Density
01
密度, 体积密度
(physics) the degree to which a substance is compacted, measured by dividing its mass by its volume
例子
Air has a much lower density compared to water, which is why objects float in water but fall through air.
与水相比，空气的密度要低得多，这就是为什么物体在水中漂浮但在空气中下落。
02
密度, 集中度
the spatial property of having elements packed closely together, typically expressed as the number of units per given area or volume
例子
The forest survey measured tree density at 550 specimens per hectare.
森林调查测量了树木的密度为每公顷550株。
03
the degree to which light is blocked or absorbed by a photographic filter or film, usually measured in stops or optical density units
例子
The technician calibrated the density of the photographic plate.
