密度: density; thickness光学: optics; photology; photics光学密度: optical density (od)光学密度计: optical densitometer内光学密度: internal optical density本底光学密度: background optical density大气光学密度: optical density of atmosphere可变光学密度: variable optical density; varying optical density质量光学密度: mass optical density光学密度计;密度计: desitometer光学密度比较片: density comparison strip显微光学密度计: microphotodensitometer有效光学密度范围: usefulde ityrange声学密度计: acoustic de itometer; acoustic densitometer地图印刷光学密度量测规范: specification for optical densitometric measurements of printed maps放射学密度减低: decreased radiologic density放射学密度增高: increased radiologic density声学密度定量技术: ad acquisition densitometry正常放射学密度: normal radiologic density缩微摄影时检验负像光学密度用测试标板: micrographics-test target of optical density measurement for microfilming negative净(光学)密度: netde ity密度: 1.(密集的程度) density; thickness 火力密度 density of fire; 兵力密度 density of troops; 那个国家的人口密度为每平方英里685人。 the population density of that country is 685 per square mile.2.[物理学] (物体的质量和其体积的比值) density 电流密度 current density; 海水密度 seawater density; 水银的密度比水大得多。 mercury has a much greater density than water.; 密度计 densimeter; densitometer; density gage; density indicator; gravitometer 光学显微密度计: optical microde itometer; optical microdensitometer显微密度计光学: optics of microdensitometry轨密度 道密度: track density