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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Plasma chemistry and plasma processing 19 (1999), S. 111-130 
    ISSN: 1572-8986
    Keywords: dc glow discharge ; microwave measurements ; electron density determination by microwaves ; microwave resonator method ; high-frequency electron current ; electron velocity distribution function ; time-dependent Boltzmann equation ; temporal electron relaxation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract A improved method of the microwave diagnostics for the determination of the electron density in the column plasma of dc glow discharges is presented. This method overcomes significant limitations involved in the conventional method. The latter is mainly based on the measurement of the resonance frequency shift of the resonator cavity caused by the presence of the dc column plasma and is strictly valid only in the so-called high field frequency limit of the resonator operation. Of significant importance with respect to the improved method is the additional inclusion of the measurable phase delay between the electric hf field, superimposed on the dc plasma by the microwave field of the resonator, and the induced hf electron current. This new method has been critically evaluated with respect to its extended applicability and has been successfully applied to the experimental determination of the electron density in dc plasmas of neon and molecular nitrogen.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Plasma chemistry and plasma processing 20 (2000), S. 111-135 
    ISSN: 1572-8986
    Keywords: dc glow discharge ; microwave measurements ; electron density determination by microwaves ; microwave resonator method ; high-frequency electron current ; electron velocity distribution function ; time-dependent Boltzmann equation ; temporal electron relaxation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The high-frequency (HF) electron current induced in a dc discharge plasma bysuperimposing a HF electric field presents a useful tool for the diagnosticsof the time-dependent electron behavior of the plasma. This response to theHF field has been recently studied in diffusive discharge plasmas at lowergas pressures and discharge currents. These studies are extended tomedium-pressure plasmas operating in the diffusive as well as in theconstricted mode. In particular, the impact of the electron–electroninteraction on the phase delay between the HF field and electron current inconstricted column plasmas has been experimentally and theoreticallyanalyzed. Furthermore, the problem has been studied if, under the conditionsof pronounced electron–electron interaction, the determination of theelectron density will further on be possible by using the phase delay. Themeasurements of the delay have been performed by means of the microwaveresonator method in a medium-pressure krypton glow discharge operating inthe diffusive as well as the strongly constricted mode. In addition, thedelay has been theoretically determined by treating the appropriatetime-dependent electron kinetic equation at high frequencies of thesuperimposed microwave field.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es werden die wichtigsten Synthesen verzweigtkettiger Alkane hinsichtlich Ausbeute und Reinheit der Endprodukte diskutiert. Am geeignetsten wurde für die Synthese der 4n-propyl- und 2-Methyl-3-isopropyl-Alkane die GRIGNARD-Reaktion gefunden.Von den dargestellten verzweigtkettigen Alkanen wurden Dichte, Brechungsindex, Oberflächenspannung, Kochpunkt, % C und % H bestimmt, Molvolumen, Molrefraktion und Parachor berechnet. Weiterhin wurden IR-Spektrogramme aufgenommen und die Fähigkeit der Adduktbildung mit Harnstoff untersucht.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 36 (1953), S. 1319-1324 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Als neue Bezeichnung für die Substanz F aus Herbstzeitlosen wird der Trivialname Demecolcin vorgeschlagen.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 37 (1954), S. 721-754 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Samen von Dregea volubilis (L.) Benth ex Hook. erwiesen sich als recht glykosidreich, doch stiess die Isolierung reiner Stoffe auf Schwierigkeiten. Durch Verteilung zwischen Wasser und organischen Lösungsmitteln, teilweise unter Verwendung des Reagens T von Girard & Sandulesco sowie durch Chromatographie an Al2O3 liessen sich vier verschiedene Glykosidpräparate erhalten, die als „Drevoside A, B, C und D“ bezeichnet wurden. Alle vier Präparate waren aber amorph und nicht einheitlich. Das Gemisch zeigte bei der biologischen Prüfung keine digitalisartige Wirkung, auch das gereinigte „Drevosid A“ war unwirksam.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 50 (1967), S. 2497-2500 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,4-Dihydroxyanthraquinones are transformed into the corresponding chlorohydroxy-ana-anthraquinone dienophiles, which are subjected to Diels-Alder addition with 1,3-dienes. The adducts formed are dehydrogenated to known and to new hydroxynaphthacene quinones.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 51 (1968), S. 592-597 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The amination and oxidation of naphthazarin-diene adducts leads to known and to new anthraquinone and tricyclic naphthazarin dyestuffs and their intermediates. The new products allow extension of the hitherto known (especially green) color range of dyes. The mechanism of the reaction is discussed.
    Type of Medium: Electronic Resource
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