在碰撞检测领域,对碰撞后样车进行必要修复可实现一辆样车完成多次碰撞试验,从而有效降低检测成本。将汽车电路修复与碰撞检测工作相结合,既拓展了车辆修复技术的应用空间,也为碰撞试验领域注入了新的动力。从实际碰撞标准出发提炼了碰...在碰撞检测领域,对碰撞后样车进行必要修复可实现一辆样车完成多次碰撞试验,从而有效降低检测成本。将汽车电路修复与碰撞检测工作相结合,既拓展了车辆修复技术的应用空间,也为碰撞试验领域注入了新的动力。从实际碰撞标准出发提炼了碰撞后车辆需要维修的典型功能,根据修复对象的特征对相关维修工作进行分类。以高压故障维修为重点方向详述了电路修复在碰撞检测领域的应用技术要点。针对高速碰撞后车辆损坏严重、通信网络易瘫痪的维修难点,提出一种外置网关法以避开事故车辆的故障通信网络,及时读取车辆事故信息和故障码。最后,结合CAN(controller area network,控制器局域网)总线拓扑图,精准维修并恢复必要CAN总线子系统的通信功能,实现碰撞后车辆的高效维修。展开更多
针对无线传感器网络自身的可靠性和维护问题,提出了一种基于FPAA(field programmable analog arrays)的自修复智能无线传感器节点的实现方法。该方法以FPAA为核心构成传感器的主要信号调理电路,节点设计有硬件故障自诊断功能,在节点部...针对无线传感器网络自身的可靠性和维护问题,提出了一种基于FPAA(field programmable analog arrays)的自修复智能无线传感器节点的实现方法。该方法以FPAA为核心构成传感器的主要信号调理电路,节点设计有硬件故障自诊断功能,在节点部分硬件模块发生故障的情况下,可修复相应故障,确保节点在无人职守及野外应用时的可靠性,避免节点的直接丢弃。重点介绍了自修复节点的实现方法、软硬件研发并对节点进行了自修复实验研究,分析了自修复节点的功耗及可工作时间,节点能够在2节具有1 700 mAh的AA电池的供电下工作半年时间。展开更多
聚焦离子束扫描电子显微镜(Focused Ion Beam Scanning Electron Microscope,FIB-SEM)双束系统结合了扫描电子显微镜与聚焦离子束系统的优势。基于该系统的高分辨率、原位加工及观测的特点,研究了它在缺陷与像元解剖分析、透射电镜样品...聚焦离子束扫描电子显微镜(Focused Ion Beam Scanning Electron Microscope,FIB-SEM)双束系统结合了扫描电子显微镜与聚焦离子束系统的优势。基于该系统的高分辨率、原位加工及观测的特点,研究了它在缺陷与像元解剖分析、透射电镜样品制备以及电路修复等方面的应用。详细介绍了用FIB-SEM系统定位问题像元的方法和修复电路的具体过程,并阐明了它对红外焦平面探测器研制的重要作用。该系统是高性能红外探测器研制过程中不可或缺的重要表征手段。展开更多
Fluorine-free proton exchange membranes(PEMs)capable of healing from physical damage are important for PEM fuel cells(PEMFCs)with extended service life and enhanced reliability.Herein,highly elastic fluorine-free PEMs...Fluorine-free proton exchange membranes(PEMs)capable of healing from physical damage are important for PEM fuel cells(PEMFCs)with extended service life and enhanced reliability.Herein,highly elastic fluorine-free PEMs with excellent self-healing ability and high proton conductivity are fabricated through complexation of phytic acid(PA)with sulfonated polyvinyl alcohol(SPVA),followed by subsequent grafting of SPVA with positively charged 4-(1H-imidazol-1-yl)benzenecarbaldehyde(IBZ).Compared with recast Nafion membranes,the as-prepared SPVA-IBZ/PA membranes exhibit an enhanced mechanical strength and elasticity and can spontaneously recover from a^50%strain to their initial states within^30 s at room temperature.Meanwhile,the SPVA-IBZ/PA membranes have a proton conductivity of^0.095 S cm-1at^70°C,which is higher than that of recast Nafion membranes.The hydrogen-powered PEMFCs using the SPVA-IBZ/PA membranes,which show an open circuit voltage of^0.98 V and maximum power density of^609 mW cm-2,exhibit a satisfactory cell performance.Importantly,the SPVA-IBZ/PA membranes can spontaneously heal mechanical damage of several tens of micrometers in size and restore their original proton conductivity and cell performance under the working conditions of PEMFCs.展开更多
文摘在碰撞检测领域,对碰撞后样车进行必要修复可实现一辆样车完成多次碰撞试验,从而有效降低检测成本。将汽车电路修复与碰撞检测工作相结合,既拓展了车辆修复技术的应用空间,也为碰撞试验领域注入了新的动力。从实际碰撞标准出发提炼了碰撞后车辆需要维修的典型功能,根据修复对象的特征对相关维修工作进行分类。以高压故障维修为重点方向详述了电路修复在碰撞检测领域的应用技术要点。针对高速碰撞后车辆损坏严重、通信网络易瘫痪的维修难点,提出一种外置网关法以避开事故车辆的故障通信网络,及时读取车辆事故信息和故障码。最后,结合CAN(controller area network,控制器局域网)总线拓扑图,精准维修并恢复必要CAN总线子系统的通信功能,实现碰撞后车辆的高效维修。
文摘聚焦离子束扫描电子显微镜(Focused Ion Beam Scanning Electron Microscope,FIB-SEM)双束系统结合了扫描电子显微镜与聚焦离子束系统的优势。基于该系统的高分辨率、原位加工及观测的特点,研究了它在缺陷与像元解剖分析、透射电镜样品制备以及电路修复等方面的应用。详细介绍了用FIB-SEM系统定位问题像元的方法和修复电路的具体过程,并阐明了它对红外焦平面探测器研制的重要作用。该系统是高性能红外探测器研制过程中不可或缺的重要表征手段。
基金supported by the National Natural Science Foundation of China(21774049 and 21905105)。
文摘Fluorine-free proton exchange membranes(PEMs)capable of healing from physical damage are important for PEM fuel cells(PEMFCs)with extended service life and enhanced reliability.Herein,highly elastic fluorine-free PEMs with excellent self-healing ability and high proton conductivity are fabricated through complexation of phytic acid(PA)with sulfonated polyvinyl alcohol(SPVA),followed by subsequent grafting of SPVA with positively charged 4-(1H-imidazol-1-yl)benzenecarbaldehyde(IBZ).Compared with recast Nafion membranes,the as-prepared SPVA-IBZ/PA membranes exhibit an enhanced mechanical strength and elasticity and can spontaneously recover from a^50%strain to their initial states within^30 s at room temperature.Meanwhile,the SPVA-IBZ/PA membranes have a proton conductivity of^0.095 S cm-1at^70°C,which is higher than that of recast Nafion membranes.The hydrogen-powered PEMFCs using the SPVA-IBZ/PA membranes,which show an open circuit voltage of^0.98 V and maximum power density of^609 mW cm-2,exhibit a satisfactory cell performance.Importantly,the SPVA-IBZ/PA membranes can spontaneously heal mechanical damage of several tens of micrometers in size and restore their original proton conductivity and cell performance under the working conditions of PEMFCs.
