中古二等韵介音和《切韵》元音数量

The Division Ⅱ Medial and the Amount of Vowels in Middle Chinese

学者们构拟的上古音里，二等韵的声母常常是个带－ｌ－或－ｒ－的复辅音，或者韵母带有某种介音。然而在中古音的构拟中，二等韵一般都没有介音。有相当多的证据证明，上古这类复辅音里面的流音成分到中古时并没有简单地消失，它作为二等韵介音保留到中古时期。如果二等韵存在着某种介音，那么，中古汉语的元音或许是一个七元音的系统。

The division Ⅱ finals in the Archaic Chinese have the consonant clusters with the liquid-l-or-r-, which did not emerge behind the initials in the Middle Chinese phonology systems reconstructed by most schol- ars. A considerable amount of evidences have proved that the liquid did not simply vanish in the Middle Chi- nese, and a certain kind of medial must have remained in the division Ⅱ finals in the Middle Chinese. If the division Ⅱ medial presumably exists, the vowel system in the Midde Chinese should be a seven vowels system.