With Zunyi CINRAD/CD Doppler radar data and other data,a hail wind and heavy rainfall in short time occurred on July 10,2008 in northern Guizhou Province was analyzed in this study.The results showed that the system w...With Zunyi CINRAD/CD Doppler radar data and other data,a hail wind and heavy rainfall in short time occurred on July 10,2008 in northern Guizhou Province was analyzed in this study.The results showed that the system was affected by the southward of cold air pressure in a low-shear vortex zone.Echo monomer initially developed and arranged along the shear line,and there was hail weather in echo location with intense development.Before the hail shooting,the strongest echo value was 60-65 dBz.When the hail shooting,the low-elevation echo intensity sharply increased to 55-60 dBz with echo height of 11-15 km and VIL values>35 kg/m2,and its echo distribution showed band characteristics of vortex.When the vortex center moved to the original echo,echo intensity increased,resulting in a profound and lasting convergence of cyclones,and hail or strong wind occurred on the ground.Hail and strong short-term precipitation in towns of northern Renhuai might be related to the left inverted U-terrain.Echoes from Yongxing and Yuquan in Meitan,Xuekong and Xitou in Renhuai were the supercell echoes,and other regional hail shooting echoes were strong multi-monomer echoes.展开更多
基于超声波时差测量流量的方法具有非接触、易安装、不改变流体的运动状态等优点,被广泛应用于油田井下流体流速测量分析领域,能够实时测量流体流速,准确分析管道中流体流量的变化。针对传统的超声波流量计功耗高、电路复杂的缺点,根据...基于超声波时差测量流量的方法具有非接触、易安装、不改变流体的运动状态等优点,被广泛应用于油田井下流体流速测量分析领域,能够实时测量流体流速,准确分析管道中流体流量的变化。针对传统的超声波流量计功耗高、电路复杂的缺点,根据超声波时差法测量流量的原理,结合井下高温测量环境,以及未来测井仪器低功耗、小型化的需求,以dsPIC33EV为主控芯片,设计了一种低功耗、小型化的井下超声波流量测量系统。该系统利用dsPIC33EV的充电时间测量单元CTMU(Charging Time Measurement Unit),实现声波传播时差与流量的高精度测量与计算。室内实验平台测试数据表明,该文设计的井下超声波流量测量系统测量相对误差为±7.2%,典型功耗为20mW,技术指标满足生产井流量监测需求。展开更多
文摘With Zunyi CINRAD/CD Doppler radar data and other data,a hail wind and heavy rainfall in short time occurred on July 10,2008 in northern Guizhou Province was analyzed in this study.The results showed that the system was affected by the southward of cold air pressure in a low-shear vortex zone.Echo monomer initially developed and arranged along the shear line,and there was hail weather in echo location with intense development.Before the hail shooting,the strongest echo value was 60-65 dBz.When the hail shooting,the low-elevation echo intensity sharply increased to 55-60 dBz with echo height of 11-15 km and VIL values>35 kg/m2,and its echo distribution showed band characteristics of vortex.When the vortex center moved to the original echo,echo intensity increased,resulting in a profound and lasting convergence of cyclones,and hail or strong wind occurred on the ground.Hail and strong short-term precipitation in towns of northern Renhuai might be related to the left inverted U-terrain.Echoes from Yongxing and Yuquan in Meitan,Xuekong and Xitou in Renhuai were the supercell echoes,and other regional hail shooting echoes were strong multi-monomer echoes.
文摘基于超声波时差测量流量的方法具有非接触、易安装、不改变流体的运动状态等优点,被广泛应用于油田井下流体流速测量分析领域,能够实时测量流体流速,准确分析管道中流体流量的变化。针对传统的超声波流量计功耗高、电路复杂的缺点,根据超声波时差法测量流量的原理,结合井下高温测量环境,以及未来测井仪器低功耗、小型化的需求,以dsPIC33EV为主控芯片,设计了一种低功耗、小型化的井下超声波流量测量系统。该系统利用dsPIC33EV的充电时间测量单元CTMU(Charging Time Measurement Unit),实现声波传播时差与流量的高精度测量与计算。室内实验平台测试数据表明,该文设计的井下超声波流量测量系统测量相对误差为±7.2%,典型功耗为20mW,技术指标满足生产井流量监测需求。
