Study on Deformation Failure Mechanism and Control Technology of Surrounding Rock in Soft Rock Roadway

Geotechnical and Geological Engineering - In order to reveal the mechanism of surrounding rock deformation and instability of soft rock roadway in 12# working face of Puhe coal mine, and...     

基于性能的抗震设计方法在剪力墙结构中的应用

本文对基于性能的抗震设计方法中最具有代表性的直接基于位移的设计方法在剪力墙结构中的应用进行了研究。采用结构非线性分析程序探讨了墙厚、混凝土强度等级、纵筋配筋率、钢筋级别、轴压比、墙长等因素对单肢剪力墙屈服位移的影响,从而对现有的屈服曲率计算公式进行了改进。另外将按顶点荷载作用下的屈服位移计算公式求出的屈服位移与实际倒三角形荷载作用下的剪力墙屈服位移进行了比较,,从而推导出倒三角形荷载作用下的屈服位移计算公式。     

基于城市规划的城市地下空间开发适宜性评价探讨

随着城市化进程的持续推进,城市地下空间开发利用的重要性日益凸显。但各城市地下空间资源开发存在盲目性,未能与城市规划要求充分对接,亟须构建面向城市地下空间开发的适宜性评价体系。本文阐述了城市规划与地下空间开发间的关系,提出在城市规划指导下进行地下空间开发的重要性。针对不同的城市类型,需要采取针对性的探测技术,评价地质、环境、资源和技术经济等方面,并根据评价结果划分开发适宜性等级。研究认为,在城市规划指导下,运用开发适宜性评价体系,可以实现地下空间的有序可持续利用。     

Mapping 3D visibility in an urban street environment from mobile LiDAR point clouds

ABSTRACT

Visibility determination is a key requirement in a wide range of national and urban applications, such as national security, landscape management, and urban design. Mobile LiDAR point clouds can depict the urban built environment with a high level of details and accuracy. However, few three-dimensional visibility approaches have been developed for the street-level point-cloud data. Accordingly, an approach based on mobile LiDAR point clouds has been developed to map the three-dimensional visibility at the street level. The method consists of five steps: voxelization of point-cloud data, construction of lines-of-sight, construction of sectors of sight, construction of three-dimensional visible space, and calculation of volume index. The proposed approach is able to automatically measure the volume of visible space and openness at any viewpoint along a street. This approach has been applied to three study areas. The results indicated that the proposed approach enables accurate simulation of visible space as well as high-resolution (1 m × 1 m) mapping of the visible volume index. The proposed approach can make a contribution to the improvement of urban planning and design processes that aim at developing more sustainable built environments.     

Multiple Unmanned Underwater Vehicles Consensus Control with Unmeasurable Velocity Information and Environmental Disturbances Under Switching Directed Topologies

China Ocean Engineering - A consensus algorithm proposed in the paper is applied to tackle remarkable problems of unmeasurable velocities, the environmental disturbances, and the limited...     

Influence Analysis and Vibration Restraint Solutions Research on the Underwater Acoustic Monitoring System

China Ocean Engineering - In order to reduce the hydrodynamic and structural influences on the detection accuracy especially in the very-low-frequency range, some vibration restraint methods are...     

贵州罗甸纳饶剖面石炭系维宪阶-谢尔普霍夫阶界线附近的有孔虫

贵州罗甸纳庆剖面是竞争谢尔普霍夫阶底界全球界线层型剖面和点位的最有力候选剖面之一.纳饶剖面紧邻纳庆剖面,是其辅助剖面.纳饶剖面维宪阶-谢尔普霍夫阶(Viséan-Serpukhovian)界线层段的牙形刺生物地层已经初步建立,可与纳庆剖面直接对比.纳饶剖面V/S界线位于41.8 m处,是以牙形刺演化谱系L.nodosa...     

Archaeal community structure in sediments from a seamount in the Mariana Volcanic Arc

Seamounts are subsurface mountains in the ocean. Examination of the abundance and distribution of Archaea in seamount ecosystems may provide a better understanding of their ecological functions. Most studies of marine archaeal assemblages in seamount area have focused on hydrothermal vents or ferromanganese crusts. We investigated the archaeal communities from a seamount of the Mariana Volcanic Arc, in the tropical western Pacific Ocean by using high-throughput sequencing. Thaumarchaeota was dominant in the sediments of all sample stations. Community diversity and species richness were greatest at stations near the top of the seamount, and lowest at the deepest station. One sample station on the steep southeast slope that faced the Yap-Mariana trench had a unique composition of Archaea. In summary, depth has an important influence on archaeal community structure, and the geographic properties and sediment characteristics may explain the unique distribution patterns of Archaea in this seamount. This study provides a foundation for future research on Archaea in seamounts.     

耀变体在射电波段的偏振研究

利用UMRAO数据库22个耀变体源的偏振数据,根据Lazarian&Pogosyan理论模型分析研究了耀变体射电波段的偏振随波长的变化,得出不同类的耀变体偏振随波长变化的原因。结果表明,与Lazarian&Pogosyan理论模型吻合较好。由此得出如下结论:(1)反常去偏振耀变体源中反常法拉第旋光起主导作用,反常去偏振相对较少;(2)热辐射与同步辐射混合作用,高频波段的偏振度小于低频波段的偏振度(反常去偏振);(3)当被观测波段波长小于吸积盘热辐射对应的维恩波长时,高频波段的偏振度大于低频波段的偏振度(常规去偏振)。     

"资源一号"02C卫星影像土地利用变化检测能力分析

“资源一号”02C卫星自成功发射以来,被广泛应用于土地资源、矿产资源、地质环境调查,以及国土资源、地质灾害应急监测等应用领域。“资源一号”02C卫星是一颗填补我国高分辨率遥感数据空白的卫星,是根据国土资源主体业务需求定制的第一颗国产高分辨率业务卫星。本文以吉林省和浙江省某试验区“资源一号”02C卫星数据为例,对“资源一号”02C卫星数据融合影像进行了土地利用遥感监测变化信息检测能力的方法试验。根据试验区数据变化信息提取试验结果,对“资源一号”02C卫星影像在土地利用动态遥感监测中的变化检测能力和适用性开展了试验、分析和评价工作。