6644
As a result , an alumina membrane with a three - dimensionally distributed nanopore structure is formed , which can be used as a general template to fabricate hierarchical micro - / nano - structures .
 Chemical: alumina
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: alumina