*) In http://node.kg.qq.com/play?s=Lov88GL9jNbX1L9a&g_f=personal right click -> View Page Source
*) Search .m4a, in your case, it's would be a URL to your audio file
*) Pase the URL for .m4a to address bar and it would download
*) Use freeware to convert .m4a to .mp3
BTW:我也曾是学计算数学的:)