If, however, they are subjected instead to pyrolysis-a process of controlled burning in a low-oxygen atmosphere-the result is charcoal, a substance that is mostly elemental carbon.
但如果经过高温分解—在低氧环境下有控制的燃烧—它将会形成木炭，其大部分是永久碳。
2
This tunnel is, in substance, a simple air flow bench with necessary test devices offering various controlled streams for experiments.
这种风洞实质上是一种简单的气流试验台，它通过配套的设备能为实验提供各种可控制的气流。
3
The engineering properties of the weak layer are controlled by the basic substance and environment conditions.