substrata
n. 底土,下层土壤地基; 底层,下层( substratum的名词复数 )
A substratum of something is a layer that lies under the surface of another layer, or a feature that is less obvious than other features.
...its deep substratum of chalk...
深厚的白垩地层
His recreation of the city is credible, with a substratum of fact to bolster the fiction.
他对该城历史的再现是可信的,虚构的小说情节隐念着一些事实作为支撑。
There are substrata competition between the heterotrophic denitrification bacteria and ANAMMOX bacteria when organics the influent.
厌氧氨氧化污泥中存在着异养反硝化菌,有机物的存在会导致其与厌氧氨氧化菌之间的基质竞争.