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Based on the detailed characterization , two mechanisms are proposed and evaluated : nonequilibrium nano-dispersed oxides impeding the grain growth due to grain boundary pinning , or grain boundary segregation of magnesium and oxygen reducing the grain boundary energy .
 material: nano-dispersed oxides; concept or principle: grain growth; concept or principle: grain boundary; concept or principle: grain boundary; material: magnesium; material: oxygen; concept or principle: grain boundary energy
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 material: nano-dispersed oxides; concept or principle: grain growth; concept or principle: grain boundary; concept or principle: grain boundary; material: magnesium; material: oxygen; concept or principle: grain boundary energy