Heterogeneous strain engineering offers a promising approach for developing high-performance stretchable strain sensors,but the optimal strain distributions remain unexplored.Herein,we derive the optimal strain topolo...Heterogeneous strain engineering offers a promising approach for developing high-performance stretchable strain sensors,but the optimal strain distributions remain unexplored.Herein,we derive the optimal strain topology for achieving maximum sensitivities using Monte Carlo simulations,and identify the key sensitivity-regulating parameters,thus establishing a general computational design guideline.Mathematical analysis demonstrates that within the optimal topology,sensitivity is maximized by reducing the strain value of low-strain regions or increasing their area proportion.As proof of concept,patterned graphene strain sensors(PGSSs)featuring parameterized grooves are designed with their small strain values and proportions precisely modulated via finite element analysis.Adjusting these parameters enhances sensitivity by factors of~10.7 and 3.3,with the highest gauge factor reaching 25,600 at 100%strain.Furthermore,the PGSSs can effectively detect human body motions and gauge object dimensions when integrated with robot grippers.The computational framework exhibits applicability across different heterogeneous strain engineering methods.展开更多
针对大视场(field of view,FOV)、宽波段、高精度的星载激光告警成像需求,开展了基于光谱补偿技术的超大视场成像光学系统设计。设计并实现了182°成像视场的超广角光学系统,并通过滤光片光谱透过率设计对探测器光谱响应不均匀性进...针对大视场(field of view,FOV)、宽波段、高精度的星载激光告警成像需求,开展了基于光谱补偿技术的超大视场成像光学系统设计。设计并实现了182°成像视场的超广角光学系统,并通过滤光片光谱透过率设计对探测器光谱响应不均匀性进行了有效补偿。通过鬼像分析优化了光学系统的结构布局,并提出了系统的杂散光抑制措施。试验结果表明:采用所提光谱补偿措施,在实现太阳直射光抑制的同时,光学系统在激光告警波段内的光谱响应度差异由8.0 dB降低至0.5 dB;采用滤光片与衰减片分离放置的结构形式,杂散光强度与信号光主峰强度的比值降低至1.7×10-5,实现了杂散光的有效抑制。展开更多
本文针对高压直流输电(high-voltage direct current,HVDC)工程中交流滤波电容器桥差保护电流表测量值异常偏大的问题展开研究。理论分析与现场实测表明,因电流表测量导线与电容器塔、导线与地面以及导线之间存在杂散电容,且导线对地布...本文针对高压直流输电(high-voltage direct current,HVDC)工程中交流滤波电容器桥差保护电流表测量值异常偏大的问题展开研究。理论分析与现场实测表明,因电流表测量导线与电容器塔、导线与地面以及导线之间存在杂散电容,且导线对地布线存在物理不对称,引起差模干扰,导致不平衡电流测量值大于真实值。研究建立了杂散电容的等效电路模型,推导了测量误差的计算公式,并分析了杂散电容对测量结果的影响程度。为精确量化杂散电容参数,基于COMSOL Multiphysics软件构建了电容器塔与测量导线的高保真三维静电场模型,为误差分析提供了关键输入。最后结合新疆哈密某±800 kV特高压直流工程实例,通过现场试验验证了理论分析的正确性,并提出以采集电压替代电流的方案,实现不平衡电流的等效测量。展开更多
基金supported by the Research Center for Nature-Inspired Science and Technology,The Hong Kong Polytechnic University(Project No.:CE1T).
文摘Heterogeneous strain engineering offers a promising approach for developing high-performance stretchable strain sensors,but the optimal strain distributions remain unexplored.Herein,we derive the optimal strain topology for achieving maximum sensitivities using Monte Carlo simulations,and identify the key sensitivity-regulating parameters,thus establishing a general computational design guideline.Mathematical analysis demonstrates that within the optimal topology,sensitivity is maximized by reducing the strain value of low-strain regions or increasing their area proportion.As proof of concept,patterned graphene strain sensors(PGSSs)featuring parameterized grooves are designed with their small strain values and proportions precisely modulated via finite element analysis.Adjusting these parameters enhances sensitivity by factors of~10.7 and 3.3,with the highest gauge factor reaching 25,600 at 100%strain.Furthermore,the PGSSs can effectively detect human body motions and gauge object dimensions when integrated with robot grippers.The computational framework exhibits applicability across different heterogeneous strain engineering methods.
文摘针对大视场(field of view,FOV)、宽波段、高精度的星载激光告警成像需求,开展了基于光谱补偿技术的超大视场成像光学系统设计。设计并实现了182°成像视场的超广角光学系统,并通过滤光片光谱透过率设计对探测器光谱响应不均匀性进行了有效补偿。通过鬼像分析优化了光学系统的结构布局,并提出了系统的杂散光抑制措施。试验结果表明:采用所提光谱补偿措施,在实现太阳直射光抑制的同时,光学系统在激光告警波段内的光谱响应度差异由8.0 dB降低至0.5 dB;采用滤光片与衰减片分离放置的结构形式,杂散光强度与信号光主峰强度的比值降低至1.7×10-5,实现了杂散光的有效抑制。
文摘本文针对高压直流输电(high-voltage direct current,HVDC)工程中交流滤波电容器桥差保护电流表测量值异常偏大的问题展开研究。理论分析与现场实测表明,因电流表测量导线与电容器塔、导线与地面以及导线之间存在杂散电容,且导线对地布线存在物理不对称,引起差模干扰,导致不平衡电流测量值大于真实值。研究建立了杂散电容的等效电路模型,推导了测量误差的计算公式,并分析了杂散电容对测量结果的影响程度。为精确量化杂散电容参数,基于COMSOL Multiphysics软件构建了电容器塔与测量导线的高保真三维静电场模型,为误差分析提供了关键输入。最后结合新疆哈密某±800 kV特高压直流工程实例,通过现场试验验证了理论分析的正确性,并提出以采集电压替代电流的方案,实现不平衡电流的等效测量。
