基于物联网的大型地震区域监控系统设计

当前大型地震区域监控系统采用有线网络对人工指挥台进行数据传输,易导致灾害条件下受损无法及时有效地传通监控结果,存在地震实时监测信息准确性低、系统稳定性差的问题。因此设计基于物联网的大型地震区域监控系统。该设计系统进行数据采集交换的网络拓扑采用ZIGBEE实现通信。基于VS.NET基础设计系统架构,通过地震的现场指挥部建设支持可视化的调度指挥台,实现综合调度和集中指挥的目的。系统中智能地震救灾控制中心采用服务器进行数据存储和智能运算,实现对地震检测区的精准、高效检测和工作指导。通过数据采集交换与应急调度平台,监测地震实时监控与设备使用情况。采用地震救灾数据采集分析软件对物联网中地震区域监测数据进行全面、准确分析,系统采用多源信息融合技术实现地震救灾信息多视角的全面处理。实验结果说明,所设计系统测算结果实时性高、功耗低,具有较高的准确度和稳定性。     

腹板摩擦式钢框架节点震后可更换性能的试验研究

主要针对梁腹板带有摩擦耗能螺栓的自复位钢框架节点结构进行抗震性能和可更换性能的试验研究,探讨该类节点在往复荷载作用下的滞回性能以及节点域的变形特征。在参数选型的基础上,对5组钢框架节点试件进行了低周反复荷载作用下的拟静力试验,其中:4组试件具有自复位能力,分析了各试件的承载力、刚度、耗能性能和滞回特性等性能。综合研究结果表明:所提出的拼接节点能够利用摩擦螺栓的滑移提高节点的耗能能力,有效减少梁和柱主体构件的损伤,同时预应力筋提供了结构的自复位能力。试验结果表明:在地震作用之后,通过更换腹板及摩擦螺栓可以使结构的承载能力和耗能性能与震前基本一致,从而实现结构功能的快速恢复。     

强震下拱式体系桥梁震害特征及抗震研究

以汶川地震中拱式体系桥梁震害为主线,总结主拱圈、横向连接系和其它附属构件及减隔震设计拱桥的破坏情况,对国内外拱桥的震害特征及原因进行了剖析。以目前应用数量占优的钢管混凝土肋拱桥为具体背景,对拱式体系桥梁的抗震理论、抗震试验和减隔震设计进行了评述。分析认为拱式体系桥梁竖向和纵桥向抗震存在一定的安全储备,但横桥向存在明显的抗震薄弱环节。针对钢管混凝土肋拱桥横桥向振动及倒塌特点,就目前在拱式体系桥梁中引入防屈曲支撑代替横撑以形成耗能减震结构提出了建议及具体可行设计方式。     

面向景观规划设计的数字地形交互式编辑技术

 数字地形编辑是虚拟地理环境、三维景观仿真系统中一个重要的研究内容,在城市与乡村、区域道路网、风景园林的数字化规划设计实践中具有重要价值。本文以规则格网的数字地形为研究对象,面向城市和园林景观规划设计中的实际应用,提出了交互式数字地形编辑的解决方案,重点给出了分页技术的地形交互式编辑具体过程和相关的主要实现技术。数字地形编辑的实现,首先,通过鼠标交互式操作,结合射线求交算法,在地形表面选取目标编辑区域;然后,结合夹角之和检测算法,获取区域下地形数据,设定新的地形高程值,最后,将编辑操作传输至地形其他层,更新整个地形,并在地形编辑后,采用方格网计算法,统计出区域下地形填挖方量。此外,在经过平整的地形区域,植入树和三维建筑模型,构建虚拟城镇小区景观。本文初步实现了编辑操作功能的计算机软件,并展示了数字地形编辑在城镇小区景观设计中的应用结果。试验表明,基于规则格网和分页技术的数字地形编辑方法具有算法简单、计算量小、易实现等特点。此外,通过鼠标交互式的操作,能够实时、直观地显示编辑结果,达到"所见即所得"的效果。     

近40年洞庭湖区内湖水面面积变化及其驱动因素

选择1979-2016年间多时期、多类型、多光谱遥感数据,分析评价洞庭湖区内湖近40年的面积变化.结果表明,最近40年洞庭湖区内湖面积保持相对稳定,丰水期间呈上升趋势,枯水期间波动下降,2016年内湖总面积比1980s初减少3.94%.随着湖泊面积增加,湖泊水面面积变化的比例和幅度逐渐减小,大型湖泊（>10 km²）和中型湖泊（5~10 km²）面积相对稳定,小型内湖（<5 km²）面积变化尤为剧烈.内湖水面面积主要受降雨、蒸发等气候因素和生产生活取水、防洪排涝和退田还湖等人为活动调控.1980-2000年和2001-2015年两个时期,洞庭湖区多年平均降雨量呈现不同程度的下降趋势,多年平均蒸发量明显上升.三峡工程运行后,三口分流衰减,但水资源需求量不断增长,退田还湖和留蓄雨洪作为水资源使得丰水期间内湖水面面积增长,气候变化和水资源开发利用导致枯水期水面面积趋于减少.有必要加强洞庭湖区内湖的研究和保护,适当退田还湖提高湖泊率,优化三口水系格局,实施河湖水系连通工程,缓解洞庭湖区季节性水资源紧张问题.     

基于Van Allen Probes EMFISIS波动仪器观测的内磁层下频带哨声合声波全球分布的统计分析

基于Van Allen Probes近三年的EMFISIS仪器波动观测数据,对内磁层下频带哨声模合声波幅度的全球分布特性对地磁活动水平的依赖性进行了详细的统计分析,着重研究下频带合声波平均场强幅度随磁壳值L、磁地方时、地磁纬度的分布特征及不同强度区间的合声波的发生概率.结果表明,下频带合声波的波动强度与地磁活动密切正相关,处于强磁扰期间的合声波具有更大的振幅,其发生率与地磁活动强度具有同样的正相关特性.下频带合声波主要发生于午夜至下午的磁地方时区间,其余的磁地方时时段下频带合声波较弱.赤道面附近的下频带合声波主要分布在夜侧至黎明这一时段内,随着磁纬度的增加逐步向日侧扩展.下频带合声波在午夜侧(21-03 MLT)主要出现在15°的磁纬范围内,在晨侧(03-09 MLT)可以到达15°磁纬甚至更高纬度.下频带合声波主要发生于L=~4.5的附近区域.随着地磁活动的增加,下频带合声波所覆盖的L-shell空间区域增大,趋势为向高、低L值区域同时扩展.建立的下频带哨声合声波的全球分布模型将有助于进一步深入理解该重要磁层波动对辐射带电子的波粒作用散射效应和对辐射带动力学过程的定量贡献.     

骨巨细胞瘤影像学特征及误诊分析

目的:研究骨巨细胞瘤(GCT)的X线平片、CT、MRI影像学表现,分析误诊的原因,提高诊断准确性。方法:搜集30例手术病理证实的GCT病例,回顾性分析其术前X线平片、CT平扫、MRI影像学表现。结果:GCT发生于股骨远端13例,胫骨近端6例,股骨近段4例,肱骨近端3例,桡骨远端2例,腰椎1例,髂骨1例。术前误诊5例,约占16.7%。结论:X线平片、CT和MRI从不同角度反映GCT的病理特征,合理结合三种检查方法,能更全面显示GCT的影像学特征,有利于诊断及鉴别诊断。      

INTERPRETATION AND ANALYSIS OF THE FINE FAULT GEO-METRY BASED ON HIGH-RESOLUTION DEM DATA DERIVED FROM UAV PHOTOGRAMMETRIC TECHNIQUE: A CASE STUDY OF TANGJIAPO SITE ON THE HAIYUAN FAULT

Fault-related tectonic geomorphologic features are integrated expressions of multiple strong seismological events and long-term surface processes, including crucial information about strong earthquake behavior of a fault. It's of great significance to identify the strong seismic activity information from faulted landscapes, which include the date and sequence of the seismic activities, displacements, active fault features, for studying the seismic rupture process, predicting the future seismic recurrence behavior and evaluating the seismic hazard of the fault. However, due to the restriction of measuring techniques and the subsequent poor quality of the acquired data, it has been difficult to accurately extract such information from complex tectonic landforms to study active faults for a long time. Recently, "small Unmanned Aerial Vehicle(sUAV)" photogrammetric technique based on "Structure from Motion(SfM)" provides a cost-efficient and convenient access to high-resolution and high-accuracy "digital elevation models(DEMs)" of tectonic landforms. This paper selects the Tangjiapo area at the Haiyuan Fault to conduct data collection, in which the structural and geomorphic features are well preserved. Using a small quadrotor unmanned aerial vehicle(Inpire 2), we collect 1598 aerial photographs with a coverage area of 0.72km². For calibrating the accuracy of the aerial data, we set 10 ground control points and use differential-GPS to obtain the spatial coordinates of these control points. We use model software Agisoft PhotoScan to process these digital pictures, obtaining high-resolution and high-accuracy DEM data with the geographic information, in which data resolution is 2.6cm/pix and the average density of point cloud is 89.3 point/m². The data with these accuracy and resolution can fully show the real geomorphic features of the landform and meet the requirements for extracting specific structural geomorphic information on the surface. Through the detailed interpretation of the tectonic landforms, we identify a series of structures associated with the strike-slip fault and divide the alluvial fan into four stages, named s₁, s₂, s₃, and s₄, respectively.Wherein, the s₁ is the latest phase of the alluvial fan, which is in the extension direction of the Haiyuan Fault and there isn't any surface fracture, indicating that the s₁ was formed after the M8.5 Haiyuan earthquake in 1920. The rupture zone on the s₂ fan is composed of varied kinds of faulting geomorphologic landforms, such as a series of en echelon tension-shear fractures trending 270°~285°, fault scarps and seismic ridges caused by the left-lateral motion of the seismic fault. In addition, a number of field ridges on the s₂ fan were faulted by the 1920 Haiyuan M8.5 earthquake, recording the co-seismic displacements of the latest earthquake event. Relatively speaking, the surface rupture structure of the s₃ fan is simple, mainly manifested as linear fault scarp with a trend of 270°~285°, which may indicate that multiple earthquakes have connected the different secondary fractures. And a small part of s₄ fan is distributed in the southwest of the study area without fault crossing. Furthermore, we measured the horizontal displacements of river channels and vertical offsets of fault scarps. The faulted ridge on the s₂ fan and faulted gully on the s₃ fan provide good linear markers for obtaining the fault left-lateral dislocation. We used the graphical dislocation measurement software LaDiCaoz developed based on Matlab to restore the gully position before the earthquake by comparing the gully morphology on both sides of the fault, and then determined the horizontal offset of s₂, which is(4.3±0.4)m and that of s₃ is(8.6±0.6)m. In addition, based on the DEM data, we extracted the fault scarp densely along the fault strike, and obtained the vertical offset of s₂, which is(4.3±0.4)m and that of s₃ is(1.79±0.16)m. Moreover, we detect slope breaks in the fault scarp morphology. For compound fault scarps generated by multiple surface rupture earthquakes, there are multiple inflection points on the slope of the topographic section, and each inflection point represents a surface rupture event. Therefore, the slope break point on the scarp becomes an important symbol of multiple rupture of the fault. The statistical result shows that the slope breaks number of s₂ is 1 and that of s₃ is 2. Based on the analysis of horizontal displacements of river channels and vertical offsets of fault scarps as well as its slope breaks, two surface rupturing events can be confirmed along the Tangjiapo area of the Haiyuan Fault. Among them, the horizontal and vertical displacements of the older event are(4.3±0.95)m and(0.85±0.22)m, respectively, while that of the latest event are(4.3±0.4)m and(0.95±0.14)m, which are the coseismic horizontal and vertical offsets of the 1920 Haiyuan earthquake. These recognitions have improved our cognitive level of the fine structure of seismic surface rupture and ability to recognize paleoearthquake events. Therefore, the high-resolution topographic data obtained from the SfM photogrammetry method can be used for interpretation of fine structure and quantitative analysis of microgeomorphology. With the development of research on tectonic geomorphology and active tectonics toward refinement and quantification, this method will be of higher use value and practical significance.     

青藏高原区域构造应力场特征分析

利用区域测震台网的地震波形及震相数据基于CAP方法反演北纬26°~42°,东经90°~110°内的270个M_S>3.0以上地震的震源机制解;并结合GCMT目录和一些前人研究结果中该区域的共759个震源机制解数据,运用SATSI方法计算了研究区域的应力场。将研究区域按1°×1°网格化后得到了154个局部应力场分布结果,从结果上看,整个青藏高原的最大主压应力方向大致表现为顺时针且向右的旋转方式。该结果反映了青藏高原块体向NE和NNE挤压的过程中,分别在其北部和东部受到鄂尔多斯和阿拉善两个坚硬块体的阻挡,造成青藏块体增厚,块体之间物质的侧向流动。对研究区域应力型因子R值的研究显示青海祁连、甘东南区域、四川龙门山断裂带等沿青藏高原块体与阿拉善块体以及鄂尔多斯块体交界处相对应力值偏大,与近年来这些地区的地震活动性成正比。本文研究结果对比其他应力场研究结果、GPS研究结果、以及数值模拟结果具有很好的一致性,可为青藏高原地区的孕震机理、活动构造以及地震趋势判定提供可靠的参考依据。     

大面积连续分布是页岩层系油气的标志特征——以鄂尔多斯盆地为例

非常规页岩层系油气资源大面积连续分布,是未来全球油气供应的重要接替领域。提出了页岩层系油气的地质内涵,即烃源层系生成、滞留或就近聚集在生烃层系内部或紧邻生烃层系的致密储集层中,利用新技术可实现工业开采的连续分布油气资源,包括源储一体型和源储紧邻型两种资源类型。鄂尔多斯盆地是致密油气、页岩油气等非常规页岩层系油气资源的有利发育区,中生界三叠系延长组、上古生界石炭系—二叠系源储接触面积大,页岩油气、致密油气主要在源内或近源大面积连续分布,具有“普遍含油气、储层致密、低压、低丰度”的典型地质特征,具有稳定平缓的构造面貌、较高成熟源岩广布式生排烃和大面积致密储层叠置分布的有利成藏地质背景,致密油气“甜点区(段)”主要受生烃中心和厚层砂岩分布共同控制,页岩油气“甜点区(段)”主要受富有机质页岩规模、热演化程度、天然裂缝等共同控制。随着页岩层系油气的深入勘探开发,以大面积连续分布为标志特征的页岩层系油气地质理论将深入发展,成为石油天然气地质学的下一次大飞跃。