【化】 吸收系数; 吸光系数; 光谱吸光系数
【医】 吸收系数, 本生氏吸收系数

[ noun ]
a measure of the rate of decrease in the intensity of electromagnetic radiation (as light) as it passes through a given substance; the fraction of incident radiant energy absorbed per unit mass or thickness of an absorber
<noun.quantity>
absorptance equals 1 minus transmittance