Short wave is good for broadcasting verylong distances. The short wave signals bounce off the ionosphere that surrounds the Earth, back to the ground and then back to the ionosphere.
短波有利于长距离传输广播节目，短波信号被围绕地球的电离层反射，能在大地和电离层间来回反射。
2
Comparing with the flux of turbulent exchange of latent heat and the flux of upward long-wave radiation the flux of sensible heat exchange is very small.
与潜热的湍流输送及海表面向上的长波辐射通量相比，感热的湍流输送量很小。
3
Vector acoustic field is a very important part of sound wave, but the vector information of acoustic wave has been unwitnessed for a long time.