additional wall layer的用法和样例：
- The microencapsulated linseed oil was prepared by spray encapsulation using porous starch as supporter and zein as wall layer in spin-boiler.
- The micro-encapsulated fish-liver oil was prepared and embed with microporous starch as supporter and zein as wall layer and oleic acid as plasticizer.
- The anther wall layers consist of the epidermis, the one layered endothecium, two middle layers and the tapetum of one layer.
- The inner layer of the wall of a spore.