Cast Mg-6 wt pct Al alloy solution-treated at 683 K for 16 h and aged at 498 K was coated by plasma electrolytic oxidation （PEO） method.The Mg-6 wt pct Al alloy aged for 16 h exhibited the highest microhardness and ...Cast Mg-6 wt pct Al alloy solution-treated at 683 K for 16 h and aged at 498 K was coated by plasma electrolytic oxidation （PEO） method.The Mg-6 wt pct Al alloy aged for 16 h exhibited the highest microhardness and wear resistance.After PEO coating,however,the microhardness and wear resistance of coatings on Mg- 6 wt pct Al alloy showed a tendency to decrease with increasing aging time,which was in aggrement with the change of thickness with aging time.In addition,the coatings on solution-treated Mg-6 wt pct Al alloy had better microhardness and wear resistance than those on aged Mg-6 wt pct Al alloys.Consequently,it can be understood that the aging treatment has a deleterious influence on the mechanical properties of coatings on Mg-6 wt pct Al alloy.展开更多
Food waste treatment plants （FWTPs） are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound （VOC） emissions. This study investigated the VOC emissions...Food waste treatment plants （FWTPs） are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound （VOC） emissions. This study investigated the VOC emissions from a selected full-scale FWTP in China. The feedstock used in this plant was mainly collected from local restaurants. For a year, the FWTP was closely monitored on specific days in each season. Four major indoor treatment units of the plant, including the storage room, sorting/crushing room, hydrothermal hydrolysis unit, and aerobic fermentation unit, were chosen as the monitoring locations. The highest mean concentration of total VOC emissions was observed in the aerobic fermentation unit at 21,748.2-31,283.3 μg/m^3, followed by the hydrothermal hydrolysis unit at 10,798.1-23,144.4 μg/m^3. The detected VOC families included biogenic compounds （oxygenated compounds, hydrocarbons, terpenes, and organosulfur compounds） and abiogenic compounds （aromatic hydrocarbons and halocarbons）. Oxygenated compounds, particularly alcohols, were the most abundant compounds in all samples. With the use of odor index analysis and principal components analysis, the hydrothermal hydrolysis and aerobic fermentation units were clearly distinguished from the pre-treatment units, as characterized by their higher contributions to odorous nuisance. Methanthiol was the dominant odorant in the hydrothermal hydrolysis unit, whereas aldehyde was the dominant odorant in the aerobic fermentation unit. Terpenes, specifically limonene, had the highest level of propylene equivalent concentration during the monitoring periods. This concentration can contribute to the increase in the atmospheric reactivity and ozone formation potential in the surrounding air.展开更多
金属钒具有吸氢量大、抗粉化性能好等优点 ,但是有效吸氢量较低 ,只有一半的氢能够释放出来 ,没有实用价值。在V Ti二元合金的基础上形成的三元合金V Ti M(M代表Cr,Mn ,Fe ,Ni等 )具有良好的贮氢性能。Ti/Cr比对V Ti Cr合金性能影响很大...金属钒具有吸氢量大、抗粉化性能好等优点 ,但是有效吸氢量较低 ,只有一半的氢能够释放出来 ,没有实用价值。在V Ti二元合金的基础上形成的三元合金V Ti M(M代表Cr,Mn ,Fe ,Ni等 )具有良好的贮氢性能。Ti/Cr比对V Ti Cr合金性能影响很大 ,Ti/Cr比值为 0 .75时V Ti Cr合金具有最大的贮氢量和有效吸氢量 ,同时热处理可以有效地提高V Ti Cr合金的有效吸氢量 ,并降低V的使用量。添加Mn的三元合金具有BCC和Laves相双相结构。V Ti Fe合金的贮氢量很高 ,并有希望利用便宜的钒铁做钒源。此外 ,V基固溶体合金还可以用于镍氢电池负极 ,如V Ti Ni合金具有很高的放电容量 。展开更多
文摘Cast Mg-6 wt pct Al alloy solution-treated at 683 K for 16 h and aged at 498 K was coated by plasma electrolytic oxidation （PEO） method.The Mg-6 wt pct Al alloy aged for 16 h exhibited the highest microhardness and wear resistance.After PEO coating,however,the microhardness and wear resistance of coatings on Mg- 6 wt pct Al alloy showed a tendency to decrease with increasing aging time,which was in aggrement with the change of thickness with aging time.In addition,the coatings on solution-treated Mg-6 wt pct Al alloy had better microhardness and wear resistance than those on aged Mg-6 wt pct Al alloys.Consequently,it can be understood that the aging treatment has a deleterious influence on the mechanical properties of coatings on Mg-6 wt pct Al alloy.
基金supported by the Environmental Protection Public Welfare Project (No. 201109035)
文摘Food waste treatment plants （FWTPs） are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound （VOC） emissions. This study investigated the VOC emissions from a selected full-scale FWTP in China. The feedstock used in this plant was mainly collected from local restaurants. For a year, the FWTP was closely monitored on specific days in each season. Four major indoor treatment units of the plant, including the storage room, sorting/crushing room, hydrothermal hydrolysis unit, and aerobic fermentation unit, were chosen as the monitoring locations. The highest mean concentration of total VOC emissions was observed in the aerobic fermentation unit at 21,748.2-31,283.3 μg/m^3, followed by the hydrothermal hydrolysis unit at 10,798.1-23,144.4 μg/m^3. The detected VOC families included biogenic compounds （oxygenated compounds, hydrocarbons, terpenes, and organosulfur compounds） and abiogenic compounds （aromatic hydrocarbons and halocarbons）. Oxygenated compounds, particularly alcohols, were the most abundant compounds in all samples. With the use of odor index analysis and principal components analysis, the hydrothermal hydrolysis and aerobic fermentation units were clearly distinguished from the pre-treatment units, as characterized by their higher contributions to odorous nuisance. Methanthiol was the dominant odorant in the hydrothermal hydrolysis unit, whereas aldehyde was the dominant odorant in the aerobic fermentation unit. Terpenes, specifically limonene, had the highest level of propylene equivalent concentration during the monitoring periods. This concentration can contribute to the increase in the atmospheric reactivity and ozone formation potential in the surrounding air.
文摘金属钒具有吸氢量大、抗粉化性能好等优点 ,但是有效吸氢量较低 ,只有一半的氢能够释放出来 ,没有实用价值。在V Ti二元合金的基础上形成的三元合金V Ti M(M代表Cr,Mn ,Fe ,Ni等 )具有良好的贮氢性能。Ti/Cr比对V Ti Cr合金性能影响很大 ,Ti/Cr比值为 0 .75时V Ti Cr合金具有最大的贮氢量和有效吸氢量 ,同时热处理可以有效地提高V Ti Cr合金的有效吸氢量 ,并降低V的使用量。添加Mn的三元合金具有BCC和Laves相双相结构。V Ti Fe合金的贮氢量很高 ,并有希望利用便宜的钒铁做钒源。此外 ,V基固溶体合金还可以用于镍氢电池负极 ,如V Ti Ni合金具有很高的放电容量 。
