-A two-dimensional.nonlinear numerical model is used to study the residual current generated by tides in the East China Sea (ECS)and the South Huanghai Sea (SHS). At first, the principal semidiurnal lunar tide (M2)and...-A two-dimensional.nonlinear numerical model is used to study the residual current generated by tides in the East China Sea (ECS)and the South Huanghai Sea (SHS). At first, the principal semidiurnal lunar tide (M2)and the tidal current are derived in these areas. The results obtained with the model are strongly supported by the observational results available. Then, the tide-induced residual flow is determined by using the currents generated by the tidal input. The main features of the residual current in ECS and SHS are presented by analyzing the calculated results. Some of the problems are discussed such as the cause of generating residual current and the contribution of the residual current to the observed current.展开更多
A simple method for determining 33 pesticides with a wide polarity range（log Kow0.6-4.5） in aquatic products was developed based on LC–MS/MS. The target analytes included three types of widely used pesticides： ins...A simple method for determining 33 pesticides with a wide polarity range（log Kow0.6-4.5） in aquatic products was developed based on LC–MS/MS. The target analytes included three types of widely used pesticides： insecticides, fungicides and herbicides. Based on the optimization of ultrasonic assisted extraction and GPC clean-up procedures, the matrix effect, extraction recoveries and LOD were improved distinctively. LOQ of this method was below 0.5 ng/g for all pesticides, which is superior to values in the literature, and the matrix effect was reduced effectively（-14.7% to 7.5%）. The method was successfully applied to investigate the pesticide residue levels of twenty-five samples including seven common kinds of fishes from Northeast China. The results showed that all targeted pesticides were present in the fish samples; however, their levels were low, except for atrazine, linuron,ethoprophos, tetrachlorvinphos, acetochlor and fenthion. Atrazine and linuron caught our attention because the concentrations of atrazine in fish samples from Liaoning province were in the range of 0.5-8 ng/g（w/w） with mean concentration of 2.3 ng/g, which were far above those of other pesticides. The levels of linuron were in the range of 0.6-6 ng/g（mean concentration 2.8 ng/g）, which were the highest among all targeted pesticides in the Inner Mongolia. This is the first systematic investigation on the characteristics and levels of these pesticides in aquatic products from northeast China. Considering their toxicity and bioaccumulation, the potential risk of atrazine and linuron from consuming aquatic products should be paid more attention.展开更多
文摘-A two-dimensional.nonlinear numerical model is used to study the residual current generated by tides in the East China Sea (ECS)and the South Huanghai Sea (SHS). At first, the principal semidiurnal lunar tide (M2)and the tidal current are derived in these areas. The results obtained with the model are strongly supported by the observational results available. Then, the tide-induced residual flow is determined by using the currents generated by the tidal input. The main features of the residual current in ECS and SHS are presented by analyzing the calculated results. Some of the problems are discussed such as the cause of generating residual current and the contribution of the residual current to the observed current.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest(No.201503108)the National Natural Science Foundation of China(No.21577139)+1 种基金the Science and Technology Service Network Program,CAS(No.KFJ-EWSTS-099)the National Basic Research Program(973)of China(No.2015CB453100)
文摘A simple method for determining 33 pesticides with a wide polarity range（log Kow0.6-4.5） in aquatic products was developed based on LC–MS/MS. The target analytes included three types of widely used pesticides： insecticides, fungicides and herbicides. Based on the optimization of ultrasonic assisted extraction and GPC clean-up procedures, the matrix effect, extraction recoveries and LOD were improved distinctively. LOQ of this method was below 0.5 ng/g for all pesticides, which is superior to values in the literature, and the matrix effect was reduced effectively（-14.7% to 7.5%）. The method was successfully applied to investigate the pesticide residue levels of twenty-five samples including seven common kinds of fishes from Northeast China. The results showed that all targeted pesticides were present in the fish samples; however, their levels were low, except for atrazine, linuron,ethoprophos, tetrachlorvinphos, acetochlor and fenthion. Atrazine and linuron caught our attention because the concentrations of atrazine in fish samples from Liaoning province were in the range of 0.5-8 ng/g（w/w） with mean concentration of 2.3 ng/g, which were far above those of other pesticides. The levels of linuron were in the range of 0.6-6 ng/g（mean concentration 2.8 ng/g）, which were the highest among all targeted pesticides in the Inner Mongolia. This is the first systematic investigation on the characteristics and levels of these pesticides in aquatic products from northeast China. Considering their toxicity and bioaccumulation, the potential risk of atrazine and linuron from consuming aquatic products should be paid more attention.
