苯酐催化剂表面纹理的表征及表面纹理模型的探讨

大多数实用催化剂均为复杂体系,对其结构和性能进行表征并加以关联是一个重要的问题~[1].表征催化剂可提供化学组成及结构、催化剂纹理及机械性质、催化活性等信息.催化剂纹理是指其几何结构和表面形貌,包括宏观及微观尺度,如颗粒形状、表面积、孔结构、物     

表面氧化外延制备钇系涂层导体隔离层

采用表面氧化外延(SOE)方法, 在金属基底上研制NiO隔离层. 通过研究温度、时间等工艺参数对形成立方织构NiO的影响, 摸索出一套可获得单一、尖锐的立方织构NiO, 重复性好, 适合于长带发展的工艺技术. 同时研究了金属基带的表面状态、织构取向对NiO(100)表面的影响. X射线极图观测可直观地看到单一的立方织构, φ扫描检测其半高宽(FWHM)均为7.5°. 扫描电镜观察NiO(100)膜层表面形貌, 无裂纹且较为致密.     

计算机图象识别辅助菌种筛选及对甾体激素微生物酶反应的研究

将分形理论和计算机图象纹理分析技术移植到微生物发酵研究中，对菌落和菌丝本形态的定量描述了探讨，并利用菌种的分维特征作为筛选高产菌株的直观指标，有效地提高了菌种筛选工作的效率与准确度，探讨了沃氏底物霉菌转化的工艺过程，并以生物全息观念与分形理论为依托，在分形尺度上对生物体形态及其发育过程进行了描述，建立起菌体生长的形态动力学模型，并与生长（浓度）动力学模型相结合，设计出可判别理论最佳投料点的酶活描述     

具有联苯核和悬挂基聚甲亚胺醚的液晶行为

用偏光显微镜、DSC和WAXD对新的主链型聚甲亚胺醚系列的液晶行为进行了表征,发现7种聚合物均显示向错和条带织构,其熔点呈奇偶变化规律.     

某些含二维液晶基元的热致液晶高分子的向列态纹影织构

发现某些含二维液晶基元的热致液晶高分子容易产生反向壁织构与含有高强度向错点(|S|大于1)的向列态纹影织构。这类液晶高分子的织构与形态学特点与含一维棒状液晶基元的其他液晶高分子不同。     

含NLO单元的聚丙二酸酯液晶的电晕极化及稳定性研究

采用针尖电晕极化方式对非线性光学单元与液昌基元交替排列的聚丙二酸酯液晶进行极化取向，通过紫外－可见光谱吸收的变化求出了取向序参数并考察了取向的稳定性，发现极化膜处在高于其玻璃化温度１０℃以上的环境７２ｈ以上，序参数的稳定保留率仍达７５％，并通过偏光显微镜考察极化前后的织构变化，首次直接测定到两类不同侧链在电场极化下取向方向扭转近９０°现象。     

碳氢／碳氟表面活性剂复配体系溶致液晶的研究

以全氟辛酸钠－十六烷基三甲基溴化铵／正丁醇／水体系为研究对象，通过其相图的测定确立了液晶区．其液晶区域面积大于十六烷基三甲基溴化铵／正丁醇／水体系的液晶区．摄制了该体系液晶区系列样品的纹理照片，用小角Ｘ光衍射法测定了液晶各种组分变化时的层间距，并结合２ＨＮＭＲ谱图和纹理照片的对照和分析，从分子水平上研究了液晶的微观结构．     

Mechanisms of hydroxyapatite formation on porous gel-silica substrates

The variables affecting the nucleation and crystallization of biological hydroxy carbonate apatite (HCA) on porous gel-silica substrates are examined. Texture is the critical variable with the rate of HCA formation increasing as pore size and pore volume increase, with pore sizes >2 nm required to achieve rapid kinetics (4–6 days) of fully crystallized HCA. The concentration of silanol groups on the silica surface does not control the rate of HCA formation although metastable surface defects, such as trisiloxane rings, may be involved in HCA nucleation.     

Synthesis and characterization of new thermotropic liquid crystalline polymers with paired mesogens containing azobenzene unit: Poly(malonic ester)s

New thermotropic liquid crystalline poly(malonic ester)s with two symmetrical mesogenic units (paired mesogens) were prepared by the polycondensation of 1,6-dibromohexane and novel malonic ester compounds with different flexible ethyleneoxy spacer lengths linked to azobenzene group. All the prepared malonic esters and the resulting polymers exhibited monotropic liquid crystallinity with a nematic texture. The length of the spacer had influence on the temperature of phase transition of them. A possibility of application of the prepared polymers to reversible optical information storage media was also identified through a trans–cis isomerization of azobenzene by UV irradiation.     

Structure and permeability of gels

The textures of silica gels made by two-step acid/base and acid/acid catalysis of TEOS have been examined by thermoporometry (TPM) and NMR, and their permeabilities (D) have been measured by a thermal expansion technique. Using the pore size distribution given by TPM, which includes a large proportion of macropores (30 nm), calculated values of D are seriously overestimated. We conclude that, consistent with a theoretical prediction, compliant materials such as gels undergo contraction during freezing in the calorimeter, so that most of the macropore volume reported by TPM is actually extracted from mesopores. The mesopore radius reported by TPM is underestimated by only 20%, even if 50% of the pore liquid is drained during crystallization, assuming that the change in pore radius is related to the cube root of the volume change. NMR does not distinguish macropores, because of diffusional averaging, but provides an apparent distribution that permits an accurate estimate of the permeability.