Search for dissertations about: "divergence times"

Showing result 21 - 25 of 33 swedish dissertations containing the words divergence times.

  2. 21. Extreme Electron Beams and Brilliant X-rays : Generation, Manipulation and Characterization of Relativistic Electron Beams for and from Plasma-Based Accelerators

    Author : Jonas Björklund Svensson; Atomfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; laser; plasma; wakefield; acceleration; accelerator; relativistic; electrons; x-rays; ultra-fast; betatron; laser-wakefield acceleration; plasma-wakefield acceleration; Fysicumarkivet A:2020:Björklund;

    Abstract : This thesis is based on work done by the author on the development of plasma-based electron accelerators driven by ultra-intense laser pulses and dense electron bunches. Plasma based accelerators have several benefits, such as accelerating fields around 1000 times stronger than in “conventional” radio-frequency accelerators, which can allow for shrinking the overall footprint of the accelerator. READ MORE

  4. 22. Biochemical genetic variation, intraspecific genetic structure and postglacial evolution of select north European vertebrate species

    Author : Ulf Gyllensten; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Evolution biologi ; Populationsgenetik;

    Abstract : Analysis of the tempo and mode of intraspecific differentiation provides important information for understanding subspeciation, for construction of taxonomic hierarchies within a species and for management of genetic variation in natural populations.The present thesis describes the genetic structure of natural populations of willow grouse (Lagopus tagopus L. READ MORE

  5. 23. Light-Matter Interaction on the Attosecond Timescale

    Author : Marcus Dahlström; Atomfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fysicumarkivet A:2011:Dahlström; Temporal characterization; Two-color harmonic generation; High-order harmonic generation; Attosecond pulse trains; Electron wave packets; Two-photon ionization; Coherent control;

    Abstract : Attosecond science refers to physical processes that occur on the natural timescale of electron motion in atomic and molecular systems. Attosecond time resolution can be obtained experimentally through a process called high-order harmonic generation where sharp attosecond pulses are formed in the time domain. READ MORE

  6. 24. Heterobasidion root rot : genetic mapping of virulence and evolutionary history

    Author : Kerstin Dalman; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Abstract : Heterobasidion annosum (Fr.) Bref. sensu lato (s.l. READ MORE

  7. 25. Evolutionary studies of the Gnetales

    Author : Chen Hou; Catarina Rydin; Richard Saunders; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; växtsystematik; Plant Systematics;

    Abstract : The Gnetales consist of three distinct genera, Ephedra, Gnetum and Welwitschia with considerable divergence among them regarding morphological, ecological and molecular characters. A longstanding debate of the similarity between the Gnetales and angiosperms and the unresolved seed plant phylogeny intrigues plant scientists to further investigate the evolutionary history of the Gnetales. READ MORE