Kinetics and mechanisms of atmospheric hydrocarbon oxidation and particle formation

每立方厘米的空气中含有数百到10万个直径小于1微米的细小颗粒。这些粒子可以吸收和散射阳光，也可以作为云滴形成的核心。因此，它们在气候中扮演着重要角色；我们对这些颗粒如何形成的不完全知识是全球气候模型中不确定性的一个主要原因。研究还表明，这些颗粒物对人类健康有重大的负面影响。细颗粒主要是通过一种称为气粒转化的过程形成的，在这个过程中，二氧化硫、芳香烃(来自石油产品)和萜烯(由植物排放)等气体发生反应，将它们转化为化合物，如硫酸和含氧有机化合物，形成固体和液体颗粒。

Every cubic centimeter of air contains hundreds to over a hundred thousand fine particles with diameters less than one micrometer. These particles can absorb and scatter sunlight and also act as the nuclei on which cloud droplets form. As a result, they play a major role in climate; our incomplete knowledge of how these particles form is a major cause of uncertainty in global climate models. It has also been demonstrated that these particles have a significant negative impact on human health. Fine particles are largely formed by a process called gas-to-particle conversion in which gases, such as sulfur dioxide, aromatic hydrocarbons (from petroleum products) and terpenes (emitted by plants) undergo reactions that convert them to compounds, such as sulfuric acid and oxygenated organic compounds, that form solid and liquid particles.