摘要:

Since the time the first1dispersive broad-band infrared (IR) photoacoustic spectra of solids were reported, practically all IR photoacoustic and photothermal beam deflection work has been done with interferometers. The sample illumination and consequent spectra obtained with interferometers are, of course, much better than those obtained with a dispersion instrument2-5. However, continuously-scanning interferometers lead to continuously-varying modulation frequencies with attendant difficulties involving penetration depth and signal phase6, and spectral profiles can change when different scan speeds are used7. With such instruments one has, essentially, little control over some parameters which might be vital in certain circumstances; a step drive would be better.

ISSN:0038-7010    

DOI:10.1080/00387018508062307

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

By means of the force field and mean amplitudes of vibration of furan, thiophene, selenophene and tellurophene molecules, we have concluded that the ground-state aromaticity order in the series is thiophene > tellurophene > selenophene > furan. The reactivity of these molecules to the electrophilic substitution follows the order furan > selenophene ∼ tellurophene > thiophene.

ISSN:0038-7010    

DOI:10.1080/00387018508062308

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

CW line-tunable CO2laser-induced optogalvanic effects were observed from molecular plasmas excited by the electrodeless radio-frequency discharge. The optogalvanic effects were applied to detect laser output spectra and to optimize laser output power in CO2discharge plasmas and to measure optogalvanic (absorption) spectra in SF6and NH3plasmas. Other applications were briefly mentioned.

ISSN:0038-7010    

DOI:10.1080/00387018508062309

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Atomic emission and fluorescence signals were collected simultaneously with sinusoidal wavelength modulation and detection of the second harmonic mode. The system consisted of a continuum source, argon-separated air/acetylene flame and a wavelength-modulated monochrometor. Limits of detection of several elements were measured. This method was applied to the analysis of a copper alloy, and Co, Cu, Fe, Mn, Ni, Pb and Zn were successfully determined.

ISSN:0038-7010    

DOI:10.1080/00387018508062310

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Normal unenhanced Raman spectra (NURS) of low-polarizability CO molecules adsorbed on Ni(111) at liquid nitrogen temperature have been recorded. The13CO has been used for the first time to confirm previously reported Raman spectra of12CO adsorbed on Ni(111). The exposure used in one set of experiments was 106L13CO. Residual12CO gas was present and gave rise to spectra identical to that reported previously. The expected shifted Raman bands due to13CO were observed. These included the13C-O stretches and their matching Ni-13C frequencies. Another set of experiments were performed while the Ni(111) sample was exposed to a static 1-atmosphere13CO pressure. Striking features were observed at such high pressure. Two tentative models are presented to explain the observed spectra.

ISSN:0038-7010    

DOI:10.1080/00387018508062311

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The use of a pneumatic nebulization with impaction bead system for sample introduction of dissolved solids in flame and furnace atomic absorption spectrometry is investigated. The distance between the aerosol emerging from the capillary tip and the impaction bead is critical for dissolved solids in terms of nebulization efficiency, imprecision, absorbance signal, and interferences. The experimental results are considered to be dependent on the particle size generated by the pneumatic nebulization with impaction bead system.

ISSN:0038-7010    

DOI:10.1080/00387018508062312

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The natural abundance15N-NMR chemical shifts of 1, 10-phenanthroline, pyridazine and 7-azaindole have been measured as a function of the nature of the solvent. Hydrogen bonding and protonation result in upfield shift of both the pyridine type nitrogens in 1, 10-phenanthroline and pyridazine where as in 7-azaindole, the effect is larger at the pyridine ring nitrogen. The chemical shifts due to protonation far exceeded those from hydrogen bonding. In addition to identifying the site of donation, the15N-NMR data establishes the mechanism of charge transfer and hydrogen bonded complex formation.

ISSN:0038-7010    

DOI:10.1080/00387018508062313

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Interactions between proteins or peptides and transition metal play an important role in biological systems (1–5). An approach to the study of metal ion binding is the chemical synthesis of a metallo-model site and analogues thereof and the comparison of their metal ion binding characteristics (6, 7). Among the peptide models interacting with different metals we are engaged with the tetrapeptide segment Ac-Asp-Val-Asp-Ala-OH (Ac-DVDA-OH) which can be considered as a simplified model of calcium binding sites of several proteins (8, 9). Previous study in solution, argued to a high stability constant of metal-Ac-DVDA-OH complexes at neutral pH (10). NMR results suggest the chelation of calcium or rare earth cations (Pr3+) through the two carboxylate groups of aspartyl residues (11). The main purpose of the present paper is to give a contribution to the study of interactions between copper and nickel and the tetrapeptide model by Infrared spectroscopy.

ISSN:0038-7010    

DOI:10.1080/00387018508062314

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The13C nmr assignments for all carbons except the methylene groups were made for artemisinin (1), artemether (2) and desoxyartemisinin (3). The assignments were based on chemical shift theory and confirmed by selective band decoupling experiments.

ISSN:0038-7010    

DOI:10.1080/00387018508062315

出版商:Taylor & Francis Group    

年代:1985

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:10.1080/00387018508062306

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor