. "2018-02-12 16:53:18.0" . "SDN:P07::1HQVJE57" . . "false" . "surface_radioactivity_content_of_121mSn"@en . "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. \"Sn\" means the element \"tin\" and \"121mSn\" is the metastable state of the isotope \"tin-121\" with a half-life of 1.82e+04 days."@en . "" . "1" . "accepted"@en . . "SDN:P07::1HQVJE57" . "1" . "SDN:P07::1HQVJE57" . "2018-02-12 16:53:18.0" . . . .