Newly discovered remains of the early Middle Eocene (Lutetian) sirenian Protosiren (Protosirenidae) in shark tooth rich conglomerates from a coastal delta environment northwest of the European Rhenish Massif at Fü...Newly discovered remains of the early Middle Eocene (Lutetian) sirenian Protosiren (Protosirenidae) in shark tooth rich conglomerates from a coastal delta environment northwest of the European Rhenish Massif at Fürstenau (northwestern Germany), represent the most northerly occurrence of this genus whose global distribution was generally restricted to warm waters. Its presence of the remains so far north can be explained by seasonal inflow of warm Tethys surface water into the cool, upwelling-influenced, basin. The existence of two discrete centers of sirenian evolution can be explained by the opening of the Atlantic and the upwelling that separated the North American warm water faunal province from those of Africa and Eurasia. A slightly modified evolutionary model is presented in which the oldest Early Eocene manatee sirenians evolved in the Caribbean of Central America. Protosiren, however, appears to have developed polyphyletically along the African coastline of the Tethys, and represents the oldest known dugong ancestor. Younger (Oligocene) European sirenian skeletons of Halitherium and Anomotherium are included in the phylostratigraphic model in which sirenians had generally reduced their teeth by 28 Ma as an adaptation for feeding on sea-plants (macroalgae/seagrass). Teeth from early megatooth sharks, which preyed on sirenians, have been recorded from shallow marine Eocene and Oligocene coastlines of the southern proto-North Sea Basin, and shark bite marks have been found on sirenian skeletons.展开更多
为揭示南水北调中线工程水体中溶解性有机质(Dissolved Organic Matter,DOM)的组成变化特征,采集南水北调中线总干渠沿线及丹江口水库水样,利用傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometr...为揭示南水北调中线工程水体中溶解性有机质(Dissolved Organic Matter,DOM)的组成变化特征,采集南水北调中线总干渠沿线及丹江口水库水样,利用傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR MS)分析了DOM的分子组成及其空间变化,并探讨了总干渠沿线DOM变化成因和环境意义。结果表明:丹江口水库和总干渠均检出DOM物质3200余种,仅含C、H和O的物质(CHOs)为主要组分,约占所有检出物质的61%,含C、H、O和N的物质(CHONs)占30.5%~31.5%,含C、H、O和S的物质(CHOSs)仅占7.3%~8.4%,结合O/C和H/C分类,丹江口水库和总干渠水体DOM主要组分为木质素(60%以上)。相较于丹江口水库,总干渠水体DOM组分发生了较大变化,蛋白质类组分占比由3.70%升至8.65%,表明总干渠中有蛋白质生成;稠环类物质占比由9.43%下降至4.77%,单宁酸类的变化趋势与稠环类物质类似。总干渠局部区域藻类增殖过程是引起总干渠中CHONs和CHOSs类DOM组分和占比升高的主要原因。研究成果可为科学认识南水北调中线工程水体水质变化过程提供科学依据。展开更多
This article considers that in the process of Middle Route Project of SouthNorth Water Transfer, importance must be attached to the ecological environment protection in the headwater area--Hanjiang Basin. It discuss...This article considers that in the process of Middle Route Project of SouthNorth Water Transfer, importance must be attached to the ecological environment protection in the headwater area--Hanjiang Basin. It discusses not only the emigration region, the reservoir area, the project construction and the problem arised from water resources utilization and the ecological environment protection, but also the soil and water erosion, the flood and drought, the pollution and the ecological environment in the whole drainage basin. It also puts forward the countermeasures about the ecological environment protection in the drainage basin.展开更多
文摘Newly discovered remains of the early Middle Eocene (Lutetian) sirenian Protosiren (Protosirenidae) in shark tooth rich conglomerates from a coastal delta environment northwest of the European Rhenish Massif at Fürstenau (northwestern Germany), represent the most northerly occurrence of this genus whose global distribution was generally restricted to warm waters. Its presence of the remains so far north can be explained by seasonal inflow of warm Tethys surface water into the cool, upwelling-influenced, basin. The existence of two discrete centers of sirenian evolution can be explained by the opening of the Atlantic and the upwelling that separated the North American warm water faunal province from those of Africa and Eurasia. A slightly modified evolutionary model is presented in which the oldest Early Eocene manatee sirenians evolved in the Caribbean of Central America. Protosiren, however, appears to have developed polyphyletically along the African coastline of the Tethys, and represents the oldest known dugong ancestor. Younger (Oligocene) European sirenian skeletons of Halitherium and Anomotherium are included in the phylostratigraphic model in which sirenians had generally reduced their teeth by 28 Ma as an adaptation for feeding on sea-plants (macroalgae/seagrass). Teeth from early megatooth sharks, which preyed on sirenians, have been recorded from shallow marine Eocene and Oligocene coastlines of the southern proto-North Sea Basin, and shark bite marks have been found on sirenian skeletons.
文摘为揭示南水北调中线工程水体中溶解性有机质(Dissolved Organic Matter,DOM)的组成变化特征,采集南水北调中线总干渠沿线及丹江口水库水样,利用傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR MS)分析了DOM的分子组成及其空间变化,并探讨了总干渠沿线DOM变化成因和环境意义。结果表明:丹江口水库和总干渠均检出DOM物质3200余种,仅含C、H和O的物质(CHOs)为主要组分,约占所有检出物质的61%,含C、H、O和N的物质(CHONs)占30.5%~31.5%,含C、H、O和S的物质(CHOSs)仅占7.3%~8.4%,结合O/C和H/C分类,丹江口水库和总干渠水体DOM主要组分为木质素(60%以上)。相较于丹江口水库,总干渠水体DOM组分发生了较大变化,蛋白质类组分占比由3.70%升至8.65%,表明总干渠中有蛋白质生成;稠环类物质占比由9.43%下降至4.77%,单宁酸类的变化趋势与稠环类物质类似。总干渠局部区域藻类增殖过程是引起总干渠中CHONs和CHOSs类DOM组分和占比升高的主要原因。研究成果可为科学认识南水北调中线工程水体水质变化过程提供科学依据。
文摘This article considers that in the process of Middle Route Project of SouthNorth Water Transfer, importance must be attached to the ecological environment protection in the headwater area--Hanjiang Basin. It discusses not only the emigration region, the reservoir area, the project construction and the problem arised from water resources utilization and the ecological environment protection, but also the soil and water erosion, the flood and drought, the pollution and the ecological environment in the whole drainage basin. It also puts forward the countermeasures about the ecological environment protection in the drainage basin.
