条带织构装饰技术观察含T─型液晶基元的热致性聚芳酯液晶态的向错

采用条带织构装饰新技术研究了含Ｔ─型液晶基元的热致性聚芳酯液晶态的向错形态．经过培养的液晶样品无需剪切，淬火后便可呈现出围绕向错点取向排列的条带织构，而条带织构长轴的垂直方向正代表了液晶基元的指向矢方向，这样，在普通偏光显微镜下就能直接观察到这些条带织构装饰的强度Ｓ＝±１／２和Ｓ＝±１的向错，并观察到Ｓ＝－３／２的高强度向错和闭环状的反转壁．     

条带织构装饰技术观察含T─型液晶基元的热致性聚芳酯液晶态的向错

采用条带织构装饰新技术研究了含Ｔ─型液晶基元的热致性聚芳酯液晶态的向错形态．经过培养的液晶样品无需剪切，淬火后便可呈现出围绕向错点取向排列的条带织构，而条带织构长轴的垂直方向正代表了液晶基元的指向矢方向，这样，在普通偏光显微镜下就能直接观察到这些条带织构装饰的强度Ｓ＝±１／２和Ｓ＝±１的向错，并观察到Ｓ＝－３／２的高强度向错和闭环状的反转壁．     

硫酸铈接触法在碘盐检测中的应用

用硫酸铈接触法对哈尔滨市动力区（１９９２年）和呼兰县（１９９３年）的居民末稍碘盐和碘盐加工点销售点碘盐共２３２份盐样进行了测定分析，其结果：动力区居民末稍盐ｎ＝７６，ｘ±ＳＤ＝１９．５８±１２．８６；碘盐销售点，ｎ＝７７，ｘ±ＳＤ＝２０．５９９±２０．１７４．呼兰县居民末稍盐ｎ＝７５，ｘ±ＳＤ＝８．８９±５．９１；加工点ｎ＝１９，ｘ±ＳＤ＝４６．０８±３８．９３；销售点，ｎ＝４，ｘ±ＳＤ＝２０．７５±１７．７０．平均回收率为９８％．     

刚性链侧链型液晶高分子合成与研究

以自由基聚合方法，合成了一系列含有３个苯环通过酯键相联的液晶性单体及其聚合物，这类刚性液晶基元不通过柔性间隔基而直接竖挂在聚丙烯酸酯大分子主链上，具有很高的Ｔｇ·ＤＳＣ及偏光显微镜结果表明，所有的单体和聚合物均为向列型热致性液晶。     

高分子液晶向列相的向错结构

高分子液晶态向错结构在正交偏振片下呈现出具有不同数目黑刷子的纹影织构，是由于分子指向矢取向排列上的不连续性所引起的一种光学效应。近年来，高分子液晶态向错结构的研究已取得了较大进展，发展和应用片晶装饰、条带织构装饰和表面裂纹装饰等技术可以在电镜和偏光显微镜下直接观察各种向错结构。本文简要介绍高分子液晶态向列相的向错和反转壁结构的几何学、高强度向错以及近年在实验上观察各类型向错形态的研究进展。     

CO(υ)高振动激发态向C2H2的振动传能研究

用时间分辨富里叶红外发射谱研究了高振动激发态ＣＯ向Ｃ２Ｈ２的传能，得到了ＣＯ（ｖ＝１－３）各振动态布居及其随时间的变化。利用微分法解出弛豫微分方程组，获得ＣＯ（ｖ＝１－３）向Ｃ２Ｈ２的传能速率常数分别为：２．０±０．１，６．０±０．２和９．４±０．８（１０＾－１３ｃｍ＾３·ｍｏｌｅｃｕｌｅ＾－１·ｓ＾－１）。传能速率随着振动量子数的增加而迅速增加。ＣＯ的振动能应向Ｃ２Ｈ２的对称伸缩模ｖ２近共振Ｖ－     

甲基丙烯酸甲酯和联苯酯的基团转移共聚研究

研究了甲基丙烯酸甲酯（ＭＭＡ）和甲基丙烯酸联苯酯（ＢＰＭＡ）的基团转移共聚．用１Ｈ ＮＭＲ、ＩＲ、ＧＰＣ和ＤＳＣ等手段对共聚物进行了表征．测得两种单体在苯、四氢呋喃和乙腈中的竞聚率（３０℃）分别为γ１＝０５６±００３、０５２±００３、０４６±００３和γ２＝０７９±００３、０８１±００３、０８５±００３．得到了实测分子量和理论分子量相近，分散性较小的共聚物     

含邻位羟基Schiff碱近晶相液晶中的高强向错

含邻位羟基Ｓｃｈｉｆｆ碱近晶相液晶中的高强向错张其震，崔利，孙继润（山东大学化学院，济南，２５０１００）关键词高强向错点，近晶相纹影织构，液晶纹影（Ｓｃｈｌｉｅｒｅｎ）是向列相液晶织构的常见形式，某些近晶相液晶也可出现纹影织构，其特征为以消光黑点为中...     

液晶基元直接竖挂于主链上的液晶共聚物的研究

合成了含液晶基元的单体，４＋４＇－（对甲氧基－苯甲酰氧基）－苯甲酸氧基］－苯基－甲基丙烯酸酯，以及由此单体与苯乙烯，通过自由基共聚合反应合成了一系列含液晶性和非液晶性两种序列结构的共聚物．采用ＤＳＣ、偏光显微镜和Ｘ－衍射方法研究了共聚物的液晶行为，发现单体和所有的共聚物（除ＣＰ—９外）均有很好的热致液晶性及较宽的液晶态温度范围；随苯乙烯单体单元摩尔百分含量的增加，共聚物的分子量、相转变温度和热失重温度基本上呈下降趋势．通讯联系人０．ｓｇ／ｄｌ的溶液，于４０ｏＣ用乌氏粘度计测定．ｌ·２单体合成合成路线如下：化合物Ｉ、１１、Ｉｌｌ和ＩＶ的制备按文献ｌ’］的方法进行．化合物１、１１、Ｉｌｌ和ＩＶ经元素分析、‘Ｈ—ＮＭＲ和ＭＳ等表征，结果与其化学结构～致．１．３聚合物的合成聚合反应和共聚物结构式表示如下：按单体（ＩＶ）与苯乙烯不同摩尔比，以ＤＭＦ为溶剂，ＡＩＢＮ为引发剂（相当于单体摩尔数的０．５０）．通过封管聚合，在６０ｏＣ水浴中反应３６ｈ，升温至７０ｏＣ反应１２ｈ，抽滤，用ＤＭＦ和甲醇洗，真空干燥．２结果与讨论２．ｌ含液晶基元的单体（Ｉ）化合物１、１１、Ｉｌｌ和ＩＶ经测试分析结果与其化学结构一致．由表１可见，单体?     

原发性肝癌患者血清多种微量元素、铜蓝蛋白、T淋巴细胞测定与分析

应用ＩＣＰ－ＡＥＳ、酶氧化反应、酸性非特异性酯酶方法，对３３例原发性肝癌患者，测定血清多种微量元素、铜蓝蛋白及Ｔ淋巴细胞，分别与１７例、３６例、３４例健康者对照．原发性肝癌组血清铜ｘ±ｓ＝１９．１９±６．７０８μｍｏｌ／Ｌ）高于对照组（ｘ±Ｓ＝１４．８２±４．３７μｍｏｌ／Ｌ），血清钼（０．４３７±０．３１２μｍｏｌ／Ｌ）、锌（１５．５１±８．７７μｍｏｌ／Ｌ）、铁（２０．９７±２６．１３μｍｏｌ／Ｌ）均低于对照组铝（１．１８６±０．３１２μｍｏｌ／Ｌ）、锌（２０．９４±６．３１μｍｏｌ／Ｌ）、铁（４６．７２±２９．８９μｍｏｌ／Ｌ），Ｐ值均＜０．０５；肝癌组铜蓝蛋白（ｘ±Ｓ＝５．３８±２．３５活性单位／ｍＬ）高于对照组ｘ±Ｓ＝３．９２±０．８７活性单位／ｍＬ，Ｐ＜０．０５；Ｔ淋巴细胞（ｘ±Ｓ＝５７．７８±１１．７１活性单位／ｍＬ），低于对照组（ｘ±Ｓ＝６６．８０±１２．８２活性单位／ｍＬ），Ｐ＜０．０５．结果提示原发性肝癌微量元素代谢异常，直接影响酶系统，使自由基失控、机体内促氧化和抗氧化平衡失调，估计这一学说在肝癌的发病中起重要作用。     

Surface microcracks decoration and disclination defects of wholly aromatic liquid crystalline copolyesters

An intensive study has been conducted to map the director fields of disclination of nematic liquid crystalline copolyesters. In this study, films of two wholly aromatic main-chain polyesters containing para- (ABA/MH/TFTA) and meta-linkages (ABA/MH/TFIA) (ABA, p-acetoxybenzoic acid; MH, maleic hydrazine; TFTA, tetrafluoroterephthalic acid; TFIA, tetrafluoroisophthalic acid) were synthesized to investigate the effects of kinks on liquid crystallinity, disclination strength (S), and surface microcracks decoration. These two copolyesters were prepared by in-situ thin film polymerization and characterized by polarizing light microscope, wide-angle X-ray diffraction, as well as "rotational isomeric states" (RIS) Metropolis Monte Carlo (RMMC) simulation. An optical microscope shows that the surface microcracks forms in the nematic-mosaic texture during a rapid quenching. The ABA/MH/TFTA film exhibits disclination strength with S = +1 and S = -(1)/(2); however, disclination strengths with S = +/-1 have been observed in the ABA/MH/TFIA system. To our best knowledge, this is the first paper reporting the effects and evidence of kink (meta and para moieties) on topological defect of disclination. In addition, the RMMC analysis supports the liquid crystal formation in both polyester films with a persistence ratio greater than 6.42.     

芳香共聚酯B-N多种向列织构的形态研究

从一种聚芳酯B-N得到了丝状(包括细丝和粗丝)、纹影状和大理石纹状等与小分子向列液晶相似的多种织构。由于样品淬火后晶片装饰在织构上而不影响分子取向矢的分布,因而可以用化学刻蚀和电镜技术揭示其向错和取向矢图。电镜和光学显微镜的结果相互补充,表明了细丝和粗丝状织构的分子取向矢分布很不相同,是两种不同的织构,而粗化始于第二熔融降温。在这些向列织构中分别发现了S=±(1/2)和s=+1的向错的例子和平面内微区转向壁的证据。     

Direct decoration of disclinations by solidification-induced band texture and focal-conic texture for a low molar mass liquid crystal

Two decoration methods, solidification-induced band texture decoration and focal-conic texture decoration, were established to map the director field of disclinations in a low molar mass methacrylate liquid crystal. It was found that when the specimen film is quenched from the nematic melt to room temperature, solidification-induced band texture is observed arrayed along with the schlieren texture, and the orientation of the director field can be displayed. Moreover, when the specimen is cooled from the nematic melt to 63°C and annealed, the focal-conic texture of the smectic A phase is found to grow around the corresponding disclination core with good orientation to reveal the director field. By the two decoration techniques, the director fields of disclinations with strength s = 1/2 and s = ± 1 were revealed. Two types of inversion wall, loop-like wall and splay-type wall, were found by both solidification-induced band texture decoration and focal-conic texture decoration.     

芳香共聚酯B-N多种向列织构的形态研究

 从一种聚芳酯B-N得到了丝状(包括细丝和粗丝)、纹影状和大理石纹状等与小分子向列液晶相似的多种织构。由于样品淬火后晶片装饰在织构上而不影响分子取向矢的分布,因而可以用化学刻蚀和电镜技术揭示其向错和取向矢图。电镜和光学显微镜的结果相互补充,表明了细丝和粗丝状织构的分子取向矢分布很不相同,是两种不同的织构,而粗化始于第二熔融降温。在这些向列织构中分别发现了S=±(1/2)和s=+1的向错的例子和平面内微区转向壁的证据。     

The use of bowed reverse twist disclination lines for the measurement of long pitch lengths in chiral nematic liquid crystals†

A novel method is described for the measurement of long pitch lengths in chiral nematic liquid crystals using the bowing of reverse twist disclination lines in 90° twisted nematic devices. The method has been used to measure pitch lengths of up to 50 mm, significantly longer than previously possible using existing methods.     

Optical microscopy study for director patterns around disclinations in side-chain liquid crystalline polymer films

Polarizing optical microscopy is employed to study director fields around disclinations in side-chain liquid crystalline polymer films. Optical black brushes together with stripes around disclinations are observed. The stripes run parallel to the local director and thus decorate overall patterns of nematic director around disclinations. Three director patterns involving radial, spiral, and circular microstructures of a positive integer disclination with s = +1 and one hyperbolic pattern of a negative integer disclination with s = -1 are observed in the thin film. It is found that the specific configurations of a pair of (+1, -1) disclinations form during the late stage of annihilation. Increasing the film thickness leads to disclination instability. We observe that black four-brushes of disclinations with s = +/-1 split into black two-brushes, where two types of director patterns of disclinations with half-integer strengths of s = +/- 1/2 produce. Theoretical analysis is presented to explain this instability.     

Direct decoration of disclinations by solidification-induced band texture for a nematic side chain liquid crystalline polymer

For a nematic polymethacrylate side chain liquid crystalline polymer, g 154 N 298 I (°C), the solidification-induced band texture has been observed aligned along the disclination under a polarizing optical microscope, when the specimen was quenched from 280°C to room temperature. The decoration technique of solidification-induced band texture, which is usually reported for main chain liquid crystalline polymers, was then introduced to reveal the director field pattern along a disclination for this side chain liquid crystalline polymer. It was found by infra-red dichroism measurements that the director orientation is parallel with the direction of the band. On this basis, disclinations with strength s=±1/2 and s=±1 were mapped according to the corresponding pattern of solidification-induced band texture. In addition, two types of inversion wall, loop-like and splay-type walls, were also found to be decorated by the solidification-induced band texture.     

Direct observation of director fields of disclinations in the nematic mesophase of a main chain thermotropic aromatic polyester by surface microcrack decoration

For a main chain thermotropic aromatic polyester with a flexible spacer, Cr 194 N 245 I (°C), the director fields around disclinations in the nematic mesophase can be decorated by both the solidification-induced band texture and surface microcracks. Director fields of various types of disclinations, including inversion walls, in the nematic mesophase of this semi-rigid polyester have been observed directly by polarizing optical microscopy. It was found that when the polymer was pre-sheared in the nematic state and then quenched to room temperature, a shear-induced band texture was observed, which relaxed slowly during annealing at 200°C, and then on quenching the solidification-induced band texture and surface microcracks appeared, displaying the pattern of the disclination fields. Pre-shearing is a necessary condition for the appearance of microcracks. On annealing, disclinations of various types were generated, quite often connected by inversion walls in the direction of pre-shearing. In some areas of the specimen where the shear-induced bands had not been completely relaxed during annealing, the shear-induced band texture was shown by the birefringence and surface microcracks to have a supermolecular structure of sinusoidal chain fibrils.