secular equilibriumとは 意味・読み方・使い方

名詞

secular equilibrium (複数形 secular equilibria または secular equilibriums)

1. (nuclear physics) The situation of the quantity of a radioisotope remaining constant because it is produced (by decay of a parent isotope) at the same rate that it decays.

   Synonym: radioactive equilibrium

   • 1998, Michael F. L'Annunziata, Handbook of Radioactivity Analysis, Academic Press, page 61,

     In decay schemes of this type, the following three conditions may predominate: (1) secular equilibrium, (2) transient equilibrium, and (3) the state of no equilibrium.

   • 2016, Tobias L. Ross, Frank Roesch, Life sciences: Nuclear medicine diagnosis, Frank Rösch (editor), Nuclear- and Radiochemistry, Volume 2: Modern Applications, Walter de Gruyter, page 443,

     The ${\displaystyle {\ce {^{68}Ge/^{68}Ga}}}$ and the ${\displaystyle {\ce {^{82}Sr/^{82}Rb}}}$ generators represent secular equilibria.

   • 2020, David J. Burdige, Geochemistry of Marine Sediments, Princeton University Press, page 43,

     At the same time, because of differences in the chemistry of the daughter and parent elements involved in such secular equilibria, this parent:daughter ratio may not be equal to 1.