理学 3D打印中的几何计算 释 fused deposition modeling; FDM 支撑结构的计算与优化 熔融沉积式打印机（fused deposition modeling，FDM）由于价格低廉、操作简单而具有较高的普及程度。但其最大的缺点是无法直接打印模型中的悬空部位。这时往往需要用户在切片之前给悬空部分添加支撑结构，将支撑结构连同模型一起被打印，并在结束后人为去除。
网络与数据通信 协议体系与组成结构 释文 frequency division multiplexing, FDM 频分多路复用
- A Continuation of Mysteris and Monsters, block-printed edition by Yin's Bookstore in Lin'an, Song Dynasty
- A Continuation of Tongjian gangmu
- A Continuation of Travel Notes, hand-copied edition by Qian Gu (1561), fortieth year of the Jiajing era, Ming Dynasty
- A Contiuation of Painting History and A Supplement to Paintings of the Five Dynasties, block-printed edition by Chen Daoren Bookstore in Lin'an, Song Dynasty
- A-control
- A Cool Fish
- acoptic polyhedron
- A Copying of Wei Yan’s Grazing Painting
- acorite
- acorn cell
- A Corner of the Little Waterfall
- acorn worm
- A Coruña
- acos
- acoumetry
- A countermeasure from Liu Fen
- A county administered by a native officials
- acouphone
- A couple, Yinmaung and Meima
- acoustic
- acoustic absorption of sea water
- acoustic activity
- acoustic admittance
- acoustical
- acoustical absorption coefficient