半透性

微胶囊化（Microencapsulation）是指由天然或合成高分子材料包埋微小的固体颗粒、液滴或气体，形成的具有半透性或密封性囊膜粒子的过程。

Microencapsulation is the process of preparing semi-permeable or sealed capsules using natural or synthetic macromolecule materials to embed solid particles , liquid drops or gas .

也称细胞膜，是一层紧贴细胞壁内侧，包围细胞质的柔软、脆弱而有弹性的半透性薄膜。

Cytoplasmic membrane , or cell membrane , plasma membrane , is a soft , fragile and flexible semi-permeable membrane , which underlines cell wall and surrounds cytoplasm .

天然牙和牙科陶瓷半透性的研究

The Study of Translucency of Natural Human Tooth and Dental Ceramics

模拟天然牙的牙科陶瓷，除了颜色的匹配外，还要有与牙体组织相近的半透性。

In order to imitate natural tooth , dental ceramics should have similar translucency besides the color space .

因此，对天然牙半透性的分析和测量以及了解天然牙与牙科陶瓷半透性的关系是十分必要的。

So it is necessary for us to measure and analysis the translucency of natural tooth and relationship between translucency of tooth and dental ceramics .

天然牙的视觉外观除了颜色的三要素色相、明度、饱和度以外，还有许多第二光学特征：半透性、浑浊度、晕色、表面光泽度、荧光性，其中以半透性最为重要。

In addition to value , hue and chroma , there are many subtle secondary optical properties of natural human tooth , such as translucency , opacity , iridescence , surface gloss and fluorescence .

修复体的半透性对美观性能的影响极为重要，有学者提出应在颜色系统三要素的基础上增加对透明度的重视，形成一种新的四要素颜色系统的观点。

Translucency of prosthesis plays a very important role in the esthetics of prosthesis . Some researchers believed that translucency should be added into the three-dimension color system to form a new four-dimension system .

种子半透层是指种子覆盖物中存在具半透性的某层组织，它允许种子内外气体和水分的自由出入，而阻止其他物质的交换。

Seed semi-permeable layer may be defined as the layer of seed coverings to allow water and gas exchange while solution is restricted or prevented .