18162
Reduction of fiber diameter from 2 . 8 mu m to ~ 100 nm resulted in simultaneous increases in elastic modulus from 0 . 36 to 48 GPa , true strength from 15 to 1750 MPa , and toughness from 0 . 25 to 605 MPa with the largest increases recorded for the ultrafine nanofibers smaller than 250 nm .
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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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