Sökning: "NATURVETENSKAP Kemi Teoretisk kemi Kvantkemi"
Visar resultat 26 - 30 av 47 avhandlingar innehållade orden NATURVETENSKAP Kemi Teoretisk kemi Kvantkemi.
26. Global bifurcations and chaotic dynamics in physical applications
Sammanfattning : The aim of this work has been to analyse global bifurcations arising in a laser with injectedsignal and in a catalytic reaction on a surface of Pt, from the point of view of dynamicalsystems theory.The 3-dimensional ordinary differential equation which models the laser was found to contain a homoclinic orbit to a saddle-focus equilibrium, what corresponds to the Šil´nikov phenomenon. LÄS MER
27. Theoretical Photochemistry : Halogenated Arenes, Phytochromobilin, Ru(II)polypyridyl complexes and 6-4 photoadducts
Sammanfattning : This thesis presents Quantum Chemical calculations on the Photochemistry of Halogenated benzenes, Phytochromobilin, Ruthenium Polypyridyl complexes and 6-4 photoadducts in DNA. The work is focused on improving the understanding of a number of experimentally observed photochemical processes in these systems. LÄS MER
28. Quantum Chemical Studies of Protein-Bound Chromophores, UV-Light Induced DNA Damages, and Lignin Formation
Sammanfattning : Quantum chemical methods have been used to provide a better understanding of the photochemistry of astaxanthin and phytochromobilin; the photoenzymic repair of UV-light induced DNA damages; and the formation of lignin. The carotenoid astaxanthin (AXT) is responsible for the colouration of lobster shell. LÄS MER
29. Quantum Chemical Modeling of Dye-Sensitized Titanium Dioxide : Ruthenium Polypyridyl and Perylene Dyes, TiO2 Nanoparticles, and Their Interfaces
Sammanfattning : Quantum chemical calculations have been used to model dye-sensitized nanostructured titanium dioxide systems that can be used in solar cells for solar energy to electricity conversion. Structural, electronic and spectral properties of isolated dyes and both bare and dye-sensitized TiO2 have been calculated with density functional theory, providing detailed information about both the separate parts and the dye-TiO2 interface. LÄS MER
30. Extending the Reach of Accurate Wavefunction Methods
Sammanfattning : Multiconfigurational quantum chemistry methods, and especially the multiconfigurational self-consistent field (MCSCF) and multireference perturbation theory (MRPT2), are powerful tools, particularly suited to the accurate modeling of photochemical processes and transition metal catalysis. However, they are limited by their high computational cost compared to other methods, especially density functional theory. LÄS MER