non-synchronous       
adjective (also nonsynchronous) uk/ˌnɒnˈsɪŋ.krə.nəs/ us/ˌnɑːnˈsɪŋ.krə.nəs/
 formal非同时的,非同步的 
not happening at the same time or speed
  The use of non-synchronous sound played a major part in the early days of film-making. 非同步声音的使用在早期的电影制作中发挥了重要作用。 
 You can have two windows open on your screen and choose either synchronous or non-synchronous scrolling.
 Compare: asynchronous
 - More examples
 - The outcrops are the result of non-synchronous erosion of the rock.
 - The patient was observed to shake his legs violently in a nonsynchronous fashion.
 - The analysis highlighted the nonsynchronous development of ice cover in this glaciated region.