准稳旋涡结构zhǔn wěn xuán wō jié gòuzhunwenxuanwojiegouquasi-stationary spiral structure QSSS (astrophysics)Characters in this word准standard, accurate旋to revolve, to orbit, to return构to compose, to make涡eddy, swirl, whirlpool稳steady, stable结knot, tieStudy it in Yanamino