The phrase "a dark phase of" is correct and usable in written English.
It can be used to describe a difficult or troubling period in someone's life or in a particular situation.
Example: "After the loss of her job, she entered a dark phase of uncertainty and despair."
Alternatives: "a troubling period of" or "a difficult time in".
Perhaps we're experiencing a dark phase of social with hyper-relevant targeting, and algorithms adjusted for maximum monetization changing our relationship with social media.
The anti-communist McCarthyism of the 1950s, a dark phase of cultural censorship, had cowed many artists, and led them to vacate the political arena.
This series of experiments was timed so that the introduction of culture into the media took place at the start of a dark phase of the 12∶12h dark∶light-adapted C. watsonii culture.
In the specimen produced with a lower arc current and lower dilution a protective layer of Si O is formed, while in the specimen produced with a higher current two layers could be identified: an external one of Fe2O3, with small features of Fe3O4 and NiFe2O4 spinel rich phases, and an internal one of Fe3O4 with small amount of a dark phase evenly distributed rich in silicon, nickel and iron.
The diameter of a region with a dark phase contrast coincides with the size of central elastic compression zone [16] for two non-worn steel balls.
At the beginning of a dark phase, three chicks were placed underneath each female in a nest box and then each box was shut up for the night.
Levels of phosphorylation reached a peak during the dark phase of the daily cycle when mice were active (feeding), and dropped low during the middle of the light part of the daily cycle, when mice slept/rested (fasting), supporting the previously published observations on the regulation of mTORC1 by feeding.
There was a significant effect of genotype observed during the dark phase of a normal L∶D cycle with KO mice exhibiting greater activity [F 1,34) = 5.1, P<0.05].
The experiments were conducted during the dark phase of a light dark cycle in a quiet room with homogenous illumination (2 4 lx) directed towards the apparatus [ 17].
Matings were conducted during the dark phase of a 10 14 hour reversed light:dark cycle, under a red light.
Since the condition in which FAA is investigated during the dark phase of a LD condition is missing in our study, we cannot conclude whether the FAA deficit is independent of light.
