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
- focusing criterion
- focusing cup
- focusing current
- focusing defect
- focusing distance
- focusing electrode
- focusing event theory
- focusing factor
- focusing foil
- focusing geometry
- focusing glass
- focusing glass measuring distance
- focusing hood
- focusing knob
- focusing lens
- focusing magnet
- focusing magnetic field
- focusing magnifier
- focusing method
- focusing mount
- focusing of sound
- focusing on infinity
- focusing optics
- focusing range
- focusing reflector