. . . "2018-02-12 16:53:18.0" . "accepted"@en . "SDN:P07::95SAHUOK" . . "false" . "2018-02-12 16:53:18.0" . "SDN:P07::95SAHUOK" . "surface_radioactivity_content_of_90Sr"@en . "SDN:P07::95SAHUOK" . . "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. \"Sr\" means the element \"strontium\" and \"90Sr\" is the isotope \"strontium-90\" with a half-life of 1.02e+04 days."@en . "1" . . "" . "1" .