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61.
Alard JP Basrak Z Bastid N Belayev IM Bini M Blaich T Bock R Buta A Caplar R Cerruti C Cindro N Coffin JP Crouau M Dupieux P Erö J Fan ZG Fintz P Fodor Z Freifelder R Fraysse L Frolov S Gobbi A Grigorian Y Guillaume G Herrmann N Hildenbrand KD Hölbling S Houari O Jeong SC Jorio M Jundt F Kecskemeti J Koncz P Korchagin Y Kotte R Krämer M Kuhn C Legrand I Lebedev A Maguire C Manko V Matulewicz T Mgebrishvili G Mösner J Moisa D Montarou G Morel P Neubert W Olmi A Pasquali G Pelte D Petrovici M 《Physical review letters》1992,69(6):889-892
62.
63.
Thermal nebulization of nickel-base alloys, corundum plates and residues of solutions was performed with a laser beam. The solid aerosol was aspirated into an acetylene-air flame by an ejector. Linear analytical curves in wide concentration ranges were established and an average relative standard deviation of 10% was found. The detection limit is in the ng range for iron and copper, and lower for zinc, cadmium and sodium. 相似文献
64.
Films of low density polyethylene have been degraded under an oxygen atmosphere at temperatures above the semicrystalline melting point. Time, conversion and temperature dependence of carboxyl group formation and chain scission have been studied. After induction periods we found linear dependences both in function of time and conversion. One third of absorbed oxygen forms carboxyl groups and the absorption of 3·57 mmol oxygen per monomer unit is needed for one chain scission. Maximum rates of carboxyl formation and chain scission have Arrhenius temperature dependence with 33·5 kcal/mole activation energy. The number of carboxyl groups and chain scissions are always practically the same; we assume that the isomerisation of secondary alkyl peroxy radicals simultaneously causes chain scission and carboxyl formation. 相似文献
65.
A new type of radiofrequency capacitively coupled plasma torch is presented. The torch electrode geometry is coaxial with a tubular central electrode and one or two outer ring electrodes. The argon plasma is generated at 275 W radiofrequency power and 27.12 MHz and it has a very good stability and a low gas consumption of 0.4 l min(-1). The nebulized sample is introduced through the tubular electrode into the core of the annular shaped plasma thus achieving a better atomisation and a lower background. The limits of detection for 20 elements are in the range of ng ml(-1) and the dynamic range between 2.5 and 3.5. The best results are obtained with the torch with two outer ring electrodes. 相似文献
66.
Improving selenium extraction by sequential enzymatic processes for Se-speciation of selenium-enriched Agaricus bisporus 总被引:1,自引:0,他引:1
Sample preparation methods based on the use of proteolytic and cell wall digesting enzymes for the speciation analysis of selenized mushroom were investigated. The sample (Agaricus bisporus; 160 microg total Se per g sample) was grown on compost supplemented with selenized yeast. Experiments were carried out to elucidate the possible role of the cell wall digesting enzymes--Lysing enzyme and Driselase--in the improvement of extraction efficiency with and without inhibiting proteolysis during cell wall digestion. A 3-step procedure applying Lysing enzyme and pronase gave the highest extraction efficiency (89%); however, the best species recovery was achieved by a one-step proteolytic procedure. All the procedures of selenium speciation were controlled by independent ICP-AES analysis measuring the total amount of selenium. 相似文献
67.
H. v. Euler C. Zimmerlund C. van der Hoeven R. Riwlin A. Fodor A. K. Goard J. Effront F. König P. Surun J. M. Kolthoff A. S. Coolidge W. Bachmann L. Maier O. Wolff J. E. Teeple und P. Mahler 《Fresenius' Journal of Analytical Chemistry》1929,78(7-8):297-304
Ohne Zusammenfassung 相似文献
68.
Mester Z Horváth G Vitányi G Lelik L Fodor P 《Rapid communications in mass spectrometry : RCM》1999,13(5):350-353
A gas chromatography/mass spectrometry (GC/MS) method has been developed to determine two methylated arsenic species in human urine samples. The yield of derivatization for dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) using thioglycol methylate (TGM) was measured. The detection limit for the derivatized DMA and MMA using the GC/MS method are 0.95 and 0.8 ng cm-3, respectively. This simple and rapid method has good precision and accuracy. Fragmentation routes of derivatized MMA and DMA are suggested on accurate mass measurements. 相似文献
69.
Lajos Fodor János Szabó Erzsébet Szúcs Gábor Bernáth Pál Sohár József Tamás 《Tetrahedron》1984,40(20):4089-4095
6,7-Dialkoxy-2-aryl-41-1,3-benzothiazines (1a?) react with chloroacetyl chlorlde to give condensed β-lactam derivatives (2a?). Basic treatment of 2a? in methanol led to the corresponding 1,4-banzothiazepine derivativee (3a?) ring expansion. The structures of the products were determined by IR, NMR and MS studies 相似文献
70.
I. Bang J. A. Mandel H. Steudel O. Folin L. Pincussen F. Fregl F. Emich H. Lieb J. V. Dubsky A. Fodor J. Herzog W. Denis R. D. Bell L. Hannaert R. Wodon C. Vallée A. Polonowski P. E. Howe E. L. Kennaway K. L. Gad-Andresen R. Fosse M. Nicloux G. Welter 《Analytical and bioanalytical chemistry》1923,63(1-2):72-80