Study on structure-property relationship of polyimide blends

Summary Three pairs of polyimide/polyimide blends (50/50 wt%) with different molecular structures were prepared by two ways, i.e. mixing of the polyamic acid precursors with subsequent imidization, and direct solution mixing of the polyimides. The blends were studied with DMA technique. The results obtained show that all the blends prepared with these two different ways are miscible, as there existed only one glass transition temperature (Tg) for all the blends. It is suggested that the miscibility of these polyimide/polyimide blends is a result of the strong inter-molecular charge-transfer interaction between the chains of their components.     

油田联合站油水分离的模糊-PID控制

联合站油水分离过程是将高含水原油处理成为合格产品的重要生产过程，从控制理论角度看，此过程具有多变量、干扰因素复杂、非线性、大滞后、压力与界面强耦合的特点，为了实现此过程的自动控制，本文针对典型的两段式脱水工艺进行了理论分析，通过对人工智能控制经验的总结，确定了模糊-PID控制策略。     

纤维素衍生物液晶相转变和织态结构

本文综述了纤维素衍生物液晶态相转变和织态结构。描述了纤维素衍生物从各向同性态向液晶态的转变过程和液晶态的织构特征。讨论了溶液浓度和温度对液晶相织构的影响。探讨了各种因素,如溶剂、取代基含量、外加力场和外加磁场等对液晶相的形成及织态结构的影响。     

Effect of temperature on polymer migration II: Concentration equation

Polymer migration is a generally well-known phenomenon in a flow field, and it has been verified that the sources of such phenomena are nonhomogeneity of the flow, concentration effects and hydrodynamic interactions between the polymer molecules. In addition, temperature effects were found to be another source of polymer migration. The Langevin equation for a polymer molecule was first derived from single chain dynamics using a kinetic theory for the bead-spring elastic harmonic dumbbell model, as described in part I (reference [1]). In this paper the diffusion equation and concentration profile of the polymer molecules induced by a temperature gradient are obtained from the Fokker-Planck equation. A new differential operator is also introduced to calculate the concentration profile. From the concentration equation obtained in the general flow geometry, we find that in dilute polymer solution there are significant effects on the polymer migration not only due to the nonhomogeneity of the flow field but also due to temperature gradients.     

模拟三相流化床中颗粒尺寸对单气泡传质系数的影响

本文在模拟三相流化床中,测量了单气泡的传质系数,实验结果表明颗粒直径对气-液传质系数影响显著。颗粒直径较大时,传质系数有明显提高。     

新型陶瓷刀具材料的研究与开发

工业用钢材的质量提高使材料加工难度增加,耐高温的高硬度高强度陶瓷材料被用做切削刀具并逐渐推广应用。本文对陶瓷刀具的材质、种类、性能特点作了比较和评价,并重点介绍了新型的晶须增韧陶瓷刀具。最后,对陶瓷刀具的市场前景进行了预测,并指出了陶瓷刀具研制方面应该深入研究的课题。     

近十年常温干法精脱硫专利技术发展动态

收集了近十年来国内的常温干法精脱硫专利，并分类列举出各种脱硫剂的物化性质和几种常温精脱硫工艺，重点阐述了该技术的优缺点及其未来发展方向。     

利用煤层气发展山西合成油工业探讨

介绍了国外利用天然气生产油口的生产工艺，探讨了山西省利用丰富的煤层气资源发展合成油的可能性和优势，并提出了相应的发展建议。     

聚丙烯结构壁管专用料的开发

阐述了塑料结构壁管的基本情况和国内外现状．重点就扬子石油化工股份有限公司研究院研制的聚丙烯结构壁管专用料的情况进行了介绍。     

DCS在酸相法氯化聚乙烯生产中的应用

把DCS应用于酸法生产CPE中，描述了DCS的硬件配制，生产中的控制要点及自控方案，在工业化生产中取得了良好效果。