. "2009-07-06 15:41:29.0" . "Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Terpenes are hydrocarbons, that is, they contain only hydrogen and carbon combined in the general proportions (C5H8)n where n is an integer greater than on equal to one. The term \"terpenes\" is used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names exist for some individual terpene species, e.g., isoprene and limonene."@en . . . . "1" . "false" . . "accepted"@en . "1" . . "SDN:P07::CF12N321" . "mass_concentration_of_terpenes_in_air"@en . "SDN:P07::CF12N321" . "SDN:P07::CF12N321" . "" . . . "2009-07-06 15:41:29.0" .