Annihilation radiation
electromagnetic radiation produced by the coalescence and mutual annihilation of a positron and an electron, each pair forming two photons having a minimum energy of 0.5 million electron volts each.
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- Annihilator
a person or thing that . Mathematics. the set of all linear functionals that map to zero all elements of a given subset of a vector space. Historical Examples She did not care for “eternal card-parties,” and considered the card-table “an annihilator of ideas.” Anna Seward Stapleton Martin It is nature as the annihilator that […]
- Anniston
a city in E Alabama. Contemporary Examples Chris McCary and John Sullivan live in Anniston, Ala., a small city even by Alabama standards. Gay, Southern, and Loving It Constantino Diaz-Duran March 26, 2013 Historical Examples Many thousands greeted the President on his arrival at Anniston. Speeches of Benjamin Harrison Benjamin Harrison Anniston is an important […]
- Anniv.
. anniversary
- Anniversary
the yearly recurrence of the date of a past event: the tenth anniversary of their marriage. the celebration or commemoration of such a date. . returning or recurring each year; annual. pertaining to an anniversary: an anniversary gift. Abbreviation: anniv. Contemporary Examples On the 10th anniversary of the U.S. invasion, see how the war played […]
- Anniversary reaction
a psychological reaction, as depression, occurring at a regularly fixed time and associated with the recollection of an emotionally upsetting past experience, as loss of a loved one.