这是因为当水银柱跌落, 生长也随之变缓——直到几乎无法测出的程度.That's because as the mercury drops , growth slows the point where it's almost imperceptible.但随着拉丝速度增大,超声振动引起的拉拔力减小变缓.Ultrasonic oscillation also decrease uneven deformation of ...