Sökning: "timescale"

Visar resultat 11 - 15 av 99 avhandlingar innehållade ordet timescale.

  1. 11. Investigation of Ultrafast Molecular Dynamics via Covariance Mapping : A Tool for Intense XUV Light Sources

    Författare :Jan Lahl; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Covariance; Ultrafast; High-order harmonic generation; Extreme Ultraviolet; Pump probe; FLASH; Velocity map imaging; wavefront; FEL; photodissociation; Coulomb explosion; Fysicumarkivet A:2019:Lahl;

    Sammanfattning : The study of molecular dynamics involves observations of the motion of nuclei and electrons. While nuclear motion is usually on the picosecond or femtosecond timescale, attosecond precision is necessary to directly observe the motion of electrons. LÄS MER

  2. 12. Time-resolved plasmonics in designed nanostructures

    Författare :Eleonora Lorek; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasmon; Nanostructure fabrication; High-order harmonic generation; Photoemission electron microscopy; Focused ion beam; Fysicumarkivet A:2016:Lorek;

    Sammanfattning : A metal nanoparticle can be considered as consisting of a base of positive ion cores and a sea of free electrons. When the free electrons are displaced, for example, by an incident electric field, a restoring force acts on the electrons. The electrons may then oscillate back and forth until equilibrium is reached. LÄS MER

  3. 13. X-ray - Based Studies of Structural Dynamics in Solids and Liquids

    Författare :Ralf Nüske; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The wavelength of x-ray radiation is much shorter than that of visible light. In fact, it is comparable to the distances between atoms in solids, which is on the order of one tenth of a nanometer. Using light of such a short wavelength, it is possible to study the structure of materials on the atom level. LÄS MER

  4. 14. Creating Ultrafast Biosensors for Neuroscience

    Författare :Yuanmo Wang; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; quantification; glucose; choline oxidase; gold nanoparticles; enzyme monolayer; enzymatic activity; Biosensor; adsorption; brain slice; enzyme stability; acetylcholine esterase; artificial cell; exocytosis; glucose oxidase; deformation; glutamate; glutamate oxidase; acetylcholine; amperometry;

    Sammanfattning : Neuronal communication is the basis for all our brain function and relies on regulated exocytosis, a cell function that involves release of quantal amounts of neurotransmitters into the gap space between interconnected neurons to serve as chemical signals. To study exocytosis, which is a fast process that occurs on the timescale of sub-milliseconds to milliseconds, a toolbox of analytical methods has been developed where the electrochemical based techniques offer quantitative and sufficient high temporal recording speed. LÄS MER

  5. 15. Tree Rings as Sensitive Proxies of Past Climate Change

    Författare :Håkan Grudd; Wibjörn Karlén; Brian Luckman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tree ring; width; density; climate; temperature; change; variability; sensitivity; Torneträsk; Tornetrask; Sweden; Fennoscandia; explosive; volcanic; eruption; Santorini; Thera; subfossil; Fitzroya; Chile; Physical geography; Naturgeografi;

    Sammanfattning : In the boreal forests of the Northern Hemisphere, time series of tree-ring width (TRW) and maximum density in the latewood (MXD) are highly correlated to local instrumental summer-temperature data and are thus widely used as proxies in high-resolution climate reconstructions. Hence, much of our present knowledge about climatic variability in the last millennium is based on tree-rings. LÄS MER