新疆库马苏-小土尔根一带化探异常特征及找矿前景     

王晓刚  陈根  严云峰  范小军 《四川地质学报》2011,(3):353-358

诺尔特地区下石炭统红山嘴组火山岩为Pb、Zn、Ag、Au矿源层,燕山期岩浆活动对矿源层中的成矿元素进一步富集,并在构造有利部位成矿。该区1∶20万、1∶5万水系沉积物测量和l∶2.5万土壤化探测量资料显示,区内下石炭统中-酸性火山岩出露区以P b、Zn、Ag、Au元素组合为特色的化探综合异常带具有规模大,强度高,浓集中心明显的特点,在异常周边已先后发现了多个铅锌、金、多金属矿床、矿点和矿化点,显示了库马苏-小土尔根地区具有非常好的找矿前景。  相似文献   

不同温室气体排放情景下未来中国地面气温变化特征   总被引：2，自引：1，他引：1  

闫冠华李巧萍邢超 《南京气象学院学报》2011,34(1):36-46

由于高光谱大气红外探测器（AIRS）有2378个通道,如何从众多的通道中提取主要的有用信息。针对这点,文中提出了基于主成分累计影响系数的通道选择方法。首先,进行通道的预处理。然后,考虑白天的通道组合,分别对温度和湿度雅可比矩阵进行主成分分析,得到每个通道对主成分的累计影响系数,根据累计影响系数的大小,进行通道排序。最后,考虑夜晚的通道组合,加入受太阳光影响的通道。最终得到白天和夜晚的入选通道子集。进行温度和湿度廓线反演的实验表明,该方法用于通道选择是可行的。  相似文献   

基于主成分累计影响系数法的高光谱大气红外探测器的通道选择试验          下载免费PDF全文

张建伟  王根  张华  黄静  陈靖  吴玲玲 《大气科学学报》2011,34(1):36-42

由于高光谱大气红外探测器(AIRS)有2 378个通道,如何从众多的通道中提取主要的有用信息。针对这点,文中提出了基于主成分累计影响系数的通道选择方法。首先,进行通道的预处理。然后,考虑白天的通道组合,分别对温度和湿度雅可比矩阵进行主成分分析,得到每个通道对主成分的累计影响系数,根据累计影响系数的大小,进行通道排序。最后,考虑夜晚的通道组合,加入受太阳光影响的通道。最终得到白天和夜晚的入选通道子集。进行温度和湿度廓线反演的实验表明,该方法用于通道选择是可行的。  相似文献   

A numerical investigation of the hydraulic fracturing behaviour of conglomerate in Glutenite formation     

Lianchong Li  Qingmin Meng  Shanyong Wang  Gen Li  Chunan Tang 《Acta Geotechnica》2013,8(6):597-618

Rock formations in Glutenite reservoirs typically display highly variable lithology and permeability, low and complex porosity, and significant heterogeneity. It is difficult to predict the pathway of hydraulic fractures in such rock formations. To capture the complex hydraulic fractures in rock masses, a numerical code called Rock Failure Process Analysis (RFPA2D) is introduced. Based on the characteristics of a typical Glutenite reservoir in China, a series of 2D numerical simulations on the hydraulic fractures in a small-scale model are conducted. The initiation, propagation and associated stress evolution of the hydraulic fracture during the failure process, which cannot be observed in experimental tests, are numerically simulated. Based on the numerical results, the hydraulic fracturing path and features are illustrated and discussed in detail. The influence of the confining stress ratio, gravel sizes (indicated by the diameter variation), and gravel volume content (VC) on the hydraulic fracturing pattern in a conglomerate specimen are numerically investigated, and the breakdown pressure is quantified as a function of these variables. Five hydraulic fracturing modes are identified: termination, deflection, branching (bifurcation), penetration, and attraction. The propagation trajectory of the primary hydraulic fractures is determined by the maximum and minimum stress ratios, although the fracturing path on local scales is clearly influenced by the presence of gravels in the conglomerate, particularly when the gravels are relatively large. As the stress ratio increases, the fractures typically penetrate through the gravels completely rather than propagating around the gravels, and the breakdown pressure decreases with increasing stress ratio. Furthermore, the breakdown pressure is affected by the size and volume content of the gravel in the conglomerate: as the gravel size and volume content increase, the breakdown pressure increases.  相似文献   

Demonstration and application of NMM‐based fractured porous medium flow model     

Qi‐Hua Zhang  Shao‐Zhong Lin  Hai‐Dong Su  Gen‐Hua Shi 《国际地质力学数值与分析法杂志》2021,45(1):132-153

In natural rock masses, the shapes of three‐dimensional (3‐D) blocks cut by arbitrary fracture networks may be very complex. Owing to the geometric complexity and difficulty of mesh discretization of 3‐D blocks and fracture facets, explicit consideration of fracture networks in flow analysis of fractured porous medium (FPM) is very challenging. Using the numerical manifold method based on independent covers (NMMIC), an FPM flow model was proposed that can deal with very complex 3‐D fracture networks. In this paper, the convergence of NMMIC was first demonstrated. The theoretical basis of the arbitrary refinement of computational meshes was proven. Moreover, three peculiarities of NMMIC meshes, that is, arbitrary shape, arbitrary connection, and arbitrary refinement of independent covers, were concluded. Finally, some two‐dimensional (2‐D) tunnel flow examples were analyzed and the numerical results were compared with the analytical results. 3‐D examples with complex fracture distributions were also analyzed. In addition, the computational scale of the developed program was tested by increasing the number of computational elements. The results show that our model can accurately analyze the groundwater flow of rocks surrounding tunnels with complex fracture distributions.  相似文献   

2018年松原5.7级地震前地磁垂直分量日变化低点时间时空演化特征     

戴勇  高立新  姚丽  杨彦明  格根  梁沙沙 《大地测量与地球动力学》2020,40(6):601-607

本文对松原5.7级地震前地磁垂直分量日变化低点时间时空演化特征进行研究，结果显示：1）以去除经度效应后低点时间为0 h的等值线作为低点位移分界线，松原5.7级地震的震中分别位于2018-04-13分界线上和2018-04-24分界线附近；2）异常日期间，中国大陆地磁垂直分量日变形态存在分区特征，去除经度效应后低点时间为正、负的区域内日变形态分别以“W”型和“V”型为主；3）在2018-04-13和2018-04-24这2个异常日期间，中国大陆都存在去除经度效应后的低点时间高梯度带，松原5.7级地震的震中分别位于2018-04-13高梯度区边缘和2018-04-24高梯度区东侧。  相似文献   

珠江口海洋软土不排水抗剪强度及循环弱化特性试验研究     

郭小青  朱斌  刘晋超  熊根  黄根清 《岩土力学》2016,37(4):1005-1012

为了获得广东珠江口海洋软土的不排水抗剪强度,分别开展了不固结不排水剪切和固结不排水剪切三轴试验、无侧限抗压试验、现场取土离心机正常固结模型地基的T-bar静力贯入试验以及现场十字板剪切试验和静力触探试验（CPT）,并采用土力学经验公式进行计算,确定了珠江口海洋软土不排水抗剪强度沿深度的分布规律,并综合评价了各种方法的有效性。为了获得该区域软土的循环弱化规律,分别开展了循环动三轴试验、现场取土离心机正常固结模型地基的T-bar循环贯入试验和现场单桩水平循环加载试验,揭示了软土循环动模量比与循环次数之间的双对数线性关系,获得了3种试验条件下珠江口海洋软土的循环弱化因子。其研究结果可为该区域海洋建筑物设计提供直接依据,也可为其他类型工程提供借鉴。  相似文献   

页岩气藏缝网压裂裂缝间距优化研究     

郭建春  李根  周鑫浩 《岩土力学》2016,37(11):3123-3129

页岩气藏一般具有低孔隙、低渗透等特征,对其实施缝网压裂是高效开发页岩气的最佳途径。采用位移不连续法建立线弹性二维均质地层诱导应力场分布数学模型,通过水平应力差异系数对顺序压裂和交替压裂的裂缝间距进行优化研究。结果表明,水平应力差异系数受到裂缝净压力、裂缝缝长、原地应力场等因素的影响;裂缝净压力越大、缝长越长,水平应力差异系数越小;随着与裂缝距离的增加,水平应力差异系数呈现先减小后增加的趋势,因此,存在后续裂缝形成复杂网络的最佳裂缝间距;顺序压裂裂缝间距不宜过大,且后续压裂裂缝间距应适当减小;交替压裂裂缝间距最优时,缝间水平应力差异系数最小,对中间裂缝形成缝网最有利。  相似文献   

传感网环境下传感器信息建模与注册方法研究     

陈瑶  陈能成  黄晓萍  郭际元  屠艮 《地理信息世界》2013,(1):51-57,67

如何对传感器资源进行重新组合并用于发现来实现高级的信息共享是目前亟待解决的问题。本文针对目前传感器的建模现状和发现机制现状,选择传感器模型语言(Sensor ML)实现传感器信息的建模。针对Sensor ML用于发现机制的Profile规则,提出了面向处理的传感器抽象模板建模方法。并且使用传感器实例注册(Sensor Instance Registry,SIR)客户端传感器信息模型。基于本文提出的方法,采用自主设计开发的传感器建模软件SensorModel完成了对传感器的快速实例化建模,应用SIR客户端完成了对所建传感器信息模型有效的注册和发现。  相似文献   

Indices of El Nio and El Nio Modoki:An Improved El Nio Modoki Index     

李根  任保华  杨成昀  郑建秋 《大气科学进展》2010,(5)

In recent years, El Nio Modoki (a type of pseudo-El Nio) has been distinguished as a unique large-scale ocean warming phenomenon happening in the central tropical Pacific that is quite different from the traditional El Nio. In this study, EOF analysis was used to successfully separate El Nio and El Nio Modoki. The abilities of the NINO3 index, NINO3.4 index, NINO1+2 index and NINO4 index in characterizing El Nio were explored in detail. The resulting suggestion was that, comparatively, NINO3 is the op...  相似文献