by Mok Hing-Yim = 蛋白質結構鬆弛之超聲測量 / 莫慶炎. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1983. / Includes bibliographical references (leaves 76-77). / by Mok Hing-Yim = Dan bai zhi jie gou song chi zhi chao sheng ce liang / Mo Qingyan.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

This thesis presents experimental studies of gas phasemolecular relaxation after excitation with synchrotron photonsin the 15-35 eV and in the 70-350 eV regions. In the 15-35 eV region, molecular relaxation by neutraldissociation processes and non Franck-Condon effects in N2 and O2 molecules have beenstudied by means of dispersed fluorescence and photoelectronspectroscopy experimental techniques, respectively. From thedispersed fluorescence data, excitation functions for themeasured atomic fluorescence spectra have been obtained. Fromthe recorded photoelectron spectra vibrational branching ratioshave been produced. The results obtained reveal that Rydbergseries and singly and doubly excited valence states of theappropriate symmetry energetically accessible in the studiedregion and interactions between themaccount for most of theobserved effects in these two type of experiments. In the 70-350 eV range, molecular relaxation processesresulting in fragmentation of CD4 and SF6 after absorption ofsynchrotron light have been studied by energy resolved electronion coincidence technique using a multicoincidence experimentalstation developed by our group during the last five years forsuch type of experiments. The coincidence measurements yieldedmass spectra from which information about the kinematics of thedetected fragments has been deduced by means of Monte Carlosimulations of the experimental peak shapes. The obtainedresults show completely different dissociation patternsdepending on the molecular electronic states studied. Thesepatterns reflect the bonding properties of the excited orbitalsand they permit the description and in some cases theidentification of the different molecular relaxation pathwaysobserved. The achievements presented in this thesis exemplifythe potential of the multicoincidence station used in thereported experiments.

<p>This thesis presents experimental studies of gas phasemolecular relaxation after excitation with synchrotron photonsin the 15-35 eV and in the 70-350 eV regions.</p><p>In the 15-35 eV region, molecular relaxation by neutraldissociation processes and non</p><p>Franck-Condon effects in N2 and O2 molecules have beenstudied by means of dispersed fluorescence and photoelectronspectroscopy experimental techniques, respectively. From thedispersed fluorescence data, excitation functions for themeasured atomic fluorescence spectra have been obtained. Fromthe recorded photoelectron spectra vibrational branching ratioshave been produced. The results obtained reveal that Rydbergseries and singly and doubly excited valence states of theappropriate symmetry energetically accessible in the studiedregion and interactions between themaccount for most of theobserved effects in these two type of experiments.</p><p>In the 70-350 eV range, molecular relaxation processesresulting in fragmentation of CD4 and SF6 after absorption ofsynchrotron light have been studied by energy resolved electronion coincidence technique using a multicoincidence experimentalstation developed by our group during the last five years forsuch type of experiments. The coincidence measurements yieldedmass spectra from which information about the kinematics of thedetected fragments has been deduced by means of Monte Carlosimulations of the experimental peak shapes. The obtainedresults show completely different dissociation patternsdepending on the molecular electronic states studied. Thesepatterns reflect the bonding properties of the excited orbitalsand they permit the description and in some cases theidentification of the different molecular relaxation pathwaysobserved. The achievements presented in this thesis exemplifythe potential of the multicoincidence station used in thereported experiments.</p>

The PHD project has two main goals. The first one is specifically related to investigations on molecular dynamics, structural conformations and packing of polyfluorene-based polymers. For this purpose, Wide Angle X-Ray Diffraction (WAXD), Solid-State Nuclear Magnetic Resonance (NMR) and Dynamical-Mechanical Thermal Analysis (DMTA) are being used as the main techniques. The second goal is to correlate molecular phenomena, as characterized in the first part, with opto-electronic properties of polyfluorene when used as active layer in an electronic device, such as a Polymer Light-Emitting Diode (PLED). In the second part, fabrication of devices and their electrical characterization as a function of temperature are the main objectives. Impedance Spectroscopy, Current-Voltage characterization of the devices and Time-Of-Flight (TOF) techniques are among the main techniques to be used in the second part of the project. Therefore, the project combines fundamental studies on molecular dynamics with technological performance of organic electronic. / O projeto de doutorado entitulado \"Correlação das Propriedades Óticas e Elétricas com a Estrutura Física e Dinâmica Molecular de Filmes e Dispositivos de Polifluorenos e Derivados\". O primeiro é especificamente ligado a investigação da dinâmica molecular, conformação estrutural e empacotamento de polímeros derivados do polifluoreno. Para isso, Difração de Raio-X de Alto Ângulo (WAXD)1, Ressonânica Magnética no Estado Sólido (RMN) e Análise Térmica Dinâmico Mecânica (DMTA) serão utilizadas como técnicas principais. O segundo objetivo é o de correlacionar, os fenômenos observados na primeira parte do projeto, com as propriedades opto-eletrônicas dos filmes poliméricos sendo utilizados como camada ativa em dispositivos eletrônicos do tipo Diodo Polimérico Emissor de Luz (PLED). Na segunda parte, a fabricação dos dispositivos e sua caracterização como função da temperatura serão os principais objetivos. Espectroscopia de Impedância, Corrente-Voltagem, Tempo de Vôo (TOF) e Photo-CELIV serão as principais técnicas de caracterização utilizadas. Dessa forma, o projeto combina estudos fundamentais de aspectos moleculares com o desempenho tecnológico de dispositivos optoeletrônicos.

The PHD project has two main goals. The first one is specifically related to investigations on molecular dynamics, structural conformations and packing of polyfluorene-based polymers. For this purpose, Wide Angle X-Ray Diffraction (WAXD), Solid-State Nuclear Magnetic Resonance (NMR) and Dynamical-Mechanical Thermal Analysis (DMTA) are being used as the main techniques. The second goal is to correlate molecular phenomena, as characterized in the first part, with opto-electronic properties of polyfluorene when used as active layer in an electronic device, such as a Polymer Light-Emitting Diode (PLED). In the second part, fabrication of devices and their electrical characterization as a function of temperature are the main objectives. Impedance Spectroscopy, Current-Voltage characterization of the devices and Time-Of-Flight (TOF) techniques are among the main techniques to be used in the second part of the project. Therefore, the project combines fundamental studies on molecular dynamics with technological performance of organic electronic. / O projeto de doutorado entitulado \"Correlação das Propriedades Óticas e Elétricas com a Estrutura Física e Dinâmica Molecular de Filmes e Dispositivos de Polifluorenos e Derivados\". O primeiro é especificamente ligado a investigação da dinâmica molecular, conformação estrutural e empacotamento de polímeros derivados do polifluoreno. Para isso, Difração de Raio-X de Alto Ângulo (WAXD)1, Ressonânica Magnética no Estado Sólido (RMN) e Análise Térmica Dinâmico Mecânica (DMTA) serão utilizadas como técnicas principais. O segundo objetivo é o de correlacionar, os fenômenos observados na primeira parte do projeto, com as propriedades opto-eletrônicas dos filmes poliméricos sendo utilizados como camada ativa em dispositivos eletrônicos do tipo Diodo Polimérico Emissor de Luz (PLED). Na segunda parte, a fabricação dos dispositivos e sua caracterização como função da temperatura serão os principais objetivos. Espectroscopia de Impedância, Corrente-Voltagem, Tempo de Vôo (TOF) e Photo-CELIV serão as principais técnicas de caracterização utilizadas. Dessa forma, o projeto combina estudos fundamentais de aspectos moleculares com o desempenho tecnológico de dispositivos optoeletrônicos.