emission spectrum
An emission of something such as gas or radiation is the release of it into the atmosphere. [Formal]
The emission of gases such as carbon dioxide should be stabilised at their present level…
二氧化碳等气体的排放应该稳定在当前水平。
Sulfur emissions from steel mills become acid rain.
炼钢厂排放出的硫形成了酸雨。