permagn.清洁金属用粉permn.电烫发v.电烫（头发）permeation property透气性permuted redundancy末端重复循环排列丰余permeability tuning导磁调谐permeability alloys导磁合金permeance resistance防渗工程permeating the plant渗进作物内部permonosulfuric acid过一硫酸permeability of coal煤岩透气性permucosal extention愈合基台permeability barrier透性障