It begins with Maarten Schmidt who hypothesized that star formation rate (SFR) was related to the surface density of atomic hydrogen gas in the cloud.
最早是MaartenSchmidt猜测恒星形成率(SFR)与云层中氢原子气体密度有关。
The surface density of galaxies in a cluster can be measured from photographs.
一个星系团中星系的表面密度可从其照片上测得。
The surface density of cracks increases with the increasing of the degree of pre-damage.
随着预损伤程度的增加，裂纹面密度增大。
Objective: To explore the post-operative change of blood flow and surface density of vascular network of the pure venous flap.
目的：观测纯静脉皮瓣术后血流量和血管网面密度变化。
Objective: To explore the post-operative change of blood flow and surface density of vascular network of the pure venous flap.
目的：观测纯静脉皮瓣术后血流量和血管网面密度变化。
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