Metasurfaces in the long wave infrared(LWIR)spectrum hold great potential for applications in ther-mal imaging,atmospheric remote sensing,and target identification,among others.In this study,we designed and experiment...Metasurfaces in the long wave infrared(LWIR)spectrum hold great potential for applications in ther-mal imaging,atmospheric remote sensing,and target identification,among others.In this study,we designed and experimentally demonstrated a 4 mm size,all-silicon metasurface metalens with large depth of focus opera-tional across a broadband range from 9µm to 11.5µm.The experimental results confirm effective focusing and imaging capabilities of the metalens in LWIR region,thus paving the way for practical LWIR applications of met-alens technology.展开更多
非甲烷总烃(non-methane total hydrocarbons,NMHCs)作为挥发性有机物(volatile organic compounds,VOCs)的重要组成部分,具有强烈的光化学活性,在一定程度上可以反映城市环境空气VOCs的总体污染情况。为研究烟台市区NMHCs特征,在深入探...非甲烷总烃(non-methane total hydrocarbons,NMHCs)作为挥发性有机物(volatile organic compounds,VOCs)的重要组成部分,具有强烈的光化学活性,在一定程度上可以反映城市环境空气VOCs的总体污染情况。为研究烟台市区NMHCs特征,在深入探讨2021年烟台市芝罘区NMHCs日浓度随时间变化特征的基础上,系统分析了NMHCs浓度时空分布特征以及不同气象要素对NMHCs浓度的影响。结果表明:甲烷日浓度数值稳定,NMHCs(以碳计)日均浓度年度变化呈典型单峰型,高浓度值出现在5—7月。春、夏两季NMHCs浓度约为秋、冬两季浓度2.5倍,具有明显的季节特征。NMHCs浓度与日均温度、相对湿度、气压呈现较高相关性,首次考察了日均温度和相对湿度对NMHCs浓度的综合影响。风向、风速对局部地区NMHCs的扩散补充具有很大的影响。各因素对NMHCs浓度的影响为气压>相对湿度>气温。在周五至周一、高日均温度、低相对湿度、低气压等情况下易出现相对较高浓度NMHCs。通过本研究可以达到对城市环境空气NMHCs浓度时空分布特征的初步了解,为进一步开展大气污染物防治工作奠定基础。展开更多
基金Supported by National Key R&D Program of China(2021YFA0715500)National Natural Science Foundation of China(NSFC)(12227901)+1 种基金Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB0580000)Chinese Academy of Sciences President's In-ternational Fellowship Initiative(2021PT0007).
文摘Metasurfaces in the long wave infrared(LWIR)spectrum hold great potential for applications in ther-mal imaging,atmospheric remote sensing,and target identification,among others.In this study,we designed and experimentally demonstrated a 4 mm size,all-silicon metasurface metalens with large depth of focus opera-tional across a broadband range from 9µm to 11.5µm.The experimental results confirm effective focusing and imaging capabilities of the metalens in LWIR region,thus paving the way for practical LWIR applications of met-alens technology.
基金Supported by the National Key R&D Program of China(2021YFA0715500)National Natural Science Foundation of China(NSFC)(12227901)Chinese Academy of Sciences President’s International Fellowship Initiative(2021PT0007)。
文摘非甲烷总烃(non-methane total hydrocarbons,NMHCs)作为挥发性有机物(volatile organic compounds,VOCs)的重要组成部分,具有强烈的光化学活性,在一定程度上可以反映城市环境空气VOCs的总体污染情况。为研究烟台市区NMHCs特征,在深入探讨2021年烟台市芝罘区NMHCs日浓度随时间变化特征的基础上,系统分析了NMHCs浓度时空分布特征以及不同气象要素对NMHCs浓度的影响。结果表明:甲烷日浓度数值稳定,NMHCs(以碳计)日均浓度年度变化呈典型单峰型,高浓度值出现在5—7月。春、夏两季NMHCs浓度约为秋、冬两季浓度2.5倍,具有明显的季节特征。NMHCs浓度与日均温度、相对湿度、气压呈现较高相关性,首次考察了日均温度和相对湿度对NMHCs浓度的综合影响。风向、风速对局部地区NMHCs的扩散补充具有很大的影响。各因素对NMHCs浓度的影响为气压>相对湿度>气温。在周五至周一、高日均温度、低相对湿度、低气压等情况下易出现相对较高浓度NMHCs。通过本研究可以达到对城市环境空气NMHCs浓度时空分布特征的初步了解,为进一步开展大气污染物防治工作奠定基础。
