共查询到20条相似文献，搜索用时 62 毫秒
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定向钻孔设计是定向钻进技术中重要的一环，它直接地关系到定向钻进在技术上能否成功以及在经济上是否合理。当矿区钻孔方位角变化不大可以忽略时，我们可以仅仅按顶角变化在垂直剖面内来设计定向钻孔。按此原则设计单个定向钻孔有许多方法，本文主要根据国外有关文献，介绍三种方法，即作图法，作图—计算法以及计算法。 相似文献
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采用受控定向钻探技术，在我省固体矿产地质勘探中尚属首次，结合栾川冷水北沟铅锌银多金属矿区设计的ZK2701定向孔，探讨总结出了以螺杆钻完成的受控定向钻探技术的操作方法、计算方法及采取的主要技术措施。 相似文献
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通过对国内外有关定向取心的方法、以及工具仪器进行认真的调研，并对各种方法和工具仪器进行细致的分析对比后，我们确定了“随钻定向取心方法”方案，并设计试制了定向取心工具和测量仪器。81年3月间，所、厂分别完成了工具和仪器的试制与室内调试工作。四月间全部组装配套在成都探矿工艺研究所试验机台进行了浅孔的钻进试验，取得了成效。8月 相似文献
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KDJ-1型磁性定向仪，是采用罗盘磁针式测斜仪，对孔底定向工具及孔底直接定向方法等结合设计的直接定向仪器，即用测斜仪可直接测定孔内定向标记方向。该仪器采用了简易和经济的办法解决了直孔定向问题。一、用 途KDJ-1型磁性定向仪适用于非磁性矿区，直径56mm以上钻孔连续作用造斜器、偏心楔以及孔底动力钻具（螺杆钻，涡轮钻）的测斜定向。该仪器一次下井测量可同时测得钻孔方位角，顶角和造斜工具面向角三个参数。特别适用于解决钻孔顶角小于3°时的测斜定向，但也用于钻孔顶角大于3°时的测斜定向。该 相似文献
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栾川冷水北沟铅锌银多金属矿区设计的ZK2701定向孔，是在河南省固体矿产地质勘探中首次采用受控定向钻探技术施工的钻孔，探讨总结了以螺杆钻完成受控定向钻探技术的操作方法、计算方法及采取的主要技术措施。 相似文献
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非开挖技术中定向钻进效果与弯曲问题分析 总被引：3，自引：0，他引：3
非开相中的导(定)向技术巳成为非开挖技术中不可缺少的重要组成部分。由于一般导向设备具有体积庞大的特点，对于窄小拥挤的巷道明显不适应，因此传统定向钻进中的简单孔口定向方法显得尤为重要，而且这种方法不论从设备还是技术人力资源上我国都有较好的基础。但在非开挖中如何运用简单孔口定向方法要求设计及施钻人员必须对钻孔的守曲特点有较深入的了解，并要求要一定的施工经验。作对定向钻进中的一般规律进行了总结；在实践中运用这些规律取得了较好的效果。 相似文献
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在山西省引黄工程隧道电缆钻孔的施工中，采取常规钻探方法无法进行施工，而采取高精度定向钻探技术后，使工程顺利完成并达到工程质量要求。介绍了工程的进展及高精度定向钻探的施工过程。 相似文献
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勘探矿床时，在合适的地质、地理条件下，施工定向孔，特别是孔内分枝定向孔，可以取得较好的地质效果和社会、经济效益。其中定向孔孔身剖面型式的选择和设计计算方法极为重要。实际工作中，为了施工方便和节约，一般都选用方位角基本上不变化而顶角变化的平面弯曲型定向孔孔身剖面。 相似文献
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CSAMT 法在辽西康杖子区深部探矿中的应用 总被引：5，自引：0，他引：5
可控源音频大地电磁法(CSAMT)具有探测深度大、横向分辨率高、抗干扰能力强的特点,在深部找矿勘探中有着重要的指导意义。肖家营子铜钼矿床是辽西地区一个大型矽卡岩型金属矿床,大部分矿体是隐伏矿体,矿区外围的康杖子区与本区有相似的成矿地质环境,成矿地质条件优越.矿体与围岩电性差异明显,通过应用CSAMT,矿体具有低电阻特点,根据成果推断解释,对深部有利成矿部位进行了钻探验证,取得了理想的探矿效果,在矿区外围取得第二深度空间找矿重大突破。 相似文献
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Trends in landslide occurrence in Nepal 总被引：2，自引：0，他引：2
David N. Petley Gareth J. Hearn Andrew Hart Nicholas J. Rosser Stuart A. Dunning Katie Oven Wishart A. Mitchell 《Natural Hazards》2007,43(1):23-44
Nepal is a mountainous, less developed kingdom that straddles the boundary between the Indian and Himalayan tectonic plates.
In Nepal, landslides represent a major constraint on development, causing high levels of economic loss and substantial numbers
of fatalities each year. There is a general consensus that the impacts of landslides in countries such as Nepal are increasing
with time, but until now there has been little or no quantitative data to support this view, or to explain the causes of the
increases. In this paper, a database of landslide fatalities in Nepal has been compiled and analysed for the period 1978–2005.
The database suggests that there is a high level of variability in the occurrence of landslides from year to year, but that
the overall trend is upward. Analyses of the trends in the data suggest that there is a cyclicity in the occurrence of landslide
fatalities that strongly mirrors the cyclicity observed in the SW (summer) monsoon in South Asia. Perhaps surprisingly the
relationship is inverse, but this is explained through an inverse relationship between monsoon strength and the amount of
precipitation in the Hill District areas of Nepal. It is also clear that in recent years the number of fatalities has increased
dramatically over and above the effects of the monsoon cycle. Three explanations are explored for this: land-use change, the
effects of the ongoing civil war in Nepal, and road building. It is concluded that a major component of the generally upward
trend in landslide impact probably results from the rural road-building programme, and its attendant changes to physical and
natural systems. 相似文献
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Julie Okpala 《GeoJournal》1990,20(1):37-43
This paper traces the development of geographic education in Nigeria and examines the views of geographers, other academics,
students and the public at large about the importance of geography. Geography's value is immense despite the non-professional
nature of the discipline. Nevertheless, there is a need to define geography's status and ensure career prospects for students.
The Nigerian Geographical Association (from classroom teaachers to top geographers) must promote geography, improve its status
in schools and universities, and continuously restructure its content and methods to address pertinent social needs. 相似文献
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Takeshi Nose Dr. 《GeoJournal》1985,10(3):261-276
Conclusions During the last ten years, aquaculture, especially mariculture has undergone remarkable expansion to counter-balance the gap between the supply and demand of fishery products in Japan. Its expansion has also been supported by the traditional preference of the Japanese people for seafood. Mariculture is now being forced to change its structure due to adverse economic circumstances such as the rise in the cost of energy, feeds and other materials for culture, low market prices, deterioration of environmental conditions, and many other factors. Before these constraints can be resolved, advanced scientific knowledge and technologies must be integrated to develop new types of aquaculture. Expansion of maricultural activities to more open-sea and off shore areas would be one route to follow. Technologies for the development of formulated diets not only for young but also for adults and larvae, establishment of feeding standards, prevention of epizootic diseases must support the establishment of modern aquaculture.The culture-based fisheries, or marine ranching, is becoming a subject for further development in Japan. Much research work has been conducted with a great degree of governmental support. Establishment of a net work of seedstock production farms has made it possible to carry out releasing experiments on a large scale. A newly integrated restoration system could be developed on the basis of these experiments, even though the profits resulting from the artificial restoration of stocks is not thouroughly verified at present. The commencement of a national scheme for culture-based fisheries would be a manifestation of the enthusiasm of the Japanese fish industry. 相似文献
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2010年,美国铀矿总共施工7 209个钻孔,总进尺1 493 520 m;生产铀1 628.55 t;铀矿业总支出费用为2.773亿美元,其中铀矿地勘费支出为3 450万美元,占铀矿业总费用的12.44%。铀矿地勘钻探费用为4 460万美元,占铀矿业总费用的16.08%。 相似文献
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硫代砷是富硫化物地下水中砷的重要形态,对环境和人类健康有潜在威胁。目前硫代砷研究程度尚低,本次主要针对国内外地下水（地热水）中硫代砷的存在形态,水文—生物—环境地球化学过程,样品保存,定量检测方法等方面进行研究。结论如下:pH, 氧化还原电位,硫化物含量和微生物作用等是影响地下水中硫代砷稳定存在和形态分布的重要因素。含铁矿物能与水中的硫代砷形成配位键对其进行吸附,吸附性普遍弱于（亚）砷酸盐,因此,地下水中硫代砷可能表现出更强的迁移性。用于硫代砷检测的自然水样在采集中可采取过滤,速冻,厌氧和低温短期保存的操作流程,以减缓该形态的转化甚至消失。色谱联用ICP-MS系统可用于自然水样中硫代砷的分离定量检测,紫外—可见分光光度法和X射线吸收光谱法在不同场景下也可对硫代砷进行定量和表征分析。地热水和浅层地下水中均可能存在硫代砷,由于水样中硫代砷的不稳定性,室内检测和分析难以准确反映现场过程,因此,野外样品保存技术和现场检测方法的更新可能在未来有更大研究空间,值得进一步探索。 相似文献
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内蒙古苏尼特地下水氟污染形成机理研究 总被引：4，自引：1，他引：3
为了研究内蒙古苏尼特地区地下水氟污染机理,本文运用水文地球化学分类方法,从水文地质、水化学特征两方面研究其地下水的水质特征、氟的起源、分布规律及污染形成机理。研究结果发现:高氟地下水的主要水质类型为HCO3—Na型,pH值在7.08～9.38之间,氟浓度与井深有关,即井越浅,氟浓度越高;地下水中氟浓度最高达14.78mg/L,5～9月地下水氟浓度相对增长率在7.8～23.1之间;F-浓度与Li+、Br-相关系数达0.89和0.82,受断层影响的深层地下水中F-浓度几乎与Li+、Br-没有相关关系,这暗示着氟来源于浅部,并受到强烈的蒸发作用影响而使水中的氟浓缩;地质调查发现该地区还有数个萤石矿存在,显微镜分析结果证实表层土壤中普遍存在CaF2,地下水中的氟来自CaF2。高氟地下水存在于潜水层,深部含水层的地下水可供开采。从断层带涌出的水对潜水层有稀释作用。 相似文献
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Radon is a radioactive gas emanating naturally from uranium rich granites and shales. It may be emitted from the ground surface into the atmosphere as a gas, or it may be dissolved into stream water and transported over distance. The levels of radon gas in soils at ground surface depend on a number of factors relating to the source of the gas and to its transmission. Igneous rocks contain the highest mean concentrations of radium and uranium. The depth of cover is relevant also. Surveys over the years by the National Radiological Protection Board (NRPB) and others have indicated that the highest concentrations in the United Kingdom occur in Cornwall, Devon and northeast Scotland. However, recent reports have indicated that high concentrations of the gas may be detected in small pockets in counties outside of those considered at high risk. This survey relates to a series of measurements taken in and around Darlington, County Durham. The results showed the presence of small areas with strong concentrations of radon in soil gas, but only minor levels of dissolved gas in stream waters. 相似文献