[Objectives] This study was conducted to investigate the toxic effects of 2,2',4,4',5,5'-hexabromobiphenyl ether on Chlorella vulgaris and provide basic data for protecting aquatic ecosystems. [Methods] Th...[Objectives] This study was conducted to investigate the toxic effects of 2,2',4,4',5,5'-hexabromobiphenyl ether on Chlorella vulgaris and provide basic data for protecting aquatic ecosystems. [Methods] The acute toxicity effects of 2,2',4,4',5,5'-hexabromodiphenyl ether on C. vulgaris was investigated by the semi-static water contacting acute toxicity method. [Results] The 48,72 and 96 h-EC(50) of 2,2',4,4',5,5'-hexabromodiphenyl ether to C. vulgaris were23. 58,18. 71 and 14. 75 μg/L,respectively,and the safe concentration of 2,2',4,4',5,5'-hexabromodiphenyl ether to C. vulgaris was 1. 475μg/L. For the water solubility of 2,2',4,4',5,5'-hexabromodiphenyl ether is extremely low( 1 μg/L),it could not cause the acute poisoning death of C. vulgaris. According to the grading standards for the assessment of the toxicity on algae,2,2',4,4',5,5'-hexabromodiphenyl ether was extremely highly toxic to C. vulgaris. [Conclusions]The extremely high toxicity of 2,2',4,4',5,5'-hexabromodiphenyl ether to C. vulgaris shows that it has heavy potential harm to aquatic ecosystems and the maximum residue limit standards of 2,2',4,4',5,5'-hexabromodiphenyl ether in water should be formulated to better protect aquatic ecosystems.展开更多
Developing the Nabucco engineering infrastructure was the most challenging task imaginable and required state-of-the-art technologies.For this purpose,a NabuccoGlobal Positioning System(GPS)Network was established.It...Developing the Nabucco engineering infrastructure was the most challenging task imaginable and required state-of-the-art technologies.For this purpose,a NabuccoGlobal Positioning System(GPS)Network was established.It is 762 km long.Nine-hundred and two ground control unit points were established.In order to provide the relationship with ITRF96 datum,it was surrounded by TFNGN(Turkish Fundamental National GPS Network)and TNVCN(Turkish National Vertical Control Network)checkpoints.GPS observations were evaluated in the form of a unique network.After being reduced to projection segments,coordinates in ED50 datum were provided between datums by 2D-Helmert Transformation.Orthometric heights related to the GPS Network were obtained by the improvement of TG-03 data based on a GPS/leveling procedure.The objective of the study is to present the results of a comprehensive engineering project which involved many geodetic considerations including GPS,orthometric heights,and geoid undulations and gives insight into the accuracy and precision of such large projects in terms of recent geodetic practice.In this study,a Global Navigation Satellite System(GNSS)-based geodetic infrastructure is presented,methods to obtain the necessary precision requirements are provided,and experience is shared in order to provide an example of a large-scale pipeline project,and to provide insight into the planning necessary for future similar engineering projects.展开更多
基金Supported by Central Public-interest Scientific Institution Basal Research FundChinese Academy of Fishery Science (2017HY-ZD0208)China Agricultural Research System-Freshwater Fish (CARS-46)。
文摘[Objectives] This study was conducted to investigate the toxic effects of 2,2',4,4',5,5'-hexabromobiphenyl ether on Chlorella vulgaris and provide basic data for protecting aquatic ecosystems. [Methods] The acute toxicity effects of 2,2',4,4',5,5'-hexabromodiphenyl ether on C. vulgaris was investigated by the semi-static water contacting acute toxicity method. [Results] The 48,72 and 96 h-EC(50) of 2,2',4,4',5,5'-hexabromodiphenyl ether to C. vulgaris were23. 58,18. 71 and 14. 75 μg/L,respectively,and the safe concentration of 2,2',4,4',5,5'-hexabromodiphenyl ether to C. vulgaris was 1. 475μg/L. For the water solubility of 2,2',4,4',5,5'-hexabromodiphenyl ether is extremely low( 1 μg/L),it could not cause the acute poisoning death of C. vulgaris. According to the grading standards for the assessment of the toxicity on algae,2,2',4,4',5,5'-hexabromodiphenyl ether was extremely highly toxic to C. vulgaris. [Conclusions]The extremely high toxicity of 2,2',4,4',5,5'-hexabromodiphenyl ether to C. vulgaris shows that it has heavy potential harm to aquatic ecosystems and the maximum residue limit standards of 2,2',4,4',5,5'-hexabromodiphenyl ether in water should be formulated to better protect aquatic ecosystems.
文摘Developing the Nabucco engineering infrastructure was the most challenging task imaginable and required state-of-the-art technologies.For this purpose,a NabuccoGlobal Positioning System(GPS)Network was established.It is 762 km long.Nine-hundred and two ground control unit points were established.In order to provide the relationship with ITRF96 datum,it was surrounded by TFNGN(Turkish Fundamental National GPS Network)and TNVCN(Turkish National Vertical Control Network)checkpoints.GPS observations were evaluated in the form of a unique network.After being reduced to projection segments,coordinates in ED50 datum were provided between datums by 2D-Helmert Transformation.Orthometric heights related to the GPS Network were obtained by the improvement of TG-03 data based on a GPS/leveling procedure.The objective of the study is to present the results of a comprehensive engineering project which involved many geodetic considerations including GPS,orthometric heights,and geoid undulations and gives insight into the accuracy and precision of such large projects in terms of recent geodetic practice.In this study,a Global Navigation Satellite System(GNSS)-based geodetic infrastructure is presented,methods to obtain the necessary precision requirements are provided,and experience is shared in order to provide an example of a large-scale pipeline project,and to provide insight into the planning necessary for future similar engineering projects.
