通过对2013年6月6日20时-7日20时北京地区出现的中到大雨、局地暴雨的天气过程的大尺度天气环流背景、物理量场、北京多普勒雷达产品和海淀风廓线探测数据、VDRAS反演物理量等多种资料详细分析,得出如下结论：1）本次过程500 h Pa北京...通过对2013年6月6日20时-7日20时北京地区出现的中到大雨、局地暴雨的天气过程的大尺度天气环流背景、物理量场、北京多普勒雷达产品和海淀风廓线探测数据、VDRAS反演物理量等多种资料详细分析,得出如下结论：1）本次过程500 h Pa北京处于从河套以东至长江中下游地区的低槽槽前,温度槽落后于高度槽,地面处于东高西低的形势场中。2）北京处于850 h Paθ（se）高能舌的前部,为对流性天气的出现提供了良好的能量条件。3）强回波在单点稳定少动或多个降水云团先后经过同一地区,造成该地区降水偏大。4）超低空急流加强,且风向由东南转为偏南,南风分量明显加大,有利于水汽的输送和辐合,有利于出现短时强降水。5）据VDRAS反演物理量场的分析,某地区较长时间处于扰动温度相对大值区（0.9-1.2℃）,与该区域降水较大相对应。强回波的合并与维持和其位于东南风和偏南风的辐合区中相关联。6）对EC、T639数值模式降水预报的检验表明,数值模式对明显大尺度系统影响的降水过程预报效果较好,EC对本次过程的预报能力优于T639。展开更多
通过对乘务巡检作业管理需求和现场调研分析,利用N F C近场通信技术及计算机控制技术,通过采集安装在客车车厢内的电子标签信息,实时发送至地面监控主机,分析软件可将接受到的数据与旅客列车乘务员标准作业图表进行自动的比对和分析,从...通过对乘务巡检作业管理需求和现场调研分析,利用N F C近场通信技术及计算机控制技术,通过采集安装在客车车厢内的电子标签信息,实时发送至地面监控主机,分析软件可将接受到的数据与旅客列车乘务员标准作业图表进行自动的比对和分析,从而实现对客车乘务作业的过程盯控,督促车辆乘务员作业标准化的落实。展开更多
The scene of explosion in a passenger train is the objective material base of the reflection of the wxplosion process. It has such characterisitics as complex casualties, particular place and circumstance, two peculia...The scene of explosion in a passenger train is the objective material base of the reflection of the wxplosion process. It has such characterisitics as complex casualties, particular place and circumstance, two peculiar seperated scenes formed after the explosion, limit time of preverving and inspecting the scene, greatly comprehensive profession of inspection of the scene, etc.. Studies on the ways to know the main problem of inspection, follow basic principles, handle beforehead, collect remaining substances and exemin casualties, can direct the inspection in practice and is very important to the development of the theory of railway police.展开更多
First contiol in an area out of jurisdiction is the emergent management adopted by the police organ, who is at the place where the explosion occurs, according to the situation of the scene when the explosion occurs al...First contiol in an area out of jurisdiction is the emergent management adopted by the police organ, who is at the place where the explosion occurs, according to the situation of the scene when the explosion occurs along the railway line or in a passenger train. It is decided by various subjective and objective terms that first control exists in practice and is proposed as a theory of fast reaction and emergent management handling railway explosive cases in the earlier stage. The main factors include that explosive cases along the railway line and i a passenger train do great harm to the society, and that according to current rules of case jurisdiction the railway ploice organ who has the jurisdiction of putting the case on file, locates too far away from the scene of explosion to effectively handle it quickly on its own. Therefore, the local police organ and railway ploice organ at the place of explosion are required to help first control at the scence.展开更多
Purpose–This study aims to solve the problem of weld quality inspection,for the aluminum alloy profile welding structure of high-speed train body has complex internal shape and thin plate thickness(2–4 mm),the conve...Purpose–This study aims to solve the problem of weld quality inspection,for the aluminum alloy profile welding structure of high-speed train body has complex internal shape and thin plate thickness(2–4 mm),the conventional nondestructive testing method of weld quality is difficult to implement.Design/methodology/approach–In order to solve this problem,the ultrasonic creeping wave detection technology was proposed.The impact of the profile structure on the creeping wave detection was studied by designing profile structural test blocks and artificial simulation defect test blocks.The detection technology was used to test the actual welded test blocks,and compared with the results of X-ray test and destructive test(tensile test)to verify the accuracy of the ultrasonic creeping wave test results.Findings–It is indicated that that X-ray has better effect on the inspection of porosities and incomplete penetration defects.However,due to special detection method and protection,the detection speed is slow,which cannot meet the requirements of field inspection of the welding structure of aluminum alloy thin-walled profile for high-speed train body.It can be used as an auxiliary detection method for a small number of sampling inspection.The ultrasonic creeping wave can be used to detect the incomplete penetration welds with the equivalent of 0.25 mm or more,the results of creeping wave detection correspond well with the actual incomplete penetration defects.Originality/value–The results show that creeping wave detection results correspond well with the actual non-penetration defects and can be used for welding quality inspection of aluminum alloy thin-wall profile composite welding joints.It is recommended to use the echo amplitude of the 10 mm 30.2 mm 30.5 mm notch as the criterion for weld qualification.展开更多
文摘通过对2013年6月6日20时-7日20时北京地区出现的中到大雨、局地暴雨的天气过程的大尺度天气环流背景、物理量场、北京多普勒雷达产品和海淀风廓线探测数据、VDRAS反演物理量等多种资料详细分析,得出如下结论：1）本次过程500 h Pa北京处于从河套以东至长江中下游地区的低槽槽前,温度槽落后于高度槽,地面处于东高西低的形势场中。2）北京处于850 h Paθ（se）高能舌的前部,为对流性天气的出现提供了良好的能量条件。3）强回波在单点稳定少动或多个降水云团先后经过同一地区,造成该地区降水偏大。4）超低空急流加强,且风向由东南转为偏南,南风分量明显加大,有利于水汽的输送和辐合,有利于出现短时强降水。5）据VDRAS反演物理量场的分析,某地区较长时间处于扰动温度相对大值区（0.9-1.2℃）,与该区域降水较大相对应。强回波的合并与维持和其位于东南风和偏南风的辐合区中相关联。6）对EC、T639数值模式降水预报的检验表明,数值模式对明显大尺度系统影响的降水过程预报效果较好,EC对本次过程的预报能力优于T639。
文摘The scene of explosion in a passenger train is the objective material base of the reflection of the wxplosion process. It has such characterisitics as complex casualties, particular place and circumstance, two peculiar seperated scenes formed after the explosion, limit time of preverving and inspecting the scene, greatly comprehensive profession of inspection of the scene, etc.. Studies on the ways to know the main problem of inspection, follow basic principles, handle beforehead, collect remaining substances and exemin casualties, can direct the inspection in practice and is very important to the development of the theory of railway police.
文摘First contiol in an area out of jurisdiction is the emergent management adopted by the police organ, who is at the place where the explosion occurs, according to the situation of the scene when the explosion occurs along the railway line or in a passenger train. It is decided by various subjective and objective terms that first control exists in practice and is proposed as a theory of fast reaction and emergent management handling railway explosive cases in the earlier stage. The main factors include that explosive cases along the railway line and i a passenger train do great harm to the society, and that according to current rules of case jurisdiction the railway ploice organ who has the jurisdiction of putting the case on file, locates too far away from the scene of explosion to effectively handle it quickly on its own. Therefore, the local police organ and railway ploice organ at the place of explosion are required to help first control at the scence.
基金supported by the National Natural Science Foundation of China(51705470).
文摘Purpose–This study aims to solve the problem of weld quality inspection,for the aluminum alloy profile welding structure of high-speed train body has complex internal shape and thin plate thickness(2–4 mm),the conventional nondestructive testing method of weld quality is difficult to implement.Design/methodology/approach–In order to solve this problem,the ultrasonic creeping wave detection technology was proposed.The impact of the profile structure on the creeping wave detection was studied by designing profile structural test blocks and artificial simulation defect test blocks.The detection technology was used to test the actual welded test blocks,and compared with the results of X-ray test and destructive test(tensile test)to verify the accuracy of the ultrasonic creeping wave test results.Findings–It is indicated that that X-ray has better effect on the inspection of porosities and incomplete penetration defects.However,due to special detection method and protection,the detection speed is slow,which cannot meet the requirements of field inspection of the welding structure of aluminum alloy thin-walled profile for high-speed train body.It can be used as an auxiliary detection method for a small number of sampling inspection.The ultrasonic creeping wave can be used to detect the incomplete penetration welds with the equivalent of 0.25 mm or more,the results of creeping wave detection correspond well with the actual incomplete penetration defects.Originality/value–The results show that creeping wave detection results correspond well with the actual non-penetration defects and can be used for welding quality inspection of aluminum alloy thin-wall profile composite welding joints.It is recommended to use the echo amplitude of the 10 mm 30.2 mm 30.5 mm notch as the criterion for weld qualification.
