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  • 1
    Electronic Resource
    Electronic Resource
    The resonant thermonuclear reaction rate (1986)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 27 (1986), S. 2203-2207 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.526988
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  • 2
    Electronic Resource
    Electronic Resource
    Gravitational instability in a multicomponent cosmological medium (1988)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 29 (1988), S. 2069-2077 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: A systematic approach to exact solutions for the evolution of small density inhomogeneities of a two-component and in special cases for a three-component cosmological medium is presented. In general, there exists just one increasing perturbation mode. Expressing the solutions of the respective differential equations in terms of Meijer's G function [Proc. Nederl. Akad. Wetensch. A 49, 344 (1946)] various exact and asymptotic formulas for the perturbation modes are derived.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.527864
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  • 3
    Electronic Resource
    Electronic Resource
    One-dimensional magnetic flux microscope based on the dc superconducting quantum interference device (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 61 (1992), S. 598-600 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have designed and operated a magnetic flux microscope which measures the magnetic field above a sample surface by scanning a 4.2 K thin-film dc superconducting quantum interference device (SQUID) along one direction. With the SQUID and sample separated by about 160 μm, the system can image features with a spatial resolution of about 220 μm and a magnetic field resolution of 1.8×10−13 THz−1/2. We have used the system to view trapped magnetic flux, to image thin-film strips of superconducting Pb in field strengths of 0–750 nT, and to monitor the position of a sample with a resolution of approximately 0.5 nm Hz−1/2 at a frequency of 4 kHz.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.107848
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  • 4
    Electronic Resource
    Electronic Resource
    Magnetic microscopy using a liquid nitrogen cooled YBa2Cu3O7 superconducting quantum interference device (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 2128-2130 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have developed a magnetic flux microscope which uses a liquid nitrogen cooled thin-film YBa2Cu3O7 dc superconducting quantum interference device (SQUID) to produce two-dimensional images of magnetic fields. The instrument operates as a scanning probe microscope with a spatial resolution of about 80 μm and a field of view of about 100 mm2. The equivalent magnetic field noise in the SQUID ranges from 80 pT Hz−1/2 at 1 Hz to 20 pT Hz−1/2 at 1 kHz, yielding a field resolution of about 200 pT in our images. We have used the microscope to image magnetic domains in ferromagnetic samples, small currents flowing in fine wires, and trapped flux and diamagnetic susceptibility in superconducting thin films.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.109448
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  • 5
    Electronic Resource
    Electronic Resource
    Hypothesis of multisample sphericity (1986)
    Springer
    Journal of mathematical sciences 33 (1986), S. 792-796 
    Details
    ISSN: 1573-8795
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The hypothesis of multisample sphericity appears in different areas such as repeated measurement designs, checking the validity of F ratios in the analysis of variance problems, and testing circularity. This article deals with the modified likelihood ratio test for testing multisample sphericity, null and nonnull moments, as well as the null and nonnull distributions of the test statistic. Some approximations are also considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01091445
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  • 6
    Electronic Resource
    Electronic Resource
    Analytic representations of modified non-resonant thermonuclear reaction rates (1986)
    Springer
    Zeitschrift für angewandte Mathematik und Physik 37 (1986), S. 685-695 
    Details
    ISSN: 1420-9039
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Description / Table of Contents: Summary The basic physical principles common for the evaluation of all non-resonant thermonuclear reaction rates will be discussed. For the standard form of the nuclear reaction rate with Maxwell-Boltzmann distribution we give the closed-form representation by means of Meijer'sG-function. For physical reasons we consider the non-resonant thermonuclear reaction rate with modified Maxwell-Boltzmannian distribution and derive also its closed-form representation by means of Meijer'sG-function. Series representations for theG-functions appearing in non-resonant thermonuclear reaction rates are summarized and given in the Appendix, which can be used for the numerical computation of the reaction rate.
    Notes: Zusammenfassung Die grundlegenden physikalischen Prinzipien, die für die Berechnung von nichtresonanten thermonuklearen Reaktionsraten gelten, werden diskutiert. Wir geben für die Standardform der Kernreaktionsrate mit Maxwell-Boltzmannscher Verteilungsfunktion die geschlossene analytische Darstellung mit Hilfe der MeijerschenG-Funktion an. Aus physikalischen Gründen diskutieren wir die nichtresonante thermonukleare Reaktionsrate mit modifizierter Maxwell-Boltzmannscher Verteilungsfunktion und geben auch hier die geschlossene Darstellung mittels der MeijerschenG-Funktion. Für die für nichtresonante Kernreaktionsraten charakteristischeG-Funktion werden Reihendarstellungen vorgeschlagen, die für die numerische Auswertung von Kernreaktionsraten nützlich sind.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00947916
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  • 7
    Electronic Resource
    Electronic Resource
    A heuristic remark on the periodic variation in the number of solar neutrinos detected on Earth (1995)
    Springer
    Astrophysics and space science 228 (1995), S. 113-134 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Four operating neutrino observatories confirm the long standing discrepancy between detected and predicted solar neutrino flux. Among these four experiments the Homestake experiment is taking data for almost 25 years. The reliability of the radiochemical method for detecting solar neutrinos has been tested recently by the GALLEX experiment. All efforts to solve the solar neutrino problem by improving solar, nuclear, and neutrino physics have failed so far. This may also mean that the average solar neutrino flux extracted from the four experiments may not be the proper quantity to explain the production of neutrinos in the deep interior of the Sun. Occasionally it has been emphasized that the solar neutrino flux may vary over time. In this paper we do address relations among specific neutrino fluxes produced in the proton-proton chain that are imposed by the coupled systems of nonlinear partial differential equations of solar structure and kinetic equations by focusing our attention on a statistical interpretation of selected kinetic equations of PPII/PPIII branch reactions of the protonproton chain. A fresh look at the statistical implications for the outcome of kinetic equations for nuclear reactions may shed light on recent claims that the7 Be-neutrino flux of the Sun is suppressed in comparison to the pp- and8B neutrino fluxes and may hint at that the solar neutrino flux is indeed varying over time as shown by the Homestake experiment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00984971
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  • 8
    Electronic Resource
    Electronic Resource
    Solar structure in terms of Gauss' hypergeometric function (1995)
    Springer
    Astrophysics and space science 228 (1995), S. 77-86 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Hydrostatic equilibrium and energy conservation determine the conditions in the gravitationally stabilized solar fusion reactor. We assume a matter density distribution varying non-linearly through the central region of the Sun. The analytic solutions of the differential equations of mass conservation, hydrostatic equilibrium, and energy conservation, together with the equation of state of the perfect gas and a nuclear energy generation rate ∈ = ∈0ρ n T nT m ,are given in terms of Gauss' hypergeometric function. This model for the structure of the Sun gives the run of density, mass, pressure, temperature, and nuclear energy generation through the central region of the Sun. Because of the assumption of a matter density distribution, the conditions of hydrostatic equilibrium and energy conservation are separated from the mode of energy transport in the Sun.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00984968
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  • 9
    Electronic Resource
    Electronic Resource
    Experimental determination of the symmetry of the order parameter in YBCO (1995)
    Springer
    Journal of superconductivity 8 (1995), S. 491-494 
    Details
    ISSN: 1572-9605
    Keywords: Superconductivity ; pairing symmetry ; YBCO ; SQUID
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract At present, the symmetry of the order parameter in the high temperature superconductor YBCO is quite controversial. Recent experiments using SQUIDs and Josephson junctions appear to support competing theories, with some experiments supporting a dx2−y2 pairing symmetry for the order parameter and others a s-wave pairing symmetry. We note that a number of factors such as trapped flux, magnetic field gradients and SQUID asymmetries could lead such measurements astray. We use a Scanning SQUID Microscope and a time-reversal invariance test to resolve these experimental problems. We find the order parameter in YBCO has a time-reversal invariant dx2−y2 symmetric component. We estimate the amplitude of anyimaginary s-wave symmetric component to be less than 4% and anyreal s-wave component to be less than 82%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00722838
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  • 10
    Electronic Resource
    Electronic Resource
    Analytic stellar structure (1992)
    Springer
    Astrophysics and space science 197 (1992), S. 153-161 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract This paper continues to elaborate on analytic methods to construct models for the internal structure of solar-type stars. Since a detailed stellar model is desired, a nonlinear analytic density distribution in terms of a two-parameter family of models has been assumed. Hydrostatic equilibrium and energy conservation determine the conditions in the gravitationally stabilized stellar fusion reactor. The results show once more that methods of differential and integral calculus provide a laboratory for the application of special functions of mathematical physics in stellar structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00645079
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