圆锥圆弧齿轮
conical circular arc gear
板件胀缩
PCB expansion and shrinkage
单片胀缩
the substrate expansion and thecontract of substrales
底片胀缩
the expansion and the contract of film
缩胀构造
pinch-and-swell structure
土壤胀缩
Soil shrinking and swelling
soil shrinkage
土壤胀缩运动
Soil expansion and contraction
expansion and contraction of soil