sex ratio

基本解释

And it has to do with climate, it has to do with sex ratio--male to female it has to do with diet, and it has to do with movement.
它与风气有关,也与性别比例有关,男性相对于女性的人数,还与饮食有关,与迁移有关
耶鲁公开课 - 美国内战与重建课程节选

The sex ratio of 15-year-olds in 2005 was not far from the sex ratio at birth in 1990.
ECONOMIST: Gendercide
According to the most recent Washington Post poll, black voters continue to oppose same-sex marriage by a ratio of 55-45, viewing the subject as a religious issue rather than a matter of civil rights.
FORBES: Obama Support Of Gay Marriage An Act Of Political Courage Or Just Catching Up?
It shows the sex ratio at birth, whereas the census shows the ratio for children aged 0-6 (census figures for the sex ratio at birth have not been published).
ECONOMIST: Banyan

性别比
According to the censuses of our country in recent three decades, the sex ratio at birth increased gradually, and in some areas, was in serious imbalance.
我国近年来人口普查资料表明，出生性别比有逐年升高趋势，某些地区已呈现明显失衡状态。
农业科学
性比
In this paper we discussed the reasons for the change in sex ratio from 3 female : 1 male to 5 female : 1 male from the triploid female silkworm which is generated from a tetraploid female silkworm.
解释了过冷却处理诱发的四倍体后代三倍体蚕发生性比从3：1向5：1变化的现象。
生物学
性比
性比率