PHn.[化]酸碱度(=Potential Of Hydrogen)abbr.公共卫生(=Public Health)abbr.紫心勋章(=Purple Heart)phthalicadj.[化]邻苯二甲酸的酞酸的.

1. But the interior of the bilayer is not charged and forms a strong barrier against the entrance of any charged material.
   但磷脂双层内部不带电，对外来带电物质的进入是一道很大的障碍。