When the outside diameterofcylinder is infinite, the solution of cylinder problem will be made in infinite medium.
当圆筒外径为无穷大时，便得到无限介质中的筒腔问题的解。
2
While ruffled tapered header general welding in two different nominal diameterofcylinder, make two nominal diameterof different cylinder is an organic whole repeatedly!
而折边锥形封头一般焊接于两公称直径不同的筒体中间，使两公称直径不同的筒体连为一体！
3
This is a cylinder composed solely of carbon atoms, and one of its properties is good electrical conductivity. In effect, nanotubes act as wires a few billionths of a metre in diameter.