New consecutive photochemical reactions of naphtho[1,8-de]-1,3-dithiin-1-N-tosylsulfilimines via the through-space interaction between two sulfur atoms; A convenient method for preparation of N-tosylaldimines

Naphtho[1,8-de]-1,3-dithiin-1-N-tosylsulfilimines underwent facile consecutive photochemical reactions to give quantitatively the corresponding N-tosylaldimines, together with naphtho[1,8-cd]-1,2-dithiole, via a sulfur–sulfur interaction. The intermediate, 3-hydro-3-phenyl-naphtho[1,8-ef][1,4]dithia[2]-azepin, was isolated by liquid chromatography of the reaction mixtures, and its structure was determined by X-ray crystallographic analysis. The proposed mechanism for these photochemical reactions is based on quantum yield measurements, photo-intensity effects, and crossover experiments. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:29–40, 1998     

Ueber die singulären Stellen der Integrale einer linearen partiellen Differentialgleichung

Ohne Zusammenfassung     

Zur Bestimmung und Trennung des Chroms und zur Analyse von Chrom enthaltenden Substanzen

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Über die irregulären Integrale der linearen Differentialgleichungen zweiter Ordnung mit rationalen Coefficienten

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Networks of complex neurons

Networks of formal binary neurons can be used to construct associative memory models. Given the fact that real neurons have more complex features we try to find if other cognitive functions can be modeled by adding new degrees of freedom to the formal neuron. We show that complex features can be represented by dynamically modifying the threshold of the neuron. We explain how this allows us to model phenomena of free associative transitions between memories, temporal segmentation of an input into its memory components, phase locking (binding) and short term memory.     

Zur Theorie der linearen Differenzengleichungen

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The K-matrix approach to the Δ-resonance mass splitting and isospin violation in low-energy πN scattering

Experimental data on πN scattering in the elastic energy region T _π ≤ 250 MeV are analyzed within the multichannel K-matrix approach with effective Lagrangians. Isospin invariance is not assumed in this analysis and the physical values for masses of the involved particles are used. The corrections due to π ⁺-π ⁰ and p-n mass differences are calculated and found to be in a reasonable agreement with the NORDITA results. The results of our analysis describe the experimental observables very well. New values for mass and width of the Δ⁰ and Δ⁺⁺ resonances were obtained from the data. The isospin-symmetric version yields phase-shift values similar to the new solution, FA02, for the πN elastic scattering amplitude by the GW group based on the latest experimental data. While our analysis leads to a considerably smaller (≤1%) isospin violation in the energy interval T _π ∼ 30–70 MeV as compared to 7% in works by W.R. Gibbs et al. and E. Matsinos, it confirms calculations based on chiral perturbation theory. The text was submitted by the authors in English.     

Imaging surface electronic structure of NiAl(110) using low-temperature scanning tunneling microscopy

The surface electronic structure of NiAl(110) is examined by means of scanning tunneling microscopy and spectroscopy at a temperature of 4 K. Topography and conductance images for a wide range of bias voltages reveal wavelike patterns around steps and defects. Fourier transforms of conductance images are used to map the surface electronic structure of NiAl(110). We interpret the patterns in the Fourier transforms in terms of surface resonances, and analyze the details of its dispersion relation E(k_). A comparison with density-functional-based calculations and photoemission experiments is presented, and alternative explanations for the appearance of structures in Fourier transforms of conductance images are discussed.