开始加热，酚和甲醛(需有酸或碱促使其反应进行)便产生了像紫胶样的液体，能像清漆一样涂于物体表面。
Initial heating of the phenol and formaldehyde (in the presence of an acid or base to get the reaction going) produced a shellac-like liquid good for coating surfaces like a varnish.
发现国产紫胶中，紫胶桐酸C_（9、10）上的二个羟基处于交叉位，用现代光谱学手段证实了前人用化学方法推测的壳脑酸分子结构。
It was found that the two hydroxyl groups on C9,10 of aleuritic acid were in cross position. The molecular structure of shellolic acid was confirmed by modern spectrometry.
本文研究了紫胶树脂在漂白和脱氯过程中分子量、热寿命、酸价、碘价、羟基值和氯含量的变化情况。
The changes of molecular weight, life under heat, acid value, hydroxyl value and chlorine content of lac resin during bleaching and de-chlorinating processes have been studied.
提取过程中不加入任何有机溶剂，不必进行精制作业，可直接获得质量分数大于98%的紫胶桐酸产品。
The fine products with a purity above 98% can be got in the process directly without any kind of organic reagent and refinery process.
提取过程中不加入任何有机溶剂，不必进行精制作业，可直接获得质量分数大于98%的紫胶桐酸产品。
The fine products with a purity above 98% can be got in the process directly without any kind of organic reagent and refinery process.
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