utf-8 refers to the way the data is encoded for being sent from the host to the client machine. When it arrives at the client it still has to be interpreted by a font that can render it, and in the proper language.
I checked your script in three browsers. Firefox rendered the Chinese correctly, Opera and Chrome did not render them.
If you need a font family that can render in many languages, a good one to start with is the Gentium family. It's free, nice looking, and supports many characters in many languages.