Objective:To investigate the appearance of enamel on the cross section of tooth after etched with 37% phosphoric acid for different etching time .

目的：观察用37%磷酸凝胶以不同酸蚀时间处理后的牙釉质在牙齿横断面上的形态改变。

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Meanwhile, the trend of porosity and PL spectrum with changing etching time confirm that it is necessary for improving PL intensity to increase porosity.

同时，孔隙率和光致发光谱随腐蚀时间的变化趋势证实了提高孔隙率是提高多孔硅发光强度的必要条件。

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This method allows better control of the thicknesses of the silicon and glass layers, but the etching is time-consuming and requires the costly sacrifice of a wafer for each one that is made.

ECONOMIST: Chip technology