地铁的建设与运营容易引起地表的纵向沉降,从而影响城市的发展和人民生命和财产安全,因此及时掌握各地铁沿线地表沉降情况具有重要现实意义。以南宁地铁为例,利用哨兵-1A(Sentinel-1A)数据和时间序列合成孔径雷达(time series interomet...地铁的建设与运营容易引起地表的纵向沉降,从而影响城市的发展和人民生命和财产安全,因此及时掌握各地铁沿线地表沉降情况具有重要现实意义。以南宁地铁为例,利用哨兵-1A(Sentinel-1A)数据和时间序列合成孔径雷达(time series interometry synthetic aperture radar,TS-InSAR)技术,借助外部高精度的精密定轨(precise orbit determination,POD)精密轨道数据和先进星载电磁发射和反射辐射计全球数字高程模型(advanced spaceborne thermal emission and reflection radiometer global digital elevation model V2,ASTER GDEMV2)去除由去相关引起的相位跳变,获取了2017年6月—2019年1月南宁地铁网络地面沉降速率场,并在此基础上重点分析了地铁沿线地面沉降情况和沉降时空分布规律。试验结果表明,2017~2019年,南宁整体的地表沉降特征较为明显,最大累计沉降达到了-47.41 mm。大部分城区相对稳定,沉降区主要分布在各地铁沿线区域,且随着南宁经济的快速发展和城市地铁建设的加快,各地铁沿线地面沉降呈逐渐增强和扩散趋势。展开更多
Ferrography is deemed as one of the most effective methods for wear particle analysis and failure diagnosis. By analyzing the configuration, content and composition of wear particles in the lubricanting grease and the...Ferrography is deemed as one of the most effective methods for wear particle analysis and failure diagnosis. By analyzing the configuration, content and composition of wear particles in the lubricanting grease and the surface state of the worn surface with combined ferrography and surface analysis techniques, the wear mechanism of the ball groove of the master clutch's release device of a heavy load tracked vehicle was determined. Results show that the controlling wear mechanism is combined of abrasion, adhesion, contact fatigue and corrosion wear, which demonstrates the effectiveness of using combined ferrography and worn surface analysis for the study of wear mechanism of contact surface with friction.展开更多
文摘地铁的建设与运营容易引起地表的纵向沉降,从而影响城市的发展和人民生命和财产安全,因此及时掌握各地铁沿线地表沉降情况具有重要现实意义。以南宁地铁为例,利用哨兵-1A(Sentinel-1A)数据和时间序列合成孔径雷达(time series interometry synthetic aperture radar,TS-InSAR)技术,借助外部高精度的精密定轨(precise orbit determination,POD)精密轨道数据和先进星载电磁发射和反射辐射计全球数字高程模型(advanced spaceborne thermal emission and reflection radiometer global digital elevation model V2,ASTER GDEMV2)去除由去相关引起的相位跳变,获取了2017年6月—2019年1月南宁地铁网络地面沉降速率场,并在此基础上重点分析了地铁沿线地面沉降情况和沉降时空分布规律。试验结果表明,2017~2019年,南宁整体的地表沉降特征较为明显,最大累计沉降达到了-47.41 mm。大部分城区相对稳定,沉降区主要分布在各地铁沿线区域,且随着南宁经济的快速发展和城市地铁建设的加快,各地铁沿线地面沉降呈逐渐增强和扩散趋势。
文摘Ferrography is deemed as one of the most effective methods for wear particle analysis and failure diagnosis. By analyzing the configuration, content and composition of wear particles in the lubricanting grease and the surface state of the worn surface with combined ferrography and surface analysis techniques, the wear mechanism of the ball groove of the master clutch's release device of a heavy load tracked vehicle was determined. Results show that the controlling wear mechanism is combined of abrasion, adhesion, contact fatigue and corrosion wear, which demonstrates the effectiveness of using combined ferrography and worn surface analysis for the study of wear mechanism of contact surface with friction.
