9Jun-Ichiro H,Sadayoshi A,Haruok,et al.Evaluation of macromolecular structure of a brown coal by means of oxidative degradation in aqueous phase[J].Energy & Fuels(S0887-0624),1999,13:69-76.
10Alvarez R,Clemente C,Gomez-Limon D.The influence of nitric acid oxidation of low rank coal and its impact on coal structure[J].Fuel(S0016-2361),2003,82(15/16/17):2007-2015.
