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991.
Air samples collected at the second Bosporus bridge of Istanbul which carries a heavy traffic load between Asia and Europe,
were analyzed for 22 elements by the INAA method. Pb, Cd and Fe concentrations in the samples were determined by AAS. Iron
concentrations were used as a cross check between the two methods. In order to define the enrichment factors for the elements
in the bridge area, a sample collected from our university campus which can be considered as a rural site, was also analyzed.
Differences were observed especially for Br, Al, Mg, Ti, Cu and Na between the two sites. Based on the results of the samples
from the bridge, we got a value of 0.58(16) for the Br/Pb-ratio. 相似文献
992.
993.
James N. Sturgis C. Neil Hunter Robert A. Niederman 《Photochemistry and photobiology》1988,48(2):243-247
Abstract— Membranes from Rhodobacter (formerly Rhodopseudomonas) sphaeroides mutant strains that lack one or more of the bacteriochlorophyll a (BChl)-protein complexes were used to obtain spectra and molar extinction coefficients of the near-IR absorption bands. The strains examined were NF57 which lacks the B875 light-harvesting and reaction center complexes, and M21 which lacks the B800–850light-harvesting complex. The extinction coefficients obtained for the B800, B850 and B875 bands were 226 ± 10, 170 ± 5, and 118 ± 5 m M -1 cm-1 , respectively, in reasonable agreement with values reported for detergent-isolated complexes (Clayton, R. K. and B. J. Clayton, Proc. Natl. Acad. Sci. USA 78 ,5583–5587, 1981). The results also demonstrated that detergent solubilization altered the spectra, causing a band broadening on the blue side of the B875 and B800 peaks. The data obtained from the analysis of the mutant strains were used for deconvolution of the BChl species in membranes of the wild-type. A short BASIC computer program for performing this deconvolution is included. 相似文献
994.
We describe a simple method for the determination of phenobarbital, diphenylhydantoin, carbamazepine, and primidone in serum, by use of gas-liquid chromatography with temperature programming. The methylated derivatives of these anticonvulsants were well resolved, as was 5-(p-methylphenyl)-5-phenylhydantoin, the internal standard. In this procedure we used the jet tube for separation of the drug from the serum. The proposed procedure requires only 100 μl of serum and can be done in less than 30 min. The lower limit of detection for each of the drugs is 0.5 mg/liter. Analytical recoveries of drug from serum were excellent and peak height and concentration were linearly related up to twice the toxic concentration for serum. 相似文献
995.
Christian C. Van de Sande Syed Zahoor Ahmad Friedrich Borchers Karsten Levsen 《Journal of mass spectrometry : JMS》1978,13(11):666-670
Gaseous protonated aziridine ions are produced at the threshold from β-phenoxyethylamine molecular ions. The evidence for this is collisional activation spectra, using various precursors (including labelled analogues) under electron impact and field ionization conditions. Partial conversion to the acyclic \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} {\rm CH = }\mathop {\rm N}\limits^ + {\rm H}_{\rm 2} $\end{document} isomer occurs at higher electron energies and is rationalized by means of a potential energy surface constructed from energetic data. 相似文献
996.
The first example of fluorine elimination α to a carboxyl group is reported. The defluorination occurs when solution of perfluorocarboxylic esters in hexamethyl-phosphortriamide are irradiated with UV light (254 nm). Mechanistic and synthetic aspects of this new reaction are described. 相似文献
997.
The reactions of alkali metal salts of anthracene with alkyl halides result in the formation of 9,10-dialkyl 9,10-dihydroanthracenes as the principal product, although appreciable quantities of other adducts, notably the 1,2- and 1,4-dialkyl compounds, are also formed.When the disodium salt is used, these adducts account for the total anthracene consumed, but with the dilithium salt appreciable quantities of 9,(4-hydroxybutyl) anthracene compounds are produced; they resulted from additive reaction of the salt with the tetrahydrofuran solvent. In the present experiments, these adducts account for about 20 per cent of the anthracene, but this proportion may be increased by prolonging the standing of the dilithium anthracene solution before reacting with alkyl halide. 相似文献
998.
R. C. Milward 《Fresenius' Journal of Analytical Chemistry》1973,264(3):195-199
Summary This article describes a new commercial Far-Infrared Fourier Spectrometer system which has been developed for routine spectroscopy in the 10–1000 cm–1 spectral region. The instrument incorporates real-time data processing and has been automated wherever possible for foolproof operation. A versatile sample chamber allows a wide range of spectroscopic studies to be performed, on solids, liquids and gases over a wide range of temperatures. A number of spectra are presented to illustrate the performance and typical applications of this Fourier spectrometer.
Ein neues fourier-spektrometer für das ferne infrarot
Zusammenfassung Nach einer kurzen Einführung in die Methode der Fourier-Spektroskopie wird ein neues kommerzielles Fern-Infrarot-Fourier-Spektrometer mit real-time Datenverarbeitungsanlage beschrieben. Das Gerät ist für die Spektroskopie im Bereich 10–1000 cm–1 konstruiert und weitgehend automatisiert. Eine vielseitig verwendbare Probenkammer ermöglicht umfangreiche spektroskopische Untersuchungen von Festkörpern, Flüssigkeiten und Gasen in einem sehr großen Temperaturbereich. Anhand einer Reihe von Spektren werden Leistung und typische Anwendungen dieses Fourier-Spektrometers erläutert.
Lecture presented at Euroanalysis I Conference, 28. 8.–1. 9. 1972 in Heidelberg, Germany. 相似文献
999.
The chemical shift of core shell ionization energies in various perxenates relative to gaseous xenon is strongly compensated by interatomic relaxation. This effect is even more clear-cut on the Auger signals moving in the opposite direction of a (Hartree + Madelung) potential model. 相似文献
1000.
Since the band for OH stretching of HOD molecules solvating perchlorate ions is clearly resolved, the remaining band can be analysed to give values for the OH absorption for the cation solvation shell: these are closely correlated with NMR shift data. 相似文献