"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. \"Ra\" means the element \"radium\" and \"228Ra\" is the isotope \"radium-228\" with a half-life of 2.45e+03 days."@en .
"2018-02-12 16:53:18.0" .
"SDN:P07::7ZC0ORUD" .
"" .
.
"false" .
"surface_radioactivity_content_of_228Ra"@en .
"2018-02-12 16:53:18.0" .
.
.
"accepted"@en .
.
"SDN:P07::7ZC0ORUD" .
.
"1" .
"1" .
"SDN:P07::7ZC0ORUD" .
.