Emission cross sections from fragments produced by electron impact on silane

Optical emission spectroscopy in the visible and near UV of a silane plasma was performed in a low pressure hot cathode glow discharge bounded into a magnetized multipolar wall. Emissions from Si, Si⁺, SiH, SiH⁺ and H are shown to originate from the dissociative excitation of silane molecules by electron impact. The absolute cross sections for the various photoemissive processes were measured in the 17–68 eV range. The relevance of optical emission spectroscopy to silane plasma diagnostics is discussed.     

Etude par diffraction des rayons X des structures rencontrees dans les solutions aqueuses concentrees d'un polyelectrolyte amphipathique

Low and wide-angle X-ray diffraction was used to study the structure of aqueous gels of a maleic anhydride-hexadecylvinylether alternating copolymer, as a function of water content, degree of neutralization and temperature. Two types of structure have been found: a lamellar structure observed at low degrees of neutralization and a cylindrical structure observed at high degrees of neutralization. In both cases, the structural parameters have been analysed.     

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Fast gefrorene Strömung eines Gases mit thermodynamischer Relaxation

Übersicht Es wird die durch eine beliebige Bewegung eines Kolbens in einem zylindrischen Rohr verursachte Strömung eines Gases untersucht, in dem beliebige Relaxationsprozesse ablaufen können. Die Strömung wird für Zeiten, die klein gegen die Relaxationszeiten sind, durch eine Entwicklung nach der Damköhlerzahl beschrieben. Die Strömungsgrößen 1. Ordnung werden analytisch angegeben und für zwei Spezialfälle diskutiert. Der erste Fall ist ein Beispiel dafür, daß die Relaxation die Entstehung eines Verdichtungsstoßes beschleunigen kann. Im zweiten Fall wird der Einfluß der Relaxation auf ein kurzes Signal untersucht.

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Summary The one-dimensional flow induced by an arbitrary motion of a piston into a gas with arbitrary internal rate processes is studied. For times, which are smaller than the relaxation times, the flow is described by an asymptotic expansion in the Damköhler-number. The first order quantities are given analytically and discussed in two special cases. The first case is an example for relaxation to favour the formation of a shock wave. In the second case the influence of relaxation on a rapid pulse is investigated.

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Herrn Professor Dr.-Ing. Karl Klotter zur Vollendung seines 70. Lebensjahres gewidmet.     

Reaktionen von 2H-isoindolen mit aktivierten azo-verbindungen

The chemical behaviour of alkyl substituted 2H-isoindoles towards dialkyl-azodicarboxylates has been investigated and the structure of the resulting 1:1- and 1:2-adducts elucidated. The reaction of the o-quinonoid hetarenes with the activated dienophiles can be considered as a Michael addition.     

Calculation of charge vibration in fission with Strutinsky shell correction

The Strutinsky shell correction method has been applied to the two spheroid model to study charge vibrations in fission. The investigation is carried out by calculating the potential energy surface with respect to three degrees of freedom: charge vibration from the uniform value and the deformations of the two fragments. The results suggest that the effect of shells at Z = 50 and N = 82 do not cause large deviations from the liquid drop model charge density around mass 132; their effect is much more pronounced in the fragment excitation energy. The results also suggest that the fragment excitation and kinetic energies for a given mass ratio are markedly charge density dependent. Some features inherent to this treatment with respect to characteristic periods of individual degrees of freedom have been discussed.