StateKeyLaboratoryofPulpingandPaperEngineering;
ResearchDivisionofPlantResourceChemistry;
CollegeofPaperandEnvironmentEngineering;
SouthChinaUniversityofTechnology;
Guangzhou510640;
China.;
StateKeyLaboratoryofOrganicGeochemistry;
InstituteofGeochemistry;
ChineseAcademyofSciences;
Guangzhou510641;
China;