摘要:

Anodic processes were studied for eugenol, isoeugenol and 2,6-dimethoxy-4-allylphenol by cyclic voltammetry at a glassy carbon electrode in methanol. Preparative electrolyses were also applied coulometrically to these phenols, followed by the separation and the determination of the structures of -e, -2e and -4e products. It was indicated that both radical and cationic reactions were controlled by the applied potentials, the solvent media and the substituents on the aromatic rings.

ISSN:0003-2719    

DOI:10.1080/00032717908082535

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Studies of the background currents for polythioxyl electrodes in 1NH2SO4supporting electrolyte shows that oxygen strongly chemisorbs on both parallel and perpendicular surfaces. On fresh surfaces the principle product on anodic breakdown is oxygen but on prolonged cycling surface hydroxides of (SN)xare the major surface functional groups at anodic breakdown.

ISSN:0003-2719    

DOI:10.1080/00032717908082536

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Poly (crown ether) was employed as a catalyst of derivatization of lower fatty acids to thep-bromophenacyl esters for gas chromatographic determination of them. The esterification reaction proceeds quantitatively under mild conditions, i.e. at room temperature and within 30 min. The poly (crown ether) did not interfere with the gas chromatogram of the esters unlike monomeric crown ethers. Normal fatty acid (C1-C6) and the isomers could be determined simultaneously near to the detection limit of FID.

ISSN:0003-2719    

DOI:10.1080/00032717908082537

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Empirical data is presented to describe the relationship between the fluorescence lifetimes (τf) and the position of substituents on the parent molecule, Phenyl-N-Methylcarbamate. The fluorescence lifetimes are determined using time correlated single photon counting technique1. It is found that increasing lifetimes with position of substitution follows the order, meta > para > ortho in the case of mono-alkyl substituted carbamates. Also, the results below indicate that the long fluorescence lifetime of 4-Dimethylamino-3,5-Xylyl-N-Methylcarbamate, τf108 ns2originates from an n-II* lowest excited state and not the usual II-II* lowest excited states of the other N-Methylcarbamates studied.

ISSN:0003-2719    

DOI:10.1080/00032717908082538

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The adsorption of a number of polyaromatic hydrocarbons onto aqueous colloidal kaolin was studied. The fluorescence polarization and hence the fluorescence anistropy of the hydrocarbons was measured as a function of their concentrations in aqueous solutions containing the colloid. The fluorescence anisotropy was found to be highest for dilute solutions of polyaromatic hydrocarbons, with often sharp decreases at higher concentrations. More concentrated solutions gave an isotropies similar to those of plain aqueous solutions of the fluorophores. The concentrationversusfluorescence anisotropy curves and BET surface area data were used to calculate surface coverage of the colloid by the adsorbed hydrocarbons. Coverage in the range of 1% to 14% of the colloid surface was found at surface saturation for the compounds studied. This suggested that colloidal clays have the potential of transporting polyaromatic hydrocarbons through environmental waters.

ISSN:0003-2719    

DOI:10.1080/00032717908082539

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Ion implantation standards were used to calibrate a spark source mass spectrometer (SSMS) near surface region analytical method. Standards were prepared by ion implanting11B+at 100 keV into Zircaloy-2 at doses in the 3 × 1015to 3 × 101611B atoms/cm2range. The analytical method was predicated on the idea that both standards and samples could be sparked in a SSMS under essentially identical and reproducible conditions. Calibration plots gave linear log-log results for plots of11B+/122Sn+versus B concentration in the standards. Calibration plots were determined on the basis of 5 to 6 replicate determinations for 3 different implant standard concentration levels. A series of irradiated Zircaloy-2 cladding samples were analyzed and shown to contain not more than 0.06 μg/cm2total B in the near surface region.

ISSN:0003-2719    

DOI:10.1080/00032717908082540

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0003-2719    

DOI:10.1080/00032717908082534

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor