The hydrogen distribution curve along cross-section of high pressure hydrogen charged spec- imens of 21Cr-7Ni-9Mn-N austenitic steel was obtained quantitatively by IMMA(Ion Microprobe Mass Analyzer).Thus the hydrogen ...The hydrogen distribution curve along cross-section of high pressure hydrogen charged spec- imens of 21Cr-7Ni-9Mn-N austenitic steel was obtained quantitatively by IMMA(Ion Microprobe Mass Analyzer).Thus the hydrogen solubility and diffusivity may be measured, and the hydrogen permeability and other parameters may be calculated indirectly.The hydrogen distribution in specimens either long-term aged in air or in electron beam weld seam after high pressure hydrogen charging was also examined.展开更多
PM（2.5） samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM（2.5） concentrations and annual avera...PM（2.5） samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM（2.5） concentrations and annual average values exceeded the Chinese National Ambient Air Quality Daily and Annual Standards, indicating serious PM（2.5） pollution. The average concentration of water-soluble inorganic ions was 2.4 times higher in heavily polluted days（daily PM32.5 concentrations ＆gt; 250 μg/mand visibility ＆lt; 3 km） than that in other days, with sulfate, nitrate, and ammonium as major ions. According to the ratio of NO-3/SO2-4,stationary sources are still the dominant source of PM（2.5） and vehicle emission could not be ignored. The ratio of secondary organic carbon to organic carbon indicated that photochemical reactivity in heavily polluted days was more intense than in other days.Crustal elements were the most abundant elements, accounting for more than 60% of 23 elements. Chemical Mass Balance results indicated that the contributions of major sources（i.e., nitrate, sulfate, biomass, carbon and refractory material, coal combustion, soil dust,vehicle, and industry） of PM（2.5） were 13%, 16%, 12%, 2%, 14%, 8%, 7%, and 8% in heavily polluted days and 20%, 18%, 9%, 2%, 27%, 14%, 15%, and 9% in other days, respectively.Extensive combustion activities were the main sources of polycyclic aromatic hydrocarbons during the episode（Jan 1-9, 2015） and the total benzo[a]pyrene equivalency concentrations in heavily polluted days present significant health threat. Because of the effect of regional transport, the pollution level of PM（2.5） in the study area was aggravated.展开更多
文摘The hydrogen distribution curve along cross-section of high pressure hydrogen charged spec- imens of 21Cr-7Ni-9Mn-N austenitic steel was obtained quantitatively by IMMA(Ion Microprobe Mass Analyzer).Thus the hydrogen solubility and diffusivity may be measured, and the hydrogen permeability and other parameters may be calculated indirectly.The hydrogen distribution in specimens either long-term aged in air or in electron beam weld seam after high pressure hydrogen charging was also examined.
基金supported by the public welfare projects from MEPPRC (No. 201409010)
文摘PM（2.5） samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM（2.5） concentrations and annual average values exceeded the Chinese National Ambient Air Quality Daily and Annual Standards, indicating serious PM（2.5） pollution. The average concentration of water-soluble inorganic ions was 2.4 times higher in heavily polluted days（daily PM32.5 concentrations ＆gt; 250 μg/mand visibility ＆lt; 3 km） than that in other days, with sulfate, nitrate, and ammonium as major ions. According to the ratio of NO-3/SO2-4,stationary sources are still the dominant source of PM（2.5） and vehicle emission could not be ignored. The ratio of secondary organic carbon to organic carbon indicated that photochemical reactivity in heavily polluted days was more intense than in other days.Crustal elements were the most abundant elements, accounting for more than 60% of 23 elements. Chemical Mass Balance results indicated that the contributions of major sources（i.e., nitrate, sulfate, biomass, carbon and refractory material, coal combustion, soil dust,vehicle, and industry） of PM（2.5） were 13%, 16%, 12%, 2%, 14%, 8%, 7%, and 8% in heavily polluted days and 20%, 18%, 9%, 2%, 27%, 14%, 15%, and 9% in other days, respectively.Extensive combustion activities were the main sources of polycyclic aromatic hydrocarbons during the episode（Jan 1-9, 2015） and the total benzo[a]pyrene equivalency concentrations in heavily polluted days present significant health threat. Because of the effect of regional transport, the pollution level of PM（2.5） in the study area was aggravated.
