r(kunkar)

• 印度石灰石

英英释义

名词 r:

1. a unit of radiation exposure; the dose of ionizing radiation that will produce 1 electrostatic unit of electricity in 1 cc of dry air

2. (physics) the universal constant in the gas equation: pressure times volume = R times temperature; equal to 8.3143 joules per kelvin per mole

3. the 18th letter of the Roman alphabet

4. the length of a line segment between the center and circumference of a circle or sphere