Sökning: "Crystallography"

Visar resultat 26 - 30 av 309 avhandlingar innehållade ordet Crystallography.

  1. 26. Oxidation of some Late Transition Metal Surfaces: Structural Studies from UHV to Atmospheric Pressure

    Författare :Johan Gustafson; Synkrotronljusfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Kondenserade materiens egenskaper:struktur; phase equilibria; crystallography; thermal and mechanical properties; Condensed matter:stucture; density functional theory; scanning tunneling microscopy; surface x-ray diffraction; high resolution core level spectroscopy; low energy electron diffraction; metal surfaces; oxidation; catalysis; egenskaper termiska och mekaniska ; kristallografi; fasjämvikt;

    Sammanfattning : The oxidation of Rh, Pd and Pt is studied under conditions ranging from ultra high vacuum to ambient pressures, with emphasis on a complete understanding of the geometry of the various oxide structures found. The investigations use a combination of various experimental methods, including high resolution core level spectroscopy, low energy electron diffraction, surface x-ray diffraction and scanning tunneling microscopy, as well as density functional theory calculations. LÄS MER

  3. 27. Crystallographic studies of non-equilibrium structural changes in cathode materials

    Författare :Olof Gustafsson; William Brant; Marnix Wagemaker; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Diffraction; Crystallography; Li-ion battery cathode materials; Spinel; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

    Sammanfattning : Battery cathode materials are a key focus for improvement of Li-ion battery chemistries due their limits in terms of capacity and cost. During insertion and extraction of Li, many cathode materials exhibit structural changes, ranging from e.g. phase transitions to amorphization. LÄS MER

  4. 28. Molecular Structure and Packing of Platinum(II) Complexes with S-donor Ligands in the Solid State An X-ray Crystallographic Study

    Författare :Christian Hansson; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; low temperature; high-pressure; structural class concept; hydrogen bonding; intermolecular interactions; crystallography; platinum coordination compounds; packing; phase transitions; Inorganic chemistry; Oorganisk kemi;

    Sammanfattning : How do molecules arrange themselves in a crystal? It is today not possible to definite predict the three-dimensional packing arrangement of molecules in the crystalline solid state. The aim of the work presented in this thesis has been to gain more knowledge of what principles that govern molecular packing. LÄS MER

  5. 29. Generation and Applications of Short-Pulse X-ray Radiation

    Författare :Michael Harbst; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; egenskaper termiska och mekaniska ; Kondenserade materiens egenskaper:struktur; crystallography; phase equilibria; Material science; Condensed matter:stucture; thermal and mechanical properties; time-resolved; X-ray diffraction; kristallografi; fasjämvikt; Material technology; Materiallära; materialteknik;

    Sammanfattning : This thesis summarizes work using hard X-ray radiation on nanosecond and picosecond timescales. The focus is on the experimental part including detailed descriptions of setups for laser pumped - X-ray probe experiments. X-ray diffraction is sensitive to structural properties on the length scale of chemical bonds. LÄS MER

  7. 30. Control of Quasi-Equivalence in Virus Capsids

    Författare :Charlotte Helgstrand; B. V. Venkataram Prasad; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cell and molecular biology; crystallography; bacteriophage; virus; RNA; capsid; quasi-equivalence; assembly; Cell- och molekylärbiologi; Cell and molecular biology; Cell- och molekylärbiologi; Molecular Biotechnology; Molekylär bioteknik;

    Sammanfattning : Many T=3 plant and insect viruses use a molecular switch in form of order/disorder of a segment of the polypeptide chain to regulate the quasi-equivalent contacts. The structure of a mutant of the T=3 capsid of bacteriophage fr confirms that this virus and other members of the Leviviridae family lack a switch mechanism. LÄS MER