air-circulationCOCA²⁸⁰¹³⁶⁺⁵ 基本例句 建空气循环；空气环流 Firstly, the experimental conditions of dynamic headspace air-circulation collection method were optimized, screening the PVC pipe made in USA is suitable to collect trace volatiles; 首先优化了动态顶空采样法采集痕量植物挥发物的实验条件，筛选出美国产食品级聚氯乙烯管 PVC符合沙棘挥发物的采集； fabiao