英语语法分析

That polyacetylene are present in flames has been demonstrated many times.

已多次证实火焰中存在聚乙炔。

For third harmonic generation our result is in good accordance with the experiment of prestine polyacetylene.

对于三次谐波产生系数得到了与实验一致的结果。

Resonance Raman spectra have been reported firstly for soluble polyacetylene prepared by rare-earth catalyst.

报道了用稀土催化体系制备的可溶性聚乙炔的拉曼光谱。