| 释义 |
specific activity
specific activity[spə′sif·ik ak′tiv·əd·ē] (nucleonics) The activity of a radioisotope of an element per unit weight of element present in the sample. The activity per unit mass of a pure radionuclide. The activity per unit weight of a sample of radioactive material. In these three cases, specific activity can be expressed in such units as millicuries per gram, disintegrations per second per milligram, or counts per minute per milligram. specific activity
spe·cif·ic ac·tiv·i·ty1. radioactivity per unit mass of the stated element or compound; 2. for an enzyme, the amount of substrate consumed (or product formed) in a given time under given conditions per milligram of protein; 3. activity per unit mass of the stated radionuclide. spe·cif·ic ac·tiv·i·ty (spĕ-sif'ik ak-tiv'i-tē) 1. Radioactivity per unit mass of the stated element or compound. 2. For an enzyme, the amount of substrate consumed (or product formed) in a given time under given conditions per milligram of protein. 3. Activity per unit mass of the stated radionuclide. |