使推断出

In the three systems, system realizes the crosslinking of PVC bases on the peroxide crosslinking mechanism, the tensile strength of crosslinked PVC has been improved somewhat, the IR spectrum of gel demonstrates that there are characteristic absorption peaks of n-alcohol that belongs to ethanol amine and benzenoid group. From the analysis of gel structure , deduces that the mechanism of crosslinking reaction: under the initiations of peroxide and high temperature, PVC yields macromolecules free radicals, at the same time , styrene"s polymerization and grafting onto PVC takes place, at last the system forms crosslinking structure through coupling between radicals; confirms that triethanol amine can absorb HC1 produced by degradation of PVC, so improves the crosslinking efficiency of peroxide, decreases the HCl"s promotion for PVC"s degradation; deduces that triethanol amine can activate the PVC macromolecules and prolong the free radicals" life-time of PVC macromolecules; the effect to the PVC macromolecule makes styrenes graft reaction easy, and thus improves the crosslinking efficiency.

三种体系中三乙醇胺/过氧化二异丙苯/苯乙烯体系基于过氧化物交联机理实现了聚氯乙烯的交联，聚氯乙烯交联后拉伸强度有一定提高，凝胶红外光谱分析证实了凝胶结构中含有乙醇胺的伯醇基团特征吸收和苯环的特征吸收，由凝胶结构分析，推断出交联反应的机理：聚氯乙烯在过氧化物和热作用下产生大分子自由基，苯乙烯在过氧化物和大分子自由基的作用下发生聚合和接枝反应，最终通过自由基之间的偶合产生交联；证实三乙醇胺可以吸收聚氯乙烯分解产生的HCl，提高了过氧化物的交联效率，消弱了HCl对聚氯乙烯降解的促进作用；推断三乙醇胺可以活化聚氯乙烯大分子并有可能使聚氯乙烯大分子自由基存在的时间得以延长，对聚氯乙烯大分子的作用使苯乙烯的接枝反应易于发生，从而提高了交联效率。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。