Emission spectra of porphyrins

Factors influencing fluorescence spectra of free porphyrins.

We recorded fluorescence excitation and emission spectra of uro- and coproporphyrin under different experimental conditions, to see how these conditions influence quantifications based on measurement of fluorescence intensity. We found that, for bands alpha and beta of the emission spectra and the main peak of the excitation spectra, fluorescence depends on pH and is minimal near pH 5 and near ...

Pulsar spectra of radio emission

We have collected pulsar flux density observations and compiled spectra of 281 objects. The database of Lorimer et al. (1995) has been extended to frequencies higher than 1.4 GHz and lower than 300 MHz. Our results show that above 100 MHz the spectra of the majority of pulsars can be described by a simple power law with average value of spectral index < α >= −1.8 ± 0.2. A rigorous analysis of s...

A new method for Eosin preparation and examination of its absorption and emission spectra

Eosin is one of the original dyes of xanthenes derivatives. It is also one of the main derivatives of fluorescein and has brilliant fluorescence. Eosin disodium salt called "Eosin Y" is the most useful form of this compound. In common procedures, eosin is usually obtained by the action of bromine on fluorescein, which has not good yield and purity degree. In this research, it is prepared by the...

Theoretical Elements of Acoustic Emission Spectra

Infrared Emission Spectra of Flames 451

The infrared emission spectra of a hydrogen flame and' of a natural gas flame have been compared in the region from 1. 7p. to 24p.. Emission bands have been observed at 1.87p., 2.78p. , 4.37p., 6.20p., and 15p. that a re produced by molecules of H 20 and CO2• Another band at 3.316p. is attributed to methane. From 3.0p. to 3.8p. there are a number of rotational lines, some of which may be produc...