2,3-二氯对苯二酚酯类负性液晶的合成和性能研究

设计合成了新的负性液晶双—(对烷基苯甲酸)—2,3—二氯—1,4—苯二酚酯类化合物,其结构为这里R·CH_3,C_2H_3,n—C_4H_9和n—C_7H_(15).合成了相应的一些中间体,测定了液晶的相变温度和相态,通过磁场法,测定了R=CH2的介电各向异性.     

利用聚丙烯腈废料研制“八○”建筑涂料

讨论了利用聚丙烯腈废料生产建筑涂料的理论依据、制作方法、助剂的选择、技术性能和经济效果。     

带EBBA液晶的F—P腔的光学双稳态和多级双稳态

应用带EBBA液晶薄膜的F-P腔,激光感应折射率变化所提供二种竞争机制显示出光学双稳态和多级双稳态。从理论上分析了在液晶中由于激光感生热效应所产生的折射率变化。实验时采用了连续A~+激光器和EBBA液晶薄膜。     

梳型高分子聚合物液晶的相变

利用Freiser关于液晶分子相互作用模型,建立了梳型高聚物分子的哈密顿量,适用变分程序导出高聚物液晶结合相序参数自洽方程,得到在给定分子结构参数时的各向同性相至单轴向列相以及单轴至双轴向列相的相变。结果表明,当分子主、侧链间隔基团的耦合项中排斥作用以及结合相中较强向列相场者强度增大时,单轴至双轴向列相相变温度升高,并从一级相变逐渐变为二级相变。     

氯化锂对沉析法成形腈纶浆粕的影响

研究了在腈纶浆液中加入氯化锂对沉析法成形腈纶浆粕的影响。用旋转式黏度计测定了含有不同氯化锂质量分数的腈纶浆洼的黏度，并对不同浆液沉析成形的腈纶浆粕进行了表面形貌及比表面积的表征。结果表明，加入质量分数2％的氯化锂可有效地降低腈纶浆液的黏度，降低幅度达到原来未添加氯化锂浆液黏度的80%以上，有利于得到更均匀更细的PAN浆粕，且浆粕的比表面积提高到原来的2倍左右。     

The influence of clusters in the melt of Fe80Si10B10 alloy on the subsequent glass-formation

The structure of Fe80Si10B10 alloy melt was investigated by ab initio molecular dynamic simulation from the local atomic environments. It presents that Fe80Si10B10 alloy can be considered as the combination of B-centered prism-like clusters and bcc-like Fe-Si solid solution. The poor glass-forming ability of the alloy has been investigated and can be attributed to the bcc-like environment around Si atoms and the relative high content of pure Fe clusters.     

Numerical analysis of the two-phase pressure drop and liquid distribution in single-screw expander prototype

In this paper, the numerical simulations have been carried out to evaluate the two-phase pressure drop and liquid distribution in screw channel. The numerical models are validated against the present experimental data with statistical accuracy. The effects of pitch circle diameter （PCD）, inlet velocity and inlet sectional liquid holdup on the pressure drop and liquid distribution characteristics in the screw channel are illustrated. It is found that decreasing the PCD and increasing the inlet sectional liquid holdup can increase the liquid holdup on the outer side in screw channel. The PCD and the inlet sectional liquid holdup need to be considered in evaluating the two-phase frictional pressure drop per unit length in the screw channel. The PCD has an effect on the development of the average pressure in the various cross sections, and the inlet sectional liquid holdup has no visible impact on the changing process of the pressure drop in the screw channel. The correlation developed predicts the two-phase frictional pressure drop in the screw channel with great statistical accuracy.