13－臂星形文化聚苯乙烯的某些溶液性质

本文对合成的四个不同分子量的１３－臂星形聚苯乙烯试样，用ＧＰＣ－粘度计联用装置对之进行了测定．用良溶剂中的粘度数据，通过一定的线性外推，得到了它们在θ条件下的ｇθ’因子对良溶剂中的ｇ’因子和ｇθ’因子之间存在的差异以及ｇθ’因子与ｇθ因子间关系式中ε的选值问题进行了详细的实验验证和讨论，并与前文［７］所得４－臂和７－臂星形支化聚苯乙烯试样的结果进行了比较．     

等规聚苯乙烯的分子量分级

用配位聚合法得到的高等规度的等规聚苯乙烯(i-PS),一般具有较宽的分子量分布,对其进行分子量分级是比较难的,迄今已有不少这方面的报道,其中包括采用热力学的方法,以及采用分子量降解的方法。为了获得分子量分布较窄的i-PS样品来研究单链单晶,我们也进行了i-PS的分级研究,我们选用了一种新的溶剂/不良溶剂体系对i-PS     

梳形支化聚苯乙烯模型化合物的合成及表征

本文用阴离子聚合的聚苯乙烯进行氯甲基化,再将此带有活泼氯的甲基化聚苯乙烯作为主链与活性聚苯乙烯阴离子偶合接枝,制备了12个具有等长度支链沿主链无规分布的、结构明确的梳形聚苯乙烯模型化合物,并用GPC—粘度计联用装置对之进行了表征.     

线性分析法来解热脱附动力学参数

TPD方法是研究表面常规手段之一.对于如何从实验结果获得正确的脱附动力学参数,已有不少工作发表。然而,现有方法均存在一定的适用范围,尤其是重叠谱解叠,仍然没有很好地解决。本文介绍的线性分析法,不仅适用于简单的一级和二级脱附TPD谱的解析,而且也适用于重叠谱解叠,从而为实验上确定动力学级数和复杂谱解叠提供了依据。     

热分析标准试验方法

本文参照国外标准及一些较为重要的文献,介绍玻璃化转变温度、熔融和结晶温度及比热容的热分析标准方法。     

用线性回归与单纯形优化法研究配合物的组成

本文讨论了用线性回归和单纯形最优化法确定配合物实际组成的两种方法。这两种方法简单方便,既适用于水溶液也适用于非水溶液。     

THE OBSERVATION OF INTERNAL MOTION OF LINEAR POLYSTYRENE CHAINS IN CYCLOHEXANE AROUND 0 TEMPERATURE

A high molecular weight (M_w=1.85×10~7) polystyrene (PS) with narrow distribution was prepared by high vacuum anionic polymerization in tetrahydrofuran.By use of dynamic light scattering,the dynamics of PS chains in cyclohexane was studied around theθtemperature.For the first time,we have observed the internal motion of polymer chains in solutions below theθtemperature by using dynamic light scattering at smaller angles (even qR_g<1).     

校准蒸发光散射检测器选用标准物质的比较与分析

通过对葡萄糖和三氯蔗糖的物理、化学性质的比较,采用高效液相色谱仪和蒸发光散射检测器进行标准溶液色谱峰面积的检测,并用G rubbs检验法对其数据进行异常值检验。结果表明,三氯蔗糖相对于葡萄糖较为稳定,选用三氯蔗糖作为蒸发光检测器校准用标准物质比较合适。     

磁性聚苯乙烯微球的制备与性能研究

以聚苯乙烯和二氯甲烷为油相,十二烷基苯磺酸钠 (SDBS) 为表面活性剂,采用溶剂挥发法制备了磁性聚苯乙烯微球.研究了温度、搅拌速度、Fe3O4用量和pH值等操作因素对磁性微球的形貌、粒径和磁学性能的影响.结果表明,采用溶剂挥发法可以制备含有磁性颗粒Fe3O4的磁性微球.磁性微球的粒径,磁响应性能与制备磁性微球的温度、搅拌速率、水溶液的pH值、磁粉用量等操作参数有关.综合考虑微球的粒径大小、分布以及磁响应性得出,在本实验体系中,20℃的操作温度、1000r/min的搅拌速率、弱碱性的水相溶液以及1.5:10 (磁粉:聚苯乙烯) 的比例是制备磁性微球的适宜操作条件.     

盐酸环丙沙星及其制剂含量测定方法的探讨

非水滴定法测定盐酸环丙沙星的含量时,需要预先加入冰乙酸和乙酸汞进行转化处理,两种试剂的加入顺序对盐酸环丙沙星的溶解速度影响较大,先加入乙酸汞时,盐酸环丙沙星溶解较快。用高效液相色谱法测定盐酸环丙沙星片及盐酸环丙沙星胶囊的含量时,如果以水作溶剂,测定值明显偏低,宜改用0.l mol／L盐酸溶液作溶剂。     

星形支化聚苯乙烯模型化合物的合成及表征

本文用阴离子聚合方法,首先合成了线形‘活’的聚苯乙烯大分子阴离子,然后用二乙烯基苯为偶联成核剂,制备了十三个4-80臂较窄分子量分布的等臂长规则星形支化聚苯乙烯的模型化合物,并用GPC—粘度计联用装置对之进行了表征。     

无规支化聚苯乙烯模型化合物的合成及表征

本文首次用两次偶合接枝的方法制备了不但在主链上有支链。而且在支链上也有支链的结构明确的无规支化聚苯乙烯模型化合物，并对所制备的１５个试样用ＧＰＣ－粘度计联用装置进行了表征。     

PHYCOBILIPROTEINS: COMPARISON OF SOLUTION AND SINGLE CRYSTAL FLUORESCENCE FOR C-PHYCOCYANIN AND B-PHYCOERYTHRIN*

Abstract— Trimeric and hexameric solution forms of C-phycocyanin (CPC) from the cyanophyte Agme-nellum quadruplicatum have been isolated and their spectral properties compared to those obtained from single crystals. Although the absorbance peak of a suspension of small C-phycocyanin crystals is red-shifted only 7 nm relative to the solution forms, the single crystal fluorescence is red-shifted 60 nm relative to the solution forms. The crystal fluorescence spectrum exhibits a single peak at LD_max= 708 nm when excited at 514.5 or 530.9 nm and two peaks (LD_max= 661 and 708 nm) when excitation occurs at 568.2 nm. Fluorescence depolarization measurements indicate that extensive energy transfer could occur for both solution and crystal forms with the latter being dependent upon the relative orientation of the crystal with respect to the excitation dipole. Similar results were obtained with B-phycoerythrin (BPE) from the red alga Porphyridium cruentum where the single crystal fluorescence is red-shifted =50nm relative to the solution spectra with two peaks (LD_max= 583 and 617 nm) observed whose relative intensities are dependent on the excitation wavelength (LD_max– 514.5 and 530.9 nm). Single crystal fluorescent lifetimes exhibited considerable shortening relative to that observed for the solution forms. The implications of these results are discussed with respect to the possible relationships of the crystalline structures to the assembly forms present within phycobilisomes.     

THE MORPHOLOGY AND STRUCTURE OF ETHYLCYANOETHYL CELLULOSE IN STYRENE AND POLYSTYRENE

<正> Ethyl-cyanoethyl cellulose （（E-CE）C）/styrene solution could form anisotropic system when the concentration was high enough. The （E-CE）C/polystyrene（PS）multiphase polymer could be obtained by radical polymerization of the styrene in the solution. The （E-CE）C/PS multiphase polymer maintained both the crystalline structure of the （E-CE）C and the amorphous structure of the PS. In the multiphase polymer produced from the isotropic solution, however, the （E-CE）C formed spherulites and spread in the PS amorphous phase. While, in the multiphase polymer produced from the anisotropic solution, the （E-CE）formed cylinderic crystalline aggregates. Moreover, the ordered lamellar texture was also observed in the multiphase polymer produced from the anisotropic solution.     

凝胶型苯乙烯系离子交换树脂的强度及抗渗透性的影响因素研究 (I)

本文就单体组成中不同引发剂，链转移剂，环二烯，烯丙基类化合物和氧气等对凝胶型苯乙烯系阳离子交换树脂的强度和抗渗透性的影响进行了系统研究。结果显示，采用0．30％的过氧化2－乙基己酸叔丁酯（OT）和0．01％的过氧化苯甲酸特丁酯（CP）代替过氧化二苯甲酰（BPO作引发剂，或者加入0．02％的链转移剂十二烷基硫醇，均能够在一定程度上改善共聚物珠粒的结构均匀性，提高其合成的离子交换树脂的磨后圆球率和抗渗透性能。     

用于免疫分析的聚苯乙烯微孔板功能化研究

为满足固相时间分辨荧光免疫分析研究需要,将聚苯乙烯微孔板内表面固相功能化,研制一种在聚苯乙烯微孔板内表面形成耐受强酸、强碱、有机溶剂的尼龙6膜层,并在膜层表面烷基化得到活性基团与己二酸二酰肼进行"手臂"连接,用双功能团戊二醛活化.检测结果表明,经修饰的聚苯乙烯微孔板化学连接蛋白质结合率比物理吸附高出5～10倍,在-4℃环境中存放6个月活性降低小于15%.灵敏度和稳定性显著提高.     

电子等排体的噻吩多烯与苯多烯同系递变的比较Ⅱ

为了比较噻吩多烯和苯多烯三岔共轭体系的性能,合成了三个系列带两个拉电子基团的噻吩多烯三岔化合物(TDn,TEn,TFn),测定了它们在环已烷和乙醇中的电子吸收光谱。实验表明,带两个拉电子基团的噻吩多烯三岔共轭化合物的电子吸收光谱频率也都遵守同系线性规律,相关系数Υ>0.99。与相应的苯多烯化合物的电子光谱相比,吸收峰普遍地红移一个插烯双键所引起的红移数值。相应的同系直线相距很近。△λ_(th)/△λ_E值为0.83-1.10。第一个拉电子基团的引入,化合物的电子吸收峰红移30nm左右,但当第二个拉电子基团引入时,电子吸收峰仅红移3—17nm,其作用只相当于一个取代基。     

EFFECT OF TISSUE ABSORPTION AND MICROSCOPE OPTICAL PARAMETERS ON THE DEPTH OF PENETRATION FOR FLUORESCENCE AND REFLECTANCE MEASUREMENTS OF TISSUE SAMPLES

Abstract— An equation has been derived that is concerned with the measurements of fluorescence or reflectance intensities in reflectance or incident light microscopy. A theoretical basis for the linear relationship between relative fluorescence and reflectance changes is given. This equation predicts both the contributions of different volume elements below the surface of a tissue sample to the total intensity and the depth of penetration of the measured intensities. The relationship requires knowledge of the effective focal points of the excitation beam and the apparent absorption coefficient of the sample. Two procedures are given to provide the empirical values of the effective focal point. The absorption coefficient of mouse liver tissue at 420 nm was determined to be 3.3/mm. The fluorescence intensities of liver slices of differing thickness containing pyrene butyric acid were measured and were found to compare favorably with the calculated values for tissue absorption of 3/mm.     

CATALYSIS OF POLYSTYRENE N-HYDROXYL SULFONAMIDE FOR ESTERIFICATION OF BUTANOL WITH ACETIC ANHYDRIDE

Polystyrene N-hydroxyl sulfonamide resin l was prepared and used to catalyze the esterification of n-butanol and acetic anhydride. The mechanism of catalytic esterification proved by IR spectra of the resins was found that O-H and N-H of the N-lrydroxyl sulfonamide resin reacted with the acetic anhydride respectively to form the active intermediate polystyrene N.O-diaceyl sulfonamate which was cleaved by n-butanol to produce butyl acetate. The catalytic esterification by resin I was in good agreement with the kinetic model of “bi-bi-ping-pong“ mechanism.     

CATALYSIS OF POLYSTYRENE N-HYDROXYL SULFONAMIDE FOR ESTERIFICATION OF BUTANOL WITH ACETIC ANHYDRIDE

1. INTRODUCTION The development of efficient polymer-supported catalysts has attracted much attention [1]. For obtaining polymeric catalysts, catalytically active groups were introduced onto polymers mostly by copolymerization of the appropriate monomers bearing the desired catalyticfunctionalities (e.g. imidazole, OH, and COOH) or by modification of preformed polymers.Another possibility involves the attachment of side chains, containing the desired arrangement of functional groups, o…