航空高光谱遥感固体矿产预测方法与示范应用

高光谱遥感是当前遥感地质领域应用的前沿和热点,目前国内外都在积极进行探索。高光谱遥感技术的发展为遥感的直接找矿带来了新的希望,航空高光谱遥感技术由于可以获得高空间分辨率(可达亚米级)的高光谱遥感数据,能够识别规模小的近矿围岩蚀变,从而具有直接找矿的效果。直接找矿的核心是对矿产的预测,预测效果是矿产勘查取得突破的关键环节。本文利用核工业北京地质研究院遥感信息与图像分析技术国家级重点实验室的CASI/SASI/TASI(可见光-近红外,短波红外,热红外)航空高光谱成像系统,在甘肃北山柳园—方山口和新疆雪米斯坦地区获取的航空高光谱遥感数据,对固体矿产预测技术进行了研究,建立了基于航空高光谱遥感的成矿环境分析法、矿床定位模型识别法和含矿构造追踪法等预测方法,并对每种方法进行了应用示范,共发现7处金属矿化地段,取得了明显的找矿效果。该项成果不仅为研究区的进一步找矿提供了新的有利地区,而且建立的预测方法,将会助力于高光谱遥感技术在其它地区的推广应用。     

滇中红层软岩微观结构及水理特性试验研究

滇中红层软岩具有成岩作用差、易产生较大变形、遇水易软化、易崩解等特征,本文采用环境扫描电镜试验和水理特性试验,对红层软岩的微观结构特征,崩解、膨胀、软化等水理特性进行了研究。试验结果表明,红层软岩矿物粒间空隙大多被粘土矿物填充,粘土矿物以伊利石和蒙脱石为主,为混层结构,结晶程度相对较差,多数有蚀变的痕迹。具有微小裂隙的红层软岩在1~2次充分饱水烘干后,崩解性开始显现;随着干湿循环次数增加,岩样的质量变化呈减小趋势;干湿循环次数继续增加,崩解性指数趋于平缓。红层软岩由于风化作用影响程度和自然含水率的差异,岩体内部崩解张力具有明显不均匀性。经过自由浸水48h后,红层软岩的单轴抗压强度降低29.83%~58.47%,各地层软化系数在0.4~0.7之间,遇水后呈现显著软化效应。这些结果为红层软岩地区公路工程建设的工程地质研究提供了一定参考。     

Experimental and modelled mechanical behaviour of a rock fracture under normal stress

Summary  The mechanical and hydromechanical behaviour of isolated rock joints is of prime importance for a correct understanding of the behaviour of jointed rock masses. This paper focuses on the mechanical behaviour of a fracture under normal stress (fracture closure), using approaches based on both experimentation and modelled analysis. Experimental closure tests were carried out by positioning four displacement transducers around a fracture, leading to results which tended to vary as a function of transducer location. Such variations can be explained by the non-constant void space distribution between both walls of the fracture. The present study focuses on the importance of transducer location in such a test, and on the significant role played, in terms of mechanical response, by the morphology of the fracture surfaces. An analytical mechanical model is then developed, which takes into account the deformation of surface asperities and of the bulk material surrounding the fracture; it also includes the effects of mechanical interaction between contact points. The model is validated by simulating the behaviour which is very similar to experimental observations. Various parametric studies (scale effect, spatial distribution of contact points) are then carried out. The study of scale effects reveals a decrease in the normal stiffness with increasing fracture size. Finally, analysis of the role of various mechanical parameters has shown that the most influential of these is Young’s modulus corresponding to the bulk material surrounding the joint. Many applications, such as geothermal fluid recovery from fractures, could benefit from these results. Correspondence: Antoine Marache, Université Bordeaux 1, GHYMAC, Av. des Facultés, 33405 Talence Cedex, France     

Assessment and Control of Ore Dilution in Long Hole Mining: Case Studies

Unplanned ore dilution has a direct and large influence on the cost of a stope, and ultimately on the profitability of a mining operation. This paper presents the results of an examination of factors influencing ore dilution in a blasthole stoping environment. For the study, a comprehensive database was established, incorporating information related to the design, construction, excavation and cavity surveys of 172 sequentially mined long hole stope case histories from two orezones. Through a review of the case studies, it was demonstrated that, in addition to stope dimension, the amount of unplanned dilution differed according to stope type. Five stope types were identified, based on their position within a tabular blasthole mining sequence. Measured overbreak varies with stope type, with secondary stopes generating a greater volume of hanging-wall dilution than do primary stopes. Furthermore, a case study is presented to demonstrate the role cablebolts installed in the stope hanging-wall play to control ore dilution. The study illustrates relationships between measured hanging-wall overbreak, cablebolt orientation and stope type.     

关于黄土高原陆面过程及其观测试验研究

总结了国际上陆面过程及其试验研究的现状,分析了黄土高原陆面过程的特殊性和重要意义,探讨了黄土高原陆面过程试验研究中需要关注的一些重要科学问题。并且,对如何开展黄土高原陆面过程试验研究提出了一些初步思路。     

中美地理学近百年发展脉络的比较研究——基于《地理学报》和Annals of the Association of American

基于《地理学报》和Annals of the Association of American Geographers学术论文的统计,对比近百年中美两国地理学的发展脉络,着重从总体特征、重点研究内容及其变化、理论—实践关系三方面对比异同,获得经验和借鉴。美国地理学经过初期发展、高速发展后,目前进入持续发展阶段;中国地理学在曲折中崛起,目前正处在高速发展时期。美国地理学中人文地理学一直居主导地位,中国则从重视自然地理开始逐渐向自然、人文、方法三足鼎立方向迈进;美国地理学家非常重视微观、中观实践,但在国家宏观决策中远没有中国地理学家发挥作用更直接。美国地理学研究水平高于中国,但这种差距正在缩小,研究方向的变化相差3~5年。世界地理研究中心有向亚太地区、向中国转移的可能,中国地理学家要勇于创建具有中国特色的地理学派。     

Oracle数据库空间数据类型和空间函数扩展实现

Oracle数据库是海量空间数据存储和查询的首选数据库之一,其对面向对象技术的支持和扩展为对象-关系空间数据库的实现奠定了坚持基础。这里详细介绍了Oracle数据库的对象类型、对象类型方法和其对继承、多态这两个面向对象核心概念的支持,并在Oracle92中参照OpenGIS矢量几何对象模型,扩展了空间数据类型和空间函数。并基于这些空间数据类型和空间函数构建了空间数据表,进行了空间查询试验。     

南华北盆地阜阳区块古生代地震层序划分及地震相研究

阜阳区块位于南华北盆地的周口坳陷东部,面积约11000km^2,占坳陷面积的三分之一;该盆地按照中、新生界构造特征将其划分为六凹四凸;随着油气勘探的深入和地质研究的深化,笔者利用该区地震剖面进行地震层序研究与划分,并进一步进行了沉积相的研究,为该区古生代的油气勘探提供科学依据。     

义煤集团西部四矿奥灰水防治技术研究

2006年曹窑东井27080工作面突然发生大型奥灰滞后突水,最大涌水量达到1693m^3／h,通过矿井水文地质条件分析,曹窑东井及相邻西部四矿大部分区域已处于“突水危险区”。为避免奥灰突水灾害再次发生,提出了“以防为主”的预防奥灰突水的技术手段和方法步骤,以探索深部煤炭开采的防治水工作。