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Adaptive-parametric modeling of some complex physical systems


Author: CIOBU Victor
Degree:doctor of Physics
Speciality: 01.04.02 - Theoretical and mathematical physics
Year:2017
Scientific adviser: Florentin Paladi
doctor habilitat, professor, Moldova State University
Scientific consultant: Gheorghe Căpăţână
doctor, associate professor (docent), Moldova State University
Institution: Moldova State University

Status

The thesis was presented on the 18 January, 2017
Approved by NCAA on the 16 February, 2017

Abstract

Adobe PDF document0.93 Mb / in romanian

Thesis

CZU [53:004.004+005.53](043.2)

Adobe PDF document 3.25 Mb / in romanian
172 pages


Keywords

fullerene, rare earth ions, electron-vibrational interaction, electron-phonon interaction, modeling, adaptive application, complex system

Summary

Thesis Structure: The thesis consists of introduction, three chapters, conclusions and recommendations, bibliography of 173 references. It contains 25 figures, 7 tables, 5 annexes and is carried on 172 pages (131 pages – basic text). The presented results are published in 20 research papers.

Field of study is theoretical and applied computer modeling, and adaptive applications development for the research of complex physical systems.

Goals and objectives of thesis are the development of theoretical models and techniques for creating adaptive applications for computer modeling of molecular vibration and spectra in symmetrical complex systems with many degrees of freedom, determining the eigenstates of fullerene molecule and ion, electron-phonon interaction for rare earth ions in laser crystals, comparison of the obtained theoretical results with experimental data, thereby setting up the appropriate values of the parameters in the applied physical models.

Scientific novelty and originality of the obtained results. The oscillation spectrum of the fullerene molecule was calculated based on the proposed algorithm. It was shown that the absorption line width of the fullerene ion depends on the probability of spontaneous radiative transition. The resonance electron-phonon interaction was simulated based on the developed adaptive computer application.

Important scientific solved problem consists in modeling of the molecular vibration and spectra in the symmetrical physical systems with many degrees of freedom and determination of the eigenstates of fullerene molecule and ion, as well as in modeling of the electron-phonon interaction for rare earth ions in laser crystals based on the adaptive application.

Theoretical significance of the thesis is to develop an improved algorithm for decomposition of the mechanical representation of the system into irreducible representations, as well as the study of four-center resonance energy transfer in the formalism of multipolar interaction Hamiltonian of ions. It was also proposed and implemented the adaptive application for assistance in computer modeling of complex physical problems.

Applicative value of the work is determined primarily by the development of adaptive application to determine the eigenstates of fullerene molecule and modeling the resonance electron-phonon interaction for rare earth ions in various laser crystals, and the validation of the method itself for drawing the adaptive applications for assistance in computer modeling of problems in the field of physics of complex systems.

Implementation of results: the obtained results are used in the institutional fundamental research project 15.817.02.29F, strategic direction „Materials, Technologies and Innovative products.” These investigations are reflected, for example, in the university courses curricula „Physics of Clusters” and „Complex Systems Modeling” held at the Moldova State University, as well as in designing and building of computer applications.