Nanoporous metals with bicontinuous ligament-channel structure are of great importance in catalysis,electro-catalysis,actuation and energy storage and conversion.However,the intrinsic brittleness of nanoporous metals ...Nanoporous metals with bicontinuous ligament-channel structure are of great importance in catalysis,electro-catalysis,actuation and energy storage and conversion.However,the intrinsic brittleness of nanoporous metals has always been the“Achilles heel”that impedes their practical applications.Utilizing the vapor pressure difference of metals,herein we propose a flexible and general vapor phase alloying(VPA)-dealloying strategy to fabricate nanoporous layers supported on the substrates with the same element.By adjusting the VPA time and temperature,the thickness and microstructure control over nanoporous layers can be realized by combining with diverse dealloying methods.Besides,various metals including Ag,Au,Cu,Co and Ni with different macro sizes and shapes can be fabricated into nanoporous structures through this method.More importantly,the greatly improved tensile ductility owing to the nanoporous layersubstrate structure and well enhanced catalytic performance for hydrogen evolution reaction of the as-fabricated nanoporous metals signify great potentials of the VPA-dealloying strategy for practical applications.展开更多
针对宏微超声电机驱动系统内部电路需求多路相互独立的高稳定精度电压,设计了逻辑链路控制(logical link control,简称LLC)变换器+开关型集成稳压两级结构的多路独立输出稳压电源。采用LLC变换器将220V交流电降压变换为多路输出,主功率...针对宏微超声电机驱动系统内部电路需求多路相互独立的高稳定精度电压,设计了逻辑链路控制(logical link control,简称LLC)变换器+开关型集成稳压两级结构的多路独立输出稳压电源。采用LLC变换器将220V交流电降压变换为多路输出,主功率用闭环控制实现高精度稳压输出,其他辅助输出用高效开关型MP1584降压稳压电路实现二次稳压输出。用设计的电源、宏微超声电机、宏微驱动器、光栅尺及激光测振仪构建了宏微超声电机驱动控制系统。试验结果证明,本电源解决了传统单级多路输出电源存在的交叉调整率问题,能提供±1%内的稳定电压,整机效率≥80%,且线路简单、体积小,工程设计上易于实现;优化了宏微超声电机驱动控制系统的体积,提高了效率和可靠性。展开更多
基金The authors gratefully acknowledge the financial support by the National Natural Science Foundation of China(51871133 and 51671115)Taishan Scholar Foundation of Shandong Province,the program of Jinan Science and Technology Bureau and the Department of Science and Technology of Shandong Province.
文摘Nanoporous metals with bicontinuous ligament-channel structure are of great importance in catalysis,electro-catalysis,actuation and energy storage and conversion.However,the intrinsic brittleness of nanoporous metals has always been the“Achilles heel”that impedes their practical applications.Utilizing the vapor pressure difference of metals,herein we propose a flexible and general vapor phase alloying(VPA)-dealloying strategy to fabricate nanoporous layers supported on the substrates with the same element.By adjusting the VPA time and temperature,the thickness and microstructure control over nanoporous layers can be realized by combining with diverse dealloying methods.Besides,various metals including Ag,Au,Cu,Co and Ni with different macro sizes and shapes can be fabricated into nanoporous structures through this method.More importantly,the greatly improved tensile ductility owing to the nanoporous layersubstrate structure and well enhanced catalytic performance for hydrogen evolution reaction of the as-fabricated nanoporous metals signify great potentials of the VPA-dealloying strategy for practical applications.
文摘针对宏微超声电机驱动系统内部电路需求多路相互独立的高稳定精度电压,设计了逻辑链路控制(logical link control,简称LLC)变换器+开关型集成稳压两级结构的多路独立输出稳压电源。采用LLC变换器将220V交流电降压变换为多路输出,主功率用闭环控制实现高精度稳压输出,其他辅助输出用高效开关型MP1584降压稳压电路实现二次稳压输出。用设计的电源、宏微超声电机、宏微驱动器、光栅尺及激光测振仪构建了宏微超声电机驱动控制系统。试验结果证明,本电源解决了传统单级多路输出电源存在的交叉调整率问题,能提供±1%内的稳定电压,整机效率≥80%,且线路简单、体积小,工程设计上易于实现;优化了宏微超声电机驱动控制系统的体积,提高了效率和可靠性。
