Sökning: "RELAXATION"

Visar resultat 11 - 15 av 913 avhandlingar innehållade ordet RELAXATION.

  1. 11. Formation and Dynamics of Molecular Excitons and their Fingerprints in Nonlinear Optical Spectroscopy

    Författare :Pär Kjellberg; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; supraledare; magnetisk resonans; spektroskopi; Physical chemistry; Fysikalisk kemi; Photochemistry; Fotokemi; Kondenserade materiens egenskaper:elektronstruktur; magnetiska och optiska ; egenskaper elektriska; supraconductors; magnetic resonance; relaxation; spectroscopy; Fysik; Chemistry; Kemi; Condensed matter:electronic structure; electrical; Physics; Redfield relaxation theory ; Inhomogeneous broadening ; Time-dependent density functional theory ; Conjugated polymers ; Three-pulse photon echo ; Molecular excitons ; magnetic and optical properties; Nonlinear spectroscopy ;

    Sammanfattning : An efficient transfer of energy in molecular systems has proven to be of fundamental importance both in nature and industrial applications. The ability of molecules to work together forming collective excitations, so-called excitons, plays a key role in for example the extraordinary fast energy transfer involved in the first steps of photosynthesis. LÄS MER

  2. 12. Pushing diffusion MRI towards new dimensions

    Författare :Joao Martins; Fysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NMR; MRI; diffusion; relaxation; multidimensional diffusion MRI; relaxation-diffusion correlations; Laplace NMR; porous media; tissue microstructure; heterogeneity; anisotropy;

    Sammanfattning : Diffusion-MRI techniques allow the non-invasive investigation of microstructural changes in living tissues. However, a detailed interpretation of the data is complicated by the fact that multiple microscopic environments with varying diffusion properties all contribute to the measured signal. LÄS MER

  3. 13. Chiral Ruthenium Dipyrodiphenazine Complexes: DNA Binding and Excited State Relaxation

    Författare :Björn Önfelt; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polarization spectroscopy; DNA-probe; dppz; excited-state relaxation; intercalation; solvent relaxation; DNA-threading;

    Sammanfattning : Ruthenium complexes with aromatic ligands have been extensively studied due to their interesting photophysical properties, including photophysics and electron transfer upon interaction with nucleic acids. For example, the broad absorption spectrum makes them suitable as antenna molecules in photochemical reaction systems and their ability to accept or donate electrons in their excited state could have potential in opto-electronical devices. LÄS MER

  4. 14. Detection for multiple input multiple output channels : analysis of sphere decoding and semidefinite relaxation

    Författare :Joakim Jaldén; Björn Ottersten; Zhi-Quan Luo; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Telekommunications; MIMO; Detection; Sphere Decoder; Semidefinite Relaxation; Telecommunication; Telekommunikation;

    Sammanfattning : The problem of detecting a vector of symbols, drawn from a finite alphabet and transmitted over a multiple-input multiple-output (MIMO) channel with Gaussian noise, is of central importance in digital communications and is encountered in several different applications. Examples include, but are not limited to; detection of symbols spatially multiplexed over a multiple-antenna channel and the multiuser detection problem in a code division multiple access (CDMA) system. LÄS MER

  5. 15. Gas phase molecular relaxation probed by synchrotron radiation experiments

    Författare :Jaume Rius i Riu; KTH; []
    Nyckelord :Molecular relaxation; synchrotron radiation; dispersed fluorescence; photoelectron spectroscopy; energy resolved electron ion coincidence technique;

    Sammanfattning : 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 nonFranck-Condon effects in N2 and O2 molecules have beenstudied by means of dispersed fluorescence and photoelectronspectroscopy experimental techniques, respectively. LÄS MER