光谱法研究N-烃基吖啶满和10,10''''-二烃基-9,9''''-联二吖啶烯的氧化反应

ＵＶ，ＩＲ，ＥＳＲ和荧光光谱法研究了Ｎ－烃基吖啶满和１０，１０’－二烃基－９，９’－联二吖啶烯与π－电子受体：ＤＤＱ、ＴＣＮＱ、ＴＣＮＥ、ＣＡ的氧化反应过程，提出了它们的氧化反应机理。     

Effect of cyclodextrin solutions on chemiluminescence of 10,10′-dimethyl- 9,9′biacridinium nitrate

Solutions of alpha, beta, and gamma cyclodextrin have been shown to enhance the chemiluminescence of the reaction between hydrogen peroxide and 10,10'-dimethyl-9,9'biacridinium nitrate. A 20-fold increase in chemiluminescence intensity is observed in 10^-2 M beta cyclodextrin. The enhancement is attributed to an increase in the excitation efficiency and the rate of the reaction through the inclusion of a reaction intermediate in the cyclodextrin cavity.     

Influence of solvent polarity and temperature on dual fluorescence of 10,10′-dibromo, 9,9′-bianthryl

Fluorescence of 10,10′-dibromo, 9,9′-bianthryl (DBrBA) in solvents of different polarities (n-hexane, dibutyl ether, tetrahydrofuran, and acetone) has been investigated as a function of temperature. Changing of the solvent and variation of temperature modifies the ratio of local (LE) and charge transfer (CT) fluorescence quantum yields. From the basic fluorescence data (quantum yields, lifetimes, ratio of CT to LE fluorescence quantum yields) the temperature-dependent equilibrium constants for the charge transfer process in the excited singlet state were calculated and discussed on the basis of the modern electron transfer theories. It has been found that the intersystem crossing in DBrBA in nonpolar n-hexane, leading to the population of the lowest triplet state, proceeds via the third triplet state. It has been confirmed by the fluorescence measurements and quantum mechanical calculations. Surprisingly, the experimentally obtained intersystem crossing rate constants are very weakly dependent on temperature. Thus, the electron transfer reaction leading to the population of the molecular triplet state is probably an adiabatic reaction with a rate constant controlled by the dielectric relaxation of the solvent.     

分光光度法研究可吸入性颗粒物的吸收特性

探讨用紫外可见光分光光度法研究采样在滤膜上的粗颗粒(PM10-2.5)和细颗粒(PM2.5)的光学吸收特性.结果表明:细颗粒质量虽小,但对光的吸收比粗颗粒贡献大,而粗颗粒对某些波长的光吸收特征非常明显.     

采用椭偏法结合分光光度法研究极薄银的光学常数

极薄银在滤光片、高反射镜等中有广泛的应用,其光学常数严重影响着膜系的特性。在室温条件下,采用电阻热蒸发技术分别在硅和玻璃基底上沉积5.3 nm~26 nm不同厚度的极薄银薄膜,用TalySurfCCI非接触式轮廓仪测量了薄膜的厚度,研究了不同厚度银薄膜的光学常数n和k。镀制厚度5.3 nm、7.9 nm、14.1 nm、26.0 nm的银薄膜,结果显示极薄银的光学常数与块状银光学常数不同,当膜厚小于14.1 nm时,折射率n在380 nm~600 nm随波长增加而增加,在600 nm~1 600 nm随波长增加缓慢减小至趋于稳定值2.6;消光系数k在380 nm~500 nm随着波长增加而增加,在500 nm~1 600 nm随波长增加而缓慢减小至趋于0不变;当膜厚大于14.1 nm时,折射率随波长增加而增加,消光系数随波长近似呈线性增加。整体上,膜厚增加时折射率减小且趋于块状银的折射率,k随厚度增加而增加并最终趋于块状膜。用此拟合的光学常数代入TFc膜系设计软件计算其透射率,发现与分光光度计测得的透射率吻合较好。     

Study on oxidation of pyrite by in situ absorption spectroscopy

Pyrite is one of the common natural mineral It is easily oxidized and brings heavy metal contaminations,therefore it is the main source of acidity mine drainage.The study on the dynamics of pyrite is helpful to comprehending the mechanism of its pollution.In the present paper,an experimental method was designed that phenanthroline reacts with Fe2+that is released from pyrite in solution,and produces stable orange-red complex compound.It can be detected by absorption spectroscopy.Insitu characterization of oxidation of pyrite can be achieved by this method.The results showed that the method is reliable and accurate,and it has high sensitivity and little interference; the reaction rate of oxidation increased linearly with time,corresponding to the characterization of zero-order reaction; oxidation of pyrite belongs to the surface reaction and the process of surface reaction is rate determining step.     

在线式分光测色仪发展现状

介绍了颜色测量原理,归纳了在线式颜色测量的特点、要求及技术难点,阐述了在线式颜色测量技术发展历程。详细介绍了当前几种国外典型的在线式分光测色仪的主要技术指标、应用范围、系统结构等,指出了每一种仪器的特点和优势。从技术和应用需求两方面对在线式分光测色仪的发展趋势做了展望,为在线式分光测色仪的发展起到一定的借鉴作用。     

利用光学多通道分析仪与分光光度计测定叶绿素的紫外-可见光区吸收光谱

应用分析化学中常用的吸光光度法,通过光学多通道分析仪和紫外-可见分光光度计对叶绿素提取液和叶绿素晶体分别进行了紫外-可见光区吸收光谱的探测,并对其吸收曲线进行了分析和研究.根据实验结果对文献中的一些数据进行了讨论.     

Study of solvent-conjugated polymer interactions by polarized spectroscopy: MEH-PPV and Poly(9,9′-dioctylfluorene-2,7-diyl)

Absorption, emission, and anisotropy measurements were performed on poly-[2-methoxy-5(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and poly-(9,9′-dioctylfluorene-2,7-diyl) (PF) solutions of various solvents, and in thin films deposited from them. The good correlation of MEH-PPV absorption and emission energy with Hildebrandt's dispersive parameter indicate that dispersive forces regulate the effective extent of the luminophore. The excitation and the emission spectra of α and β chains can be distinguished in PF solutions using the steady-state anisotropy. PF films show greater memory effect from the solutions from which they were spun than MEH-PPV. Anisotropy of MEH-PPV is very low, both in solutions and in films reflecting efficient energy migration. Anisotropy of PF in solutions and films demonstrates great differences in energy transfer efficiency within the α and β phases, while there is no energy transfer between these chain conformations.