The queue service model of anti-aircraft gun missile system is established on the base of queue theory and air defense theory.

防空兵力弹炮结合系统排队服务系统模型，基于排队论和防空作战理论建立。

youdao

The barrel liquid-cooling technology is widely used in ground-based air-defense and anti-missile small-caliber automatic gun and ship-borne medium or small caliber guns.

身管液冷技术在陆基防空反导小口径自动炮和舰载中、小口径火炮中被广泛采用，研究身管液冷状态下的温度分布对于火炮发射安全性和武器效能具有重要意义。

youdao

He added that gun-carrying pilots, federal air marshals and airline crew members trained in self-defense provided security to protect against the misuse of the newly added items.

WSJ: NY Senator opposes plan to allow knives on planes

The presence on flights of gun-carrying pilots traveling as passengers, federal air marshals and airline crew members trained in self-defense provide additional layers of security to protect against misuse of the items, he said.

NPR: TSA To Allow Small Knives, Bats, Clubs On Planes