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  • 1
    Electronic Resource
    Electronic Resource
    On the concept of temperature for a small isolated system (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 114 (2001), S. 6518-6525 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The microcanonical temperature is shown to be a useful concept in calculations of the decay of a small isolated system with well defined energy. A simpler and more transparent description is obtained than in Klots' formulation of finite-heat-bath theory, where the system is represented by a canonical ensemble. As a further illustration of the utility of the microcanonical temperature concept, we discuss a formula derived by Dunbar for the probabilities for excitation of a single oscillator in a collection of harmonic oscillators with well defined total energy. This formula expresses the excitation probabilities in terms of the temperature for a canonical ensemble with mean energy equal to the energy of the system. However, a much improved accuracy is obtained if the canonical temperature and heat capacity are replaced by their microcanonical values. We justify this replacement through a modified derivation, in which the microcanonical temperature appears as the canonical temperature of a fictitious system with level density ρ′(E), the derivative of the level density ρ(E) of the collection of oscillators. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1357794
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  • 2
    Electronic Resource
    Electronic Resource
    Double-blind, placebo-controlled food challenge with apple (2001)
    Copenhagen : Munksgaard International Publishers
    Allergy 56 (2001), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The aim of the study was to develop and evaluate different methods of double-blind, placebo-controlled food challenge (DBPCFC) with apple. Three different DBPCFC models were evaluated: fresh apple juice, freshly grated apple, and freeze-dried apple powder. All challenges were performed outside the pollen season and took place from 1997 to 1999. The freeze-dried apple material was characterized by means of leukocyte histamine release (HR), skin prick test (SPT), and immunoblotting experiments. The study population consisted of birch pollen-allergic patients with a history of rhinitis in the birch-pollen season and positive specific IgE to birch. For comparison of the DBPCFC models, 65 patients with a positive open oral challenge with apple were selected. In the characterization of the freeze-dried apple material, 46 birch pollen-allergic patients were included. The IgE reactivity to apple was evaluated by measurement of specific IgE, HR, and SPT. Golden Delicious apples were used in all experiments. The results of this study showed that it was possible to perform DBPCFC with apple in birch pollen-allergic individuals. The model with freshly squeezed apple juice had a low sensitivity and displayed a high frequency of reactions to placebo, probably due to the ingredients used for blinding. The sensitivity of the models with freshly grated apple and freeze-dried apple powder was 0.74/0.60. An increase in sensitivity is desirable. The freeze-dried apple powder proved to be useful for SPT, HR, and oral challenges, but further investigation of the stability and the allergenic profile of the material is needed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1034/j.1398-9995.2001.056002109.x
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  • 3
    Electronic Resource
    Electronic Resource
    Zur Luminiszenz von Cr(3)-Verbindungen (1966)
    Springer
    Theoretical chemistry accounts 6 (1966), S. 272-277 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Whereas 2.4 is likely to be an upper limit for the Dq/B-value of Cr(3)-complexes which show fluorescence the existence of a lower bound is rather unlikely. Experimental evidence suggests that the energy difference between the minima of the 2 E g- and the 4 T 2g-potential curves is one of the factors determining the relative intensities of phosphorescence and fluorescence.
    Abstract: Résumé Alors que 2,4 apparaît comme une limite supérieure du rapport Dq/B pour les complexes fluorescents de Cr(3), l'existence d'une limite inférieure est peu probable. L'évidence expérimentale suggère que l'intensité relative de la phosphorence et de la fluorescence est déterminée par la différence d'énergie entre les minima des courbes de potentiel des états 2 E g et 4 T 2g .
    Notes: Zusammenfassung Während 2,4 wahrscheinlich die obere Grenze für den Dq/B-Wert fluoreszierender Cr(3)Komplexe ist, gibt es für die Existenz eines unteren Grenzwerts keine Anzeichen. Experimentelle Ergebnisse legen nahe, daß das Verhältnis von Phosphoreszenz- zu Fluoreszenzemission durch die relative Höhe der Minima der 2 E g- und 4 T 2g-Potentialkurven bestimmt wird.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000007
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  • 4
    Electronic Resource
    Electronic Resource
    Zur Luminiszenz von Cr(3)-Verbindungen (1966)
    Springer
    Theoretical chemistry accounts 6 (1966), S. 272-277 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Whereas 2.4 is likely to be an upper limit for theDq/B-value of Cr(3)-complexes which show fluorescence the existence of a lower bound is rather unlikely. Experimental evidence suggests that the energy difference between the minima of the2 E g- and the4 T 2g-potential curves is one of the factors determining the relative intensities of phosphorescence and fluorescence.
    Abstract: Résumé Alors que 2,4 apparaît comme une limite supérieure du rapportDq/B pour les complexes fluorescents de Cr(3), l'existence d'une limite inférieure est peu probable. L'évidence expérimentale suggère que l'intensité relative de la phosphorence et de la fluorescence est déterminée par la différence d'énergie entre les minima des courbes de potentiel des états2 E g et4 T 2g .
    Notes: Zusammenfassung Während 2,4 wahrscheinlich die obere Grenze für denDq/B-Wert fluoreszierender Cr(3)Komplexe ist, gibt es für die Existenz eines unteren Grenzwerts keine Anzeichen. Experimentelle Ergebnisse legen nahe, daß das Verhältnis von Phosphoreszenz- zu Fluoreszenzemission durch die relative Höhe der Minima der2 E g- und4 T 2g-Potentialkurven bestimmt wird.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02394704
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  • 5
    Electronic Resource
    Electronic Resource
    Erratum (1966)
    Springer
    Theoretical chemistry accounts 6 (1966), S. 452-452 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00528471
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  • 6
    Electronic Resource
    Electronic Resource
    Radiative cooling of fullerene anions in a storage ring (2001)
    Springer
    The European physical journal 17 (2001), S. 189-204 
    Details
    ISSN: 1434-6079
    Keywords: PACS. 36.40.-c Atomic and molecular clusters – 36.40.Cg Electronic and magnetic properties of clusters – 36.40.Qv Stability and fragmentation of clusters – 36.40.Wa Charged clusters – 39.10.+j Atomic and molecular beam sources and techniques
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: Thermionic emission from hot fullerene anions, CN -, has been measured in an electrostatic storage ring for even N values from 36 to 96. The decay is quenched by radiative cooling and hence the observations give information on the intensity of thermal radiation from fullerenes. The experiments are analysed by comparison with a simulation which includes the quantisation of photon energy and the statistics of emission. Experiments with heating of the molecules with a laser beam confirm the interpretation of the observations in terms of radiative cooling and give an independent estimate of the cooling rate for C60 -. The measured cooling rates agree in general within a factor of two with the prediction from a classical dielectric model of a thermal radiation intensity of ∼ 300 eV/s for C60 at 1 400 K, scaling approximately with the 6th power of the temperature and with the number of atoms in the molecule.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100530170022
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