Radiative cooling fabric creates a thermally comfortable environment without energy input,providing a sustainable approach to personal thermal management.However,most currently reported fabrics mainly focus on outdoor...Radiative cooling fabric creates a thermally comfortable environment without energy input,providing a sustainable approach to personal thermal management.However,most currently reported fabrics mainly focus on outdoor cooling,ignoring to achieve simultaneous cooling both indoors and outdoors,thereby weakening the overall cooling performance.Herein,a full-scale structure fabric with selective emission properties is constructed for simultaneous indoor and outdoor cooling.The fabric achieves 94%reflectance performance in the sunlight band(0.3–2.5μm)and 6%in the mid-infrared band(2.5–25μm),effectively minimizing heat absorption and radiation release obstruction.It also demonstrates 81%radiative emission performance in the atmospheric window band(8–13μm)and 25%radiative transmission performance in the mid-infrared band(2.5–25μm),providing 60 and 26 W m−2 net cooling power outdoors and indoors.In practical applications,the fabric achieves excellent indoor and outdoor human cooling,with temperatures 1.4–5.5℃ lower than typical polydimethylsiloxane film.This work proposes a novel design for the advanced radiative cooling fabric,offering significant potential to realize sustainable personal thermal management.展开更多
Selective emitters are crucial as the key component determining the energy conversion efficiency of radioisotope thermophotovoltaic(RTPV)systems.Developing selective emitter materials with high selective emissivity,hi...Selective emitters are crucial as the key component determining the energy conversion efficiency of radioisotope thermophotovoltaic(RTPV)systems.Developing selective emitter materials with high selective emissivity,high spectral efficiency and excellent high-temperature stability can effectively improve the energy conversion efficiency and service life of RTPV systems.To adjust the selective emissivity and spectral efficiency,a series of rare earth tantalate selective emitters(Er(Ta_(1−x)Nb_(x))O_(4)(0≤x≤0.2))matching GaSb batteries were prepared by high-temperature solidstate reaction and pressureless sintering method.The as-prepared Er(Ta_(1−x)Nb_(x))O_(4)(0≤x≤0.2)ceramics exhibit high emissivity(49%–93%)in the selective band(1.40–1.60μm),high spectral efficiency(59.46%–62.12%)and excellent high-temperature stability at 1400℃.On one hand,doping Nb^(5+)into the B-site changes the crystal local structure symmetry around Er^(3+),which promotes the f–f transition of Er^(3+)and enhances the selective emission performance.On the other hand,doping Nb^(5+)ions into the B-site can alter the bandgap and oxygen vacancy concentration to suppress non-selective emissivity.Increasing the selective emissivity and reducing the non-selective emissivity is beneficial for improving the spectral efficiency of selective emitters.Hence,the selective emissivity and spectral efficiency of Er(Ta_(1−x)Nb_(x))O_(4)(0≤x≤0.2)can be effectively enhanced through compositional design,providing a new strategy for developing selective emitter materials for RTPV applications.展开更多
Infrared camouflage based on artificial thermal metasurfaces has recently attracted significant attention.By eliminating thermal radiation differences between the object and the background,it is possible to hide a giv...Infrared camouflage based on artificial thermal metasurfaces has recently attracted significant attention.By eliminating thermal radiation differences between the object and the background,it is possible to hide a given object from infrared detection.Infrared camouflage is an important element that increases the survivability of aircraft and missiles,by reducing target susceptibility to infrared guided threats.Herein,a simple and practicable design is theoretically presented based on a multilayer film for infrared stealth,with distinctive advantages of scalability,flexible fabrication,and structural simplicity.The multilayer medium consists of silicon substrate,carbon layer and zinc sulfide film,the optical properties of which are determined by transfer matrix method.By locally changing the thickness of the coating film,the spatial tunability and continuity in thermal emission are demonstrated.A continuous change of emissive power is further obtained and consequently implemented to achieve thermal camouflage functionality.In addition,other functionalities,like thermal illusion and thermal coding,are demonstrated by thickness-engineered multilayer films.展开更多
Intense heat waves pose a serious threat to public health and well-being,especially in outdoor spaces.Outdoor high-temperature environments without air conditioners are major challenges for humanity.However,an achieva...Intense heat waves pose a serious threat to public health and well-being,especially in outdoor spaces.Outdoor high-temperature environments without air conditioners are major challenges for humanity.However,an achievable approach that can provide outdoor cooling without consuming any energy is lacking.Hence,this work presents a novel hierarchical fabric emitter(HFET)used for sunshade sheds to provide radiative outdoor cooling for humanity,the HFET is composed of polyethylene/silicon dioxide/silicon nitride film,melt-blown polypropylene film,and polydimethylsiloxane film from top to bottom.In addition to reflecting 94%solar irradiance by its top surface,the HFET shows selective emission(0.82 in the atmospheric window and 0.38 outside the atmospheric window)on its top surface to outer space and broadband absorption(0.80 in the longwave infrared band)on its bottom surface from the inside.This bidirectional asymmetric emission enables the simulated skin to avoid overheating by 2-11°C relative to the reverse HFET and bare cases under direct sunlight.Due to its excellent cooling capability,the HFET will be one of the most considerable solutions for outdoor cooling in hot sum-mer environments.展开更多
Currently the flexible demand for high proportion penetration of renewable energy depends on coal-fired units(CFUs),and the large-scale phase-out of CFUs in a short time is not realistic in China.Due to urban expansio...Currently the flexible demand for high proportion penetration of renewable energy depends on coal-fired units(CFUs),and the large-scale phase-out of CFUs in a short time is not realistic in China.Due to urban expansion,approximately 458 Chinese coal-fired power plants(CFPPs)are now located in cities.Limited by space,urban CFUs face difficulty in becoming equipped with carbon capture and storage systems.This presents a sizeable challenge for the low-carbon transition of urban CFPPs and carbon neutral processes.Here,we present a ready-to-implement method to reduce the carbon emission of CFPPs in limited space:roof photovoltaic-assisted power generation combined with sludge cocombustion for coal-fired power generation systems(PVSCs).We also consider nonurban CFPPs with the method of roof photovoltaic-assisted power generation(PVs)only.Based on remaining life cycle analysis,we find that the PVSCs could save 28.47 Mt of coal,reduce CO_(2)emissions by 69.76 Mt,treat 125.70 Mt of sludge,and also generate 12.08 billion RMB worth of electricity revenue per year.In addition,our scenario analysis shows that PVSCs are more profitable when choosing an urban CFU with a remaining life of more than 12 years and while the sludge treatment subsidy is set at 100 RMB t1.Under strict and lenient CFU decommissioning policies,CFUs with a remaining life of between 19 and 30 years and between 13 and 24 years should be selected for PVs,respectively.Thus,we conclude that PVSCs can not only generate economic benefits but also facilitate carbon reduction and solid waste treatment.展开更多
基金financially supported by Heilongjiang Postdoctoral Fund(Grant No.LBH-Z24057)Outstanding Master’s and Doctoral Thesis of Longjiang in the New Era(Grant No.LJYXL2023-076).
文摘Radiative cooling fabric creates a thermally comfortable environment without energy input,providing a sustainable approach to personal thermal management.However,most currently reported fabrics mainly focus on outdoor cooling,ignoring to achieve simultaneous cooling both indoors and outdoors,thereby weakening the overall cooling performance.Herein,a full-scale structure fabric with selective emission properties is constructed for simultaneous indoor and outdoor cooling.The fabric achieves 94%reflectance performance in the sunlight band(0.3–2.5μm)and 6%in the mid-infrared band(2.5–25μm),effectively minimizing heat absorption and radiation release obstruction.It also demonstrates 81%radiative emission performance in the atmospheric window band(8–13μm)and 25%radiative transmission performance in the mid-infrared band(2.5–25μm),providing 60 and 26 W m−2 net cooling power outdoors and indoors.In practical applications,the fabric achieves excellent indoor and outdoor human cooling,with temperatures 1.4–5.5℃ lower than typical polydimethylsiloxane film.This work proposes a novel design for the advanced radiative cooling fabric,offering significant potential to realize sustainable personal thermal management.
基金supported by the National Natural Science Foundation of China(No.52402093)the Self-deployment Project Research Programs of Haixi Institutes,Chinese Academy of Sciences(No.CXZX-2023-JQ07)+3 种基金the National Key R&D Program of China(No.2022YFB3504302)the Young Elite Scientists Sponsorship Program by CAST(No.YESS20210336)the XMIREM Autonomously Deployment Project(Nos.2023GG03 and 2023CX01)the Natural Science Foundation of Xiamen(No.3502Z202472048).
文摘Selective emitters are crucial as the key component determining the energy conversion efficiency of radioisotope thermophotovoltaic(RTPV)systems.Developing selective emitter materials with high selective emissivity,high spectral efficiency and excellent high-temperature stability can effectively improve the energy conversion efficiency and service life of RTPV systems.To adjust the selective emissivity and spectral efficiency,a series of rare earth tantalate selective emitters(Er(Ta_(1−x)Nb_(x))O_(4)(0≤x≤0.2))matching GaSb batteries were prepared by high-temperature solidstate reaction and pressureless sintering method.The as-prepared Er(Ta_(1−x)Nb_(x))O_(4)(0≤x≤0.2)ceramics exhibit high emissivity(49%–93%)in the selective band(1.40–1.60μm),high spectral efficiency(59.46%–62.12%)and excellent high-temperature stability at 1400℃.On one hand,doping Nb^(5+)into the B-site changes the crystal local structure symmetry around Er^(3+),which promotes the f–f transition of Er^(3+)and enhances the selective emission performance.On the other hand,doping Nb^(5+)ions into the B-site can alter the bandgap and oxygen vacancy concentration to suppress non-selective emissivity.Increasing the selective emissivity and reducing the non-selective emissivity is beneficial for improving the spectral efficiency of selective emitters.Hence,the selective emissivity and spectral efficiency of Er(Ta_(1−x)Nb_(x))O_(4)(0≤x≤0.2)can be effectively enhanced through compositional design,providing a new strategy for developing selective emitter materials for RTPV applications.
基金supported by the EIPHI Graduate School(No.ANR-17-EURE-0002)the French Investissements d’Avenir program,project ISITEBFC(No.ANR-15-IDEX-03)+1 种基金the National Natural Science Foundation of China(Nos.12172102,11872160 and 11732002)the support of the Alexander von Humboldt Foundation through the Feodor Lynen Fellowship。
文摘Infrared camouflage based on artificial thermal metasurfaces has recently attracted significant attention.By eliminating thermal radiation differences between the object and the background,it is possible to hide a given object from infrared detection.Infrared camouflage is an important element that increases the survivability of aircraft and missiles,by reducing target susceptibility to infrared guided threats.Herein,a simple and practicable design is theoretically presented based on a multilayer film for infrared stealth,with distinctive advantages of scalability,flexible fabrication,and structural simplicity.The multilayer medium consists of silicon substrate,carbon layer and zinc sulfide film,the optical properties of which are determined by transfer matrix method.By locally changing the thickness of the coating film,the spatial tunability and continuity in thermal emission are demonstrated.A continuous change of emissive power is further obtained and consequently implemented to achieve thermal camouflage functionality.In addition,other functionalities,like thermal illusion and thermal coding,are demonstrated by thickness-engineered multilayer films.
基金Priority Academic Program Development of Jiangsu Higher Education Institution(PAPD)National Natural Science Foundation of China(52204222)National Students’Platform for Innovation and Entrepreneurship Training Program(202210291001Z).
文摘Intense heat waves pose a serious threat to public health and well-being,especially in outdoor spaces.Outdoor high-temperature environments without air conditioners are major challenges for humanity.However,an achievable approach that can provide outdoor cooling without consuming any energy is lacking.Hence,this work presents a novel hierarchical fabric emitter(HFET)used for sunshade sheds to provide radiative outdoor cooling for humanity,the HFET is composed of polyethylene/silicon dioxide/silicon nitride film,melt-blown polypropylene film,and polydimethylsiloxane film from top to bottom.In addition to reflecting 94%solar irradiance by its top surface,the HFET shows selective emission(0.82 in the atmospheric window and 0.38 outside the atmospheric window)on its top surface to outer space and broadband absorption(0.80 in the longwave infrared band)on its bottom surface from the inside.This bidirectional asymmetric emission enables the simulated skin to avoid overheating by 2-11°C relative to the reverse HFET and bare cases under direct sunlight.Due to its excellent cooling capability,the HFET will be one of the most considerable solutions for outdoor cooling in hot sum-mer environments.
基金the National Key R&D Program of China(No.2019YFB1505400).
文摘Currently the flexible demand for high proportion penetration of renewable energy depends on coal-fired units(CFUs),and the large-scale phase-out of CFUs in a short time is not realistic in China.Due to urban expansion,approximately 458 Chinese coal-fired power plants(CFPPs)are now located in cities.Limited by space,urban CFUs face difficulty in becoming equipped with carbon capture and storage systems.This presents a sizeable challenge for the low-carbon transition of urban CFPPs and carbon neutral processes.Here,we present a ready-to-implement method to reduce the carbon emission of CFPPs in limited space:roof photovoltaic-assisted power generation combined with sludge cocombustion for coal-fired power generation systems(PVSCs).We also consider nonurban CFPPs with the method of roof photovoltaic-assisted power generation(PVs)only.Based on remaining life cycle analysis,we find that the PVSCs could save 28.47 Mt of coal,reduce CO_(2)emissions by 69.76 Mt,treat 125.70 Mt of sludge,and also generate 12.08 billion RMB worth of electricity revenue per year.In addition,our scenario analysis shows that PVSCs are more profitable when choosing an urban CFU with a remaining life of more than 12 years and while the sludge treatment subsidy is set at 100 RMB t1.Under strict and lenient CFU decommissioning policies,CFUs with a remaining life of between 19 and 30 years and between 13 and 24 years should be selected for PVs,respectively.Thus,we conclude that PVSCs can not only generate economic benefits but also facilitate carbon reduction and solid waste treatment.
