pH is a measure of the hydrogen ion activity in a solution,which is a function of temperature.Under normal seawater conditions,it is well constrained.Nowadays,with an increasing interest in complex environments(e.g.,s...pH is a measure of the hydrogen ion activity in a solution,which is a function of temperature.Under normal seawater conditions,it is well constrained.Nowadays,with an increasing interest in complex environments(e.g.,sea ice),a better understanding of the temperature change on pH under extreme conditions is needed.The objective of this paper was to investigate the temperature coefficient of the seawater pH(△pH/△T)over a wide range of temperature,pH,dissolved inorganic carbon(DIC)and salinity by a method of continuous pH measurement with the temperature change,and to verify the application of CO2SYS for pH conversion under extreme conditions(on the National Bureau of Standards(NBS)scale and the total proton scale).Both experimental results and CO2SYS calculations showed that△pH/△T was slightly affected by temperature over the range of 0℃ to 40℃ and by pH(at 25℃)from 7.8 to 8.5.However,when pH was out of this range,△pH/△T varied greatly with pH value.According to the experimental results,changes in DIC from 1 mmol/kg to 5 mmol/kg and salinity from 20 to 105 had no significant effect on△pH/△T.CO2SYS calculations showed a slight increase in△pH/△T with DIC on both the NBS scale and the total proton scale;and underestimated△pH/△T at high salinity(i.e.,beyond the oceanographic range)on the NBS scale.Nevertheless,CO2SYS is still suitable for pH conversion even under extreme conditions by simply setting the input values of DIC and salinity in CO2SYS within the oceanographic range(e.g.,DIC=2 mmol/kg and S=35).展开更多
A new approach named“caterpillar melt method”was developed to prepare wire type antimony oxide electrode for pH measurement in agar medium for tissue culture.A micro antimony wire was prepared from melt of the metal...A new approach named“caterpillar melt method”was developed to prepare wire type antimony oxide electrode for pH measurement in agar medium for tissue culture.A micro antimony wire was prepared from melt of the metal with the help of a glass capillary and the surface of the wire was oxidized in nitrate melt to obtain an antimony oxide electrode. Characterization results showed that the oxide layer is dense and uniform,with high physical and chemical stability.The electrode has a fast and stable response toward pH change for aqueous solutions.The potential of the antimony electrode has a linear relationship with the pH of the solution (R^2=1.00) with a sensitivity of 54.1mV/pH.The electrode works well and is more stable in agar medium during tissue culture for pH monitoring.展开更多
基金The National Natural Science Foundation of China under contract No.41806094the Young Scholars Program of Shandong University under contract No.2018WLJH43。
文摘pH is a measure of the hydrogen ion activity in a solution,which is a function of temperature.Under normal seawater conditions,it is well constrained.Nowadays,with an increasing interest in complex environments(e.g.,sea ice),a better understanding of the temperature change on pH under extreme conditions is needed.The objective of this paper was to investigate the temperature coefficient of the seawater pH(△pH/△T)over a wide range of temperature,pH,dissolved inorganic carbon(DIC)and salinity by a method of continuous pH measurement with the temperature change,and to verify the application of CO2SYS for pH conversion under extreme conditions(on the National Bureau of Standards(NBS)scale and the total proton scale).Both experimental results and CO2SYS calculations showed that△pH/△T was slightly affected by temperature over the range of 0℃ to 40℃ and by pH(at 25℃)from 7.8 to 8.5.However,when pH was out of this range,△pH/△T varied greatly with pH value.According to the experimental results,changes in DIC from 1 mmol/kg to 5 mmol/kg and salinity from 20 to 105 had no significant effect on△pH/△T.CO2SYS calculations showed a slight increase in△pH/△T with DIC on both the NBS scale and the total proton scale;and underestimated△pH/△T at high salinity(i.e.,beyond the oceanographic range)on the NBS scale.Nevertheless,CO2SYS is still suitable for pH conversion even under extreme conditions by simply setting the input values of DIC and salinity in CO2SYS within the oceanographic range(e.g.,DIC=2 mmol/kg and S=35).
基金This project is sponsored by the Scientific Research Foundation for the Returned 0verseas Chinese Scholars；State EducationMinistry；the Zhejiang Natural Science Foundation under Grant No. Y404325.
文摘A new approach named“caterpillar melt method”was developed to prepare wire type antimony oxide electrode for pH measurement in agar medium for tissue culture.A micro antimony wire was prepared from melt of the metal with the help of a glass capillary and the surface of the wire was oxidized in nitrate melt to obtain an antimony oxide electrode. Characterization results showed that the oxide layer is dense and uniform,with high physical and chemical stability.The electrode has a fast and stable response toward pH change for aqueous solutions.The potential of the antimony electrode has a linear relationship with the pH of the solution (R^2=1.00) with a sensitivity of 54.1mV/pH.The electrode works well and is more stable in agar medium during tissue culture for pH monitoring.
