通过自蔓延燃烧法制备Sm掺杂的CeO2基材料,研究前驱粉体进行不同低温烧结热处理及改变压强对Ce0.9 Sm0.1 O2-δ(SDC)电解质电学性能的影响,并分别用X射线衍射、扫描电子显微镜和交流阻抗谱研究不同控制变量下样品的相组成、微观结构和SDC电解质的电学性能.结果表明,当烧结温度升高时,S D C样品的平均粒径...
In order to study the atmospheric PM2.5 pollution characteristics and sources in winter and spring in Changchun City, environmental samples were successively collected from 2018-01-06—2018-05-14, we analyzed inorganic elements and water-soluble anions in PM2.5. The results show that the average mass concentration of PM2.5 in Changchun City during the sampling period is (46.4±24.4) μg/m3, and the average mass concentration in winter and spring is (51.0±25.8) μg/m3 and (32.6±11.5) μg/m3, respectively. The rate of exceeding the standard is 11%, all of them occur in winter. The mass concentration of PM2.5 is low and remains stable during the Spring Festival(2018-02-15—2018-02-21). The mass concentration of all water-soluble anions and some inorganic elements (Al,As,Pb,Se and Ti) are higher in winter than that of in spring. The inorganic elements mainly come from coal combustion, traffic pollution and fugitive dust. The NO-3 and SO2-4 in PM2.5 are the result of the combined action of vehicle exhaust and coal combustion, and the latter plays a more important role. The main sources of PM2.5 in winter and spring are secondary aerosol (28.2%), soil dust (12.6%), traffic emissions (10.7%), coal combustion and industrial dust (28.6%), industrial dust and others (19.8%).