Study of the thermal behavior of Al(III) and In(III)-diclofenac complexes in solid state

The Al and In-diclofenac compounds were prepared. Thermogravimetry (TG) and X-ray diffraction powder patterns were used to characterize these compounds. Details concerning the dehydration and thermal decomposition as well as data of kinetic parameters have been described here. The kinetic studies of these stages were evaluated from several heating rates with mass sample of 2 and 5 mg in open crucibles under nitrogen atmosphere. The results of the present study improve the knowledge on these compounds including their dehydration and thermal stability. The obtained data leads to a dependence on the sample mass, which results in two kinetic behavior patterns.     

Photodynamical simulations of cytosine: characterization of the ultrafast bi-exponential UV deactivation

Deactivation of UV-excited cytosine is investigated by non-adiabatic dynamics simulations, optimization of conical intersections, and determination of reaction paths. Quantum chemical calculations are performed up to the MR-CISD level. Dynamics simulations were performed at multiconfigurational level with the surface hopping method including four electronic states. The results show the activation of four distinct reaction pathways at two different subpicosecond time scales and involving three different conical intersections. Most trajectories relax to a minimum of the S(1) state and deactivate with a time constant of 0.69 ps mainly through a semi-planar conical intersection along the n(O)π* surface. A minor fraction deactivate along ππ* regions of the S(1) surface. Sixteen percent of trajectories do not relax to the minimum and deactivate with a time constant of only 13 fs.     

Realization of cartesian closed topological hulls

The cartesian closed topological (CCT) hull of a concrete categoryK is the smallest full CCT extension ofK. A general method for describing the CCT hulls is presented and applied to render unified proofs for the basic examples ofK: topological spaces, uniform spaces, pretopological spaces, compact T₂ spaces, metrizable spaces, and completely regular spaces.     

Iterative method for the calculation of atomic cluster probabilities from pair correlations in binary systems

A variational method is presented for determining n-site cluster probabilities for the short-range ordered state in binary systems. The derived frequency distribution is the most probable one that is consistent with given pair probabilities and with the most probable frequency distribution for all subclusters.The theory is applied to triplets and tetrahedra of nearest neighbours in the f.c.c. lattice. The results are compared with those obtained from the probability variation method, the superposition approximation and computer simulations. Also the frequency distribution for a special octahedron cluster is derived and the generalisation of Pauling's electrostatic valence rule is checked. The basic ideas and assumptions of the present method are discussed and compared with those of the probability variation method.     

Two-dimensional classical representations of the partition function of the spin-1/2 chain

Starting from the Trotter formula, we derive several classical representations of the partition function of a spin-1/2 chain. We investigate the rate of convergence of the different approximants by means of exact calculations for small systems. We demonstrate that it is important to use approximants that have the same symmetry properties as the original quantum model.     

Periodische Erscheinungen bei Kaltverstreckung

Ohne Zusammenfassung     

Определение средней величины кристаллик ов кварца И графита на основани и первичной экстинкц ии

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Untersuchungen über Chelidonsäure

Ohne Zusammenfassung