酶联免疫法(enzyme immunoassay method,EIA)作为一种二口恶英物质的半定量筛选方法被越来越多的实验室使用。与经典的高分辩气相色谱-高分辨质谱法(high-resolution gas chromatrography coupled with high-resolution mass spectromet...酶联免疫法(enzyme immunoassay method,EIA)作为一种二口恶英物质的半定量筛选方法被越来越多的实验室使用。与经典的高分辩气相色谱-高分辨质谱法(high-resolution gas chromatrography coupled with high-resolution mass spectrometry,HRGC-HRMS)不同,ELISA方法得到检测样本总二口恶英类物质的含量,两种方法之间存在偏差。文章引入校正调节因子(calibration adjustment factor,CAF)来减少这种偏差。通过对本实验室前期工作中得到的47组土壤样品二口恶英数据进行统计分析,计算得到土壤来源二口恶英EIA检测方法的校正调节因子为0.6。后期实验室进行崇明岛土壤二口恶英水平研究时,对得到的土壤样品EIA检测结果使用本文得到的CAF值进行校正,验证CAF值的作用。校正前,两组数据之间存在显著性差异,校正后,数据相近,且无显著性差异。证明此CAF值在土壤样品中的适用性。展开更多
The visible infrared radiometer(VIRR)is the first instrument with longest measurements equipped on the Fengyun(FY)polar-orbiting satellites.Through re-processing of the historic VIRR measurements,long-term(over 20 yr)...The visible infrared radiometer(VIRR)is the first instrument with longest measurements equipped on the Fengyun(FY)polar-orbiting satellites.Through re-processing of the historic VIRR measurements,long-term(over 20 yr)global data can be integrated from multiple participating VIRRs on a consistent radiometric scale,which are valuable to climate and climate change studies.Due to lack of an onboard calibration system for VIRR,the reflective solar bands must be vicariously calibrated.This study applied the multi-site vicarious approach for consistent calibration of the VIRR visible(VIS)and near-infrared(NIR)data,and produced calibration coefficients for five VIRRs on FY-1 C/D and FY-3 A/B/C.The data quality was then evaluated with observations.The reflectance predicted by using the radiative transfer model over multiple invariant desert and ocean targets was used to derive the calibration slope via a weighted fitting scheme,in which the weights are the inverse of the variance from a radiative transfer simulation evaluated with reference to Aqua moderate resolution imaging spectroradiometer(MODIS).The sensor-specific calibration coefficients were derived on a daily basis by using piecewise polynomials.The calibration reference of the VIRR solar band record was further traced to the Aqua MODIS Collection 6.1 reference calibration with a systematic correction derived from the Libya4 desert.The VIRR record was compared with the Aqua MODIS C6.1 calibration over the polar region based on simultaneous nadir overpass observations.The lifetime relative difference for each sensor are within 3.3%and 4.5%for channels 1 and 2.Invariant deserts were also employed to evaluate the stability and consistency of the VIRR record.In general,the means of the directional and spectral corrected reflectance for each sensor are within 1%of the 20-yr average,implying that the VIRR reflectance of the invariant targets is consistent to within 1%among the sensors for channels 1 and 2.The VIRR data thus derived are reliable.展开更多
文摘酶联免疫法(enzyme immunoassay method,EIA)作为一种二口恶英物质的半定量筛选方法被越来越多的实验室使用。与经典的高分辩气相色谱-高分辨质谱法(high-resolution gas chromatrography coupled with high-resolution mass spectrometry,HRGC-HRMS)不同,ELISA方法得到检测样本总二口恶英类物质的含量,两种方法之间存在偏差。文章引入校正调节因子(calibration adjustment factor,CAF)来减少这种偏差。通过对本实验室前期工作中得到的47组土壤样品二口恶英数据进行统计分析,计算得到土壤来源二口恶英EIA检测方法的校正调节因子为0.6。后期实验室进行崇明岛土壤二口恶英水平研究时,对得到的土壤样品EIA检测结果使用本文得到的CAF值进行校正,验证CAF值的作用。校正前,两组数据之间存在显著性差异,校正后,数据相近,且无显著性差异。证明此CAF值在土壤样品中的适用性。
基金Supported by the National Key Research and Development Program of China(2018YFB0504905 and 2018YFB0504900)。
文摘The visible infrared radiometer(VIRR)is the first instrument with longest measurements equipped on the Fengyun(FY)polar-orbiting satellites.Through re-processing of the historic VIRR measurements,long-term(over 20 yr)global data can be integrated from multiple participating VIRRs on a consistent radiometric scale,which are valuable to climate and climate change studies.Due to lack of an onboard calibration system for VIRR,the reflective solar bands must be vicariously calibrated.This study applied the multi-site vicarious approach for consistent calibration of the VIRR visible(VIS)and near-infrared(NIR)data,and produced calibration coefficients for five VIRRs on FY-1 C/D and FY-3 A/B/C.The data quality was then evaluated with observations.The reflectance predicted by using the radiative transfer model over multiple invariant desert and ocean targets was used to derive the calibration slope via a weighted fitting scheme,in which the weights are the inverse of the variance from a radiative transfer simulation evaluated with reference to Aqua moderate resolution imaging spectroradiometer(MODIS).The sensor-specific calibration coefficients were derived on a daily basis by using piecewise polynomials.The calibration reference of the VIRR solar band record was further traced to the Aqua MODIS Collection 6.1 reference calibration with a systematic correction derived from the Libya4 desert.The VIRR record was compared with the Aqua MODIS C6.1 calibration over the polar region based on simultaneous nadir overpass observations.The lifetime relative difference for each sensor are within 3.3%and 4.5%for channels 1 and 2.Invariant deserts were also employed to evaluate the stability and consistency of the VIRR record.In general,the means of the directional and spectral corrected reflectance for each sensor are within 1%of the 20-yr average,implying that the VIRR reflectance of the invariant targets is consistent to within 1%among the sensors for channels 1 and 2.The VIRR data thus derived are reliable.
