汉字转拼音去掉音标该怎么解决啊？

let transliterator = i18n.Transliterator.getInstance('Any-Latn'); 
let res = transliterator.transform('中国'); 
 
let transliterator2 = i18n.Transliterator.getInstance('Latin-ASCII'); 
let res2 = transliterator2.transform(res);