标志-干井环形槽围阻
Mark I drywell-torus containment
环形形变光栅
toroidally-deformed grating
矩形环形复合感应器
inductor of rectangle-cycle multiplex structure
扭转环环槽
keystone design ring groove
扭转环环槽量规
keystone piston ring groove gauge
端部半填槽槽形
the end half-filled slots shape