Sökning: "molecular orientation"

Visar resultat 16 - 20 av 168 avhandlingar innehållade orden molecular orientation.

  1. 16. Molecular electronic,  vibrational and rotational motion in optical and x-ray fields

    Författare :Sergey Gavrilyuk; Faris Gelmukhanov; Stephane Carniato; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; x-ray; nonlinear optics; photobleaching; recoil; anisotropy; Auger; Chemical physics; Kemisk fysik;

    Sammanfattning : The subject of this theoretical  study is the role ofelectronic structure as well as of rotational and vibrational motionson interactions between molecules and electromagnetic radiation,ranging from optical to x-ray. The thesis concerns both linear and nonlinear regimes of the light-matter interaction. LÄS MER

  2. 17. Calculations of Reaction Mechanisms and Entropic Effects in Enzyme Catalysis

    Författare :Masoud Kazemi; Johan Åqvist; Per E. M. Siegbahn; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Enzyme catalysis; Entropy; Cytidine deamination; Ribosome; Peptidyl-tRNA hydrolysis; Peptide bond formation; Empirical valence bond method; Density functional theory; Biology with specialization in Structural Biology; Biologi med inriktning mot strukturbiologi; Biokemi; Biochemistry; Biology with specialization in Molecular Biotechnology; Biologi med inriktning mot molekylär bioteknik;

    Sammanfattning : Ground state destabilization is a hypothesis to explain enzyme catalysis. The most popular interpretation of it is the entropic effect, which states that enzymes accelerate biochemical reactions by bringing the reactants to a favorable position and orientation and the entropy cost of this is compensated by enthalpy of binding. LÄS MER

  3. 18. Two-Photon Excited Fluorescence Depolarisation : Experimental and Theoretical Development

    Författare :Linus Ryderfors; Emad Mukhtar; Lennart B.-Å. Johansson; Yehudi K. Levine; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Two-photon excitation; Fluorescence; Fluorescence depolarisation; Fluorescence anisotropy; Time-correlated single photon counting; Gold nanoparticles; Rotational diffusion; Excited state symmetry; Extended Förster theory; Orientation correlation functions; Donor-donor energy migration DDEM ; Chemical physics; Kemisk fysik;

    Sammanfattning : We have studied fundamental aspects of time-resolved two-photon excited fluorescence depolarisation. The thesis presents experimental as well as theoretical progress. LÄS MER

  4. 19. Atomic Layer Deposition and Immobilised Molecular Catalysts Studied by In and Ex Situ Electron Spectroscopy

    Författare :Payam Shayesteh; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ambient pressure XPS; Catalysis; Heterogenisation; Atomic layer deposition; HfO2; Gas phase; TDMAHf; TDMAT; Fysicumarkivet A:2019:Shayesteh;

    Sammanfattning : The research work that I describe in my thesis deals with three different heterogenisation approaches for synthesising a heterogeneous transition metal catalyst used for direct C-H activation reactions. The three heterogenisation approaches considered in my research are: (1) heterogenisation of a molecular catalyst on a polymer support using covalent bonds, (2) heterogenisation of a catalyst on a reduced graphene oxide (rGO) support using non-covalent interactions and (3) immobilisation of a catalyst on an inorganic surface using covalent bonds and encapsulation in an inorganic matrix. LÄS MER

  5. 20. Electronic and Molecular Surface Structures of Dye-Sensitized TiO2 Interfaces

    Författare :Maria Hahlin; Håkan Rensmo; Hans Siegbahn; Anders Sandell; Mats Göthelid; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photoelectron spectroscopy; Electron spectroscopy; Solar Cells; Dye; TiO2; Surface; Interface; Electronic structure; Molecular surface structure; coadsorbent; Physics; Fysik; Fysik; Physics;

    Sammanfattning : The dye-sensitized solar cell is a promising solar cell technology. In these systems the key process for light to electricity conversion is molecular in nature and is initiated in dye molecules adsorbed at a semiconducting surface. LÄS MER