photographic negative

基本解释

An apparatus for measuring the optical density of a material, such as a photographic negative.
比如人口密度就是指单位面积的人口数量。
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The fish collagen has special application in the photographic negative, the biological material and food industry.
鱼胶原蛋白在照相底片，生物材料和食品行业有特殊的应用。
The book bears the same relations to the traditional texts as a photographic negative does to a print:the areas of darkness and light have been reversed.
本书与那些传统历史书籍的关系犹如照相底片与相片的关系，暗区与亮区被颠倒了过来。