"1" . "1" . . "SDN:P07::2370TTAP" . "" . "accepted"@en . . "SDN:P07::2370TTAP" . . . . "2018-02-12 16:53:18.0" . "false" . "SDN:P07::2370TTAP" . "surface_radioactivity_content_of_93Zr"@en . "2018-02-12 16:53:18.0" . "The surface called \"surface\" means the lower boundary of the atmosphere. \"Content\" indicates a quantity per unit area. \"Radioactivity\" means the number of radioactive decays of a material per second. \"Zr\" means the element \"zirconium\" and \"93Zr\" is the isotope \"zirconium-93\" with a half-life of 3.47e+08 days."@en . .