The central Yunnan sub-block is an important channel for southeast migration of materials in the Qinghai-Xizang Plateau,and therefore a key area to study tectonic movement and deformation.In this study,a three-dimensi...The central Yunnan sub-block is an important channel for southeast migration of materials in the Qinghai-Xizang Plateau,and therefore a key area to study tectonic movement and deformation.In this study,a three-dimensional electrical structure of the crust and upper mantle lithosphere was derived from magnetotelluric data inversion along a survey line across the central Yunnan sub-block.Results suggest that the middle and upper crust of the central Yunnan sub-block is comprised of several independent high-resistivity bodies.Deep extension of some faults was revealed according to electrical structure and relocated microseismicity.The Chenghai fault extends downward along the eastern boundary of a high-resistivity body.The Yuanmou fault dips to the west and extends to the depth along the boundary between two high-resistivity bodies.The Tanglang-Yimen fault cuts through a high-resistivity body in the middle and upper crust.There is an obvious high-conductivity C1 layer in the lower crust in the eastern part of the central Yunnan sub-block,and its western border displays an obvious structural boundary in the shallow part.The eastern part of the central Yunnan sub-block moves eastward relative to the western part(bounded by the west side of a high-resistivity body R3 in the C1 west).C1 is speculated to be characterized by low rheological strength and viscosity,thus reducing the resistance to eastward movement of the eastern part.Owing to the combined action of C1 and its western boundary,the eastern materials slip eastward faster relative to R3.Due to South China Block resistance,the middle and upper crust in the eastern part is within a compressional tectonic environment,consistent with the negative dilatation rate and the presence of compressive faults in this region.The C1 ground surface has a low strain rate,indicating weak deformation in this region and rigid motion dominance.Our results suggest that under the decoupling effect of the high-conductivity layer in the lower crust,the independent rigid blocks in the middle and upper crust can also exhibit tectonic deformation characteristics of rigid extrusion.展开更多
为应对红外气体泄漏成像过程中因设备转动等因素导致的图像不稳定及泄漏气体检测效果不佳的问题,提出1种结合图像帧子块匹配法和改进快速鲁棒模糊C均值算法(fast and robust fuzzy c-means,FRFCM)的红外图像细节增强方法。该方法利用图...为应对红外气体泄漏成像过程中因设备转动等因素导致的图像不稳定及泄漏气体检测效果不佳的问题,提出1种结合图像帧子块匹配法和改进快速鲁棒模糊C均值算法(fast and robust fuzzy c-means,FRFCM)的红外图像细节增强方法。该方法利用图像帧子块匹配法配准图像帧,同时引入背景建模和差分方法从背景中分离动态气体目标,并在FRFCM基础上增加自适应调整模糊因子以优化图像帧的羽流强化特征效果。研究结果表明:该方法能够有效去除冗余信息,使图像帧匹配误差降低约75%,对比度增强值提高4.7%,羽流分割的平均交并比达到0.68,在保持较高分割准确度的同时显著提升检测速度,适用于油气田、集输站及氢气站等气体安全检测系统。研究结果可为气体泄漏监测技术的优化与应用提供参考。展开更多
在使用OSGEarth三维地球引擎进行大规模地理空间数据可视化时,细节层次(Level of Detail,LOD)技术通过动态调整地形和模型的细节层次,在保证视觉质量的同时,显著降低了计算负载和资源消耗。但在分开叠加影像层与地形层在线服务数据时,...在使用OSGEarth三维地球引擎进行大规模地理空间数据可视化时,细节层次(Level of Detail,LOD)技术通过动态调整地形和模型的细节层次,在保证视觉质量的同时,显著降低了计算负载和资源消耗。但在分开叠加影像层与地形层在线服务数据时,由于两类数据服务层级精度不匹配,渲染时将出现白块、断层塌陷等视觉问题,文章提出了一种通过实时重采样自动创建子瓦片的方案,对影像图层与地形图层的精细层级不同的问题进行双线性重采样,有效解决白块和断层塌陷等现象,拥有良好的应用前景。展开更多
基金supported by the Basic Research Project of the Institute of Earthquake Forecasting,China Earthquake Administration(Grant No.2020IEF0505)the Basic Research Project of the Institute of Earthquake Forecasting,China Earthquake Administration(Grant No.2021IEF0104)the National Natural Science Foundation of China(Grant Nos.U1839205&42174093)。
文摘The central Yunnan sub-block is an important channel for southeast migration of materials in the Qinghai-Xizang Plateau,and therefore a key area to study tectonic movement and deformation.In this study,a three-dimensional electrical structure of the crust and upper mantle lithosphere was derived from magnetotelluric data inversion along a survey line across the central Yunnan sub-block.Results suggest that the middle and upper crust of the central Yunnan sub-block is comprised of several independent high-resistivity bodies.Deep extension of some faults was revealed according to electrical structure and relocated microseismicity.The Chenghai fault extends downward along the eastern boundary of a high-resistivity body.The Yuanmou fault dips to the west and extends to the depth along the boundary between two high-resistivity bodies.The Tanglang-Yimen fault cuts through a high-resistivity body in the middle and upper crust.There is an obvious high-conductivity C1 layer in the lower crust in the eastern part of the central Yunnan sub-block,and its western border displays an obvious structural boundary in the shallow part.The eastern part of the central Yunnan sub-block moves eastward relative to the western part(bounded by the west side of a high-resistivity body R3 in the C1 west).C1 is speculated to be characterized by low rheological strength and viscosity,thus reducing the resistance to eastward movement of the eastern part.Owing to the combined action of C1 and its western boundary,the eastern materials slip eastward faster relative to R3.Due to South China Block resistance,the middle and upper crust in the eastern part is within a compressional tectonic environment,consistent with the negative dilatation rate and the presence of compressive faults in this region.The C1 ground surface has a low strain rate,indicating weak deformation in this region and rigid motion dominance.Our results suggest that under the decoupling effect of the high-conductivity layer in the lower crust,the independent rigid blocks in the middle and upper crust can also exhibit tectonic deformation characteristics of rigid extrusion.
文摘为应对红外气体泄漏成像过程中因设备转动等因素导致的图像不稳定及泄漏气体检测效果不佳的问题,提出1种结合图像帧子块匹配法和改进快速鲁棒模糊C均值算法(fast and robust fuzzy c-means,FRFCM)的红外图像细节增强方法。该方法利用图像帧子块匹配法配准图像帧,同时引入背景建模和差分方法从背景中分离动态气体目标,并在FRFCM基础上增加自适应调整模糊因子以优化图像帧的羽流强化特征效果。研究结果表明:该方法能够有效去除冗余信息,使图像帧匹配误差降低约75%,对比度增强值提高4.7%,羽流分割的平均交并比达到0.68,在保持较高分割准确度的同时显著提升检测速度,适用于油气田、集输站及氢气站等气体安全检测系统。研究结果可为气体泄漏监测技术的优化与应用提供参考。
文摘在使用OSGEarth三维地球引擎进行大规模地理空间数据可视化时,细节层次(Level of Detail,LOD)技术通过动态调整地形和模型的细节层次,在保证视觉质量的同时,显著降低了计算负载和资源消耗。但在分开叠加影像层与地形层在线服务数据时,由于两类数据服务层级精度不匹配,渲染时将出现白块、断层塌陷等视觉问题,文章提出了一种通过实时重采样自动创建子瓦片的方案,对影像图层与地形图层的精细层级不同的问题进行双线性重采样,有效解决白块和断层塌陷等现象,拥有良好的应用前景。
