refinement  
noun uk/rɪˈfaɪn.mənt/ us/rɪˈfaɪn.mənt/
  (CHANGE)         
  [ U ]提炼;提纯;精炼 
the process of making a substance pure
  The refinement of raw opium yields other drugs, such as morphine. 生鸦片经过提炼产生其他药物,如吗啡。 
  [ C or U ](精细的)改进,完善 
a small change that improves something
  These refinements have increased the machine's accuracy by 25 percent. 经过这些改进,机器的准确率提高了25%。 
 Clearly, the hypothesis does need some refinement, in the light of these surprising results. 很显然,从这些令人惊讶的结果来看,该假设确实需要进一步完善。 
   (POLITENESS)      
 [ U ]文雅;高雅;有教养 
a quality of politeness and education
  She's the personification of culture and refinement. 她是文化与教养的化身。