If you run fmt.Println(\"\\u554a\"), it shows \'啊\'.
fmt.Println(\"\\u554a\")
But how to get unicode-style-string \\u554a from a rune \'啊\' ?
\\u554a
fmt.Printf("\\u%X", '啊')
http://play.golang.org/p/Jh9ns8Qh15
(Upper or lowercase 'x' will control the case of the hex characters)
As hinted at by package fmt's documentation:
%U Unicode format: U+1234; same as "U+%04X"