基于Worldview-2多光谱卫星数据的浅水水深遥感反演

随着卫星遥感技术的不断发展,高分辨率卫星影像逐渐应用到水深遥感反演领域。利用Worldview-2高分辨率卫星数据和电子海图数据,基于双波段比值法,反演获得实验区域20m以浅的水深。实验表明,Worldview-2等高分辨率多光谱卫星数据,具有一定反演浅水水深的能力,但在5m以浅的水域反演误差较大;双波段比值法,这种半经验半理论的模型,在水深遥感反演中具有更好的适用性;对比了一次线性、二次多项式、指数、对数等拟合方法,发现对数拟合的方法获取绝对水深,其精度相对其他方法更高。     

In-situ experimental investigation of the influence of structure characteristics on subway-induced building vibrations

Many types of buildings have been widely constructed in the vicinity of subway lines in China. Normal life and business activities are hampered by excessive subway-induced vibrations. This study aims to determine the influence of structure characteristics on structure-borne vibrations, generally based on experimental results. Vibration measurements were performed in four typical sites in Wuxi, China, involving over-track buildings, along-track buildings, frame structure buildings and a masonry building. Special structure designs like structure transfer floor were also included. Then, the captured data was analyzed in the time domain and the frequency domain. Furthermore, the influence of building location, structure type and structure layout was investigated. Finally, vibrations were evaluated with ISO and Chinese criteria and structure optimization for vibration attenuation was proposed. It is found that over-track buildings are more severely affected than along-track buildings. Higher frequency contents(20-60 Hz) in over-track buildings and lower frequency contents(0-10 Hz) in along-track buildings should be seriously considered in vibration control. Weaker structure member joints and lower material strength would be beneficial to over-track buildings while the inverse situation would be beneficial to along-track buildings. The application of structure transfer floor-generally stiffer structure members and structure discontinuity-is also beneficial.     

基于性能的既有钢筋混凝土建筑结构抗震评估与加固技术研究

根据我国现行的建筑结构抗震规范,无论是新建建筑结构的抗震设计还是既有建筑结构的抗震评估与加固,均通过小震弹性承载力计算 抗震延性构造措施来达到"小震不坏、中震可修、大震不倒"的抗震设防目标(对于不规则且具有明显薄弱部位的建筑结构还需要进行罕遇地震作用下的弹塑性层间变形验算)。对于抗震延性构造措施不满足现行规范的既有建筑结构的评估、改建、扩建,如果仅通过小震弹性的承载力计算,显然无法达到"大震不倒"的目标。本文通过引入国际上先进的基于性能的结构抗震思想,以结构层间位移和结构构件变形作为性能目标,从定量上解决了既有钢筋混凝土建筑结构的抗震评估与加固问题。     

虚拟仪器技术在气象仪器检修、检定和教学中的应用

本文分析了虚拟仪器的概念、组成和特点,介绍了几个自行研制的气象用虚拟仪器及其应用价值,并阐明了虚拟仪器技术在气象仪器的检修、检定及教学中所具有的重要实用价值及广泛的发展前景。     

天津地震信息网络系统的安全建设1

本文从当前网络所面临的安全问题出发,阐述了天津地震信息网络系统所面临的安全威胁,以及针对这些情况所进行的信息网络系统的安全建设工作.文中详细列举了系统中使用的安全设备与应用情况,以及日常运行和维护管理中的措施要点,可为行业中网络安全系统建设提供一定参考.     

Factors Controlling Hydrocarbon Accumulation in Jurassic Reservoirs in the Southwest Ordos Basin,NW China

The sedimentary, paleogeomorphological and reservoir characteristics of the Jurassic Yan’an Formation in the southwestern Ordos Basin, northwestern China, were studied by means of casting thin sections, scanning electron microscopy, inclusion analysis and identification of low-amplitude structures. A model for reservoir formation is established, and the controlling effects of sedimentary facies, paleotopography, low-amplitude structures and formation water on oil reservoirs are revealed. There are significant differences in the sedimentary characteristics, structural morphology and paleowater characteristics between the reservoirs above the Yan 10 Member and those in the Yan 9 to Yan 7 Members. The Yan 10 Member contains fluvial sediments, whereas the Yan 9 to Yan 7 members contain delta-plain anastomosing-river deposits. The distribution of high-permeability reservoir is controlled by pre-Jurassic paleogeomorphology and sedimentary facies. Some of these facies exhibit high porosity and high permeability in a lowpermeability background. The main hydrocarbon accumulation period was the late Early Cretaceous, filling was continuous, and the charging strength altered from weak to strong and then from strong to weak. The Yan 10 reservoir is mainly controlled by the paleogeomorphology: hydrocarbons migrated upward at a high speed through the unconformity surface, and accumulated in the favorable traps formed by paleogeomorphic structural units, such as gentle slopes or channel island. Furthermore, groundwater alternation in these areas was relatively stagnant, providing good reservoir preservation conditions. The reservoirs in the Yan 9 and higher members are controlled by the sedimentary facies, lowamplitude structure and paleowater characteristics. Hydrocarbons migrated through the three-dimensional delivery system, influenced by favorable sedimentary facies and high-salinity groundwater, then accumulated in the favorable low-amplitude structural traps that formed during the hydrocarbon production period.     

火山岩—侵入岩的联系

关于侵入岩和火山岩二者之间的联系,已有上百年的争论。该争论主要集中于中—酸性岩,对于长英质火山岩的岩浆来源目前主要有2种观点：（1）由花岗质岩浆的“晶粥”中的熔体抽离而来;（2）与同期侵入岩无关,具有独立的岩浆形成过程。近些年来,随着高精度定年测试方法的进步和地球物理等研究方式的介入,对长英质火山岩和侵入岩二者的成因联系有了新的认知,“晶粥”模型和“穿地壳岩浆系统”受到较多关注,但同时也带来了新的矛盾和问题。文章系统总结了火山岩与侵入岩联系的不同观点、历史沿革、以及不同研究方法引起的争议,展望了该领域未来研究前景;提出大数据总体上展现出的长英质火山岩和侵入岩之间强烈的地球化学相似性,但这种总体上的相似性并不排除特定区域某个火山—侵入杂岩中的火山岩和侵入岩之间存在地球化学的差异,并在成因上符合“晶粥”模型。文章指出,深部探测、原位精细分析和实验模拟是火山岩—侵入岩成因联系研究方面有望取得突破的重要研究方向,而将火山岩—侵入岩形成机制与大陆演化和环境变迁等问题的研究有机结合可能是未来的重要研究领域。     

海底声学探测技术装备综述

先进的海底探测技术装备是快速和准确获取海底信息的关键,海底声学探测是目前最常用的方式之一。文章分别介绍多波束测深声呐、侧扫声呐、浅地层剖面仪和合成孔径声呐的研究现状、主流产品和发展趋势,分析我国相关技术装备存在研发较落后和产业化水平较低等问题,并提出加强军民融合,做好顶层设计以及推进产、学、研深度融合的建议。     

基于小波分析的多模多频GNSS-MR潮位反演

基于小波分析方法,利用GPS、GLONASS、Galileo和Beidou观测数据,通过对不同类型的信噪比数据进行质量分析,筛选质量较好的数据提取瞬时潮位.实验结果表明,基于小波分析的多模多频GNSS-MR潮位反演可大幅提升潮位反演结果的时间分辨率,且精度与LSP方法相当,可达到dm级.     

利用210Pb、137Cs和241Am计年法测算云南抚仙湖现代沉积速率

通过对云南抚仙湖沉积物柱芯样品的210Pb、137Cs和241Am测试表明,柱芯剖面上有明显的1963年和1986年137Cs蓄积峰,验证了1975年次级蓄积峰存在的可能性,这些峰形完好的蓄积峰对抚仙湖的现代沉积环境有明显的时标意义。利用137Cs计年法得到抚仙湖沉积物自1963年、1975年及1986年以来到2007年的平均沉积速率分别为0.063g/(cm2·a)、0.052g/(cm2·a)和0.039g/(cm2·a),说明了过去近五十年抚仙湖沉积速率整体上经历了一个由快到慢的过程。借助于241Am 的1963年蓄积峰可以提高137Cs计年的准确性。根据210PbCRS计年模式,计算出每个样品深度所对应的年代,与137Cs计年法比较存在一定的偏差,分析了两种计年方法存在差异性的原因。通过质量深度和年代分析,抚仙湖的沉积速率变化幅度比较大,表明抚仙湖近129年来的沉积环境不稳定,可能与相应历史时期的人类活动有密切的关系。