The nuclear magnetic resonance of Co59 and hyperfine fields in Fe-Co alloy

The nuclear magnetic resonance of Co⁵⁹ in an Fe-Co alloy was studied for a concentration of 4 to 17% Co. The resonance frequency was found to be independent of the concentration in this range. This observation is discussed together with the experimentally found dependence of the hyperfine field of iron in this alloy on the concentration of Co [8]. Use is made of a band model for 3d electrons of iron, in which the Co atoms behave as impurities on which certain wave functions of the band are localized and other delocalized. The values obtained for the line width show the presence of a mechanism of broadening, dependent on 3d wave functions.     

The study of the decomposition of a potassium solution in liquid ammonia by the paramagnetic electron resonance method

The quantitative results of measurements of the decomposition of a potassium solution in liquid ammonia at room temperature by paramagnetic electron resonance are given in this paper. Changes of the paramagnetic susceptibility of the solution were measured during the decomposition. Then the results of measurements were converted using data given by other authors and a dependence of the potassium concentration in the solution on the time was thus obtained. The obtained results cannot be explained by previous concepts on the course of this decomposition. A reaction kinetic diagram of this chemical decomposition has already been proposed according to our results. The obtained results show that sufficiently stable solutions can be prepared even at room temperature so that they can be used for longer-lasting physical measurements, e.g. for an accurate measurement of magnetic field intensity.     

Über die Proliferationsfähigkeit hochvernetzter glasiger Polymerer

Zusammenfassung Die Modifizierung hochvernetzter Styrol—Divinylbenzolcopolymerisate durch Zusatz von Verdünnungsmitteln bei der Polymerisation führt zur Bildung proliferationsfähiger Polymerer. Es besteht ein enger optimaler Zusammensetzungsbereich. Der Zusammenhang der Proliferationsfähigkeit mit Gleichgewichtsquellung, permanenter Porosität und Gehalt an anhängenden Doppelbindungen wird untersucht; die Morphologie des Proliferationsprozesses wird in mikrokinematographischen Zeitrafferaufnahmen festgehalten.

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The modification of highly crosslinked styrene—divinylbenzene copolymers by adding diluents to the polymerizing system yields polymers showing proliferous polymerization. There exists an optimum concentration range of diluent. The correlation of proliferous polymerization to equilibrium swelling, permanent porosity, and content of pendent double bonds is investigated. The morphology of the proliferation process is observed in micro time lapse motion pictures.

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Mit 10 Abbildungen     

The limitation of an explosive instability of two counter-streaming electron beams

Second-order perturbation calculation shows that an explosive instability of three resonantly interacting waves is limited and converted into a multi-periodic process by non-linear terms of the same order as those that destabilize the waves in the first-order approximation.