Sökning: "atomic structure"

Visar resultat 21 - 25 av 656 avhandlingar innehållade orden atomic structure.

  1. 21. Characterization of crystalline materials by rotation electron diffraction : Phase identification and structure determination

    Författare :Yifeng Yun; Xiaodong Zou; Christian W. Lehmann; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electron microscopy; phase identification; rotation electron diffraction; structure determination; three-dimensional electron diffraction; Inorganic Chemistry; oorganisk kemi;

    Sammanfattning : Electron crystallography is powerful for determination of complex structures. The newly-developed 3D electron diffraction (ED) methods make structure determination from nano- and micron-sized crystals much easier than using other methods, for example X-ray diffraction. LÄS MER

  3. 22. Solitons, vortices and shell structure in ultracold atomic quantum systems

    Författare :Gunnar Eriksson; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; few-body physics; finite-size effects; solitary waves; quantized vortices; quantum hysteresis; shell structure; dipolar interactions; Fysicumarkivet A:2020:Eriksson;

    Sammanfattning : This dissertation deals with finite-size effects in a few different quantum many-body phenomena in ultracold atomic systems. The finite-sized systems were simulated numerically using both mean-field methods and methods beyond mean-field, e.g. quadratic configuration interaction and exact diagonalization. LÄS MER

  4. 23. Measurements of High-Precision Atomic Data with Applications to Astrophysics and Cosmology

    Författare :Maria Aldenius; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atomic data; Ca; Cr; Fe; Mn; Mg; metal-poor stars; fine-structure constant; Fourier transform spectroscopy; nebulae; oscillator strengths; spectroscopy; wavelengths; Ti; Zn; Astronomy; Astronomi; Atomic and molecular physics; Atom- och molekylärfysik; rymdvetenskap; space research; cosmic chemistry; kosmisk kemi; branching fractions;

    Sammanfattning : Investigations of astrophysical spectra require accurate atomic data, such as wavelengths and transition probabilities. This thesis provides high-precision atomic data for astrophysical and cosmological applications. The measurements have been carried out using Fourier transform spectrometry on light produced in a hollow cathode light source. LÄS MER

  5. 24. Structure, Morphology, and Catalytic Properties of CuOx/CeO2 Model Catalysts

    Författare :Björn Skårman; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Synchrotron radiation; High-energy Diffraction; X-ray Absorption Fine Structure Spectroscopy.; Chemical technology and engineering; Kemiteknik och kemisk teknologi; Chemistry; Kemi; Material technology; Materiallära; materialteknik; X-ray photoelectron spectroscopy; Atomic force microscopy; Gatan Image Filter GIF ; Energy-filtered TEM; High-resolution electron microscopy; Inert gas condensation IGC ; rf Magnetron sputtering; Thermal activation; Batch reactor; Carbon monoxide oxidation; Surface sensitivity; Catalytic anisotropy; Growth; Nucleation; Topography; Roughness; Core-shell structures; Morphology; Nanostructured; Nanocomposite; Nanoparticles; Surface structure; Polycrystalline surfaces; Thin films; Copper oxide; Cerium dioxide CeO2 ; Ceria;

    Sammanfattning : Cerium dioxide, or ceria, is a chemically stable oxygen ion conducting material with a capacity to store and release oxygen, and is therefore extensively used in combustion catalysts. The Cu-Ce-O system has been identified as one of the most active catalysts for the combustion of carbon monoxide. LÄS MER

  7. 25. The Electronic Structure of Organic Molecular Materials : Theoretical and Spectroscopic Investigations

    Författare :Iulia Emilia Brumboiu; Barbara Brena; Biplab Sanyal; Olle Eriksson; Jakob Schiøtz; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; materials theory; electronic structure; photoelectron spectroscopy; near-edge X-ray absorption fine structure; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik; Materialvetenskap; Materials Science;

    Sammanfattning : In the present thesis the electronic properties of two organic molecules were studied by means of density functional theory (DFT) in connection to their possible applications in organic photovoltaics and molecular spintronics respectively.The first analysed system is the C60 derivative PCBM extensively used in polymer solar cells for the charge separation process. LÄS MER