18025
Surface chemical composition and elemental evaluation of calcined nanofibers are examined with X - ray photoelectron spectroscopy ( XPS ) , and optical properties and crystal defect analyses of the calcined nanofibers are conducted with photoluminescence spectra ( PL ) .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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