Preliminary communication Liquid crystalline cardanyl β-D-glucopyranosides

Two novel aryl glycosides were synthesized, which varied in the extent of unsaturation in the lipophilic part, from plant/crop-based renewable resource materials. Their liquid crystalline properties were characterized by optical polarizing microscopy, differential scanning calorimetry and X-ray diffraction. All the mesophases are identified as lamellar in structure.     

PHOTOINDUCED CATALYTIC DECOMPOSITION OF PYRUVIC ACID

Abstract— Electronic and catalytic properties of CuO doped by univalent or trivalent elements were investigated. Doping B or Sb into CuO was found to induce the decarboxylation reaction of pyruvic acid under irradiation with visible light. The decarboxylation reaction is accelerated by raising the temperature. The electronic conductivity of CuO is decreased by increasing the doping concentration of the trivalent element in the low concentration region and increased in the high concentration region. The doping concentration which gives the maximum production of the catalytic decarboxylation is well coincident with the concentration at the minimum electronic conductivity.     

用动态粘弹函数关系表征PMMA/α-MSAN共混物的相分离

测定了聚甲基丙烯酸甲酯／聚（α－甲基苯乙烯丙烯腈）共混物熔体的动态粘弹性．考察动态储能模量Ｇ′与动态损耗模量Ｇ″的关系，发现在终端区域两种聚合物的ｌｇＧ′～ｌｇＧ″关系曲线与温度无关，其外推直线斜率接近２；而其共混物的斜率明显小于２，并随组成变化呈现温度依赖性，由此得到的“临界温度”可用于表征这种具有ＬＣＳＴ行为的共混物的相容性．     

老化对聚(1-三甲基硅基-1-丙炔)气体渗透性能的影响

采用溶液浇铸法,制备了厚度为50~202 μm的聚(1-三甲基硅基-1-丙炔)(PTMSP)膜,研究了膜厚度、储存温度以及储存气氛对其气体渗透性能的影响。 在室温下储存时,PTMSP膜发生物理老化,气体渗透系数先是迅速下降,然后缓慢降低并趋向平稳。 在空气气氛中的下降速率要略大于在N2气气氛中。 气体渗透系数的下降速率随膜厚度的减小而增大。 在高温(100 ℃)空气气氛中,受物理及化学老化的共同作用,PTMSP膜气体渗透系数的下降速率进一步增大,IR谱图表明,聚合物氧化生成了C=O等极性基团。 随储存时间的延长,溶解度系数基本不变,扩散系数的下降是导致气体渗透系数下降的主要原因,这与聚合物体积松弛和(或)致密化及极性基团的形成所造成的自由体积的减小紧密相关。     

FE Formulation of Detonation Important by the Stabilized Galerkin Method

We introduce a finite element formulation of Detonation problems. The detonation involves supersonic combustion waves which emanate from an exothermic chemical reaction occurring behind propagating shock waves. The development of geometrically versatile schemes is required to meet practical needs. The Galerkin/Least-squares method with entropy variables possesses good accuracy and stability properties. As a first attempt to handle chemical reaction model, we use a simple two front model which has a good performance and a flexibility in adapting to the experimental data. It is emphasized that the process of generation and propagation of the shock triple points has been demonstrated.     

聚二苯基乙炔耐溶剂纳滤膜的制备与性能

聚二苯基乙炔(PDPA)不溶于有机溶剂,是理想的新型耐溶剂纳滤膜材料。采用溶液浇铸法制备聚[1-(4-三甲基硅基)苯基-2-苯乙炔](PTMSDPA)均质膜,经脱硅反应得到PDPA膜,研究其乙醇渗透性能和染料截留性能。结果表明,乙醇渗透通量与压力呈正相关性,传质机理可能介于孔流机理和溶解扩散机理之间的过渡区。染料的分子尺寸、电荷性质以及染料和膜之间的相互作用共同影响PDPA膜的截留性能。     

PMMA/α-MSAN共混体系长时弛豫区域的时温叠加失效与相分离的关系

通过考察聚甲基丙烯酸甲酯（PMMA）／聚（α－甲基苯乙烯丙烯腈）（α－MSAN）共混体系动态粘弹函数的时温叠加,发现在终端区域时温叠加失效与其相分离有关。相分离使得终端区域的动态储能模量G″（或动态损耗模量G″）与频率的关系[IgG″（IgG″）～Igω]明显偏离经典粘弹模型。随组成的改变,时温叠加的失效呈现温度依赖性,其“失效温度”（Td)可很好地表征LCST类共混物的相分离,而且在用其表征相分离时,IgG″-Igω法比IgG″-IgG″法更优越。