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721.
Herong Gui Huili Qiu Weizhong Qiu Shijie Tong Hongzhong Zhang 《Arabian Journal of Geosciences》2018,11(3):49
Since 1990s, goaf water has become a frequent cause of water disaster in China coalmines, inflicting severe human casualties and huge economic losses. Based on the analysis of the goaf water disaster cases in China coalmines, this article put forward the theoretical and technological system of goaf water control, which include (1) the area and volume of goaf water are reasonably determined due to existence form of goaf water and geophysical prospecting results, (2)retaining sufficient water-resistant coal (rock) pillar to prevent goaf water inrush from adjacent and above, (3)grouting insecure or failure water-resistant coal (rock) pillar, and (4) draining goaf water using “fanned-out” normal drill and long-distance directional drill, and of all, draining goaf water through long-distance drill has been proved to be technically superior in engineering practices. The research results can be of reference to other coal-producing countries in similar geological conditions. 相似文献
722.
Journal of Geographical Systems - This study proposes a cellular automata-based Industrial and Residential Land Use Competition Model to simulate the dynamic spatial transformation of industrial... 相似文献
723.
724.
柴达木盆地北缘西端埃达克质花岗岩的发现及地质意义 总被引:1,自引:0,他引:1
盐场北山英云闪长岩位于柴达木盆地北缘西端青海冷湖地区。岩体Si2O56%(62.86%~64.83%),A12O315%,MgO3%(含量为1.73%~1.96%),Mg#=33.4~37.0,小于50。Sr400×10-6(平均为409×10-6),Y18×10-6(Y=3.09×10-6~6.6×10-6),Yb1.9×10-6(Yb=0.4×10-6~0.58×10-6),具有埃达克岩地球化学特征;Na2O/K2O=2.39~2.73,富Na贫K,Eu、Sr正异常(δEu=1.22~1.44),属O型埃达克岩。岩体富集大离子亲石元素(K、Rb、Sr、Ba),亏损高场强元素(Nb、Ta、P),具火山弧型花岗岩特征。LA-ICP-MS锆石U-Pb测年结果表明,岩体形成于263±2 Ma。结合区域地质背景和岩石地球化学特征,认为柴达木盆地北缘西端埃达克质花岗岩可能产于与俯冲有关的活动大陆边缘火山弧环境,是俯冲板片直接熔融的产物。进而揭示中二叠世末柴达木盆地北缘地区处于洋陆俯冲的构造演化阶段。 相似文献
725.
Water Resources - In mining areas, coal production, agriculture, and drinking use had increased the demand for fresh groundwater. It was essential to obtain a deeper understanding of the... 相似文献
726.
Rhenium-Osmium (Re-Os) isotopic dating applied to the geochronology of hydrocarbon accumulation has been the forefront of international research in the last 10 years and has achieved significant achievements. However, our current researches are lacking in Re-Os isotopic chronology on the geochronology of hydrocarbon accumulation. The successful application of the Re-Os geochronology has enabled the determination of accurate and precise depositional ages for Organic-Rich Sedimentary rocks (ORS), the establishment of timing constraints of oil generation or migration, and the fingerprinting of the source of oil. On the basis of literatures study both at home and abroad, this article mainly dealt with the principle of Re-Os isotopic dating and analyzed the accumulation processes of Re and Os in a seawater-sediment system. Meanwhile, the test samples, sample preparation and analytical methodology of Re-Os isotopic dating were summarized. The results revealed that the initial 187Os/188Os ratio could constrain the age of oil generation or migration, and effectively evaluated the relationship between source rock and oil. The radiogenic 187Os/188Os ratio showed a positively correlated relationship with source rock age. This article proposed that hydrocarbon mature, biodegradation and water washing had minimal or no effect on data scatter about Re-Os isochron. However, the effects of postdepositional mobility of Re and Os, variations in the initial 187Os/188Os ratio, and thermochemical sulfate reduction could result in data scatter. The reproducibility and accuracy of Re-Os age was also closely related to the sample particle size and sample amount. Compared with other isotopic dating, the biggest advantage of Re-Os isotopic dating is to study geological body related to accumulation process, and to obtain direct evidence of hydrocarbon accumulation period. From what was discussed above, the article discussed the existing problems and put forward the future hot research and development direction of Re-Os isotope system, so as to promote the deep development of relative theory and technology of Re-Os isotopic dating. 相似文献
727.
Multiple approaches are used to study the potential seismic hazard in the North China Craton (NCC, or North China Plain), where approximately 15 % of the Chinese population resides and under which active faults are located. In this study, we develop a new modified Mercalli intensity (MMI) attenuation relationship for the NCC using intensity data from 10 instrumentally recorded events. We then utilize this relationship to infer the magnitude and epicentral location of historic events based on the method proposed by Bakun and Wentworth (Bull Seismol Soc Am 87(6):1502–1521, 1997). In addition, a modified stochastic finite fault model is employed to simulate the strong ground motions caused by these historic events. The simulated peak ground accelerations and velocities are then converted into regional MMI distributions through empirical relationships, and these synthetic MMI maps are compared to field observations. The resultant MMI attenuation versus distance models of the 1976 M w 7.6 Tangshan event and the 1679 M 8.0 Sanhe-Pinggu event are consistent with the empirical attenuation relationships, and the location and size of the meizoseismal area (>VIII) are consistent with observations. The successful modeling of these historic events indicates that a stochastic finite fault model constrained by the regional MMI attenuation relationship can be used to evaluate a wide range of scenarios based on modern computational simulations. These findings may also provide useful information for the estimation and mitigation of potential seismic hazards in this region. 相似文献
728.
The Zhujiang River Estuary is becoming eutrophic due to the impact of anthropogenic activities in the past decades. To understand nutrient dynamics and fluxes to the Lingdingyang water via four outlets(Humen,Jiaomen, Hongqimen and Hengmen), we investigated the spatial distribution and seasonal variation of dissolved nutrients in the Zhujiang River Estuary, based on fourteen cruises conducted from March 2015 to October 2017,covering both wet(April to September) and dry(October to March next year)... 相似文献
729.
针对国内飞机人工增雨指挥系统的发展现状,紧密联系业务需要,结合卫星通信、地理信息系统和.Net编程技术研制了一套基于GPS/北斗卫星和GIS技术集成的飞机人工增雨指挥系统.系统实现了资料采集、信息显示、航线设计、决策分析、实时监控、作业指挥、数据管理等系统功能,优化了飞机人工增雨业务流程,为飞机人工增雨作业提供了指挥、调度的决策依据.系统采用卫星通信技术实现了点对多地空实时通信,适合用于跨区域飞机人工增雨指挥系统建设,具有一定的推广和应用价值. 相似文献
730.
长毛对虾酸性磷酸酶功能基团的研究(Ⅱ) 总被引:1,自引:0,他引:1
用化学修饰剂pCMB、NBS、K试剂修饰长毛对虾Penaeuspenicilla-tusAlcock酸性磷酸酶(ACPase,EC3.1.3.2),在修饰剂作用下,酶活力明显下降,健康虾酶对修饰剂的敏感性(NBS除外)大都稍大于病虾酶。修饰酶的紫外280um吸收光谱以及荧光340um发射光谱的变化,表明酶活力下降的同时酶构象也产生相应的变化。结果表明,酶分子的半胱氨酸残基、色氨酸残基以及门冬氨酸、谷氨酸β或γ验基与酶活力有关,是酶的催化功能基团。 相似文献