摘要:

Anisotropy of optical transitions of monosolvate and disolvate species of chlorophyll “a” (Chl) and protochlorophyll “ a ” (PChl) have been investigated using fluorescence polarization (FP), circular dichroism (CD) and magnetic circular dichroism (MCD). The QX(o-o) transition of monosolvate species is found at 621-630 nm, while the QX(o-o) transition of Chl disolvate species at 639-642 nm. Therefore, previously accepted assignment of the Chl QX(o-o) transition is not correct. The longest wavelength transition of PChl is assigned to QX(o-o).

ISSN:0038-7010    

DOI:10.1080/00387017808063438

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Although there are numerous reports in the literature on the13C nmr spectra of transition metal carbonyls,1little attention has thus far been focused on their17O nmr spectra.2-4Oxygen-17 nmr spectra are extremely difficult to obtain because of the quadrupolar nature of the17O nucleus (I = 5/2) and its low natural abundance (0.037%). In addition, the low

ISSN:0038-7010    

DOI:10.1080/00387017808063439

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The preparation of 1,3-dinitrophenoxathiin represents the first reported synthesis of the phenoxathiin ring system. Based on known relative nucleophilicities either an unprecedented reversal of nucleophilicities or the occurrence of a Smiles Rearrangement would be required to account for the reported substituent locations. The re-examination of this synthesis with confirmation of actual substituent locations by13C-nmr and the correction of the original literature is described.

ISSN:0038-7010    

DOI:10.1080/00387017808063440

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

We found a need to optically characterize bismuth tri-iodide, BiI3, which has been used in antireflective thin film coatings on potassium chloride laser windows. We received a 7mm thick, 18mm diameter disc shaped sample of BiI3which exhibited a dark gray, glassy, metallic appearance. Several commercial spectrophotometers in the laboratory showed it to be opaque from 0.3μm to 50μm. We therefore decided to see if relevant optical data could be obtained on the sample using an in-house built photoacoustic spectrometer.

ISSN:0038-7010    

DOI:10.1080/00387017808063441

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The main purpose of potential constants,i.e., force and compliance constants, is to provide a quantitative understanding of bonding relationships. Compliance constants have been shown to possess several mathematical advantages over conventional force constants.1-3Compliance constants, however, are parameters which decrease in magnitude as bond strength increases; consequently, their use as bond strength parameters is not particularly satisfying. The desirability of a measure of bond strength which increases in magnitude as the bond becomes stronger, and at the same time possesses all the advantages of compliance constants is self evident. For this reason, the relaxed force constant Tii= 1/Ciiwas introduced by a Jones some time ago.4In the present communication, this approach is generalized to include relaxed interaction force constants. A brief discussion of their meaning is also presented.

ISSN:0038-7010    

DOI:10.1080/00387017808063442

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The range of the two techniques of multi-element atomic fluorescence spectrometry may be extended by the use of a twinport power divider to allow two multi-element electrodeless discharge lamps to be operated from a single microwave generator. Various combinations of 1/4-wave, 3/4-wave resonant cavities and an A-antenna in conjunction with a coaxial attenuator allow lamps of differing excitation requirements to be operated simultaneously.

ISSN:0038-7010    

DOI:10.1080/00387017808063443

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

A procedure has been developed for the direct determination of cadmium in whole blood by furnace atomic absorption spectroscopy. No ashing procedures are necessary thus avoiding positive errors caused by contamination in wet ashing or negative errors caused by volatilization of the cadmium during dry ashing techniques. The whole blood samples are immobilized on a pretreated small filter paper disk which is then dropped into a carbon bed atomizer, heated with an RF coil. Decomposition and atomization take place in the carbon bed and the combustion products are drawn into the optical light path for absorption measurements. In contrast to commercial furnace atomizers, there is no atomization program which thereby avoids loss of cadmium by volatilization and greatly reduces the background and chemical interference effects due to the highly variable matrix of blood. Typical results are reported.

ISSN:0038-7010    

DOI:10.1080/00387017808063444

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0038-7010    

DOI:10.1080/00387017808063445

出版商:Taylor & Francis Group    

年代:1978

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:10.1080/00387017808063437

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor