英 [ˌperɪˈɒstrəkəm] 美 [ˌperiˈɑːstrəkəm]
n. 角质层
复数periostraca
The periostracum is a thin organic coating or "skin" which is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among mollusks it is primarily seen in snails and clams, i.
外壳膜；几丁质层
角质层
角质层
表壳层;角质层
表壳层
1) 角质层 ( Periostracum ):为壳最外一层,黑褐色的薄层,易脱落.
... 水牛角（Cornu bubali 蝉蜕（Periostracum Cicadae） (3) 蝉蜕（Periostracum C ...
表壳层
[无脊椎]角质层
Hair furcation because the surface layer (or periostracum) of hair stem has been already damaged.
头发分叉是因为毛干的表层(或角质层)已经损坏。
When the hair periostracum starts breakage, internal at the time that fiber exposed, the hair would become dry.
当头发角质层开始破坏，内部纤维暴露的时候，头发就会变得干燥。
Treating the sample of periostracum cicada with suspension technique, calcium, manganese and zinc were successfully determined by FAAS.
以悬浮液技术处理样品，用火焰原子吸收光谱法成功地测定了蝉蜕中的钙、锰、锌。