双键结构 meaning in English

DNA duplex

Abstract : the preparation conditions of unsaturated polyester ( up ) resins modified by pet were introduced in this paper . the copolymerization mechanisms of the synthesis of up resins from cis - and trans - anhydride were researched . the relationship between the modified resins activities and the structure of unsaturated acids were also discussed . the reason for the differences of the exothermal curves of the two resin systems was that the activity of the cis - and trans - unsaturated bonds was different from each other
文摘:本文研究了由聚酯改性合成不饱和聚酯树脂的反应机理和工艺条件，讨论了改性树脂反应活性与不饱和酸结构之间的关系，解释了顺、反式双键结构对改性树脂固化放热特性和反应活性不同的原因。