Effect of heat treatment on the corrosion of welded low-carbon steel in 0.3 M and 0.5 M of hydrochloric acid and sodium chloride environments at ambient temperature (25oC) has been investigated. Arc welded low-carbon ...Effect of heat treatment on the corrosion of welded low-carbon steel in 0.3 M and 0.5 M of hydrochloric acid and sodium chloride environments at ambient temperature (25oC) has been investigated. Arc welded low-carbon steel sample of known composition were subjected to the corrosion reagents for 21 days (504 hours). pH and weight loss values were taken at interval of 3 days. Thereafter, weight loss method was used to measure therate of corrosion attack on the heat treated samples at ambient temperature. Results obtained showed that at low concentration, the annealed sample exhibits better corrosion characteristic as compared to the normalized and quenched samples. However, at higher concentration the normalized sample exercised better service performance over the annealed and quenched samples. Thequenched sample was found to have relatively low corrosion performance over the annealed and normalized samples at both low and high concentrations of the media.展开更多
Treatment of photosystem Ⅱ particles with NaCl-washings,low-pH washings or detergent OG-solubilizings inhibited oxygen evolution and the inhibition was reversed by addition of exogenous Ca^(2+). Dynamic analysis with...Treatment of photosystem Ⅱ particles with NaCl-washings,low-pH washings or detergent OG-solubilizings inhibited oxygen evolution and the inhibition was reversed by addition of exogenous Ca^(2+). Dynamic analysis with Ca^(2+)reconstitution revealed two Ca^(2+)binding sites with different affinities in the NaCl-washed PS Ⅱ particles or in the low-pH-treated ones.Oxygen-evolving PS Ⅱ core complex also con- tained the high and low affinity Ca^(2+)binding sites.Ca^(2+)enhanced the intensity of fluorescence emission of PS Ⅱ core complex.These results suggest that calcium play two roles in PS Ⅱ,the low affinity Ca^(2+)is associ- ated with energy transfer while the high affinity Ca^(2+)is concerned with water splitting reaction.展开更多
文摘Effect of heat treatment on the corrosion of welded low-carbon steel in 0.3 M and 0.5 M of hydrochloric acid and sodium chloride environments at ambient temperature (25oC) has been investigated. Arc welded low-carbon steel sample of known composition were subjected to the corrosion reagents for 21 days (504 hours). pH and weight loss values were taken at interval of 3 days. Thereafter, weight loss method was used to measure therate of corrosion attack on the heat treated samples at ambient temperature. Results obtained showed that at low concentration, the annealed sample exhibits better corrosion characteristic as compared to the normalized and quenched samples. However, at higher concentration the normalized sample exercised better service performance over the annealed and quenched samples. Thequenched sample was found to have relatively low corrosion performance over the annealed and normalized samples at both low and high concentrations of the media.
基金the National Natural Science Foundation of China
文摘Treatment of photosystem Ⅱ particles with NaCl-washings,low-pH washings or detergent OG-solubilizings inhibited oxygen evolution and the inhibition was reversed by addition of exogenous Ca^(2+). Dynamic analysis with Ca^(2+)reconstitution revealed two Ca^(2+)binding sites with different affinities in the NaCl-washed PS Ⅱ particles or in the low-pH-treated ones.Oxygen-evolving PS Ⅱ core complex also con- tained the high and low affinity Ca^(2+)binding sites.Ca^(2+)enhanced the intensity of fluorescence emission of PS Ⅱ core complex.These results suggest that calcium play two roles in PS Ⅱ,the low affinity Ca^(2+)is associ- ated with energy transfer while the high affinity Ca^(2+)is concerned with water splitting reaction.
