[XeTeX] How to prevent Chinese chars to be treated as part of TeX command?

[Akira Kakuto]

> Such errors occur when chinese characters (or any other non-ASCII unicode
> chars) follow a valid command immediately.
> In other words, if there is no space between Chinese characters and a
> command name,
> XeTeX will treat the Chinese characters as part of the command name, so it
> issues an error message.  I do not know whether it is a bug of XeTeX or it
> is intended.

That is not a bug and apparently intentional.

Best,
Akira