Since thick disks in SO galaxies were originally detected in 1979,thick-disk compo- nents have been discovered in many disk galaxies,and there are more and more observational evidences that the thick disk in an external galaxy should be a component of the galaxy which is structurally,chemically and kinematically distinct from the thin disk of the galaxy.
自1979年以来,越来越多的观测证据表明,在许多盘状星系中普遍存在厚盘成分,它们在结构、化学组成和运动学等方面与薄盘有着明显的不同。
The existence of thick disk in our Galaxy was first revealed by observations in 1980 s, but how it forms is still unresolved.
自20世纪80年代开始的观测表明,银河系存在厚盘结构,但其形成机制至今还是一个没有解决的问题。
A historic progress on recent studies of whether there is a possible age-metallicity relation of stars in the Galactic disk, especially in the Galactic thick disk, is reviewed in some details.
对太阳邻域内银河系盘星、特别是厚盘恒星年龄-金属度关系的研究进展作了较为详细的回顾和评述；说明目前对盘星是否确实存在年龄-金属度关系还存在争议，而厚盘恒星可能存在这种关系。
With the natural logarithm applied to the division of layers of thickness,the division of deformation resistance parameters is carried out according to different layers of thickness to solve the self-learning of rolling force.
模型通过自然对数法进行厚度族的划分,并将用于轧制力自学习的变形抗力参数按照不同的厚度族进行区分,最后模型采用了指数平滑法对各个厚度族内的变形抗力参数进行处理。
Placental acreage.
本文测定了长大二元母猪共 83胎次的胎盘效率 ,胎盘面积 ,胎盘厚度与窝均总产仔数之间的关系。