Boundary layer transition(BLT)can cause a sharp rise in heat flux and skin friction,which can seriously affect the flight performance and safety of hypersonic flight vehicles.Therefore,the mechanism,prediction and con...Boundary layer transition(BLT)can cause a sharp rise in heat flux and skin friction,which can seriously affect the flight performance and safety of hypersonic flight vehicles.Therefore,the mechanism,prediction and control of transition have become important issues that must be dealt with for the development of advanced flight vehicles,and it is also a research hotspot of particular interest to major aerospace countries.Compared to other transition research approaches,model flight tests can better present the transition problems under real flight conditions,thus have been carried out extensively over the past 30 years.The United States,Germany,France,Australia,and other countries have carried out transition research based on flight tests,such as the Pegasus wing-glove crossflow transition and the Hypersonic Boundary Layer Transition(HyBOLT)transition control flight test of the United States,the joint research project of the Hypersonic International Flight Research and Experimentation-1(HIFiRE-1)circular cone and the HIFiRE-5 elliptic cone transition flight tests between the United States and Australia,the flight test of compression surface transition of the scramjet forebody(LEA)in France and so on.Although these flight tests suffered various setbacks,they still obtained valuable transition data.Recently,the United States is carrying out the concave-surface transition flight tests of Hypersonic Boundary Layer Transition(BOLT)and BOLT-II.Since its first model flight test mission for verification purpose launched successfully in 2015,several hypersonic BLT flight tests have been conducted by China Aerodynamics Research and Development Center(CARDC).The flight tests have measured valid transition data under flight conditions,obtained the transition front and its dynamical variation on blunt cones at various angles of attack and a lifting body Hypersonic Transition Research Vehicle(HyTRV).The crossflow traveling waves in high-altitude flight were measured for the first time,and our understanding of hypersonic BLT has 展开更多
射频识别技术应用广泛,如二代身份证、一卡通、电子门票,该文将RFID技术用于校园卡,根据RFID工作原理和MF1 IC S50卡的存取控制原理,采用频段为13.56HZ的高频MF1 IC S50卡,选用Python语言和MySql数据库,设计和实现了包括波特率设置、数...射频识别技术应用广泛,如二代身份证、一卡通、电子门票,该文将RFID技术用于校园卡,根据RFID工作原理和MF1 IC S50卡的存取控制原理,采用频段为13.56HZ的高频MF1 IC S50卡,选用Python语言和MySql数据库,设计和实现了包括波特率设置、数据库连接及充值的一款校园卡,并测试成功,对各类RFID会员卡的实现有一定的参考价值。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grants 11772350,92052301).
文摘Boundary layer transition(BLT)can cause a sharp rise in heat flux and skin friction,which can seriously affect the flight performance and safety of hypersonic flight vehicles.Therefore,the mechanism,prediction and control of transition have become important issues that must be dealt with for the development of advanced flight vehicles,and it is also a research hotspot of particular interest to major aerospace countries.Compared to other transition research approaches,model flight tests can better present the transition problems under real flight conditions,thus have been carried out extensively over the past 30 years.The United States,Germany,France,Australia,and other countries have carried out transition research based on flight tests,such as the Pegasus wing-glove crossflow transition and the Hypersonic Boundary Layer Transition(HyBOLT)transition control flight test of the United States,the joint research project of the Hypersonic International Flight Research and Experimentation-1(HIFiRE-1)circular cone and the HIFiRE-5 elliptic cone transition flight tests between the United States and Australia,the flight test of compression surface transition of the scramjet forebody(LEA)in France and so on.Although these flight tests suffered various setbacks,they still obtained valuable transition data.Recently,the United States is carrying out the concave-surface transition flight tests of Hypersonic Boundary Layer Transition(BOLT)and BOLT-II.Since its first model flight test mission for verification purpose launched successfully in 2015,several hypersonic BLT flight tests have been conducted by China Aerodynamics Research and Development Center(CARDC).The flight tests have measured valid transition data under flight conditions,obtained the transition front and its dynamical variation on blunt cones at various angles of attack and a lifting body Hypersonic Transition Research Vehicle(HyTRV).The crossflow traveling waves in high-altitude flight were measured for the first time,and our understanding of hypersonic BLT has
文摘射频识别技术应用广泛,如二代身份证、一卡通、电子门票,该文将RFID技术用于校园卡,根据RFID工作原理和MF1 IC S50卡的存取控制原理,采用频段为13.56HZ的高频MF1 IC S50卡,选用Python语言和MySql数据库,设计和实现了包括波特率设置、数据库连接及充值的一款校园卡,并测试成功,对各类RFID会员卡的实现有一定的参考价值。
文摘目的初步探讨MF59/h BCG复合佐剂增强重组结核分枝杆菌蛋白（TP）免疫反应的机制。方法 MF59、h BCG、TP及其不同配伍分别体外刺激RAW264.7细胞,刺激培养24 h后收集上清,ELISA检测细胞培养上清中TNF-α、MCP-1和IL-1β含量。MF59、h BCG、TP及其配伍分别于小鼠左后腿皮下或肌肉注射,注射后24、48或72 h取注射部位的肌肉组织剪碎、PBS冲洗,采用胶原蛋白水解酶消化法和机械法结合将肌肉组织解离为单个细胞;荧光抗体标记细胞,流式细胞术分析巨噬细胞含量。结果任何免疫原刺激RAW264.7细胞,其培养上清均未检测到IL-1β;MF59和h BCG均能刺激RAW264.7细胞分泌TNF-α和MCP-1,且TNF-α分泌水平呈剂量依赖;而TP却不能刺激RAW264.7细胞分泌TNF-α和MCP-1。1∶100 MF59/h BCG（h BCG终质量浓度为25、50μg/ml）刺激RAW264.7细胞分泌TNF-α和MCP-1水平均显著高于25、50μg/ml h BCG和空白对照（所有P〈0.01）;1∶250MF59/h BCG（h BCG终质量浓度为25、50μg/ml）刺激RAW264.7细胞分泌TNF-α和MCP-1水平均显著高于25μg/ml h BCG和空白对照（P〈0.05）。1∶250 MF59/TP（TP终质量浓度为5、10μg/ml）刺激RAW264.7细胞分泌TNF-α水平显著低于1∶100 MF59/TP（TP终质量浓度为5、10μg/ml）（P〈0.01）。同一免疫原皮下注射和肌肉注射后24 h,其注射部位肌肉组织募集的巨噬细胞含量比较,差异均无统计学差异（P〉0.05）;MF59、50μg h BCG、10μg/ml TP、MF59/50μg h BCG和MF59/10μg TP肌肉注射后24 h,均未见明显的巨噬细胞募集到注射部位肌肉组织,而它们分别皮下注射（除50μg h BCG外）的注射部位肌肉组织募集到不同数量的巨噬细胞;10μg TP皮下注射及MF59/50μg h BCG/10μg TP皮下注射与肌肉注射后24 h,注射部位肌肉组织中巨噬细胞含量均显著高于PBS对照（P〈0.05）。50μg h BCG皮下注射后72 h和250μg h BCG皮下注射后24 h,其注射部位肌肉组织中巨噬细胞含量最高;但与对�
