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Visar resultat 16 - 20 av 42 avhandlingar som matchar ovanstående sökkriterier.

  1. 16. Probing Electron Correlation on the Attosecond Timescale

    Författare :Diego Guenot; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysicumarkivet A:2014:Guénot;

    Sammanfattning : This thesis describes how photoemission stimulated by an attosecond pulse train (APT) can be used to extract information on electron correlation in simple quantum systems such as atoms. The emission of the electron by an APT induces a reorganization of the electrons remaining in the ion core. LÄS MER

  3. 17. Towards single Ce ion detection in a bulk crystal for the development of a single-ion qubit readout scheme

    Författare :Ying Yan; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysicumarkivet A:2013:Yan; Ultra-violet laser spectroscopy; Single ion detection; Rare-earth-ion-doped crystals; Quantum computing; Laser stabilisation;

    Sammanfattning : The work presented in this thesis was concerned with investigating the relevant spectroscopic properties of Ce ions randomly doped in an Y2SiO5 crystal at low temperatures (around 4 K), in order to develop a technique and an experimental set-up to detect the fluorescence photons emitted by a single Ce ion. The aim of the work was to determine whether a single Ce ion (referred to as the readout ion) can be used as a local probe to sense the quantum state of a neighbouring single-ion qubit via a state-selective interaction between the readout and qubit ion. LÄS MER

  4. 18. Geographic and genetic diversity of hepatitis B

    Författare :Erik Alestig; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; hepatitis B virus; genotype; phylogeny; molecular epidemiology; sequence analysis; mutation;

    Sammanfattning : Hepatitis B Virus (HBV) infection is a global health problem and may lead to chronic hepatitis, liver cirrhosis and hepatocellular cancer. The ability of HBV to adapt to the host environment by genetic variation has lead to the evolution of 8 established (A-H) and 2 putative genotypes (I-J), each corresponding to a rather well-defined geographical distribution. LÄS MER

  5. 19. Phylogeny and macroevolution in Isoetes (Isoetales)

    Författare :Eva Larsén; Catarina Rydin; Niklas Wikström; Ove Eriksson; Richard Bateman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bayesian inference; biogeography; Cenozoic; genomic data; fossil calibration; Isoetes; Isoetales; megaspore morphology; Mesozoic; molecular clocks; node ages; phylogeny; rhizomorphic lycopsids; scanning electron microscopy; Plant Systematics; växtsystematik;

    Sammanfattning : This thesis has focused on the evolutionary history of Isoetes (Isoetales, Lycopsida), its phylogeny, megaspore morphology and evolutionary path through deep time. With a broadened sampling of species to include more of the worldwide diversity of the genus compared to previous work an unexpected sister to the rest of the genus was found. LÄS MER

  7. 20. Robustness Analysis of Intracellular Oscillators with Application to the Circadian Clock

    Författare :Camilla Trané; Elling W. Jacobsen; Eric Bullinger; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Systems Biology; Automatic control; Reglerteknik;

    Sammanfattning : Periodic oscillations underlie many intracellular functions, such as circadian time keeping, cell cycle control and locomotor pattern generation in nerve cells. These intracellular oscillations are generated in intricate biochemical reaction networks involving genes, proteins and other biochemical components. LÄS MER