单词D region
na.: 【气】D 区
网络: D层；D域
〔气〕D区(离地球表面25到40英里电离层的最低部份)。
The lowermost mantle layer is above the core mantle boundary (CMB) and composed of D " region and ultra-low velocity zone (ULVZ). "
地幔底层由具有高地震波速和高密度的D″区和超低速带（ULVZ）组成。
Design of Fuzzy Controller for Flight Control with D-region Pole Constraints
飞控系统D域极点配置模糊控制器设计