It is a difficult point to teach the students solving the wave equation on finite interval by the reflectionlaw of the wave.
用波的反射原理求解有限区间上的波动方程是数学物理方程中的基本内容，也是教学中的难点内容。
2
Methods By using the ultrasound pulse reflectionlaw, the correlation between the process of thrombosis formation and changes in the ultrasonic velocity was studied quantitatively.
方法采用超声脉冲反射法，着重就血栓形成过程中对其声速变化的相关性进行了定量研究。
3
It found that people who perceive their car as a reflection of their self-identity are more likely to behave aggressively on the road and break the law.