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Trade Accounts and Bills Receivable, net (Details) - USD ($)
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Trade Accounts and Bills Receivable, net [Abstract]      
Trade accounts receivable $ 19,054,863 $ 42,095,211  
Less: Allowance for doubtful accounts (3,657,173) (3,700,922) $ (2,761,144)
Trade accounts receivable, net 15,397,690 38,394,289  
Bills receivable 6,353,342 19,124,323  
Trade accounts and bills receivable, net $ 21,751,032 $ 57,518,612