Rivers provide key ecosystem services that are inherently engineered and optimized to meet the strategic and economic needs of countries around the world.However,limited water quality records of a full river continuum...Rivers provide key ecosystem services that are inherently engineered and optimized to meet the strategic and economic needs of countries around the world.However,limited water quality records of a full river continuum hindered the understanding of how river systems response to the multiple stressors acting on them.This study highlights the use of Sentinel-2 Multi-Spectral Imager(MSI)data to monitor changes in water color in two optically complex river systems:the Yangtze and Danube using the Forel-Ule Index(FUI).FUI divides water color into 21 classes from dark blue to yellowish brown stemming from the historical Forel-Ule water color scale and has been promoted as a useful indicator showing water turbidity variations in water bodies.The results revealed contrasting water color patterns in the two rivers on both spatial and seasonal scales.Spatially,the FUI of the Yangtze River gradually increased from the upper reaches to the lower reaches,while the FUI of the Danube River declined in the lower reaches,which is possibly due to the sediment sink effect of the Iron Gate Dams.The regional FUI peaks and valleys observed in the two river systems have also been shown to be related to the dams and hydropower stations along them.Seasonally,the variations of FUI in both systems can be attributed to climate seasonality,especially precipitation in the basin and the water level.Moreover,land cover within the river basin was possibly a significant determinant of water color,as higher levels of vegetation in the Danube basin were associated with lower FUI values,whereas higher FUI values and lower levels of vegetation were observed in the Yangtze system.This study furthers our knowledge of using Sentinel-2 MSI to monitor and understand the spatial-temporal variations of river systems and highlights the capabilities of the FUI in an optically complex environment.展开更多
为研究多次蒸晒西洋参中皂苷成分变化及其在组织中的空间分布特征,采用超高效液相色谱四极杆飞行时间串联质谱仪(ultra performance liquid chromatography quadrupole time⁃of⁃flight tandem mass spectrometry,UPLC⁃Q⁃TOF⁃MS/MS)对西...为研究多次蒸晒西洋参中皂苷成分变化及其在组织中的空间分布特征,采用超高效液相色谱四极杆飞行时间串联质谱仪(ultra performance liquid chromatography quadrupole time⁃of⁃flight tandem mass spectrometry,UPLC⁃Q⁃TOF⁃MS/MS)对西洋参提取液进行检测和鉴定。采用基质辅助激光解吸电离质谱成像(matrix⁃assisted laser desorption/ionization mass spectrometry imaging,MALDI⁃MSI)对西洋参中原型皂苷及其代谢产物的空间分布和时空变化进行可视化分析。UPLC结果显示从0~9次蒸制西洋参中共鉴定出90种主要人参皂苷,在西洋参的反复蒸晒过程中,极性人参皂苷转化成低极性或非极性人参皂苷,原型皂苷含量减少,稀有皂苷含量增加,主要为人参皂苷20(S/R)⁃Rg_(3)、20(S/R)⁃Rh_(2)、Rk_(1)、Rg_(5)、Rs_(5)、Rs_(4)等。MALDI⁃MSI组织分布结果表明生西洋参中皂苷主要分布于表皮及韧皮部,蒸晒过程导致皂苷成分发生转化,木质部和髓质中的分布增加。该研究为西洋参蒸制引起的生物活性和药理作用的变化提供了基础信息,为扩大西洋参的药用范围提供了参考。展开更多
基金sponsored by the Dragon 5 Cooperation(grant number 59193)the International Partnership Program of Chinese Academy of Sciences(grant number 313GJHZ2022085FN)+1 种基金the European Union’s Horizon Europe research and innovation programme project DANUBE4all(grant number 101093985)Fund of the International Research Center of Big Data for Sustainable Development Goals(Grant No.CBAS2022DF004).
文摘Rivers provide key ecosystem services that are inherently engineered and optimized to meet the strategic and economic needs of countries around the world.However,limited water quality records of a full river continuum hindered the understanding of how river systems response to the multiple stressors acting on them.This study highlights the use of Sentinel-2 Multi-Spectral Imager(MSI)data to monitor changes in water color in two optically complex river systems:the Yangtze and Danube using the Forel-Ule Index(FUI).FUI divides water color into 21 classes from dark blue to yellowish brown stemming from the historical Forel-Ule water color scale and has been promoted as a useful indicator showing water turbidity variations in water bodies.The results revealed contrasting water color patterns in the two rivers on both spatial and seasonal scales.Spatially,the FUI of the Yangtze River gradually increased from the upper reaches to the lower reaches,while the FUI of the Danube River declined in the lower reaches,which is possibly due to the sediment sink effect of the Iron Gate Dams.The regional FUI peaks and valleys observed in the two river systems have also been shown to be related to the dams and hydropower stations along them.Seasonally,the variations of FUI in both systems can be attributed to climate seasonality,especially precipitation in the basin and the water level.Moreover,land cover within the river basin was possibly a significant determinant of water color,as higher levels of vegetation in the Danube basin were associated with lower FUI values,whereas higher FUI values and lower levels of vegetation were observed in the Yangtze system.This study furthers our knowledge of using Sentinel-2 MSI to monitor and understand the spatial-temporal variations of river systems and highlights the capabilities of the FUI in an optically complex environment.
文摘为研究多次蒸晒西洋参中皂苷成分变化及其在组织中的空间分布特征,采用超高效液相色谱四极杆飞行时间串联质谱仪(ultra performance liquid chromatography quadrupole time⁃of⁃flight tandem mass spectrometry,UPLC⁃Q⁃TOF⁃MS/MS)对西洋参提取液进行检测和鉴定。采用基质辅助激光解吸电离质谱成像(matrix⁃assisted laser desorption/ionization mass spectrometry imaging,MALDI⁃MSI)对西洋参中原型皂苷及其代谢产物的空间分布和时空变化进行可视化分析。UPLC结果显示从0~9次蒸制西洋参中共鉴定出90种主要人参皂苷,在西洋参的反复蒸晒过程中,极性人参皂苷转化成低极性或非极性人参皂苷,原型皂苷含量减少,稀有皂苷含量增加,主要为人参皂苷20(S/R)⁃Rg_(3)、20(S/R)⁃Rh_(2)、Rk_(1)、Rg_(5)、Rs_(5)、Rs_(4)等。MALDI⁃MSI组织分布结果表明生西洋参中皂苷主要分布于表皮及韧皮部,蒸晒过程导致皂苷成分发生转化,木质部和髓质中的分布增加。该研究为西洋参蒸制引起的生物活性和药理作用的变化提供了基础信息,为扩大西洋参的药用范围提供了参考。
