摘要
为研究高原环境机动车排放颗粒物微观特性,该研究在昆明地区进行试验收集缸内直喷(GDI)汽油机、进气道喷射(PFI)汽油机和柴油机排放颗粒物。通过Matlab软件对透射电子显微镜获得的颗粒图像进行处理,结合图像算法对颗粒团聚体分形维数和初级粒子纳米结构参数进行分析。研究结果表明:高原环境下机动车源排放颗粒物团聚体都呈现出外观不规则且具有分形特征的簇状或链状结构,初级颗粒表面粗糙且近似为球形颗粒;其中PFI汽油机颗粒物分形维数大于GDI汽油机和柴油机颗粒物;GDI汽油机和PFI汽油机颗粒碳晶长度略小于柴油机颗粒物,碳晶曲率大于柴油机颗粒物,而PFI汽油机颗粒物碳晶间距最大。
Experiments were conducted in Kunming to sample particulate matter emitted from gasoline-direct-injection(GDI)engines,port-fuel-injection(PFI)gasoline engines and diesel engines for the purpose of studying the microscopic characteristics of particulate matter emissions from motor vehicles in the plateau environments.Thereby,the particulates'images obtained by transmission electron microscopy(TEM)were processed by means of Matlab software,and the fractal dimension of particulate aggregates and the nano-structure parameters of primary particles were analyzed using image algorithms.The results of the study showed that the particulate aggregates emitted from motor vehicles in the plateau environment displayed irregular and fractal-like cluster or chain structures,and the primary particles surfaces were rough and approximately spherical;the fractal dimension of particulate matter emitted from PFI gasoline engines was greater than that emitted from GDI gasoline engines and diesel engines;carbon crystal length of the particulate matter emitted from GDI gasoline engines and PFI gasoline engines was slightly smaller than that emitted from diesel engines;and carbon crystal curvature was bigger than that emitted from diesel engines,while the carbon crystal spacing of particulate matter emitted from PFI gasoline engines was the largest.
作者
王浩
何超
张健
李加强
马志磊
刘学渊
王珑迪
WANG Hao;HE Chao;ZHANG Jian;LI Jiaqiang;MA Zhilei;LIU Xueyuan;WANG Longdil(School of Mechanics and Transportation,Southwest Forestry University,Kunming 650224,China;Key Lab of Vehicle Environmental Protection and Safety in Plateau Mountain Area of Yunnan High-education Schools,Kunming 650224,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2023年第7期95-101,共7页
Environmental Science & Technology
基金
国家自然科学基金(51968065)
云南省高层次人才支持计划项目(YNWR-QNBJ-2018-066,YNQR-CYRC-2019-001)。
关键词
高原环境
机动车
颗粒物
微观特性
分形维数
纳米结构
plateau environment
motor vehicles
particulate matter
microscopic properties
fractal dimension
nano-structure
