The energy spectra of reflected electrons from the substrates of targets have been calculated by the bipartition model of electron transport, the contributions of the inner shen ionization events produced by the refle...The energy spectra of reflected electrons from the substrates of targets have been calculated by the bipartition model of electron transport, the contributions of the inner shen ionization events produced by the reflected electrons from the substrates in the targets to the x-ray counting in a St(Li) detector have been estimated. It has been confirmed that, by such correction to the measured data, the experimental results of inner shell ionization cross sections by electron impact with fine precision may be obtained under the condition of thick substrate.展开更多
A novel forming method of nickel based super-alloy thin-walled part with variable diameter sections was proposed by using inner and outer pressure with the visco-elasto-plastic pressure-carrying medium at room tempera...A novel forming method of nickel based super-alloy thin-walled part with variable diameter sections was proposed by using inner and outer pressure with the visco-elasto-plastic pressure-carrying medium at room temperature,and the principle of the method was provided.Experiments and FE simulations were carried out to analyze the deformation characteristics for the part with larger variable diameter ratio(35%).The results show that visco-elasto-plastic pressure-carrying medium can meet the requirements of the room-temperature deformation condition for nickel based super-alloy sheet.The inner and outer pressure forming with the visco-elasto-plastic pressure-carrying medium can meet the requirements of dimensional accuracy for the thin-walled part with variable diameter sections.The thinning of wall-thickness is less than 4%.This method provides a new approach for near-net shape forming of nickel based super-alloy thin-walled parts with variable diameter sections.展开更多
文摘The energy spectra of reflected electrons from the substrates of targets have been calculated by the bipartition model of electron transport, the contributions of the inner shen ionization events produced by the reflected electrons from the substrates in the targets to the x-ray counting in a St(Li) detector have been estimated. It has been confirmed that, by such correction to the measured data, the experimental results of inner shell ionization cross sections by electron impact with fine precision may be obtained under the condition of thick substrate.
文摘A novel forming method of nickel based super-alloy thin-walled part with variable diameter sections was proposed by using inner and outer pressure with the visco-elasto-plastic pressure-carrying medium at room temperature,and the principle of the method was provided.Experiments and FE simulations were carried out to analyze the deformation characteristics for the part with larger variable diameter ratio(35%).The results show that visco-elasto-plastic pressure-carrying medium can meet the requirements of the room-temperature deformation condition for nickel based super-alloy sheet.The inner and outer pressure forming with the visco-elasto-plastic pressure-carrying medium can meet the requirements of dimensional accuracy for the thin-walled part with variable diameter sections.The thinning of wall-thickness is less than 4%.This method provides a new approach for near-net shape forming of nickel based super-alloy thin-walled parts with variable diameter sections.
文摘暴雨云团的宏微观结构在不同地理环境和环流背景下表现出明显差异。黄河流域内蒙古段地处半干旱区,地形复杂,暴雨突发性强。利用风云三号G星(FY-3G)卫星搭载的降水测量雷达(Precipitation Measurement Radar,PMR)数据,结合欧洲中期天气预报中心(European Center for Medium-Range Weather Forecasts,ECMWF)的ERA5再分析资料,对2024年8月8日黄河流域内蒙古段暴雨过程的云团三维结构及环流背景进行综合分析。结果表明,暴雨发生在副热带高压与西风槽共同作用的环流背景下,700 hPa低空急流、明显的垂直风切变以及暖湿气流的强上升运动为暴雨形成提供有力动力条件。降水云系中同时存在层状云与对流云,对流云的平均粒子数浓度、有效粒子直径、降水率均高于层状云,且粒子数浓度和有效粒子直径的垂直分布与不稳定能量场高度一致;降水反射率在0℃层上下存在高频增强区,对流云在约5 km高度的潜热释放量是层状云的2倍,表明对流云团是此次极端暴雨的主要贡献者,对降水效率和降水强度具有决定性影响。云顶高度自西向东逐渐升高,极端暴雨区的云顶高度及0℃层高度的水平分布特征与地形起伏密切相关。
