作物产量准确估算在农业生产中具有重要意义。该文利用无人机获取冬小麦挑旗期、开花期和灌浆期数码影像和高光谱数据,并实测产量。首先利用无人机数码影像和高光谱数据分别提取数码影像指数和光谱参数,然后将数码影像指数和光谱参数与...作物产量准确估算在农业生产中具有重要意义。该文利用无人机获取冬小麦挑旗期、开花期和灌浆期数码影像和高光谱数据,并实测产量。首先利用无人机数码影像和高光谱数据分别提取数码影像指数和光谱参数,然后将数码影像指数和光谱参数与冬小麦产量作相关性分析,挑选出相关性较好的9个指数和参数,最后以选取的数码影像指数和光谱参数为建模因子,通过MLR(multiple linear regression,MLR)和RF(random forest,RF)对产量进行估算。结果表明:数码影像指数和光谱参数与实测产量均有很强的相关性。利用数码影像指数和光谱参数通过MLR和RF构建的产量估算模型均在灌浆期表现精度最高,在灌浆期,数码影像指数和光谱参数构建的MLR模型R2和NRMSE分别为0.71、12.79%,0.77、10.32%。对模型对比分析可知,以光谱参数为因子的MLR模型精度较高,更适合用于估算冬小麦产量。利用无人机遥感数据,通过光谱参数建立的MLR模型能够快速、方便地对作物进行产量预测,并可以根据不同生育期的产量估算模型有效地对作物进行监测。展开更多
Silver nanoparticles in size of 8.0 nm was prepared by the trisodium citrate and used to label goat anti-human fibrinogen. In the pH 5.8 Na2HPO4-NaH2O4 buffer solution (PBS) and in the presence of polyethylene glycol ...Silver nanoparticles in size of 8.0 nm was prepared by the trisodium citrate and used to label goat anti-human fibrinogen. In the pH 5.8 Na2HPO4-NaH2O4 buffer solution (PBS) and in the presence of polyethylene glycol (PEG) and KCl, the immune reaction between silver-labeled goat anti-human fibrinogen and fibrinogen took place and led the resonance scattering intensity at 465 nm (I465) to decreasing. The I465 decreased intensity was linear to the fibrinogen concentration in the range from 0.067 to 1.67 μg/mL, with a detection limit of 0.024 μg/mL. This method was applied to determination of fibrinogen in human plasma, with satisfactory results.展开更多
文摘作物产量准确估算在农业生产中具有重要意义。该文利用无人机获取冬小麦挑旗期、开花期和灌浆期数码影像和高光谱数据,并实测产量。首先利用无人机数码影像和高光谱数据分别提取数码影像指数和光谱参数,然后将数码影像指数和光谱参数与冬小麦产量作相关性分析,挑选出相关性较好的9个指数和参数,最后以选取的数码影像指数和光谱参数为建模因子,通过MLR(multiple linear regression,MLR)和RF(random forest,RF)对产量进行估算。结果表明:数码影像指数和光谱参数与实测产量均有很强的相关性。利用数码影像指数和光谱参数通过MLR和RF构建的产量估算模型均在灌浆期表现精度最高,在灌浆期,数码影像指数和光谱参数构建的MLR模型R2和NRMSE分别为0.71、12.79%,0.77、10.32%。对模型对比分析可知,以光谱参数为因子的MLR模型精度较高,更适合用于估算冬小麦产量。利用无人机遥感数据,通过光谱参数建立的MLR模型能够快速、方便地对作物进行产量预测,并可以根据不同生育期的产量估算模型有效地对作物进行监测。
基金Supported by the National Natural Science Foundation of China (Grant No. 20365001)the Guangxi Foundation of New Century Ten-Hundred-Thousand Talents
文摘Silver nanoparticles in size of 8.0 nm was prepared by the trisodium citrate and used to label goat anti-human fibrinogen. In the pH 5.8 Na2HPO4-NaH2O4 buffer solution (PBS) and in the presence of polyethylene glycol (PEG) and KCl, the immune reaction between silver-labeled goat anti-human fibrinogen and fibrinogen took place and led the resonance scattering intensity at 465 nm (I465) to decreasing. The I465 decreased intensity was linear to the fibrinogen concentration in the range from 0.067 to 1.67 μg/mL, with a detection limit of 0.024 μg/mL. This method was applied to determination of fibrinogen in human plasma, with satisfactory results.
