文章综合运用多种源解析技术针对合肥市颗粒物来源进行研究。以化学质量平衡(chemical mass balance,CMB)模型和化学质量平衡嵌套迭代(chemical mass balance-iteration,CMB-Iteration)模型为主解析一次排放源和二次源(包括硫酸盐、硝...文章综合运用多种源解析技术针对合肥市颗粒物来源进行研究。以化学质量平衡(chemical mass balance,CMB)模型和化学质量平衡嵌套迭代(chemical mass balance-iteration,CMB-Iteration)模型为主解析一次排放源和二次源(包括硫酸盐、硝酸盐、二次有机物等,简称“二次源”)对PM2.5的贡献,将排放源清单法和CMB模型结果相结合解析二次粒子前体物排放源的贡献,采用空气质量模型评估区域影响的贡献,按照行业排放清单,综合得到燃煤、工业生产、机动车及其他源类对PM2.5的贡献,并运用正定矩阵因子法(positive matrix factorization,PMF)进行源类识别。研究结果显示:合肥市全年PM2.5中主要组分占比由高到低依次为SO42-、NO3-、有机碳(organic carbon,OC)、NH4+、元素碳(elemental carbon,EC)、Si、Ca、Al、Fe,SO42-占比最高(20.50%),碳组分(OC+EC)次之(19.59%),NO3-居于第3位(16.45%);采样期间PM2.5的全年本地各源类分担率从大到小依次为燃煤尘(21.7%)、二次硫酸盐(18.0%)、二次硝酸盐(16.7%)、城市扬尘(16.6%)、其他(12.6%)、机动车尾气尘(11.0%)、建筑尘(2.3%)、钢铁尘(1.1%,此处仅为钢铁制造工艺排放的贡献)。PM2.5本地来源综合源解析结果显示,机动车尾气尘占比为16.0%、工业生产(指工业锅炉与窑炉、生产工艺过程等排放)为31.0%、燃煤尘(指电厂燃煤、居民散烧等)为21.5%、扬尘(指裸露表面、建筑施工、道路扬尘、土壤风沙等排放)为18.9%、其他(指生物质燃烧、餐饮、农业生产等排放)为12.6%。PMF模型解析结果显示,PM2.5中的二次源(指二次硫酸盐和二次硝酸盐)、燃煤尘、机动车尾气尘及地壳尘等4个因子占比达到了96.3%。展开更多
A parallel embedding overlapped iterative (EOI) algorithm about classicimplicit equations with asymmetric Saul'yev schemes (CIS-EOI) to solve one-dimensional diffusionequations is discussed to improve the properti...A parallel embedding overlapped iterative (EOI) algorithm about classicimplicit equations with asymmetric Saul'yev schemes (CIS-EOI) to solve one-dimensional diffusionequations is discussed to improve the properties of the segment classic implicit iterative (SCII)algorithm. The structure of CIS-EOI method is given and the stability of scheme and convergence ofiteration are proved by matrix method. The property of gradual-approach convergence is alsodiscussed. It has been shown that the convergent rate is faster and the property of gradual-approachconvergence also becomes better with the increasing of the net point in subsystems than with theSCII algorithm. The simulation examples show that the parallel iterative algorithm with a differentinsertion scheme CIS-EOI is more effective.展开更多
文摘文章综合运用多种源解析技术针对合肥市颗粒物来源进行研究。以化学质量平衡(chemical mass balance,CMB)模型和化学质量平衡嵌套迭代(chemical mass balance-iteration,CMB-Iteration)模型为主解析一次排放源和二次源(包括硫酸盐、硝酸盐、二次有机物等,简称“二次源”)对PM2.5的贡献,将排放源清单法和CMB模型结果相结合解析二次粒子前体物排放源的贡献,采用空气质量模型评估区域影响的贡献,按照行业排放清单,综合得到燃煤、工业生产、机动车及其他源类对PM2.5的贡献,并运用正定矩阵因子法(positive matrix factorization,PMF)进行源类识别。研究结果显示:合肥市全年PM2.5中主要组分占比由高到低依次为SO42-、NO3-、有机碳(organic carbon,OC)、NH4+、元素碳(elemental carbon,EC)、Si、Ca、Al、Fe,SO42-占比最高(20.50%),碳组分(OC+EC)次之(19.59%),NO3-居于第3位(16.45%);采样期间PM2.5的全年本地各源类分担率从大到小依次为燃煤尘(21.7%)、二次硫酸盐(18.0%)、二次硝酸盐(16.7%)、城市扬尘(16.6%)、其他(12.6%)、机动车尾气尘(11.0%)、建筑尘(2.3%)、钢铁尘(1.1%,此处仅为钢铁制造工艺排放的贡献)。PM2.5本地来源综合源解析结果显示,机动车尾气尘占比为16.0%、工业生产(指工业锅炉与窑炉、生产工艺过程等排放)为31.0%、燃煤尘(指电厂燃煤、居民散烧等)为21.5%、扬尘(指裸露表面、建筑施工、道路扬尘、土壤风沙等排放)为18.9%、其他(指生物质燃烧、餐饮、农业生产等排放)为12.6%。PMF模型解析结果显示,PM2.5中的二次源(指二次硫酸盐和二次硝酸盐)、燃煤尘、机动车尾气尘及地壳尘等4个因子占比达到了96.3%。
文摘A parallel embedding overlapped iterative (EOI) algorithm about classicimplicit equations with asymmetric Saul'yev schemes (CIS-EOI) to solve one-dimensional diffusionequations is discussed to improve the properties of the segment classic implicit iterative (SCII)algorithm. The structure of CIS-EOI method is given and the stability of scheme and convergence ofiteration are proved by matrix method. The property of gradual-approach convergence is alsodiscussed. It has been shown that the convergent rate is faster and the property of gradual-approachconvergence also becomes better with the increasing of the net point in subsystems than with theSCII algorithm. The simulation examples show that the parallel iterative algorithm with a differentinsertion scheme CIS-EOI is more effective.
