[Objective] The paper aimed to discuss effects of different concentrations of lead stress on Alternanthera philoxeroides growth and physiological indices,to explore phytoremediation methods for removal of lead polluti...[Objective] The paper aimed to discuss effects of different concentrations of lead stress on Alternanthera philoxeroides growth and physiological indices,to explore phytoremediation methods for removal of lead pollution. [Method] A. philoxeroides in water culture was treated with different concentration of lead,and then,its external injury was observed,its growth and physiological indexes were measured. [Result] A. philoxeroides biomass and chlorophyll content decreased; conductivity and malonaldehyde （MDA ） content were increased; the SOD,POD and CAT activities showed a trend of first increase and then decrease with increase in concentration of lead stress. [Conclusion] With increase in lead concentration,the cell membrane permeability increased and MDA had a higher accumulation,antioxidant enzymes activity decreased,the normal oxidative metabolism of A. philoxeroides was severely affected,leading it to wilt.展开更多
To investigate the effects of plateau environments on driving fatigue,heart rate and electroencephalogram(EEG)signals were chosen as indicators to characterize driving fatigue.The study analyzed the variation in these...To investigate the effects of plateau environments on driving fatigue,heart rate and electroencephalogram(EEG)signals were chosen as indicators to characterize driving fatigue.The study analyzed the variation in these indicators as drivers transitioned into fatigued stages.By examining the sample entropy of EEG signals and the heart rate variation coefficient,a complex indicator of driving fatigue(CIDF)was established using principal component analysis to overcome the limitations of single-indicator methods.According to the CIDF values,the driving fatigue states in plateau areas were subdivided into three categories,including alertness,mild fatigue,and severe fatigue,by cluster analysis.Optimal binning determined thresholds for different driving fatigue states,which were validated through variance analysis.The results indicate that the CIDF values effectively distinguish the driving fatigue states of drivers in plateau areas.The CIDF thresholds for the alertness and the mild fatigue states are 0.34 and 0.50,respectively.A CIDF value greater than 0.50 indicates that the driver is in a severe fatigue state.展开更多
基金Supported by National Natural Science Foundation of China(31060031)Youth Foundation of Yunnan University of Nationalities(09QN02)~~
文摘[Objective] The paper aimed to discuss effects of different concentrations of lead stress on Alternanthera philoxeroides growth and physiological indices,to explore phytoremediation methods for removal of lead pollution. [Method] A. philoxeroides in water culture was treated with different concentration of lead,and then,its external injury was observed,its growth and physiological indexes were measured. [Result] A. philoxeroides biomass and chlorophyll content decreased; conductivity and malonaldehyde （MDA ） content were increased; the SOD,POD and CAT activities showed a trend of first increase and then decrease with increase in concentration of lead stress. [Conclusion] With increase in lead concentration,the cell membrane permeability increased and MDA had a higher accumulation,antioxidant enzymes activity decreased,the normal oxidative metabolism of A. philoxeroides was severely affected,leading it to wilt.
基金The National Natural Science Foundation of China(No.51768063,51868068).
文摘To investigate the effects of plateau environments on driving fatigue,heart rate and electroencephalogram(EEG)signals were chosen as indicators to characterize driving fatigue.The study analyzed the variation in these indicators as drivers transitioned into fatigued stages.By examining the sample entropy of EEG signals and the heart rate variation coefficient,a complex indicator of driving fatigue(CIDF)was established using principal component analysis to overcome the limitations of single-indicator methods.According to the CIDF values,the driving fatigue states in plateau areas were subdivided into three categories,including alertness,mild fatigue,and severe fatigue,by cluster analysis.Optimal binning determined thresholds for different driving fatigue states,which were validated through variance analysis.The results indicate that the CIDF values effectively distinguish the driving fatigue states of drivers in plateau areas.The CIDF thresholds for the alertness and the mild fatigue states are 0.34 and 0.50,respectively.A CIDF value greater than 0.50 indicates that the driver is in a severe fatigue state.
