Dominant micro-cracking direction and anisotropic property of rocks under uniaxial compression

To explore the relationship between the dominant direction of micro-cracks and the anisotropy, this research focuses on the micro-crack initiation and propagation mechanism and the anisotropic parameters evolution in the rock under uniaxial compression. Based on the maximum circumferential stress theory and the assumption of shear slip leading to the local tensile stress, the micro-crack initiation and propagation model is established, and the anisotropic parameters of rock is further explored. To verify the theory, the marble limestone, granite porphyry and granite are selected to conduct uniaxial compression experiment. It is indicated that the experimental results of elastic moduli and Poisson’s ratio are well consistent with theoretical analysis. Finally, the relationship between the dominant direction of original and secondary micro-cracks and the effect of the micro-cracks’ dominant direction on practical engineering are discussed. The results show that the dominant direction of micro-cracks is parallel to the maximum principal stress under uniaxial compression, which leads to the anisotropy of rock. With the increase of stress, the axial and transverse elastic moduli would decrease, while the extent of the decrease of axial elastic modulus is larger. The axial Poisson’s ratio would increase and the transverse Poisson’s ratio will decrease. Moreover, the Poisson’s ratio is more sensitive to the anisotropy caused by the dominant direction of micro-cracks.     

基于MODIS数据的南昌市大气气溶胶光学厚度反演

气溶胶对气候和环境都有着重大的影响。利用MODIS L1B数据,通过结合6S辐射传输模型生成查找表(LUT),再结合地面暗像元对南昌市2016年3月份的4景影像进行反演;根据6S模式对地表反射率与表观反射率和气溶胶光学厚度的变化建立敏感性试验,最终反演得出南昌市4景影像在550 nm波长的AOD平均值分别为0.139、0.926、0.442、1.061,与根据能见度计算得出的值大小有差异,但是在可接受范围内,根据结果用暗像元法反演南昌市气溶胶光学厚度是可行的。     

机载激光雷达点云滤波算法分析与比较

机载点云数据在城市三维建模、DEM提取中应用广泛,而机载点云滤波是这些应用的基础。因此,这里对机载点云滤波算法设计所依据的地面特征和滤波结果的精度评定方法作了总结,并对现有滤波算法进行了分类描述。最后着重对滤波算法做了直观的对比分析,为后续点云数据滤波处理研究提供参考。     

怀旧消费空间地方建构的比较研究——以广州怀旧餐厅为例

在全球化深入发展的今天,都市怀旧消费风潮已渗透至社会文化生活诸多领域。许多怀旧餐厅也应运而生,形成以城市怀旧为主题的特殊消费空间和文化空间。全球与地方在消费文化转化中相互促进,地方文化形态正在发生变化,不同怀旧消费空间的地方建构是否存在差异?本文选择广州太平馆、巴打怀旧茶餐厅两个不同特点的怀旧餐厅为案例,通过参与式观察、深度访谈、问卷调查和文本分析等研究方法,收集相关媒体报道和网上讨论作为研究的文本资料。从物质空间和情感空间两个方面对比分析了怀旧餐厅的地方建构和认同。研究表明,透过记忆的呈现和展示,记忆凝视下的传统再造和怀旧消费导向下的再造传统都是适应全球文化潮流过程中不同的消费物质空间建构形式。从消费者角度来看,怀旧地方又是其情感空间的建构和地方记忆的再生产,表现在地方依恋和地方认同等方面。由于怀旧地方建构中"真实地方"和"构想地方"交集的差异,其地方认同感也存在不同,在很大程度上受到地方根植性、市场机制和后现代消费特征等因素的影响。本文有助于从新文化地理学视角理解怀旧消费空间的地方建构,对指导怀旧消费空间生产和实践有积极的现实意义。     

基于手机平台的GPS软件在野外寻点中的应用

现在手机应用广泛,而且大部分都自带GPS定位芯片,本文介绍了一款基于Android系统的手机GPS导航软件,并研究了其中不同坐标系的转换问题,结合测区地形图,成功地应用于野外测量点的寻找,发挥了极大的作用。     

Effect of Earth''s solid tides on pulsar observations

It is shown that the effect of the solid tide in the Earth's crust is not negligible in the observed period changes ΔP/P and period rate changes of pulsars.     

Deep Minerals in Ophiolitic Mantle Peridotites:Discovery and Progress

In the classic theory of plate tectonics, ophiolitic mantle peridotites (i.e., abyssal peridotite) are thought to originate in the shallow mantle beneath ocean spreading centers.Diamonds and other UHP minerals have been found in opholitic mantle peridotites and chromitites along the Neo-Tethyan Yarlung Zangbo suture of southern Tibet, and in a Paleozoic ophiolite in the Polar Urals of Russia,suggesting that UHP minerals may be widespread in ophiolitic peridotites.Diamonds from these different localities all have very similar features in C isotope and mineral inclusions,and are distinct from the other two well known types, i.e. kimberlitic diamonds and UHP metamorphicdiamonds. The occurrence of diamond in ophiolite indicate a completely new environment for diamond formation, which can be regarded as ophiolite-type diamond. These new findings indicate a need to reconsider the nature of the upper mantle and the conditions under which ophiolites form.     

基于SuperMap GIS的乌鲁木齐市矿政管理系统建设

以乌鲁木齐市矿政管理业务需求与特点为基础,对矿政管理业务系统进行了分析与设计,并基于Super-Map iServer平台进行构建。系统实现了矿权登记、储量管理、规费管理、地质环境、矿山年检、数据交换等业务需求。该矿政管理系统实现了一体化、集成化的业务管理,提升了乌鲁木齐市国土资源矿政业务的管理水平,对基层矿政管理系统的建设具有一定的借鉴意义。     

基于WebGIS的水产资源信息服务系统设计与实现

将地理信息与水产资源相结合,为水产养殖业提供一个直观的、可视化的地理信息展示和管理服务平台。综合应用Geoserver,Openlayers,J2EE等技术设计并实现了水产信息和相关专题地图的数据采集、管理、服务发布以及在线浏览、查询、空间分析、统计分析等功能。     

自然伽马拟声波曲线构建技术探讨

声波测井曲线在地震反演中起着约束和控制模型反演的作用,当其不能反映地层岩性变化时,通常会将现有的非声波测井曲线按照一定的经验公式或统计方法来重构新的声波曲线。但是,这些拟声波曲线构建技术并没有考虑到地层岩石孔隙及孔隙中流体的影响。在考虑到岩石孔隙和孔隙中流体的情况下,拟声波曲线构建技术可以先利用岩石基质的声波速度与自然伽马之间的关系来重构具有声波量纲的新曲线,然后结合原声波曲线中能够反映背景速度的低频信息,构建出新的声波曲线。该方法在鄂尔多斯盆地镇泾地区取得了不错的应用效果。