O壳层 O shell

泵壳O型环 casing O-ring ; casingO-ring ; casing Oring

壳体O型密封圈 housing seal o-ring

o羧甲基壳聚糖 0-carboxymethyl chitosan

前壳及O形密封圈 front housing and O-ring

O硫酸酯化壳聚糖 6-O-sulfochitosan