The half-dry cutting employs cryogenic compressed air cooled down to (10 to 40) and a micro-dosage of lubricating oil, called cryogenic cold air jet cutting was studied. On the basis of a comparative experiment on dr...The half-dry cutting employs cryogenic compressed air cooled down to (10 to 40) and a micro-dosage of lubricating oil, called cryogenic cold air jet cutting was studied. On the basis of a comparative experiment on dry and cryogenic cold air jet cuttings carried out for grade 45 steel, the effects of cryogenic cold air jet on the breaking of chips were discussed. The experimental results reveal that in the valid ranges of pressure and temperature, the cryogenic cold air jet widens the chip breaking areas effectively. When the cutting depth is not greater than 1 mm, the influence of chip breaking is much more significant. But different injecting angle of cold air has different influence on the chip-break. From the experiment, the optimized jet injecting angle, temperature effecting range and pressure working range of cold air are obtained. These results can offer a foundation for industrial manufacturing.展开更多
利用高空、地面常规观测资料,FY-2G黑体亮度温度TBB资料和ECWMF 0. 125°×0. 125°高分辨率资料,对2018年1月3日陕西区域性暴雪进行诊断。结果表明:500 h Pa切断低压分裂低槽、700 h Pa西南急流和850 h Pa东风回流是暴雪...利用高空、地面常规观测资料,FY-2G黑体亮度温度TBB资料和ECWMF 0. 125°×0. 125°高分辨率资料,对2018年1月3日陕西区域性暴雪进行诊断。结果表明:500 h Pa切断低压分裂低槽、700 h Pa西南急流和850 h Pa东风回流是暴雪发生的主要影响系统。700 h Pa强西南急流、偏东气流分别携带来自孟加拉湾和东海的充沛水汽是产生区域性暴雪的重要原因之一;中层冷空气的侵入是本次暴雪发生的主要触发机制;高层辐散与低层辐合的有利配置导致的强上升运动和中低层深厚正涡度的发展和维持是暴雪形成的动力机制。长约1100 km、宽约200 km、TBB≤-40℃的狭长云带东移过程中发展的TBB最低为-52℃、尺度为20~100 km的中-β尺度对流云团是造成小时降雪量超过2. 0 mm、产生区域性暴雪的主要原因。本次暴雪属于冷季高架对流,对称条件不稳定导致的倾斜对流使上升运动加强,雷达回波表现为平行于0~6 km垂直风切变的平行带状结构,且雪带随气流移动。展开更多
文摘The half-dry cutting employs cryogenic compressed air cooled down to (10 to 40) and a micro-dosage of lubricating oil, called cryogenic cold air jet cutting was studied. On the basis of a comparative experiment on dry and cryogenic cold air jet cuttings carried out for grade 45 steel, the effects of cryogenic cold air jet on the breaking of chips were discussed. The experimental results reveal that in the valid ranges of pressure and temperature, the cryogenic cold air jet widens the chip breaking areas effectively. When the cutting depth is not greater than 1 mm, the influence of chip breaking is much more significant. But different injecting angle of cold air has different influence on the chip-break. From the experiment, the optimized jet injecting angle, temperature effecting range and pressure working range of cold air are obtained. These results can offer a foundation for industrial manufacturing.
文摘利用高空、地面常规观测资料,FY-2G黑体亮度温度TBB资料和ECWMF 0. 125°×0. 125°高分辨率资料,对2018年1月3日陕西区域性暴雪进行诊断。结果表明:500 h Pa切断低压分裂低槽、700 h Pa西南急流和850 h Pa东风回流是暴雪发生的主要影响系统。700 h Pa强西南急流、偏东气流分别携带来自孟加拉湾和东海的充沛水汽是产生区域性暴雪的重要原因之一;中层冷空气的侵入是本次暴雪发生的主要触发机制;高层辐散与低层辐合的有利配置导致的强上升运动和中低层深厚正涡度的发展和维持是暴雪形成的动力机制。长约1100 km、宽约200 km、TBB≤-40℃的狭长云带东移过程中发展的TBB最低为-52℃、尺度为20~100 km的中-β尺度对流云团是造成小时降雪量超过2. 0 mm、产生区域性暴雪的主要原因。本次暴雪属于冷季高架对流,对称条件不稳定导致的倾斜对流使上升运动加强,雷达回波表现为平行于0~6 km垂直风切变的平行带状结构,且雪带随气流移动。
