. "SDN:P07::CF12N364" . "mass_fraction_of_ethyne_in_air"@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\". The chemical formula for ethyne is HC2H. Ethyne is the IUPAC name for this species, which is also commonly known as acetylene."@en . "SDN:P07::CF12N364" . . . . . "2019-03-04 17:29:46.0" . . . "2" . . "SDN:P07::CF12N364" . "2019-03-04 17:29:46.0" . . "2" . "false" . "accepted"@en . "" .