初始浓度的英文：
initial concentration

The initial concentration of aniline in aqueous solution is 200mg/L The flow rate of O3 is 5.0mg/min.
水溶液中苯胺初始浓度200mg/L，O3流量5.0mg/min。

C; and Cs = the initial and final concentrations, respectively
C;和Cs,——分别为初始浓度和终结浓度

marginal initial
边缘原始细胞[见于植物]

The body is initially at rest, and the spring is initially unstretched.
起初物体是静止的，弹簧也未拉长。

embryo initial cell
胚原始细胞

Initially, all went well.
最初，一切顺利。

It is very familiar to the initiate.
这对新加入者是很熟悉的。

concentrate troops at a strategic point
集中兵力于战略重点

Samarium europium gadolinium concentrate
GB/T8751-1988钐铕钆富集物

Ansar Concentration (detention) Camp
安萨尔集中（拘留）营

Industrial development is concentrated in the Northeast.
工业发展集中在东北地区。

It consists of a pair of concentric cylinder.
它由一对同轴的圆筒组成。