impermanence        
noun [ U ] uk/ɪmˈpɜː.mə.nəns/ us/ɪmˈpɝː.mə.nəns/
 非永久(性),短暂(性),暂时(性)
the state of not lasting for ever or not lasting for a long time
  the impermanence and fragility of life 生命的无常和脆弱 
 She says that her paintings represent the impermanence of everything.  她说,她的画表达的是万物无常。 
 - More examples
 - Life is often shaped by impermanence and solitude.
 - The impermanence of wood is in contrast to the permanence of stone.
 - A sense of impermanence is contrary to the impulse to improve your environment.