This study presents the elaboration of a simple and cheap electrode made by carbon paste introduced into a cavity of electrode body, and used for the lead traces determination in tap water. A potentiostatic pre-electr...This study presents the elaboration of a simple and cheap electrode made by carbon paste introduced into a cavity of electrode body, and used for the lead traces determination in tap water. A potentiostatic pre-electrolysis at constant voltage enables the reduction of the lead (Pb2+) and the accumulation of the metallic lead at and into the carbon paste;the reoxidation of the Pb (Linear sweep voltammetry) leads to the anodic striping peak. The effect of the main operating parameters on the shape of the peak and the magnitude of the current was examined and their optimal values were determined. Then calibration was achieved and the method was successfully applied (using all the optimized parameters) to the determination of lead in water, with a detection limit of 0.138 μg·L-1. Compared to other methods (ICP-AES for example), the proposed method offers a satisfactory detection limit of the Pb2+ (0.138 μg·L-1) because of the important specific area of the carbon paste electrode, for a significantly lower cost. Besides, there is no observed loss in the electrode answer in terms of peak current, which means that there is no any irreversible steps nor deactivation of the electrode, even after ten successive measurements;only reduction of the lead followed by the deposit oxidation was observed at the electrode.展开更多
Precisely estimating the state of health(SOH)of lithium-ion batteries is essential for battery management systems(BMS),as it plays a key role in ensuring the safe and reliable operation of battery systems.However,curr...Precisely estimating the state of health(SOH)of lithium-ion batteries is essential for battery management systems(BMS),as it plays a key role in ensuring the safe and reliable operation of battery systems.However,current SOH estimation methods often overlook the valuable temperature information that can effectively characterize battery aging during capacity degradation.Additionally,the Elman neural network,which is commonly employed for SOH estimation,exhibits several drawbacks,including slow training speed,a tendency to become trapped in local minima,and the initialization of weights and thresholds using pseudo-random numbers,leading to unstable model performance.To address these issues,this study addresses the challenge of precise and effective SOH detection by proposing a method for estimating the SOH of lithium-ion batteries based on differential thermal voltammetry(DTV)and an SSA-Elman neural network.Firstly,two health features(HFs)considering temperature factors and battery voltage are extracted fromthe differential thermal voltammetry curves and incremental capacity curves.Next,the Sparrow Search Algorithm(SSA)is employed to optimize the initial weights and thresholds of the Elman neural network,forming the SSA-Elman neural network model.To validate the performance,various neural networks,including the proposed SSA-Elman network,are tested using the Oxford battery aging dataset.The experimental results demonstrate that the method developed in this study achieves superior accuracy and robustness,with a mean absolute error(MAE)of less than 0.9%and a rootmean square error(RMSE)below 1.4%.展开更多
A sensitive method is described for the determination of trace antimony based on the antimony-bromopyrogallol red (BPR) adsorption at a carbon paste electrode (CPE). Three steps were involved in the overall analysis: ...A sensitive method is described for the determination of trace antimony based on the antimony-bromopyrogallol red (BPR) adsorption at a carbon paste electrode (CPE). Three steps were involved in the overall analysis: preconcentration,reduction and stripping. Optimal conditions were found to be an electrode containing 25% paraffin oil and 75% high purity graphite powder as working electrode;a 0.10 mol/L HCl solution containing 40 μmol/L BPR as accumulation medium;a 0.20 mol/L HCl solution as reduction and stripping electrolyte;accumulation time,150 s;reduction potential and time,-0.50 V,60 s;scan range from -0.50 to 0.20 V. Interferences by other ions were studied as well. The detection limit was found to be 0.5 nmol/L for 150 s preconcentration. The linear range was from 1.0 nmol/L to 0.50 μmol/L. Application of the proposed method to the determination of antimony in water and human hair samples gave good results.展开更多
The time course of changes in the levels of extracellular DA/DOPAC in rat striatum during brain ischemia and reperfusion was measured by the method ofin vivo differential normal pulse voltammetry(DNPV).Acute cerebral ...The time course of changes in the levels of extracellular DA/DOPAC in rat striatum during brain ischemia and reperfusion was measured by the method ofin vivo differential normal pulse voltammetry(DNPV).Acute cerebral ischemia of rats was pro- duced by four—vessel occlusion.The effects of(+)MK-801 and schizandrol A on the change of DA/DOPAC were investigated.The results showed that the DA/DOPAC peak in- creased markedly during 6 min of ischemia and,after reperfusion,the peak height decreased gradually.Both(+)-MK-801 and schizandrol A significantly inhibited the DA release after ischemia jn the striatum.展开更多
A novel method was described for the determination of ultra trace amount of scandium based on the cathodic adsorptive voltammetry of the mix-polynuclear complex of scandium-calcium-alizarin red S at a carbon paste ele...A novel method was described for the determination of ultra trace amount of scandium based on the cathodic adsorptive voltammetry of the mix-polynuclear complex of scandium-calcium-alizarin red S at a carbon paste electrode (CPE). The 2nd-order derivative linear scan voltammograms of the adsorbed complex were recorded by model JP-303 polarographic analyzer from 0.0 to -1.0 V (vs. SCE). The experimental conditions of the working procedure were optimized. The results show that the complex can be adsorbed on the surface of the CPE, yielding one peak at -0.61 V, corresponding to the reduction of the alizarin red S in the mix-polynuclear complex at the electrode. The detection limit of Sc^(3+) is 1.0×10^(-10) mol·L^(-1) for 3 min of accumulation time. The procedure was successfully applied to the determination of trace amount of scandium in the sample ores.展开更多
文摘This study presents the elaboration of a simple and cheap electrode made by carbon paste introduced into a cavity of electrode body, and used for the lead traces determination in tap water. A potentiostatic pre-electrolysis at constant voltage enables the reduction of the lead (Pb2+) and the accumulation of the metallic lead at and into the carbon paste;the reoxidation of the Pb (Linear sweep voltammetry) leads to the anodic striping peak. The effect of the main operating parameters on the shape of the peak and the magnitude of the current was examined and their optimal values were determined. Then calibration was achieved and the method was successfully applied (using all the optimized parameters) to the determination of lead in water, with a detection limit of 0.138 μg·L-1. Compared to other methods (ICP-AES for example), the proposed method offers a satisfactory detection limit of the Pb2+ (0.138 μg·L-1) because of the important specific area of the carbon paste electrode, for a significantly lower cost. Besides, there is no observed loss in the electrode answer in terms of peak current, which means that there is no any irreversible steps nor deactivation of the electrode, even after ten successive measurements;only reduction of the lead followed by the deposit oxidation was observed at the electrode.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant(No.51677058).
文摘Precisely estimating the state of health(SOH)of lithium-ion batteries is essential for battery management systems(BMS),as it plays a key role in ensuring the safe and reliable operation of battery systems.However,current SOH estimation methods often overlook the valuable temperature information that can effectively characterize battery aging during capacity degradation.Additionally,the Elman neural network,which is commonly employed for SOH estimation,exhibits several drawbacks,including slow training speed,a tendency to become trapped in local minima,and the initialization of weights and thresholds using pseudo-random numbers,leading to unstable model performance.To address these issues,this study addresses the challenge of precise and effective SOH detection by proposing a method for estimating the SOH of lithium-ion batteries based on differential thermal voltammetry(DTV)and an SSA-Elman neural network.Firstly,two health features(HFs)considering temperature factors and battery voltage are extracted fromthe differential thermal voltammetry curves and incremental capacity curves.Next,the Sparrow Search Algorithm(SSA)is employed to optimize the initial weights and thresholds of the Elman neural network,forming the SSA-Elman neural network model.To validate the performance,various neural networks,including the proposed SSA-Elman network,are tested using the Oxford battery aging dataset.The experimental results demonstrate that the method developed in this study achieves superior accuracy and robustness,with a mean absolute error(MAE)of less than 0.9%and a rootmean square error(RMSE)below 1.4%.
文摘A sensitive method is described for the determination of trace antimony based on the antimony-bromopyrogallol red (BPR) adsorption at a carbon paste electrode (CPE). Three steps were involved in the overall analysis: preconcentration,reduction and stripping. Optimal conditions were found to be an electrode containing 25% paraffin oil and 75% high purity graphite powder as working electrode;a 0.10 mol/L HCl solution containing 40 μmol/L BPR as accumulation medium;a 0.20 mol/L HCl solution as reduction and stripping electrolyte;accumulation time,150 s;reduction potential and time,-0.50 V,60 s;scan range from -0.50 to 0.20 V. Interferences by other ions were studied as well. The detection limit was found to be 0.5 nmol/L for 150 s preconcentration. The linear range was from 1.0 nmol/L to 0.50 μmol/L. Application of the proposed method to the determination of antimony in water and human hair samples gave good results.
文摘The time course of changes in the levels of extracellular DA/DOPAC in rat striatum during brain ischemia and reperfusion was measured by the method ofin vivo differential normal pulse voltammetry(DNPV).Acute cerebral ischemia of rats was pro- duced by four—vessel occlusion.The effects of(+)MK-801 and schizandrol A on the change of DA/DOPAC were investigated.The results showed that the DA/DOPAC peak in- creased markedly during 6 min of ischemia and,after reperfusion,the peak height decreased gradually.Both(+)-MK-801 and schizandrol A significantly inhibited the DA release after ischemia jn the striatum.
文摘A novel method was described for the determination of ultra trace amount of scandium based on the cathodic adsorptive voltammetry of the mix-polynuclear complex of scandium-calcium-alizarin red S at a carbon paste electrode (CPE). The 2nd-order derivative linear scan voltammograms of the adsorbed complex were recorded by model JP-303 polarographic analyzer from 0.0 to -1.0 V (vs. SCE). The experimental conditions of the working procedure were optimized. The results show that the complex can be adsorbed on the surface of the CPE, yielding one peak at -0.61 V, corresponding to the reduction of the alizarin red S in the mix-polynuclear complex at the electrode. The detection limit of Sc^(3+) is 1.0×10^(-10) mol·L^(-1) for 3 min of accumulation time. The procedure was successfully applied to the determination of trace amount of scandium in the sample ores.
