half-sine wave

例句：

1. 1. The signal is a half-sine wave that changes rapidly.
   信号是一个快速变化的半正弦波。
2. 2. The engineer used a half-sine wave to generate the desired sound.
   工程师使用半正弦波来产生所需的声音。
3. 3. The scientists discovered a new type of half-sine wave that could be used for communication.
   科学家们发现了一种新的半正弦波，可以用来进行通信。