supplementary arc是什么意思

用法例句

The angle measurement on overhead transmission line sags finds a wide use in northwest 750 kV transmission lines thanks to their special features-high altitude and large span.

西北750 kV输电线路特有的高海拔、大档距等设计特点,使角度法测量架线弧垂有了广阔天地,然而地形条件限制、六分裂导线使用和中相V串布置,又大大增加了测量难度和计算强度。