There are many good automatic, semiautomatic, and hand feeding devices available commercially.市场上已有许多优良的自动 、 半自动和手工饲喂装置出售.Manual control or electric control of pressure , time , temperature or semiautomatic control.操作采用手...
A new method for separating and purifying p - AAB ( p - aminoazobenzene ) by dry - column chromatography is developed.提出了一种干柱层析法 分离提纯 试剂对氨基偶氮苯的新方法.The present invention provides membrane separating and purifying process ...