When X-ray fluorescence （XRF） technology is used to measure the sulfur concentration in coal online, the measurement accu- racy is affected by the coal＇s uneven surface and the particle size. In order to improve th...When X-ray fluorescence （XRF） technology is used to measure the sulfur concentration in coal online, the measurement accu- racy is affected by the coal＇s uneven surface and the particle size. In order to improve the accuracy of sulfur concentration measurement, an online measurement system, consisting of a portable X-ray fluorescence instrument and an auxiliary distance correction module, was developed in this paper. By measuring the standard coal samples of known sulfur concentration, we obtained a calibration curve that can be used to analyze the sulfur concentration. We studied the relationship between the X-ray fluorescence intensity （I） and the distance （D） from surfaces to instrument. The results showed that there was a good linear re- lationship between 1 and D when the sulfur content was certain. Based on these knowledge, the distance correction formula of X-ray fluorescence intensity was proposed. By applying the distance correction formula to experimental sulfur concentration measurement, we demonstrated that the measurement accuracy can be significantly increased.展开更多
The purpose of this research is to improve the retrieval accuracy for the suspended sediment concentration(SSC) from in situ and satellite remote sensing measurements in turbid East China estuarine and coastal waters....The purpose of this research is to improve the retrieval accuracy for the suspended sediment concentration(SSC) from in situ and satellite remote sensing measurements in turbid East China estuarine and coastal waters. For this aim, three important tasks are formulated and solved: 1) an estimation of remote-sensing reflectance spectra R_(rs)(λ) after atmospheric correction; 2) an estimation of R_(rs)(λ) from the radiometric signals above the air-water surface; and 3) an estimation of SSC from R_(rs)(λ). Six different models for radiometric R_(rs)(λ) determination and 28 models for SSC versus R_(rs)(λ) are analyzed based on the field observations made in the Changjiang River estuary and its adjacent coastal area. The SSC images based on the above-mentioned analysis are generated for the area.展开更多
Application of MODIS in ocean color is mainly based on bands 8-16 with the spatial resolution of 1 000 m.This spatial resolution,however,can not meet the application demand of inland waters where the areas are relativ...Application of MODIS in ocean color is mainly based on bands 8-16 with the spatial resolution of 1 000 m.This spatial resolution,however,can not meet the application demand of inland waters where the areas are relatively small.With the assumption of the black water at shortwave infrared(SWIR) wavelengths(>1 000 nm),we first propose an atmospheric correction method for bands 1 and 2 with their spatial resolution of 250 m,and we then establish a quantitative retrieval model for suspended sediment concentration retrieval using the in-situ data collected in Taihu Lake.We also use MODIS data to retrieve the suspended sediment concentration of Taihu Lake with the retrieval model.The comparison between the retrieved and measured suspended sediment concentrations confirms that our algorithm can provide reliable data for monitoring the suspended sediment in Taihu Lake.展开更多
目的回顾分析94例(肺通气功能正常)不同血红蛋白(hemoglobin,Hb)浓度受试者其Hb浓度对肺一氧化碳弥散量(diffusion capacity for carbon monoxide of the Lung,DLCO)的影响及对其Hb浓度进行校正的意义。方法将33例Hb>12 g/100 m L受...目的回顾分析94例(肺通气功能正常)不同血红蛋白(hemoglobin,Hb)浓度受试者其Hb浓度对肺一氧化碳弥散量(diffusion capacity for carbon monoxide of the Lung,DLCO)的影响及对其Hb浓度进行校正的意义。方法将33例Hb>12 g/100 m L受试者设为对照组,30例12 g/100 m L>Hb>9g/100 m L受试者设为A组,31例Hb<9 g/100 m L受试者设为B组;经肺功能仪测试获得3组Hb浓度校正前DLCO、DLCO实测值/预计值(B/P)及校正后DLCOc及DLCOc(B/P)。结果对照组及A组各组组内Hb浓度校正前后比较,DLCO与DLCOc及DLCO(B/P)与DLCOc(B/P)变化均不明显,差异无统计学意义;B组Hb浓度校正前后DLCO与DLCOc比较差异值为(1.09±0.21),而DLCO(B/P)与DLCOc(B/P)比较差异值为(16.64±2.99),差异有统计学意义(P<0.05);同时,将A组DLCO与DLCOc、DLCO(B/P)与DLCOc(B/P)Hb校正前后差异值与对照组比较(P<0.05),与B组比较,差异有统计学意义(P<0.05);此外,A、B 2组Hb浓度校正后,弥散功能损伤比校正前有不同程度改善,其中正常达标率分别提高36.7%和35.5%,差异有统计学意义(P<0.05)。结论 Hb浓度的下降可致DLCO不同程度降低,在对肺功能测试结果进行评价时除需排除其它因素对DLCO的影响外,还需要同时观察DLCO及DLCOc,以正确评估Hb浓度对DLCO的影响。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11375087)Provincial Training Programs of Innovation and Entrepreneurship for Undergraduates(Grant No.201310287102)
文摘When X-ray fluorescence （XRF） technology is used to measure the sulfur concentration in coal online, the measurement accu- racy is affected by the coal＇s uneven surface and the particle size. In order to improve the accuracy of sulfur concentration measurement, an online measurement system, consisting of a portable X-ray fluorescence instrument and an auxiliary distance correction module, was developed in this paper. By measuring the standard coal samples of known sulfur concentration, we obtained a calibration curve that can be used to analyze the sulfur concentration. We studied the relationship between the X-ray fluorescence intensity （I） and the distance （D） from surfaces to instrument. The results showed that there was a good linear re- lationship between 1 and D when the sulfur content was certain. Based on these knowledge, the distance correction formula of X-ray fluorescence intensity was proposed. By applying the distance correction formula to experimental sulfur concentration measurement, we demonstrated that the measurement accuracy can be significantly increased.
基金Supported by the National Natural Science Foundation of China,NSFC(Nos.41371346,41271375)the Doctoral Fund of Ministry of Education of China(No.20120076110009)
文摘The purpose of this research is to improve the retrieval accuracy for the suspended sediment concentration(SSC) from in situ and satellite remote sensing measurements in turbid East China estuarine and coastal waters. For this aim, three important tasks are formulated and solved: 1) an estimation of remote-sensing reflectance spectra R_(rs)(λ) after atmospheric correction; 2) an estimation of R_(rs)(λ) from the radiometric signals above the air-water surface; and 3) an estimation of SSC from R_(rs)(λ). Six different models for radiometric R_(rs)(λ) determination and 28 models for SSC versus R_(rs)(λ) are analyzed based on the field observations made in the Changjiang River estuary and its adjacent coastal area. The SSC images based on the above-mentioned analysis are generated for the area.
基金Supported by National High Technology Research and Development Program of China (863 Program)(Nos 2006AA09Z178,2006AA09Z140)the National Natural Science Foundation of China (No 40606042)
文摘Application of MODIS in ocean color is mainly based on bands 8-16 with the spatial resolution of 1 000 m.This spatial resolution,however,can not meet the application demand of inland waters where the areas are relatively small.With the assumption of the black water at shortwave infrared(SWIR) wavelengths(>1 000 nm),we first propose an atmospheric correction method for bands 1 and 2 with their spatial resolution of 250 m,and we then establish a quantitative retrieval model for suspended sediment concentration retrieval using the in-situ data collected in Taihu Lake.We also use MODIS data to retrieve the suspended sediment concentration of Taihu Lake with the retrieval model.The comparison between the retrieved and measured suspended sediment concentrations confirms that our algorithm can provide reliable data for monitoring the suspended sediment in Taihu Lake.
文摘目的回顾分析94例(肺通气功能正常)不同血红蛋白(hemoglobin,Hb)浓度受试者其Hb浓度对肺一氧化碳弥散量(diffusion capacity for carbon monoxide of the Lung,DLCO)的影响及对其Hb浓度进行校正的意义。方法将33例Hb>12 g/100 m L受试者设为对照组,30例12 g/100 m L>Hb>9g/100 m L受试者设为A组,31例Hb<9 g/100 m L受试者设为B组;经肺功能仪测试获得3组Hb浓度校正前DLCO、DLCO实测值/预计值(B/P)及校正后DLCOc及DLCOc(B/P)。结果对照组及A组各组组内Hb浓度校正前后比较,DLCO与DLCOc及DLCO(B/P)与DLCOc(B/P)变化均不明显,差异无统计学意义;B组Hb浓度校正前后DLCO与DLCOc比较差异值为(1.09±0.21),而DLCO(B/P)与DLCOc(B/P)比较差异值为(16.64±2.99),差异有统计学意义(P<0.05);同时,将A组DLCO与DLCOc、DLCO(B/P)与DLCOc(B/P)Hb校正前后差异值与对照组比较(P<0.05),与B组比较,差异有统计学意义(P<0.05);此外,A、B 2组Hb浓度校正后,弥散功能损伤比校正前有不同程度改善,其中正常达标率分别提高36.7%和35.5%,差异有统计学意义(P<0.05)。结论 Hb浓度的下降可致DLCO不同程度降低,在对肺功能测试结果进行评价时除需排除其它因素对DLCO的影响外,还需要同时观察DLCO及DLCOc,以正确评估Hb浓度对DLCO的影响。
