主链型热致性液晶高分子芳香共聚酯的红外光谱研究

本文用傅里叶红外光谱法结合变温方法和偏振技术研究了主链型芳香共聚酯热致性高分子液晶。测定了光谱的变温性质以及液晶的有序度参数。结果表明分子链中液晶基元上苯环之间的相互作用在液晶相形成过程中起重要作用。液晶有序度参数与Roca和Yoon的理论值相一致。     

四苯基卟啉变色酸敏片

卟啉自由碱通常是紫或紫红色固体,遇酸则变成绿色,对光敏感。人工合成的卟啉最简单的是四苯基卟啉(H_2TPP)。美国专利曾将卟啉类化合物作为光氧化成象体系的增感剂。我们试图将H_2TPP作为VMD片(一种新型非银盐成象体系)的增感剂,未获成功。     

聚氯乙烯膜在玻璃化转变温度区域的傅里叶变换红外光谱研究

本文用傅里叶变换红外光谱(FTIR)研究了从高弹态缓冷、高弹态淬火以及其后在低于T_g温度热处理的三种不同热历史聚氯乙烯膜的结构差异。在升温在位FTIR测量中,发现经低于T_g温度热处理的样品在与示差扫描量热(DSC)热焓吸收牛相对应的温度区间有构象突变发生,并用高分子链缠结的观点加以解释。     

行间转移型CCD激光干扰效应阈值估算方法

电荷耦合器件(CCD)图像传感应用中,通过非实测手段获取器件的干扰效应阈值非常重要,有时甚至是唯一手段。分析了行间转移型CCD单像素饱和与串扰等典型激光干扰效应的影响因素,研究了垂直拖尾、光晕和串扰3种效应的物理本质间的内在联系与区别,初步证实垂直拖尾系数对串扰效应而言为非敏感参数。提出了基于饱和信号电荷量、像元尺寸、量子效率以及光晕抑制率等器件参数,从现有的效应数据预估相似器件单像素饱和阈值、串扰线饱和阈值的外推方法。对柯达面阵CCD器件的饱和阈值测量与干扰效应实验显示,预估结果与实验值之间的偏差量分别为3%和20%,属于可以接受的范围,表明预估方法切实可行。     

激光原子荧光光谱分析法的进展

概述了激光原子荧光光谱分析法的研究现状和发展趋势。对各种原子化学方法与激光原子荧光光谱分析法相结合的分析特性进行了描述，着重介绍了电热原子化作为原子化器的激光原子荧光光谱法近年来的发展和应用。     

C6H5C2H4Co(salen)H2O的晶体结构和性质研究

合成了标题配合物Ｃ６Ｈ５Ｃ２Ｈ４ＣＯ（ｓａｌｅｎ）Ｈ２Ｏ，并经元素分析、红外、紫外－可见光谱、差热－热重分析和循环伏安法表征．测定了晶体结构，其中轴向的Ｃｏ—Ｃ和Ｃｏ－Ｏ键长分别为１．９６２（１４）和２．２０９（９）Ａ，其Ｃｏ—Ｃ键是目前ＲＣｏ（ｓａｌｅｎ）Ｈ２Ｏ中最短的，晶体属四方晶系，空间点群为Ｐ－４２（１）Ｃ，品胞参数如下：ａ＝２４．７８９（９），ｂ＝２４．７８９（９），ｃ＝７．０６０（７）Ａ，β＝９０．００°，Ｖ＝４３３８．９Ａ３，Ｚ＝８．     

THE RHEO-OPTICAL FTIR STUDY OF POLYESTERPOLYETHER SEGMENTED COPOLYMER

The polyester-polyetber segmented copolymer has been investigated by rheo-optical FTIR during stretehing for the informastion on strain induced crystallizatinn of soft segment chains, hard and soft chain orientation.At room temperature 15℃, the soft segment chains of polyester-polyether being to crystallize at 220% strain and the degree of crystallixation increa(?)e with draw ratio, but there will not be any soft segment chains crystallization above 21℃even at bigber strain. The average orientation of hard segment chains are higher than that of the soft chain at high strain level, both are positive oriented into the stretching direction at allover strain level. This indicates that the b(?)d (?)ent ch(?)ins are dispersed into the elastomeric phase and without forming spherulite.     

Subglass-transition-temperature annealing of poly(ethylene terephthalate) studied by FTIR

Using FTIR spectroscopy we have examined conformational changes in the quenched and slowly cooled amorphous PET films during physical aging process. It was observed that the amount of trans conformers for quenched sample decreased upon sub-T_g annealing. For the slowly cooled sample that corresponds to a state closer to equilibrium, the amount of trans conformers hardly decreased, but increased gradually during sub-T_g annealing process. The conformational populations of these two samples tend to be identical with annealing time. These results demonstrate that sub-T_g annealing will lead to closer interchain packing and result in the formation of new cohesional entanglements along the chains. In situ FTIR studies on the conformational changes of these samples were also carried out during heating up of the sample through the glass transition region. The results showed that incremental changes of the amount of trans conformers in Samples Q and SC were gradual, while an abrupt change of trans conformers occurred in the sub-T_g annealed samples. These results were in agreement with the formation of the interchain cohesional entanglement due to sub-T_g annealing. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 783–788, 1998     

常用化学软件在中级无机化学教学中的应用

介绍在大学高年级中级无机化学课程中,应用常用化学软件辅助教学的一些体会和具体做法,提出了在教学中充分利用计算机化学的新成果和新方法丰富教学内容的思路。     

关于空间型中的正螺面

将正螺面引入到一般的空间型中,在Beltrami-Klein坐标系下统一加以表示,并一致地详尽考察其度量、法向、第二基本形式及主曲率,推出正螺面是极小曲面.