为研究重庆市区大气能见度变化特征，对2000 ~ 2005年的重庆能见度观测资料进行了统计分析。
Based on statistical analysis of atmospheric visibility observation data from 2000 to 2005 in Chongqing, the characteristics of atmospheric visibility were analyzed.
研究的结果提示提高北京地区大气能见度，需要控制的首要污染物为PM 2.5。
This study suggested the primary pollutant which should be controlled was PM2.5 to increase the visibility in Beijing.
表征大气对视觉影响的物理量是大气能见度，该物理量的具体定义在各种应用领域和研究文献中是比较混乱的。
The physical quantity describing atmospheric effect on vision is visibility. The definitions of visibility have been diverse in different application areas and scientific literatures.
表征大气对视觉影响的物理量是大气能见度，该物理量的具体定义在各种应用领域和研究文献中是比较混乱的。
The physical quantity describing atmospheric effect on vision is visibility. The definitions of visibility have been diverse in different application areas and scientific literatures.
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