fontconfig problem

[yufw]

I copied the Microsoft YaHei font file from my Windows 8.1 partition to ~/.fonts, and I noticed that the system is using YaHei exclusively (menu bar, text editor, web browser, etc) in place of WenQuanYi Micro Hei, the font matching for "Sans" is changing from WenQuanYi Micro Hei to Microsoft YaHei, but I only want to use YaHei in rxvt-unicode.

How can I make YaHei not mess up my desktop but still available when I want to using it?