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沙尘PM_(10)质量浓度与气温的关系初探 被引量:6
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作者 赵建华 Kyle Tietze +1 位作者 hongjun zheng 隆霄 《干旱气象》 2012年第3期339-344,366,共7页
利用甘肃民勤自动气象站观测的2004~2006年夏季的5 min一次的气温与沙尘PM10浓度资料,通过将数据分为实验组与对照组,研究了气温与沙尘天气之间的统计关系。个例显示,气温与沙尘PM10浓度之间存在降温、升温和混合型3种对应关系。实验... 利用甘肃民勤自动气象站观测的2004~2006年夏季的5 min一次的气温与沙尘PM10浓度资料,通过将数据分为实验组与对照组,研究了气温与沙尘天气之间的统计关系。个例显示,气温与沙尘PM10浓度之间存在降温、升温和混合型3种对应关系。实验组统计分析表明,气温及其变化(每5min间隔气温变化绝对值和每24 h间隔气温变化绝对值)与沙尘PM10浓度及其变化呈现出非常显著的正相关关系;沙尘暴天气下日平均气温变化与相应沙尘PM10浓度变化呈显著负相关。对照组结果表明,实验组统计关系是非常显著的。 展开更多
关键词 气温 沙尘PM10浓度 统计关系
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Few-mode fibre-optic microwave photonic links 被引量:2
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作者 He Wen hongjun zheng +9 位作者 Qi Mo Amado Manuel Velázquez-Benítez Cen Xia Bin Huang Huiyuan Liu Huang Yu Pierre Sillard Jose Enrique Antonio Lopez Rodrigo Amezcua Correa Guifang Li 《Light(Science & Applications)》 SCIE EI CAS CSCD 2017年第1期684-691,共8页
The fibre-optic microwave photonic link has become one of the basic building blocks for microwave photonics.Increasing the optical power at the receiver is the best way to improve all link performance metrics includin... The fibre-optic microwave photonic link has become one of the basic building blocks for microwave photonics.Increasing the optical power at the receiver is the best way to improve all link performance metrics including gain,noise figure and dynamic range.Even though lasers can produce and photodetectors can receive optical powers on the order of a Watt or more,the power-handling capability of optical fibres is orders-of-magnitude lower.In this paper,we propose and demonstrate the use of few-mode fibres to bridge this power-handling gap,exploiting their unique features of small acousto-optic effective area,large effective areas of optical modes,as well as orthogonality and walk-off among spatial modes.Using specially designed few-mode fibres,we demonstrate order-of-magnitude improvements in link performances for single-channel and multiplexed transmission.This work represents the first step in few-mode microwave photonics.The spatial degrees of freedom can also offer other functionalities such as large,tunable delays based on modal dispersion and wavelength-independent lossless signal combining,which are indispensable in microwave photonics. 展开更多
关键词 analogue optic-fibre link few-mode fibre fibre nonlinearity microwave photonics space-division multiplexing
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