Ein Beitrag über Katalysatoren für die Aromatisierung von Ethylen

A Contribution to Catalysts for the Aromatizing of Ethylene A series of monometallic, bimetallic, and trimetallic catalysts (with alumina as carrier) has been tested in the aromatizing of ethylene. The results are correlated with the composition and the metal dispersion of the catalysts. The catalytic activity is compared with the behaviour of the respective catalysts in other hydrocarbon reactions.     

A simple and convenient solid state microanalytical technique for identification and characterization of the high temperature superconductor YBa2Cu3O7?x

Summary The application of a new electroanalytical technique, abrasive stripping voltammetry, is described for the purpose of identification and characterization of orthorhombic YBa₂Cu₃O_7–x. The method is based on the peculiar property of this compound that the copper ions therein cannot be reduced below the +1 oxidation state, whereas all other copper compounds exhibit this property. The total analysis takes about 2 min and is very reliable.

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Eine einfache und bequeme mikroanalytische Festkörper-Technik zur Identifizierug und Charakterisierung des Hochtemperatur-Halbleiters YBa₂Cu₃O_7–x

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On leave from Deakin University, Geelong, Victoria 3217, Australia     

Detection of phase transitions in heavy silane by i.r. spectroscopy

An i.r. spectroscopic study of SiHD₃ isolated in SiD₄ reveals an apparent second-order phase transition at 38 K. In the lowest-temperature phase the SiD₄ molecules probably occupy two sites of C₁ symmetry. Between 38 K and 67 K the SiD₄ molecules probably occupy one site of C_s symmetry.     

Molecular patterning on carbon based surfaces through photobiotin activation

We have demonstrated the site-specific adhesion of photobiotin as a method of producing protein micropatterns. These patterns were created by the selective UV irradiation of a thin film of deposited photobiotin. The UV activated areas of photobiotin were then developed using fluorescently labelled avidin. The size of pattern produced is an order of magnitude smaller than those previously reported by this method. The patterns were characterised, using atomic force microscopy (AFM) to determine their microstructure. It was found that the AFM could discriminate between the areas of protein immobilised to the surface through the activated photobiotin, and the bare substrate surface where the inactivated photobiotin had been removed during the washing process. The potential of these patterns as sensing surfaces is demonstrated through the creation of a spatially patterned immunosensing surface. In this case, a biotinylated antibody was bound to the surface and the pattern developed using a second antibody specific to the immobilised biotinylated antibody. This technique could thus provide a simple and efficient method of producing high density immunoassay systems.     

Local cohomology of the algebra of C ∞ functions on a connected manifold

A multilinear version of Peetre's theorem on local operators is the key to prove the equality between the local and differentiable Hochschild cohomology on the one hand, and on the other hand the equality between the second and third local Chevalley cohomology groups and their differentiable counterpart.Aspirant du F.N.R.S.     

Infrared spectra of solid germane

An IR spectroscopic study has shown that GeH₄ molecules are situated on one set of sites of C, symmetry in phase IV. The III–IV transition at 63 K is apparently a second-order phase transition. In phases II and III the molecules are on sites of C_3v. or C₃ symmetry. The II–III phase transition was observed at 67 K. In solid GeD₄, phase transitions were observed at 68.5 and 77 K. In phases II and III the site symmetry is C_I. The II–III phase transition in GeD₄ is apparently second order. There is evidence that the ν₁, vibration of GeD₄ is IR active in the solid state.     

Matroids with given restrictions and contractions

If M is a matroid on a set S and if X is a subset of S, then there are two matroids on X induced by M: namely, the restriction and the contraction of M onto X. Necessary and sufficient conditions are obtained for two matroids on the same set to be of this form and an analogous result is obtained when (X₁,…, X_t) is a partition of S. The corresponding results when all the matroids are binary are also obtained.