试样的制备通常应经过破碎、过筛、混匀、缩分四个基本步骤。
Initially,fortheAutomaticWorkloadRepository(AWR)statistics,theretentionperiodissetto7days,thecollectionintervalissetto30minutesandthecollectionlevelissettoTypicalinyourproductiondatabase.
YouhavebeenusingtheMemoryAdvisorforthelastthreemonthstogeneraterecommendationsfortuningmemorycomponents.However,whenyouobservetheMemoryAdvisoronaFriday,youfindthatthestatisticsareavailableonlyfortwodays,ThursdayandFriday,ofthatweek.
Whatwouldhavecausedthestatisticstoberemoved?()
化学反应器的空时就是反应物料在反应器内的停留时间,用来表明反应时间长短。
对于连串反应,若目的产物是中间产物,则反应物转化率越高其目的产物的选择性越低。