一种基于神经网络快速检测震后坍塌房屋的方法

在地质灾害发生后快速进行房屋坍塌检测,可以有效地进行灾害评估,并实施抢险救援工作.传统的房屋坍塌检测方法难以适应现代海量无人机影像处理工作,既需要大量的人力、时间成本,又不能保证检测的精度,无法满足应急测绘的要求.本文提出了一种基于卷积神经网络(convo-lutional neural network,CNN)快速检...     

西秦岭中段日多玛岩体锆石U-Pb年龄、地球化学特征及其构造意义

日多玛花岗闪长岩体位于西秦岭中段美武岩体附近,对该岩体进行了岩相学、锆石U-Pb年代学和岩石地球化学方面的研究。日多玛花岗闪长岩体含有较丰富的暗色微粒包体,花岗闪长岩和暗色微粒包体LA-ICP-MS锆石U-Pb年龄分别为(236.8±3.6) Ma(MSWD=4.1)和(242.7±1.6) Ma(MSWD=1.4),属于印支早期。日多玛岩体具有富钾(2.58%~2.75%)、富碱(Na₂O+K₂O=5.57%~5.76%)、弱过铝质(A/CNK=1.48~1.51)特征,属于高钾钙碱性I型花岗岩类。日多玛岩体稀土元素表现为轻重稀土元素分馏较明显(LREE/HREE=10.4~11.9)、呈右倾特征,具有中等Eu负异常(δEu=0.68~0.81),岩石富集K、Rb、Ba、Th和U等大离子亲石元素,明显亏损Nb、Ta、Ti和P等高场强元素。岩石地球化学特征表明,日多玛花岗闪长岩来源于下地壳高钾玄武质岩石的部分熔融。此外,花岗闪长岩体具有较高的Mg^#(57~61)、Cr(149×10^-6~185×10^-6)和Ni(36×10^-6~47×10^-6),显示有少量幔源物质加入,暗色微粒包体可能代表了这种幔源岩浆。结合区域地质背景分析,认为日多玛花岗闪长岩体形成于后碰撞构造环境,可能与俯冲洋壳的断离作用有关。     

喜马拉雅造山带东构造结变形—变质作用和深熔作用的研究进展与问题

大陆碰撞造山带的造山过程是通过“变形—变质—深熔”自组织系统的高度耦合和时空上演化来实现的。因此,对经过强烈抬升的造山带核部的变形—变质—深熔作用的“三位一体”研究,为认识碰撞造山带的动力学背景具有重要的科学意义。笔者系统总结了大陆碰撞造山带内的变形和变质作用与深熔作用的研究进展,梳理了喜马拉雅东构造结在变形—变质作用和深熔作用方面的研究现状和存在问题,讨论并展望了未来的研究方向。     

喜马拉雅造山带东构造结变形—变质作用和深熔作用的研究进展与问题

大陆碰撞造山带的造山过程是通过“变形—变质—深熔”自组织系统的高度耦合和时空上演化来实现的。因此,对经过强烈抬升的造山带核部的变形—变质—深熔作用的“三位一体”研究,为认识碰撞造山带的动力学背景具有重要的科学意义。笔者系统总结了大陆碰撞造山带内的变形和变质作用与深熔作用的研究进展,梳理了喜马拉雅东构造结在变形—变质作用和深熔作用方面的研究现状和存在问题,讨论并展望了未来的研究方向。     

Seismogenic tectonics of the Qian-Gorlos earthquake in Jilin Province,China

The Qian-Gorlos earthquake, which occurred in the Songliao basin in Jilin Province in 1119 AD, was the largest earthquake to occur in NE China before the 1975 Haicheng earthquake. Based on historical records and surface geological investigations, it has been suggested previously that the earthquake epicenter was in the Longkeng area. However, other workers have considered the epicenter to be in the Halamaodu area based on the landslides and faults found in this region. No seismogenic structure has yet been found in either of these two regions. We tried to detect active faults in the urban areas of Songyuan City, where the historical earthquake was probably located. One of the aims of this work was to clarify the seismogenic structure so that the seismic risk in the city could be more accurately evaluated. The area was investigated and analyzed using information from remote sensing and topographic surveys, seismic data from petroleum exploration, shallow seismic profiles, exploratory geological trenches on fault outcrops, and borehole data. The geophysical data did not reveal any evidence of faults cutting through Cretaceous or later strata under the Longkeng scarp, which has been suggested to be structural evidence of the Qian-Gorlos earthquake. The continuous fault surfaces on the back edge of terraces in the Halamaodu area stretch for >3.5 km and were probably formed by tectonic activity. However, results from shallow seismic profiles showed that the faults did not extend downward, with the corresponding deep structure being identified as a gentle kink band. A new reverse fault was found to the west of the two suggested epicenters, which presented as a curvilinear fault extending to the west, and was formed by two groups of NE- and NW-trending faults intersecting the Gudian fault. Three-dimensional seismic and shallow seismic data from petroleum exploration revealed its distinct spatial distribution and showed that the fault may cut through Late Quaternary strata. Exploration boreholes and later geomorphological studies provided further proof of this. Based on these results and analysis, the Gudian fault was confirmed as having been an active fault since the Late Quaternary, with the possibility of earthquakes of magnitude >7 in the future. The Qian-Gorlos earthquake was most probably the result of breakage on one or two sections of this 66-km-long fault.     

基于多元空间信息技术集成的警员保护系统

近年来,袭警事件频繁发生,如何保障警员安全至关重要.基于北斗卫星导航系统和惯性导航,结合生物传感器、网络通信、深度学习和地理信息系统,设计出一套警员联动保护系统.该系统可动态跟踪警员位置,实时感知其生理指标,智能判其所处状态,并能在危机时刻,将相关信息及时送达控制中心,辅助制定救援策略.本研究对保障广大执法人员和人民生...     

应用PCA和ICA法对岩心光谱的定量解译

岩心光谱属于混合像元光谱,维度多、数据量大,在端元数量、端元光谱及混合矩阵未知的情况下,定量解译岩心光谱以提取岩心所含矿物信息难度大,噪声的存在使问题更加复杂。文章应用PCA和ICA法定量解译岩心光谱主要有三步:采用PCA法预处理混合像元光谱矩阵,在新的特征空间中保留特征值较大的少量特征矢量,有效滤除能量较小的成分,只保留主要成分信息,同时滤除数据中的噪声;采用ICA法分离岩心混合像元,得到混合像元中的端元光谱集,通过矿物识别获取岩心矿物成分;对端元光谱进行归一化处理,基于线性光谱混合模型进行丰度反演,得到岩心混合像元中各端元丰度。通过研究仿真数据获得光谱定量解译的一般规律,创建有效的算法模型,再处理实际测量的岩心光谱,获得了比较理想的结果。     

桂北“龙胜蛇绿岩”质颖

广西北部龙胜地区丹洲群广泛发育一套细碧岩和镁铁－超镁铁质岩石。细碧岩具有板内和岛弧火山岩的双重地地球化学属性,其形成时代〈８２０Ｍａ。本文作者综合地质学、岩石学、地球化学和同位素年代学的资料,提出陇胜地区丹洲群火山岩及镁铁－超镁铁质岩石不属于蛇绿岩,而是新元古代（～８２０Ｍａ）大陆裂谷进一步发展的产物,共形成与Ｒｏｄｉｎｉａ超级大陆的裂解过程相联系。这一认识对华南地区前寒武纪大南构造演化研究具有生     

论利用牙形石色变度值研究碳酸盐岩低级─极低级变质作用

牙形石色变度──ＣＡＩ值是一项有效的古地温指标，它不但可以帮助确定低级－极低级变质碳酸盐岩的最高变质温度，而且可以判别变质类型。本文在介绍牙形石ＣＡＩ值研究现状及低级－极低级变质作用研究现状的基础上，对运用ＣＡＩ值进行低级－极低级碳酸盐岩的研究进行了综述及探讨。