方向效应

低能重离子注入花生干种子深度-浓度分布的方向效应研究

directional selection

solenoid directional valve

error in bearing (tuning error, directional error)

directional response

down hole deviation drilling (directional drilling)

directional gyroscope【航】;gyrocompass【航】;gyroscopic compass【航】

directional supplementation and drainage

three tower directional antenna