High-temperature infrared(IR)radiation materials with broadband high emissivity,low thermal conductivity,and high fracture toughness are urgently needed for radiative heat management.Here,we report a Gd_(3)TaO_(7)/GdF...High-temperature infrared(IR)radiation materials with broadband high emissivity,low thermal conductivity,and high fracture toughness are urgently needed for radiative heat management.Here,we report a Gd_(3)TaO_(7)/GdFeO_(3)composite ceramic that integrates a broadband(0.78-14μm)high emissivity(close to 0.9),low thermal conductivity(1.62Wm^(−1)K^(−1)),and fracture toughness(2.3MPam^(1/2),close to YSZ).Through the introduction of second-phase GdFeO_(3),many lattice distortions,multimode vibrations,and additional oxygen vacancies(Ov)contribute to an increase in the broad-band emissivity of the composite ceramics(especially in the 2.5-6μm band,nearly 5 times greater than that of Gd_(3)TaO_(7)).This high IR emissivity significantly suppresses the elevated photonic thermal conductivity at high temperatures,resulting in ultralow thermal conductivity.Moreover,the stable atomic arrangement within the two phases contributed to the impressive high-temperature stability(1773K,200h).The improved fracture toughness is attributed primarily to the presence of the second phase promoting crack tip deflection,bridging and branching,which prevent crack expansion.All the advantages render this second-phase composite strategy fully competitive in the development of a new generation of superhigh-temperature radiative heat management materials.展开更多
针对集成稳压器对精密电压基准的要求,给出了一款新型的可同时应用于DC DC,LDO和Chargepump的BiCMOS带隙基准电路设计。该设计在采用温度系数补偿产生基准电源的同时,引进了快速基准检测电路,更加保证了输出的准确性。采用TT model HSp...针对集成稳压器对精密电压基准的要求,给出了一款新型的可同时应用于DC DC,LDO和Chargepump的BiCMOS带隙基准电路设计。该设计在采用温度系数补偿产生基准电源的同时,引进了快速基准检测电路,更加保证了输出的准确性。采用TT model HSpice模型进行仿真后的结果表明,此款带隙基准电路在较宽范围内温漂不超过4 mV。展开更多
基金supports from the NSFC Grant nos.52301084,U21B2053,and 52301085Postdoctoral Fellowship Program of CPSF(YJB20240056)+3 种基金Aeronautical Science Foundation(2023M045077001)Open Project Funding of State Key Laboratory for High Performance Tools(GXNGJSKL 2024)Opening Project Fund of Materials Service Safety Assessment Facilities(MSAF-2024-007)the Fundamental Research Funds for the Central Universities are gratefully acknowledged.
文摘High-temperature infrared(IR)radiation materials with broadband high emissivity,low thermal conductivity,and high fracture toughness are urgently needed for radiative heat management.Here,we report a Gd_(3)TaO_(7)/GdFeO_(3)composite ceramic that integrates a broadband(0.78-14μm)high emissivity(close to 0.9),low thermal conductivity(1.62Wm^(−1)K^(−1)),and fracture toughness(2.3MPam^(1/2),close to YSZ).Through the introduction of second-phase GdFeO_(3),many lattice distortions,multimode vibrations,and additional oxygen vacancies(Ov)contribute to an increase in the broad-band emissivity of the composite ceramics(especially in the 2.5-6μm band,nearly 5 times greater than that of Gd_(3)TaO_(7)).This high IR emissivity significantly suppresses the elevated photonic thermal conductivity at high temperatures,resulting in ultralow thermal conductivity.Moreover,the stable atomic arrangement within the two phases contributed to the impressive high-temperature stability(1773K,200h).The improved fracture toughness is attributed primarily to the presence of the second phase promoting crack tip deflection,bridging and branching,which prevent crack expansion.All the advantages render this second-phase composite strategy fully competitive in the development of a new generation of superhigh-temperature radiative heat management materials.
文摘针对集成稳压器对精密电压基准的要求,给出了一款新型的可同时应用于DC DC,LDO和Chargepump的BiCMOS带隙基准电路设计。该设计在采用温度系数补偿产生基准电源的同时,引进了快速基准检测电路,更加保证了输出的准确性。采用TT model HSpice模型进行仿真后的结果表明,此款带隙基准电路在较宽范围内温漂不超过4 mV。
