9104
K - edge X - ray absorption ( XAS ) , emission ( XES ) , and photoelectron ( XPS ) spectra of nitrogen doped along graphene edges are systematically investigated by using first - principles methods .
 Chemical: nitrogen; Chemical: graphene
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: nitrogen; Chemical: graphene