Sökning: "picosecond"

Visar resultat 1 - 5 av 69 avhandlingar innehållade ordet picosecond.

1. 1. Fundamental interactions in transition metal reactions

   Författare :Michael R. Coates; Michael Odelius; Markus Kowalewski; Abhik Ghosh; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; electronic structure; multiconfigurational; density functional theory; molecular dynamics; excited state molecular dynamics; non-adiabatic dynamics; solvation; organometallic complexes; x-ray absorption spectroscopy; photoelectron spectroscopy; time-resolved spectroscopy; femtosecond; picosecond; kemisk fysik; Chemical Physics;

   Sammanfattning : Transition metal complexes that participate in homogeneous reactions often perform the role of a catalyst, facilitating novel reaction pathways. When these complexes are pushed away from their equilibrium, the arrangement of the coordinating ligands around the metal center is perturbed and new reaction pathways are opened. LÄS MER

3. 2. Controlling Charge and Energy Transfer Processes in Artificial Photosynthesis : From Picosecond to Millisecond Dynamics

   Författare :Magnus Borgström; Leif Hammarström; Jan Davidsson; Sebastiano Campagna; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; Artificial photosynthesis; Electron transfer; Energy transfer; Ruthenium; Manganese; Charge-separated state; Donor-acceptor; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : This thesis describes an interdisciplinary project, where the aim is to mimic the initial reactions in photosynthesis. In photosynthesis, the absorption of light is followed by the formation of charge-separated states. The energy stored in these charge-separated states is further used for the oxidation of water and reduction of carbon dioxide. LÄS MER

4. 3. Laser Diagnostics in Combustion - Elastic Scattering and Picosecond Laser-Induced Fluorescence

   Författare :Frederik Ossler; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spray; Picosecond laser; Streak camera; Time resolved; Fluorescence lifetimes; 3 – D flow imaging; 2 - D lifetime imaging; Pressure; Temperature; Hydrogen atoms; Oxygen atoms; 3-pentanone; Acetone; Lorenz-Mie theory; Aerosol; Fysicumarkivet A:1999:Ossler; Scattering; Fysik; Physics; Polycyclic aromatic hydrocarbons.;

   Sammanfattning : Elastic scattering and the Lorenz-Mie (LM) theory in particular is used for the characterization of sub-micron- and micron-sized droplets of organic fuels in sprays and aerosols. Calculations on the Lorenz- Mie theory show that backward-sideward scattered visible radiation can be used for unambiguous detection of ensembles of homogeneous droplets of organic substances with diameters around 1 micrometer (size parameter between 2 and 6). LÄS MER

5. 4. Development and Application of Single-Ended Picosecond Laser Diagnostics

   Författare :Billy Kaldvee; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Raman Scattering; Temporal Filtering; Picosecond Laser Diagnostics; Rayleigh Scattering; Laser-spectroscopy; DIAL; Laser Combustion Diagnostics; Lidar; Laser-induced Fluorescence; Laser-induced Incandescence; Fysicumarkivet A:2012:Kaldvee;

   Sammanfattning : Light detection and ranging (lidar), a method for nonintrusive, single-ended, and range resolved measurements, has been developed and applied for combustion related diagnostics. Employing picosecond laser pulse durations and detectors providing temporal resolution on the order of picoseconds, lidar has been applied successfully for both quantitative temperature- and species concentration measurements, obtaining an ultimate range resolution of 0. LÄS MER

7. 5. Novel Technologies for Mode-Locking of Solid-State Lasers

   Författare :Niels Meiser; Valdas Pasiskevicius; Steinmeyer Günter; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; laser; mode-locked laser; pulsed laser; quantum dot; carbon nanotube; nonlinear optics; saturable absorber; Kerr-lens mode-locking; ultra-fast laser; picosecond laser; pulsed laser; semiconductor saturable absorber;

   Sammanfattning : The subject of this thesis is the investigation of novel technologies for mode-locking of diode-pumped, solid-state lasers. Novel saturable absorbers are used: quantum dots (QDs) and carbon nanotubes (CNTs), which both are low-dimensional nano-formations. In addition, mode-locking by cascaded nonlinearities is explored. LÄS MER