dark period meaning in Chinese

熄光时间
阴影周期

If the dark period was too short, the photochemical system was not completely regenerated .
如果暗周期太短，光化学系统不能完全再生。
The daily nation , kenya ' s biggest newspaper , reckons that it has been the country ' s darkest period since independence in 1963
肯尼亚最大的报纸《每日国家报》主张，这段时期是自1963年独立以来最黑暗的时期。
On january 8 , 1984 i stood before a congregation of the small church which i had founded and made an announcement which was the darkest period of my life
年十二月，我站在会众面前，这教会是我一手创立的。我正经历人生最黑暗的时期，那一天是这段时间里最黑暗的日子。