"" . "2018-02-12 16:53:18.0" . "radioactivity_concentration_of_207mPb_in_air"@en . . "SDN:P07::4RELXICV" . . "accepted"@en . "\"Radioactivity\" means the number of radioactive decays of a material per second. \"Radioactivity concentration\" means radioactivity per unit volume of the medium. \"Pb\" means the element \"lead\" and \"207mPb\" is the metastable state of the isotope \"lead-207\" with a half-life of 9.26e-06 days."@en . "false" . "2018-02-12 16:53:18.0" . . "SDN:P07::4RELXICV" . "1" . . "1" . . . "SDN:P07::4RELXICV" .