Über den Mechanismus des teilweisen Verschwindens des Phosphors beim Veraschen organischer Substanzen

Analytical and Bioanalytical Chemistry -     

Genetic and hybrid algorithms for graph coloring

Some genetic algorithms are considered for the graph coloring problem. As is the case for other combinatorial optimization problems, pure genetic algorithms are outperformed by neighborhood search heuristic procedures such as tabu search. Nevertheless, we examine the performance of several hybrid schemes that can obtain solutions of excellent quality. For some graphs, we illustrate that genetic operators can fulfill long-term strategic functions for a tabu search implementation that is chiefly founded on short-term memory strategies.     

Raman scattering of KI:Ag+: Exploration of a nearly unstable defect-lattice configuration

Abstract

The Raman spectra of Ag⁺ in KI exhibit between 6K and 25K two resonant modes and quasi-elastic scattering (QES), each with a different temperature behavior. The low-temperature Raman and infrared (ir) spectral features can be described within a harmonic force-constant model, which does not however account for the dramatic temperature dependence of the experimental data. They are compatible with a population transfer from a low-temperature on-center configuration to a second elastic configuration, in which the Ag⁺ ion is displaced from the regular lattice site. The QES, which dominates the Raman spectra above 20K, may reflect different types of rotational diffusion or the presence of a third elastic configuration.