摘要:

We investigated the spectral and electrical characteristics of a new construction discharge tube with the peculiarity that the flat cathode bottom of conventional construction hollow cathode discharge tubes has been replaced by a conical bottom. This replacement was the prerequisite to enhancement by orders of magnitude of the intensity of spectral lines of the cathode material or sample introduced in it, while the intensity of the inert gas spectral lines is changed insignificantly. Probable mechanisms for generation of the observed effect have been discussed.

ISSN:0038-7010    

DOI:10.1080/00387017908069186

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Extensive analogies exist between molecular Rydberg spectra and corresponding “united-atom” rare-gas spectra.3The united atom for HI is Xe and it is our intention to use the similarities of the Rydberg spectra of these two entities in order to assign that of HI (and CH3I).

ISSN:0038-7010    

DOI:10.1080/00387017908069187

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Chemical and Electrochemical reductions of diphenyl boron dibenzamide in 1,2-dimethoxyethane have been investigated. The boron chelate forms a green radical anion upon reduction which exhibits marked stability over the ligand radical anion itself. The ESR spectrum showed a highly resolved ESR signal. The assigned hyperfine coupling constants indicated high unpaired spin delocalization over the ligand π-system.

ISSN:0038-7010    

DOI:10.1080/00387017908069188

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The question whether excited triplet states of quinones react with a number of substrates such as alcohols, phenols, and amines, via electron transfer mechanism has attracted much attention in recent years. The existence of some triplet exciplex was postulated by Kobashi et al1in their study of hydrogen atom abstraction by p-chloranil using laser flash spectrocopic detection. In some recent e.s.r. and CIDEP studies2,3, however, there is no compelling evidence that the photoreduction of quinones and benzophenones undergoes an initial electron transfer mechanism. It should be noted that most of the e.s.r. studies of quinone radical anions had been carried out in polar solvents. In flash photolysis studies some evidence has indeed been obtained1,4in which the efficiency of hydrogen abstraction by excited triplet quinones increases with solvent polarity and therefore it is possible that the initial primary process involves electron transfer followed immediately by proton transfer. On the other hand, we

ISSN:0038-7010    

DOI:10.1080/00387017908069189

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Spurious satellite features in the Raman spectra of samples excited by the 514.52 nm line of an argon ion laser have been traced to the simultaneous lasing action of the transition corresponding to 514.15 nm. Conditions for which this phenomenon occurs and procedures recommended to suppress it are briefly described.

ISSN:0038-7010    

DOI:10.1080/00387017908069190

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

2,5- and 2,6-dideuterobenzoquinone-1,4 were prepared by a direct catalytic (NaBD4/PdCl2) exchange of bromine in the corresponding dibromo derivatives and the subsequent oxidation with Ag2O. The structure of the products was unambiguously established by proton-carbon and deuteron-carbon splitting pattern of their NMR spectra.

ISSN:0038-7010    

DOI:10.1080/00387017908069191

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The influence of temperature variations and uncorrect positioning of the cuvette in its holder on the accuracy of absorbance measurements was thoroughly discussed in the case of potassium dichromate and nicotinic acid solutions to be used as reference materials for the periodic control of spectrophotometers. Results showed that temperature control to within ± 0.5 °C is sufficient. On the other hand, the error connected with cell positioning was found to be negligible under the usual working conditions. Finally, the effect of the purity degree on the absorbance values of the above substances was investigated.

ISSN:0038-7010    

DOI:10.1080/00387017908069192

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The Raman spectrum of ethylene glycol was studied as a function of temperature in the neat liquid and at two concentrations in the solvent, DMSO. Relative intensities of the gauche C-C-O bending mode and the C-C stretch (coincident for both rotamers) were utilized to calculate δH and TδS for each of the mixtures. It was observed that dilution in the solvent stabilizes the trans conformer, whereas variation in the entropy difference appears to favor the gauche form.

ISSN:0038-7010    

DOI:10.1080/00387017908069193

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Addition of sulphur hexafluoride to the nitrogen afterglow was found to selectively quench the δ and γ bands of NO while enhancing markedly the β bands involving v' = 1 and 2 levels. These effects could be satisfactorily explained on the basis of vibrational relaxation in the a4π state brought about by collisions with SF6and the interactions of this state with the other excited states which are involved in the emission of the above band systems. Certain peculiar spectral features were also observed at the crossing of the b4σ−with the B2π state.

ISSN:0038-7010    

DOI:10.1080/00387017908069194

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:0038-7010    

DOI:10.1080/00387017908069185

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor