Polylactic acid (PLA) is a linear aliphatic polyester produced by poly-condensation of naturally produced lactic acid or by the catalytic ring opening of the lactide group.

聚乳酸(PLA)是一种线性脂肪族聚酯的聚乳酸中自然产生的或由丙交酯开环缩合催化剂组产生。

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The five quinazoline compounds were prepared by using 2 amino 4,5 dimethoxy benzoic acid as original material, which underwent ring closing, halogenation and substitution.

方法：以2 氨基4 ，5 二甲氧基苯甲酸为原料，分别经过环化、氯代、取代等反应，合成了五种目标化合物。

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There are two main methods to synthesis PLA, ring - opening polymerization of lactide and condensation polymerization of lactic acid.

聚乳酸的合成主要有两种方法：丙交酯的开环聚合和乳酸直接缩聚。

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After a few days of preliminary drinking and dancing in costumes that combine the best aspects of traditional Andean horse-riding gear with the most nightmarish aspects of traditional acid trips, the residents of Santo Tomas wake up and head to the local bullfighting ring to beat each other silly.

CNN: Takanakuy: The fighting festival of Peru