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卤钨灯光谱辐照度衰减会增加灯-板系统的光谱辐亮度不确定度,因此,有必要对卤钨灯的衰减特性展开研究,以提高灯-板系统光谱辐亮度精度。首先,根据黑体辐射定律和维尔斯特拉斯定理,在400~1300 nm波段,提出了一种包含待定阶数的卤钨灯光谱辐照度衰减模型。然后,实验测量卤钨灯的光谱辐照度衰减曲线,分别利用不同阶数的模型对其光谱辐照度衰减曲线进行最小二乘拟合。最后,以满足重建精度要求的最低阶数作为卤钨灯光谱照度模型的阶数。对于本文所用型号的卤钨灯,当模型阶数为二阶时卤钨灯光谱辐照度衰减曲线的重建精度优于0.25%。本文给出的光谱辐照度衰减模型为提高灯-板系统的光谱辐亮度精度奠定了理论基础。 相似文献
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采用宽视场设计,逐轨扫描太阳式测量方式的FY-3A太阳辐射监测仪,结合在轨一年半的太阳辐照度观测数据和地面实验与理论分析,研究了影响定标精度的因素,给出了修正方程和曲线,并通过与世界辐射基准(WRR)的地面外场定标实验,得到了FY-3A上的三台绝对辐射计的比例系数R1=1.008 3,R2=1.006 6和R3=1.006 5。日地距离的理论分析和实际太阳辐照度测量曲线均证明:地球近日点太阳辐照度值最大,远日点太阳辐照度值最小,且在±3.34%范围内随日期变化。利用天文公式,结合遥感源包中的准确测量时间,给出了日、地修正系数。另外,分析了冷空间背景辐射对定标精度的影响,给出了冷空间辐射值的计算公式,并结合宽视场设计和扫描式测量的特点,重点分析了采光结束时刻和刚捕获太阳光时刻入射角的差异给辐照度测量带来的影响,通过几何关系给出了入射角修正系数方程及修正曲线。最后,综合各定标修正系数,给出了在轨定标方程和定标曲线,并分析了定标精度。 相似文献
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本文从理论和实验上分析了水的衰减系数及有效增益长度对受激布里渊散射(SBS)输出能量的影响。实验结果表明,衰减系数越小,SBS输出能量越高。由于脉宽压缩效应,当入射光能量足够高并且有效增益长度相对较长时,SBS易获得高能量而形成极高的峰值功率。一旦这种峰值功率超过受激拉曼散射(SRS)或者二阶SBS阈值,SBS就会作为一个新的激发源去激发SRS或者二阶SBS,从而消耗掉部分SBS的能量,所以会出现后向有效增益长度越长,SBS的输出能量越低的现象。
关键词:
受激布里渊散射
衰减系数
有效增益长度
脉宽压缩 相似文献
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Calibration chain design based on integrating sphere transfer radiometer for SI-traceable on-orbit spectral radiometric calibration and its uncertainty analysis
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In order to satisfy the requirement of SI-traceable on-orbit absolute radiation calibration transfer with high accuracy for satellite remote sensors,a transfer chain consisting of a fiber coupling monochromator(FBM) and an integrating sphere transfer radiometer(ISTR) was designed in this paper.Depending on the Sun,this chain based on detectors provides precise spectral radiometric calibration and measurement to spectrometers in the reflective solar band(RSB) covering 300–2500 nm with a spectral bandwidth of 0.5–6 nm.It shortens the traditional chain based on lamp source and reduces the calibration uncertainty from 5% to 0.5% by using the cryogenic radiometer in space as a radiometric benchmark and trap detectors as secondary standard.This paper also gives a detailed uncertainty budget with reasonable distribution of each impact factor,including the weak spectral signal measurement with uncertainty of 0.28%.According to the peculiar design and comprehensive uncertainty analysis,it illustrates that the spectral radiance measurement uncertainty of the ISTR system can reach to 0.48%.The result satisfies the requirements of SI-traceable on-orbit calibration and has wider significance for expanding the application of the remote sensing data with high-quality. 相似文献
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We study the spontaneous Raman scattering(RS) in taper-drawn micro/nano-fibers(MNFs) by employing the photon counting technique. The spectra of RS in five MNFs, which are fabricated by using different heating flames(hydrogen flame or butane flame) and with different diameters, are measured within a frequency shift range of 1435 cm~(-1)–3200 cm~(-1).From the measured spectra, we observe the RS peaks originated from silica and a unique RS peak with a frequency shift of ~ 2905 cm~(-1)(~ 87.2 THz). Unlike the former ones, the latter one is not observable in conventional optical fibers.Furthermore, the unique peak becomes obvious and starts to rapidly increase with the decrease of the diameter of MNFs when the diameter is smaller than 2 μm, and the intensity of the unique peak significantly depends on the heating flame used in the fabricating process. Our investigation is useful for the entanglement generation or optical sensing using taper-drawn MNFs. 相似文献
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固相萃取-高效液相色谱-串联质谱联用测定竹笋中残留的7种杀虫剂农药 总被引:4,自引:0,他引:4
建立了高效液相色谱-串联质谱(HPLC-MS/MS)同时测定竹笋中丁烯氟虫腈、毒死蜱、氯虫苯甲酰胺、氟虫腈、吡虫啉、茚虫威和辛硫磷7种农药残留的分析方法。样品用乙腈提取后,经PSA固相萃取小柱净化,采用Atlantis T3色谱柱分离,以0.1%甲酸水溶液(含5 mmol/L乙酸铵)和乙腈为流动相,梯度洗脱分离,在电喷雾离子源正、负离子模式下采用质谱多反应监测(MRM)模式检测。结果表明,7种农药在10~100 μg/L范围内具有良好的线性关系(相关系数r为0.9900~0.9994); 4、8、32 μg/kg添加水平下的平均回收率为76.0%~102.6%;相对标准偏差为3.2%~11.0%;7种农药的检出限为0.02~0.5 μg/kg,定量限为0.08~1.5 μg/kg。该方法准确度、灵敏度高,简单、快速,可满足竹笋中7种杀虫剂残留同时检测的要求。 相似文献