理学 数据库系统设计 释 semantic data model 语义数据模型 一种基于高层语义的数据库描述和结构形式，是具有较强的语义功能的模型。
数据库 数据库应用开发 释文 semantic data model 语义数据模型
- frequency response function measurement
- frequency response method
- frequency response of motor system
- frequency response plot
- frequency reuse factor
- frequency scale
- frequency scanning antenna
- frequency selective surfaces
- frequency selectivity
- frequency sensitive starter
- frequency sensitivity
- frequency shift
- frequency-shift keying
- frequency-shift keying, FSK
- frequency-shift keying modulation and demodulation
- frequency shift of scattering light
- frequency shift theorem
- frequency-shift track circuit
- frequency-size distribution
- frequency spectrum
- frequency stability
- frequency stability criterion
- frequency stability measurement
- frequency stabilization
- frequency stabilized laser