排序方式： 共有107条查询结果，搜索用时 15 毫秒
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高放废物地质处置过程中涉及的核素在围岩裂隙地下水中的迁移问题已引起广泛关注,数值模拟是研究核素粒子运移的重要方法。目前裂隙介质中渗流模型主要是等效连续介质模型、双重介质模型和离散裂隙网络模型。对于岩体尺度裂隙地下水的流动,离散裂隙网络模型能充分表现裂隙介质的各向异性、不连续性等特征。因此,针对裂隙介质准确概化及核素迁移模拟等难点,文章结合Monte Carlo随机生成裂隙方法、裂隙渗流有限元算法和高放射性核素衰变方程等方法,依据花岗岩深钻孔裂隙统计数据,采用离散裂隙网络模型对内蒙古阿拉善高放废物地质处置预选区展开了核素粒子迁移数值模拟研究,并讨论了实例预测分析结果。结果显示:针对设定的地质模型,核素粒子从中心运移到边界的迁移路径长度平均为1293.35 m,粒子运移到边界耗费的时间平均为1.70E+11 d。 相似文献
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Since its first flight in 2007, the UAVSAR instrument of NASA has acquired a large number of fully Polarimetric SAR (PolSAR) data in very high spatial resolution. It is possible to observe small spatial features in this type of data, offering the opportunity to explore structures in the images. In general, the structured scenes would present multimodal or spiky histograms. The finite mixture model has great advantages in modeling data with irregular histograms. In this paper, a type of important statistics called log-cumulants, which could be used to design parameter estimator or goodness-of-fit tests, are derived for the finite mixture model. They are compared with log-cumulants of the texture models. The results are adopted to UAVSAR data analysis to determine which model is better for different land types. 相似文献
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蒙古国东部省道尔脑德地区于侏罗纪—早白垩世火山活动频繁,形成道尔脑德火山机构,发育基性-酸性双峰式火山熔岩及火山碎屑岩,夹有陆源碎屑岩。同期该区域由挤压到伸展的构造体制转变,构造-岩浆热作用强烈,发生大规模成矿作用,形成与火山热液有关的铀-贱金属-金-萤石矿床成矿系列。文章在分析不同矿床成因类型、成矿时代及成矿温度基础上,系统总结该矿集区铀-贱金属-金-萤石矿床系列成矿作用。综合分析矿床产出背景、岩矿关系及各类控矿要素基础上,提出围岩、蚀变、构造、地球化学及岩石物理等方面的找矿标志。 相似文献
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Li Yinglei Liu Huichuan Huangfu Pengpeng He Hongyun Liu Yongzheng 《International Journal of Earth Sciences》2018,107(6):1955-1974
International Journal of Earth Sciences - This paper presents new zircon LA-ICP-MS U–Pb ages and whole-rock geochemical data for two granitic plutons and rhyolites of the Baiyingaolao... 相似文献
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Pengpeng Ni 《Marine Georesources & Geotechnology》2013,31(6):671-682
AbstractFor land reclamation using the conventional surcharge preloading method, a sand cap layer is often fully placed at the ground surface of ultra-soft compressible estuary or marine clays. A novel strategy of distributed sand caps is proposed to save cost associated with sand materials. At an early stage of consolidation, the drainage capacity of distributed sand caps is less than the drainage demand, whereas at a later stage, the capacity exceeds the demand. Hence, the overall drainage capacity of distributed sand caps is equivalent to the drainage demand. A numerical model is developed to study the effectiveness of the proposed technique, and calculations are compared against theoretical solutions. A parametric study is conducted to optimize design parameters. It has been found that distributed sand caps should be uniformly placed with a size of 3% of the total width and a spacing of 1 times the size, such that sand materials can be saved by up to 50% without compromising the consolidation efficiency (an increase of consolidation time by less than 5%). The use of distributed sand caps will be effective regardless of soil properties, including hydraulic conductivity, elastic modulus and Poisson’s ratio. 相似文献
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Kou Hai-Lei Liu Jia-Hui Zhang Peng Wu Chuangzhou Ni Pengpeng Wang Dong 《Acta Geotechnica》2022,17(12):5375-5389
Acta Geotechnica - Coconut can be found extensively in the coastal area of south China, where sandy slopes always suffer from erosion due to typhoon. Recycled shredded coconut coir (RSC) was... 相似文献