The magnetic behaviour of diluted CrAl alloys

Magnetic susceptibility as a function of temperature of binary CrAl alloys containing 0.7,1.07,1.35,1.59, 1.79,1.98, 2.18, 2.84, 3.74 and 4.36 at %A1 is investigated. Aluminium, by alloying, acts on the Néel temperature of pure chromium giving rise to a complicated phase diagram. The bahaviour of the magnetic susceptibility as a function of temperature, in the ordered phase, for the samples containing 1.28, 2.18 and 2.84 at %A1 is found to be temperature independent. In the paramagnetic region, for the samples containing between 1.07 and 2.84 at %A1, it is found a decrease of the magnetic susceptibility as a function of temperature.     

Metall-Komplexbildung von β-Hydroxythiophenderivaten III

The acidity constants of 2-acetyl-3-hydroxy-thiophene (III) and 3-acetyl-4-hydroxy-thiophene (IV) and the stability constants of their complexes with some bivalent metal ions have been determined. The stability of the chelates is discussed as a function of the respective bond orders of the α–β and β–β′ bonds of the thiophene ring.     

Self-adjunctions and matrices

It is shown that the multiplicative monoids of Temperley-Lieb algebras are isomorphic to monoids of endomorphisms in categories where an endofunctor is adjoint to itself. Such a self-adjunction is found in a category whose arrows are matrices, and the functor adjoint to itself is based on the Kronecker product of matrices. This self-adjunction underlies the orthogonal group case of Brauer's representation of the Brauer centralizer algebras.     

Indazoles in organic synthesis: Formation of some fused heterocycles

Derivatives of pyrimido(1,2-b)indazole and s-triazino(1,2-b)indazole were prepared by several different routes and some transformations are described.     

Syntheses of some azolopyridopyrimidines

Syntheses of isomeric azolopyridopyrimidines are described. As starting material the corresponding pyridopyrimidines were used. It could be established that in many cases a transformation of a functional group with the purpose to form an annelated five-membered ring proceeded with ring opening at the pyrimidine part. Subsequent ring closure with one carbon synthons gave then the desired tricyclic heterocycles.     

Im Rahmen von Untersuchungen an Steinkohlenteerfarben

Ohne Zusammenfassung     

On the higher eigenvalues for the \infty-eigenvalue problem

We study the higher eigenvalues and eigenfunctions for the so-called -eigenvalue problem. The problem arises as an asymptotic limit of the nonlinear eigenvalue problems for the p-Laplace operators and is very closely related to the geometry of the underlying domain. We are able to prove several properties that are known in the linear case p = 2 of the Laplacian, but are unknown for other values of p. In particular, we establish the validity of the Payne-Pólya-Weinberger conjecture regarding the ratio of the first two eigenvalues and the Payne nodal conjecture, which deals with the zero set of a second eigenfunction. The limit problem also exhibits phenomena that are not encountered for any .Received: 4 January 2004, Accepted: 9 June 2004, Published online: 3 September 2004Mathematics Subject Classification (2000): 35P30, 35J70, 49R50     

Potentiometrische Titrationen in der Lebensmittelanalytik

Ohne Zusammenfassung     

Bestimmung von Nitrofurazon (5-Nitro-2-furaldehydsemicarbazon)

Ohne Zusammenfassung     

Der Nachweis des Eisens als Tri-n-butylammonium-eisen(III)-rhodanid

Ohne ZusammenfassungHierüber und über die quantitative Bestimmung des Eisens wird in Kürze berichtet.