They are backup files created automatically by Vensim.
Go to the menu tools>options and the "startup" tab to specify where you would like backup files to be created if you don't want them clogging your model directory
My best guess is that the venapp source is using a different character encoding than expected. By default Vensim uses UTF8 but order versions would use the local encoding. Try Models>Convert Charset and then select as the originating encoding Chinese, Simplified and as the output UTF8 to see if that works.