳地区下三叠统是一个完整的碳酸盐岩层序（相当于三级旋回层序）．该层序中的凝缩段由深色薄层（单层厚0．5cm～1cm）的泥晶灰岩和泥质条带灰岩组成．凝缩段中产丰富的遗迹化右．该遗迹群落为：Cochlichnus,Cosmorhaphe,Chondrites,Gordia,Huaxich－nus，Oldhamia,Phycosiphon.Protopaleodictyon,Pinnatpedus,Mammillichnus,Neonerites和生物扰动构造．遗迹化石组合与Nereites遗迹相相似。此外，文本还讨论了此遗迹群落的形成原因。  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   

新产业区与经济活动全球化的地理研究   总被引：28，自引：5，他引：28  

李小建 《地理科学进展》1997,16(3):16-23

本文评述了90年代国际经济地理学界关注的两个研究领域：新产业区和经济活动全球化。在分析两者的含义和研究关键内容基础上，提出如何在我国开展该项研究。  相似文献   

王家山煤矿地裂缝的形成及其灾害     

杨建成 《甘肃地质》1996,5(2):91-95

王家山煤矿断层密集，地裂缝发育，采空塌陷严重，这三者构成严重的地质灾害链。地裂缝的形成和发展，使矿区人民的生命财产遭受了惨重的损失。从工程地质及地质灾害的角度进行分析，认为新构造运动是动态的地质背景，黄土的特殊物理力学性质是静态的地质基础，人为的采空塌陷是地裂缝群产生的主要原因  相似文献   

湘南地区稀土矿产资源开发经济意义探讨     

张传福 《湖南地质》1996,15(2):85-88

湘南地区风化壳型稀土资源丰富，对其开发的采、选工艺和流程简单，投入资金较少，产出颇丰、经济、社会效益明显，是湘南盆困山区脱贫致富的重要途径。本文就开发湘南稀土矿的成本、效益等进行了初步测算，可供参考。  相似文献   

郴桂地区中大比例尺成矿预测的方法与效果   总被引：1，自引：0，他引：1  

曾昭健 《湖南地质》1996,15(4):221-226

郴桂地区是南岭多金属成矿带的重要地段，地质矿产工作研究程度较高，我院在此开展了大中比例尺成矿预测研究。本文扼要介绍了本区成矿预测的基本做法和预测方法，以及其主要成果和验证效果。  相似文献