n the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
词态变化
复数形式:radioactivities
常见例句
1
n a unit of radioactivity equal to the amount of a radioactive isotope that decays at the rate of 37,000,000,000 disintegrations per second s being one more than one hundred
2
n an alliance made up of states that had been Soviet Socialist Republics in the Soviet Union prior to its dissolution in Dec 1991 n a unit of radioactivity equal to the amount of a radioactive isotope that decays at the rate of 37,000,000,000 disintegrations per second
3
a unit of radioactivity equal to the amount of a radioactive isotope that decays at the rate of 37,000,000,000 disintegrations per second n
4
one (with her husband and Henri Becquerel) for research on radioactivity and another for her discovery of radium and polonium (1867-1934)
5
electronic equipment that detects the presence of radio signals or radioactivity
