例句與造句

1. In this paper , a new class of concrete high performance water reducer ( hpwr ) was designed from chemical classification of high performance wra , working principle and unit structure model of poly - carboxylate series wra . the comb - like copolymer structure of hpwr was " carboxylic group - ether link - ester link " . the synthetic chemical materials was polyethylene glycil , acrylic acid and methyl - metacrylic acid ester
   本文從高性能減水劑的化學結(jié)構(gòu)、作用機理以及聚羧酸類減水劑的單元結(jié)構(gòu)模型出發(fā)，設(shè)計出國內(nèi)所沒有的一類新型高性能減水劑? ? “羧酸?醚鍵?酯鍵”為單元結(jié)構(gòu)模型的梳型分子結(jié)構(gòu)的減水劑共聚物，并確定了以聚乙二醇( peg )系列、丙烯酸( aa ) 、甲基丙烯酸甲酯( mma )為合成該類減水劑的主要化學原料。
2. It's difficult to find metacrylic acid ester in a sentence. 用metacrylic acid ester造句挺難的