Sökning: "atomära processer"

Hittade 5 avhandlingar innehållade orden atomära processer.

  1. 1. Theoretical Atomic Spectroscopy of Earthbound and Stellar Plasma

    Författare :Jon Grumer; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; atomstruktur; atomära processer; elektronkorrelation; plasmaspektroskopi; magnetfält; hyperfinstruktur; solkoronan; rymdväder; förekomst av grundämnen i stjärnor; datorsimuleringar; Zeemaneffekt; relativistiska effekter; atomic structure; atomic processes; computer simulation; electron correlation; relativistic atomic theory; plasma spectroscopy; Zeeman effect; magnetic fields; hyperfine structure; solar corona; space weather; stellar abundances; Fysicumarkivet A:2016:Grumer;

    Sammanfattning : Motivated by spectroscopic analysis of astrophysical and laboratory plasma, this thesis concerns the fundamental structure and spectral properties of atoms and their ions. The multiconfiguration Dirac-Hartree-Fock (MCDHF) method is used to predict the emission or absorption of radiation, by atomic systems in general, and of heavy and highly charged ions in particular. LÄS MER

  3. 2. Theoretical perspectives on ultrafast and non-linear spectroscopy

    Författare :Emil Vinas Boström; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Non-linear optics; Ultrafast dynamics; Non-equilibrium Green s functions; Density functional theory; Multi-photon absorption; Second harmonic generation; Desorption dynamics; Auger decay; Charge-separation dynamics; Quantum Zeno effect; Fysicumarkivet A:2018:Vinas Boström;

    Sammanfattning : In this thesis we discuss a theoretical description of ultrafast and non-linear spectroscopy. Due to the high intensities and ultrashort pulse durations involved in such experiments, it is necessary to use an explicitly time-dependent formalism. LÄS MER

  4. 3. Above and Below Graphene: Nanoparticle Chemistry and Interface Reactions

    Författare :Elin Grånäs; Synkrotronljusfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Graphene; Scanning tunneling microscopy; X-ray photoelectron spectroscopy; Adsorption; Nanoparticles; Ir 111 ; Surface science;

    Sammanfattning : The work presented in this dissertation addresses two main topics: (i) graphene supported nanoparticles and their stability upon gas adsorption, and (ii) intercalation of different molecules under graphene and their reactions under graphene. From an interplay of X-ray photoelectron spectroscopy, scanning tunneling microscopy, low energy electron diffraction, and density functional theory an atomic scale understanding of both the nanoparticles and the intercalated structures is obtained. LÄS MER

  5. 4. DFT calculations of initial localized corrosion of aluminum : Influence of aqueous ad-layer, chloride ions, and intermetallic particles

    Författare :Min Liu; Jinshan Pan; Ying Chen; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aluminum alloys; alumina; chloride; surface adsorption; aqueous ad-layer; localized corrosion; corrosion initiation; work function; micro-galvanic effect; density-functional theory; Volta potential; scanning kelvin probe force microscopy; Kemi; Chemistry;

    Sammanfattning : Localized corrosion of aluminum (Al, here including Al alloys) involves a series of physico-chemical processes at the interface between the metal and the aqueous ad-layer or the aqueous solution. The mechanisms that govern localized corrosion are quite complex and have been the subject of many experimental studies. LÄS MER

  7. 5. Infrared and Photoelectron Spectroscopic Studies of Adsorbates on Solid Surfaces: Experiments and DFT Calculations

    Författare :Jakob Blomquist; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic resonance; supraconductors; magnetic and optical properties; electrical; Solid Surfaces; Chemistry; Kemi; Condensed matter:electronic structure; FTIR spectroscopy; DFT Cluster calculations; Anharmonicity; Photoelectron spectroscopy; relaxation; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; egenskaper elektriska; magnetiska och optiska ; supraledare; magnetisk resonans; spektroskopi; Surface and boundary layery chemistry; Ytkemi; gränsskikt;

    Sammanfattning : In general, the more complex and real a system is, with all its interactions with solvents and contaminations etc., the harder it is to accurately model it and reproduce the experimental results by calculations. LÄS MER