The reaction of copper(I) sulphide with a product of its oxidation copper(II) sulphate

The course of the reaction between copper(I) sulphide and copper(II) sulphate in SO₂ at 710–785 K was studied by the TG method under isothermal and non-isothermal conditions, as well as by the DTA method, X-ray analysis and scanning electron microscopy. It was established that the reaction is essentially dependent upon the initial composition of the substrate mixture, Cu₂SO₂ and Cu₂SO₂ being the chief intermediates in the reaction. Copper(I) oxide appears as the permanent final product of the reaction of interest. The reaction network, with the intermediate stages depending on the initial compositions in the temperature range studied, has been demonstrated.

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Zusammenfassung Der Verlauf der Reaktion von Kupfer(I)-sulfid mit Kupfer(II)-sulfat wurde in SO₂ bei 710–785 K durch isotherme und nichtisotherme Thermogravimetrie sowie DTA, Röntgenanalyse und Scanning-Elektronenmikroskopie untersucht. Es wurde festgestellt, daß die Reaktion wesentlich von der Ausgangszusammensetzung des Substratgemisches abhängt, wobei Cu₂SO₂ und Cu₂SO₄ die vorherrschenden intermediären Produkte der Reaktion sind. Kupfer(I)-oxid tritt als Endprodukt auf. Der die intermediären, im untersuchten Temperaturbereich von der Ausgangszusammensetzung abhängigen Reaktionsschritte in sich einschließende Reaktionsverlauf wird dargelegt.

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710–785 , , . , . Cu₂SO₂ Cu₂SO₄, . , .

     

Topological invariants of real Milnor fibres

 Let and be analytic germs, let be a closed ball of small radius centred at the origin, and let . Let , where λ(p) is the Morse index at a critical point p of a Morse function which approximates g|W _z . For F and g satisfying some natural assumptions, we shall show that there is a finite family of analytic germs θ _i (z) such that for a generic regular value z. Received: 8 May 2001 / Revised version: 16 May 2002 Published online: 24 January 2003 Supported by grant BW 5100-5-0256-9 Mathematics Subject Classification (2000): 14P15, 32B10     

Helicity theorem and vortex lines in superfluid4He

The helicity conservation theorem is demonstrated in the case of superfluid⁴He. As in the case of a classical barotropic fluid, the helicity integral expresses some topological properties of vortex lines.     

On the number of vertices of given degree in a random graph

This note can be treated as a supplement to a paper written by Bollobas which was devoted to the vertices of a given degree in a random graph. We determine some values of the edge probability p for which the number of vertices of a given degree of a random graph G ∈ ??(n, p) asymptotically has a normal distribution.     

Structure and stereochemistry of lactames and cyclic imides: Part VI. The structure of reaction products of 2-methylglutarimide with phenyllithium

On the basis of spectral and X-ray analyses it is established that the reaction of phenyllithium with substituted glutarimide derivatives results in the open-chain amidoketone, which can be cyclised upon the dehydration.     

EPR study of the dinitrogen tetroxide dissociation in organic solvents

The dinitrogen tetroxide homolytical dissociation constants K _DIS are determined in organic solvents. The values are the highest in non-donor and the lowest in n-donor solvents. The variations of K _DIS with solvent are interpreted in terms of electron donor-acceptor interactions between dinitrogen tetroxide and electron donor molecules.     

Magnetic moments of the nucleon octet in a relativistic light-cone quark model

The magnetic moments of the baryon octet are calculated in a relativistic constituent quark model formulated in the light-cone Fock approach. Invoking a natural idea of strangeness-dependent hadron size we find very good agreement (to an accuracy of 1σ) for the recent precision hyperon magnetic-moment data and reveal 10–15% discrepancy for the Σ⁻ and nucleon. It suggests pions as a missing ingredient in the baryon magnetic moment calculations.