Only the simpleaperture sublingual gland is observed. Its shape is horseshoes, and the colour is amber.
舌下腺只有单口舌下腺，呈马蹄铁状，淡黄色。
2
The structure design and calculation and application of the aperture restrictor with simple structure, easy assembly and reliable usage are introduced.
本文介绍了一种结构简单、安装方便、使用可靠的缝隙节流器的结构、设计计算及应用。
3
The aperture field distribution of the ring focus antenna is reviewed in view of the energy conservation law, and the simple formula for calculating its radiation pattern is deduced.