Effect of the surface roughness on Bean-Livingston surface barrier

Bean-Livingston barrier for a single Abrikosov vortex interacting with the rough surface is calculated as a function of the random characteristics of the surface roughness. It has been shown that even a respectively smooth surface roughness results in an essential decrease of the Bean-Livingston surface barrier.     

Die Knickung verwundener Stäbe als technisches Beispiel zur Schaeferschen Theorie zweiparametriger Eigenwertprobleme

Übersicht In der vorliegenden Arbeit wird die Schaefersche Theorie zweiparametriger Eigenwertaufgaben auf die Knickung verwundener Stäbe angewendet. Es wird gezeigt, daß die Schaefersche Theorie die schnelle Abschätzung der kritischen Lasten für die verwundenen Knickstäbe ermöglicht und daß der dabei begangene Fehler für alle technischen Zwecke zu vernachlässigen ist.

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Summary This paper deals with an application of Schaefer's theory of two-parametric eigenvalue problems to the stability of twisted columns. It is shown that Schaefer's theory allows a quick estimate of the critical loads of the twisted columns and that the error involved in such an estimate may be neglected for all technical purposes.

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Herrn Prof. Dr.-Ing. Hermann Schaefer zum 60. Geburtstag gewidmet. Die Verfasser danken der Deutschen Forschungsgemeinschaft für die Unterstützung dieser Arbeit.     

Ultra-low temperature transport anomalies in air annealed Pt

Measurements of electrical resistivity ? and thermoelectric ratio G on air annealed reference grade Pt samples from 4 K down to 40 mK reveal ultra-low temperature anomalies in both properties. The observed T² components of ? are consistent with values obtained by previous investigators from measurements above 1 K.     

Hölder norm estimates for elliptic operators on finite and infinite-dimensional spaces

We introduce a new method for proving the estimate

where solves the equation . The method can be applied to the Laplacian on . It also allows us to obtain similar estimates when we replace the Laplacian by an infinite-dimensional Ornstein-Uhlenbeck operator or other elliptic operators. These operators arise naturally in martingale problems arising from measure-valued branching diffusions and from stochastic partial differential equations.

     

Selective mono O-alkylation of γ-resorcylic esters

The use of diethylazodicarboxylate/triphenylphosphine for the selective mono-O-alkylation of γ-resorcylic esters is described.     

Reactions of Cl2P3/2: Absolute rate constants for reaction with H2, CH4, C2H6, CH2Cl2, C2Cl4, and c?C6H12

The absolute rate constants have been measured for several gas-phase chlorine atom-molecule reactions at 25°C by resonance fluorescence. These reactions and their corresponding rate constants in units of cm³ mole^?1 sec^?1 are: The effects of varying the substrate pressure, total pressure, light intensity and chlorine-atom source on the value of the bimolecular rate constants have been investigated for all these reactions. Conditions under which no competing side reaction occurs were established and the reported rate constants were measured under these conditions. For reactions (2), (5), (6), (7), and 8, there is a discrepancy of a factor of two between the rate constants measured in this work and values in the literature; it is suggested that this is due to an error in the previously measured value of k/k upon which the relative measurements in the literature ultimately depend.