[目的]以郑州长期肥料试验为平台,研究作物产量和土壤肥力对长期养分缺乏的响应.[方法]试验包括5个处理:①CK(不施化肥和有机肥);②NP(仅施氮磷肥);③NK(仅施氮钾肥);④PK(仅施磷钾肥);⑤NPK(施用氮磷钾肥).[结果]长期不施用氮肥和磷肥导致作物低产,而长期不施钾肥的NP处理与NPK处理并无显著差异,且能...
An active load (12) is provided for an N channel logic network (10). The active load (12) includes a P channel device (28) coupled to the output node (14) of the N channel network (10). A clock circuit (16) of the active load (12) determines whether the N channel network (10...