排序方式: 共有25条查询结果,搜索用时 15 毫秒
21.
22.
简要介绍了同步辐射的原理、装置和特点,综述了它在高分子取向态结晶、熔化、相分离、相转变和银纹产生等高分子研究方面的应用。 相似文献
23.
24.
The physical aging behavior of atactic polystyrene (aPS) films achievedunder different drawing conditions has been studied by optical birefringence and modulatedifferential scanning calorimeter (m.d.s.c.). The results show that on annealing at specifictemperature below glass transition temperatue (T_g), the enthalpy relaxation (△H) and T_gdecrease with increasing of birefringence (△n). On the other hand, the effect of moleculardraw ratio (MDR) is confusing: △H and T_g decrease with increasing of MDR in the earlystage of aging, but the MDR's effect become unobvious with the development of aging.It may be concluded that the ordered domain generated by the drawing below or aboveglass transition temperature will affect the development of physical aging behavior. Theviewpoint of cohesional entanglement is used to account for the above observations. 相似文献
25.