"2019-03-04 17:29:46.0" . . . "2" . . "false" . . . "mass_fraction_of_nitrate_radical_in_air"@en . "2019-03-04 17:29:46.0" . "SDN:P07::CF12N398" . "SDN:P07::CF12N398" . "2" . "accepted"@en . "" . . "\"Mass fraction\" is used in the construction \"mass_fraction_of_X_in_Y\", where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). A chemical or biological species denoted by X may be described by a single term such as \"nitrogen\" or a phrase such as \"nox_expressed_as_nitrogen\". In chemistry, a \"radical\" is a highly reactive, and therefore short lived, species."@en . "SDN:P07::CF12N398" . . .