漠河盆地西部二十二站组碎屑锆石U-Pb年龄、地球化学特征及其物源意义

大兴安岭北部漠河盆地内广泛发育二十二站组,其形成时代及物质来源一直以来备受争议.本文在野外地质调查及岩相学的基础上,利用碎屑锆石LA-ICP-MS U-Pb法测年,并结合岩石地球化学等方法,探讨了二十二站组形成时代、物源区大地构造环境及沉积物来源.测年结果显示132个测点年龄主要分布在4个群落,分别为508.3～492.3 Ma;486.9～435.5 Ma;278.3～254.2 Ma;209.5～178.1 Ma.本次获得二十二站组最小碎屑锆石年龄为178.1 Ma,并结合漠河盆地东西部碎屑锆石的年龄,综合认为二十二站组形成时代应为中晚侏罗世.地球化学分析结果显示,二十二站组砂岩的稀土元素与活动大陆边缘的稀土元素曲线吻合较好,且相对亏损高场强元素(Nb和Ta)和大离子亲石元素(Ba和Sr),相对富集高场强元素(La、Th、Zr、Hf),地球化学特征与活动大陆边缘相似.综合古流向、源区母岩分析、碎屑锆石测年分析、微量元素特征等诸多因素,本次研究认为本区二十二站组砂岩的母岩主要来源于盆地南缘广泛分布的前中生代沉积-变质基底(兴华渡口岩群、佳疙瘩组、额尔古纳河组等)及各期中酸性火成岩.     

Numerical investigation of the hydrodynamic response of an impermeable sea-wall subjected to artificial submarine landslide-induced tsunamis

Landslides - Landslide-induced tsunamis are common natural hazards that potentially affect the safety and stability of waterfront structures. A numerical tank was constructed using FLOW-3D to...     

Numerical simulation of direct shear test of rockfill based on particle breaking

Acta Geotechnica - In the traditional Mohr–Coulomb criterion, the shear strength is determined by cohesion and friction angle. However, the particle breakage that occurs on the shear failure...     

固体潮观测数据预处理中的常用方法及计算机实现

从地震台站产出的原始地形变前兆数据出发,提出实际操作性较强的预处理方法,从已编制好的软件中给出处理实例,从而提高地震台站观测人员的科研能力,填补资料预处理方面的某些空白,对于地震台站人员集观测、科研于一体有着十分重要的意义。从95-01-02项目厦门地震台前兆数据预处理的实践表明:这些方法取得了明显的实效,直到今天仍然具有很大的使用价值。     

逆断层地震近场地震动影响场和地表形变模拟

本文设计了一个MW7.0级地震的简单的逆断层有限移动源破裂模型,计算了断层周围64个观测点的加速度、速度和位移时程及峰值,简单讨论了近场地震动峰值、断层附近地表永久位移(或地表形变)的分布特点,并讨论了永久位移和地面运动速度大脉冲的关系。重点研究了断层附近三分量的永久位移(或地表形变)大小、方向和地震动作用特点。     

川东北地区不同构造带地层水化学特征与油气保存的关系

判断油气藏保存条件的优劣,除了盖层和断层封闭性之外,还有油气水的化学特征,如地层水的交替或油气散失。通过对川东北地区地层水的水型、矿化度、水性系数等参数的综合分析认为,川东北宣汉—达县地区与通江—南江—巴中地区的地层水具有矿化度高和氯镁系数越大,变质系数、脱硫系数和碳酸盐平衡系数就越小的特点。矿化度、水性系数及水型的变化具有很好的一致性,表明该区存在有利于油气保存的水文地质条件。     

互联网影响下的“网剧”与传统“台剧”生产网络的结构差异

选取2016—2017年最具代表性的“网剧”和“台剧”各318部,运用社会网络分析法探讨互联网影响下的“网剧”与传统“台剧”生产网络的结构差异。研究表明：① 空间分布上看,相对于“台剧”生产网络,“网剧”生产网络中的企业区位、核心城市节点和城市间强联系更加集聚,尤其是向京津冀和长三角两大城市群集聚。② 网络结构上看,相对于“台剧”生产网络,“网剧”生产网络的规模小、联系数量少、分工粗略、中心势低,核心企业节点多为民营互联网影视企业,最强凝聚子群更为开放。最后,从互联网发展的地理格局、互联网带来的消费习惯改变、互联网引发的自由竞争,以及互联网视频平台企业的崛起四个方面分析了产生上述网络结构差异的原因。     

基于POGIL理论的地理研学旅行设计研究——以山东省沂河滨河湿地研学为例

研学旅行是中小学开展综合实践活动的重要方式,本文以山东省沂河滨河湿地研学为例,使用“过程取向-指导式探究学习”理论,以问题为导向,提高学生发现问题、解决问题的能力,提高地理实践力。     

A Thermo–Hydro–Mechanical Model: Capturing the Effects of Initial Permeability and Gas Pressure on Outburst-Prone Indicators

Natural Resources Research - Coal and gas outbursts often result in a large number of casualties and economic losses. Its complex processes involve the multi-field coupling of gas flow, coal...     

A case study on Landscape Component Niche based on Landscape Pattern Indices: Yanchi,Ningxia Province,China

Yanchi County is located in the agro-pastoral ecotone and belongs to the ecologically fragile area of Northwest China.It is important to study the evolution of landscape pattern to curb its environmental degradation.In order to intuitively show how the landscape pattern of the study area changes over time,Landsat Thematic Mappers(TM)and Landsat Operational Land Imager(OLI)data of 1991,2000,2010 and 2017 were used.This paper attempts to apply niche theories and methods into landscape ecology,and constructs a niche model of landscape components by using"n-dimentional hypervolume niche theory"and landscape pattern indices.By evaluating the spatial and temporal evolution of niche from the perspective of two-dimensional space to reflect the changes of landscape pattern in the study area over the past 26 years,new theories and methods were introduced for the characterization of landscape pattern.The results indicate that:1)The larger the attribute and dominance value of landscape components,the higher the ecological niche and the stronger the control effect on the overall landscape.2)The ecological niche of each landscape component was significantly different,just as its control effect on the overall landscape.3)The dynamic change of the ecological niche of each landscape component was different,with grassland,unused land and arable land always in a high dominant position,although the ecological niche of construction land and water area was always low.In general,the introduction of niche theory into the landscape ecology provided a new method to study the changes in regional landscape pattern.