Technique of protection insullac of printed circuit board (PCB) has a strong impact on service life of electronic devices in ships.

制板的三绝缘处理对舰用电子设备的使用寿命有很大的影响,本文主要制板三绝缘漆艺的一些改进。

Services no longer run through to Vietnam, and although two or three JF51s were in service in 1987, complete dieselization is imminent.

这条线路已经不提供去越南的服务，尽管在1987年还有两三台JF51型机车，但全面内燃化马上就会到来。