无定形聚苯硫醚的X-射线衍射峰的表征函数

<正> 过去在进行计算分峰时,不同相态的X-射线衍射峰形是用不同的表征函数来描述的。其中晶相峰多采用Hindeleh的对称复合函数;非晶相峰的表征函数则有多种形式。以后提出综合函数实现了两种相态表征函数的统一。在应用中发现,这一综合函     

拖尾峰的半峰宽

实际色谱流出曲线大多是接近高斯分布的不对称拖尾峰,许多作者用指数卷积的高斯分布函数来描述,     

对数正态分布函数拟合色谱峰一例

由高分子多孔小球（有机担体４０２）填充柱流出的水的色谱峰,用对数正态分布函数拟合得较好。提出了区分ＥＭＧ峰和ＬＮ峰的判别式,ＬＮ峰为能用对数正态分布函数拟合的色谱峰。     

扫描式电感耦合等离子体光谱仪谱线峰位移的机理研究

通过对扫描式电感耦合等离子体原子发射光谱仪(ICP-AES)出射光谱线峰位移(Δλ)的机理研究,发现温度的变化、波长的变化以及光谱仪机械的系统误差是产生谱线峰位移的主要因素,首次测量了谱线峰位移与波长变化之间的非线性函数关系曲线Δλ-λ,以及谱线峰位移与温度变化之间的非线性函数关系曲线Δλ-T,并用多项式方程表达了这些函数关系。本研究还发现,不同的光栅单色仪有近似相同的Δλ-λ函数关系曲线,但是Δλ-T的函数关系曲线却很不相同。利用这些非线性函数方程式,设计开发了扫描式ICP-AES光谱仪的智能波长校正装置(IWC),用它取代传统的局部恒温系统及谱线描迹法进行样品分析的结果表明,智能波长校正的ICP光谱仪(ICP-IWC)谱线峰定位精度高,具有省时、安全、结构简单的特点,有广阔的应用前景。     

用对数正态分布描述色谱峰问题的讨论

本文指出了色谱文献中对数正态分布密度函数表示式是不正确的,并提出了符合对数正态分布的色谱峰的峰面积的表示式。     

重叠伏安峰的样条卷积法分辨

建立了分辨重叠峰的样条卷积法；利用三阶样条函数构成的峰分辨函数与原信号进行卷积，直接对重叠的伏安峰进行处理，取得了较好的结果；被处理的重叠峰可达到其线分离，且峰位置的相对误差小于3．0％（完全重叠峰为5．4％），峰面积的相对误差小于2．0％；应用于镉（Ⅱ）－铟（Ⅲ）实验体系的微分脉冲伏安信号处理，取得满意的结果。     

严重重叠的色谱峰对的解析

本文根据指数修正的高斯函数模型(EMG),并利用回归分析提出了一种解析严重重叠的色谱峰对的方法。此法可适用于相对峰谷在50％～95％的严重重叠的色谱峰对的解析。     

柱前连接管对色谱峰形的影响

实际色谱流出曲线大多是接近高斯分布的不对称拖尾峰,为此许多作者采用指数修正的高斯分布曲线来描述。 式中A为峰面积。t_g为高斯函数的保留时间,t′为卷积积分变量,σ为高斯函数的标准偏差,τ为按指数衰减的时间常数,h(t)为流出时间t时的峰高。引起色谱峰拖尾的因素有多种,目前普遍认为柱外效应是因素之一,它不仅引起谱峰扩张也引起     

色谱重叠峰分解的神经网络法

对于色谱图中两个相互重叠的峰, 本文提出了一种分解方法。首先在重叠峰的一阶导数曲线上取出五个无因次特征值, 然后用多层前传网来表达这五个特征值和重叠峰中子峰面积分率之间的关系。一系列实验的结果表明, 用神经网络方法所得子峰面积的准确度, 优于传统的垂线法及函数拟合法, 而且计算工作量较小, 可用于实时处理。     

分辨伏安分析重叠峰的研究

研究了一种处理伏安(极谱)重叠峰的数学模型。将几类具峰状的极谱电流公式归纳成一般的关系式,提出了一个通用的拟合函数,经非线性最小二乘法处理,可得到重叠组份的蜂高、峰电位和半峰宽等参数。本法适用于示差脉冲极谱、交流极谱、方波极谱、一阶导数卷积伏安法及其反向溶出伏安重叠峰的分离。已用于示差脉冲极谱和交流极谱重叠峰的分辨,得到满意结果。     

EFFECT OF INACTIVATION OF THE OXYGEN-EVOLVING SYSTEM ON THE THERMOLUMINESCENCE OF ISOLATED CHLOROPLASTS

Abstract— The effect of inactivation of water-splitting enzyme on the thermoluminescence of isolated chloroplasts was investigated. The inhibitory treatments used included Tris-washing, alkaline pH in the presence of the uncoupler gramicidin, incubation with a high concentration of magnesium ions and different chaotropic agents. It was found that inhibition of oxygen evolution resulted in the disappearance of the main thermoluminescence band at +20°C. The A band which appears at — 10°C and has been related to the S₄ state of the water-splitting enzyme (Inoue, 1981) was not considerably affected by the inhibition of oxygen evolution. The results presented here indicate that the participation of the S₄ state of water-splitting enzyme in the generation of the A band should be reinvestigated.     

EFFECTS OF MUTAGENETIC SUBSTITUTION OF PROLINES ON THE RATE OF DEPROTONATION and REPROTONATION OF THE SCHIFF BASE DURING THE PHOTOCYCLE OF BACTERIORHODOPSIN

Abstract— Membrane-buried proline residues are found in many transport proteins. To study their roles in the structure and function of bacteriorhodopsin (bR), effects of the individual substitutions ofPro–50,Pro–91 andPro–186 on the deprotonation and reprotonation kinetics of the Schiffbase (SB) were determined by flash photolysis. The obtained rate constants and the amplitudes of the slow and fast components were compared with those of ebR (wild-type bR, the native protein that is expressed in Escherichia coli). The deprotonation rates of PSB were found to be 10 times faster than that of ebR for P50A, P91A and P91G mutants, and 4 times faster for the P50G mutant. These mutations also increased the initial reprotonation rate of the SB, although the overall change in the reprotonation rate is not as significant as that in the deprotonation rate. Our results indicate thatPro–50 andPro–91, as well asPro–186, are important for the proton-pumping function of bR.     

苯并噻唑类化合物在银上的吸附机理研究

本文利用线性电势扫描的方法研究了几种苯并噻唑类化合物及巯基苯基四氮唑在银上的吸附机理。结果表明:2.巯基苯并噻唑和巯基苯基四氮唑以化学吸附方式,通过分子上巯基与银表面的作用形成分子紧密排列的吸附层。25℃下,PMT可以在银表面形成紧密单层。这种吸附在较高吸附温度下可以转化为多层,且完全覆盖银表面。在含Br^-的溶液中,它可以阻碍Br^-与表面的接触。在较大的浓度下,2-甲基苯并噻唑和苯并噻唑也可以在银表面的某些位置,通过杂环上的S原子(或N原子)形成松散的吸附,但这种吸附层不能完全覆盖银表面。电镜实验也表明以上物质在银表面发生了作用。     

THE PHOTOCHEMICAL SYNTHESIS OF THE PYRIDINE ADDUCT OF TETRAPHENYLPORPHYRINATORHODIUM(Ⅱ)AND THE MECHANISM OF PHOTOCHEMICAL REACTION

A new rhodium(Ⅱ)porphyrin complex was isolated by chromatography from the photochemical reac-tion of(μ—tetraphenylporphyrinato)bis[dicarbonylrhodium(Ⅰ)]with pyridine in benzene and has been charac-terized.From the results,the reaction mechanism is proposed.     

多元络合物在生物成分分析中的应用进展

评述了多元络合物在生物成分分析中的应用近况，内容包括用吸光光度、荧光光度、化学发光、瑞利光散射和电化学分析方法，对黄酮类化合物、茶多酚、维生素C、氨基酸、蛋白质、核酸和酶等生物成分的测定与研究，引用文献41篇。     

THE EFFECT OF CHEMICAL STRUCTURE ON THE PHOTOSENSITIZING EFFICIENCIES OF PORPHYRINS

Abstract— A kinetic investigation was performed on the photooxidation of methionine sensitized by various porphyrins at different oxygen concentrations. The rate of photooxidation was found to be strongly dependent on the nature of the sensitizer. In the case of hematoporphyrin, chelation of Mg²⁺ and Zn²⁺ and especially of Cu²⁺ and Fe²⁺ caused a significant decrease of the photosensitizing efficiency. Fluorescence and/or flash photolysis studies showed that such a decrease is ascribed to an enhancement of the non-radiative decay of the first excited singlet state as well as to a reduction of the triplet lifetime. The sensitizing efficiency is also dependent on the nature of the porphyrin side chains. A reaction mechanism involving ¹O₂ as the oxidizing agent is proposed.     

竹红菌甲素荧光光谱的环境效应

竹红菌甲素(简称HA)是从竹红菌中提取的一种光敏色素,属于苝醌的衍生物,它对许多皮肤病都有显著的光疗作用。最近发现HA能杀死肿瘤细胞并富集在肿瘤组织处(傅乃武未发表的结果),虽然刘景瑤等管对它的荧光光谱作过研究,但还有许多问题有待于进一步的探讨。本文详细研究了环境对HA荧光光谱的影响,这有助于了解不同环境中激发态HA的性质,进而弄清竹红菌的光疗机制。     

USE OF THE DYE HOECHST 33258 IN A MODIFICATION OF THE BROMODEOXYURIDINE PHOTOLYSIS TECHNIQUE FOR THE ANALYSIS OF DNA REPAIR

Abstract— A modification of the bromodeoxyuridine photolysis technique is described in which the cells are treated with the fluorescent dye Hoechst 33258 to enhance the bromodeoxyuridine photolysis produced by 365 nm or by black light. Use of the modified assay overcomes several difficulties encountered in the original 313 nm photolysis technique and demonstrates that excision repair of damage produced in the DNA by 7,12-dimethylbenz(fl)anthracene 5,6-oxide takes place by a long patch type of repair pathway.     

生物探针与脱氧核糖核酸的结合模式及其分光光度法测定的进展

对生物探针与脱氧核糖核酸（DNA）的结合模式及有机染料分光光度法测定DNA的研究进展进行了综述。引用文献71篇。     

THE MODIFICATION OF RIBONUCLEASE-A BY NEARULTRAVIOLET IRRADIATION IN THE PRESENCE OF PSORALEN

Abstract— Ribonuclease A is inactivated when irradiated under oxygen by UV-A light in the presence of psoralen. The rate of inactivation is greatly reduced by sodium azide. ascorbate or nitrogen, whereas the substrate gives only very limited protection. A ribonuclease sample modified to 40% remaining activity presented a significant modification of amino acid residues known to be sensitive to oxidation and 1.4 mol of bound psoralen per mol of protein. The secondary structure of the enzyme, as assessed by circular dicroism was not changed by irradiation; neither was aggregation of the enzyme to a higher mol wt evident. Studies on the tryptic peptides fractionated by high performance liquid chromatography showed that the photomodification occurs with very low selectivity. All the five peptides containing hystidine, tyrosine and methionine residues were greatly modified, although two, those containing histidine residues 12 and 119 in the sequence, amino acids known to be involved in the catalytic activity of ribonuclease. are modified to a greater extent. The protein bound psoralen. revealed by radioactivity in the HPLC eluate, was not found associated to only one or few peptide peaks but spread on a large zone of elution.