中文摘要：

利用同步辐射宽角X射线衍射原位研究了淬冷得到的中间相和由其被拉伸得到的取向中间相在升温和等温退火下向晶体的转变过程.实验结果表明,虽然两者开始相转变形成晶体的温度是相同的,但发生大量相转变所需的温度,取向的中间相要明显高于淬冷直接得到的中间相,这说明前者具有更高的稳定性.通过对比两种不同中间相的初始结构,发现取向后的中间相在沿拉伸方向31螺旋结构具有更大的长程有序,从而导致了其具有更高的熔点.

英文摘要：

The phase transition of quench-induced mesophase and deformed mesophase which was prepared by stretching the quench-induced mesophase during heating and isothermal annealing process was studied by in situ synchrotron radiation WAXD.The results show that though the temperature at which the phase transition of the two mesophase taken place is same,the temperature at which the phase transition has a slope increase is higher with deformed mesophase than quench-induced mesophase,and it indicates that the former one is much more stable.It is found that the regular conformation of 31 helices along stretching direction has a larger long-range order in deformed mesophase.That reason is used to explain why the deformed mesophase has a higher melt point.