Sökning: "nevada"

Hittade 3 avhandlingar innehållade ordet nevada.

  1. 1. Electron impact dissociation of molecular ions at CRYRING

    Författare :Ahmed Al-Khalili; Ronald A Phaneuf; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; fysik;

    Sammanfattning : In this thesis, the electron impact dissociation of molecular ions has been studied using the ion storage ring CRYRING at Manne Siegbahn Laboratory in Stockholm, Sweden. The electron impact dissociation of molecular ions occurs via many processes, which lead to different charge states of the product fragments. LÄS MER

  3. 2. Decoding the fossil record of early lophophorates : Systematics and phylogeny of problematic Cambrian Lophotrochozoa

    Författare :Aodhán D. Butler; Michael Streng; Lars E. Holmer; Russell Garwood; Maggie Cusack; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Brachiopoda; Chengjiang; Lagerstätte; Cambrian Explosion; palaeobiology; stem-group; entoproct; phoronid; tommotiid; exceptional preservation; Earth Science with specialization in Historical Geology and Palaeontology; Geovetenskap med inriktning mot historisk geologi och paleontologi;

    Sammanfattning : The evolutionary origins of animal phyla are intimately linked with the Cambrian explosion, a period of radical ecological and evolutionary innovation that begins approximately 540 Mya and continues for some 20 million years, during which most major animal groups appear. Lophotrochozoa, a major group of protostome animals that includes molluscs, annelids and brachiopods, represent a significant component of the oldest known fossil records of biomineralised animals, as disclosed by the enigmatic ‘small shelly fossil’ faunas of the early Cambrian. LÄS MER

  4. 3. Phylogenetic and phyloclimatic inference of the evolution of Potentilleae (Rosaseae)

    Författare :Mats H. Töpel; Göteborgs universitet; []
    Nyckelord :Potentilla; Ivesia; Horkelia; allopolyploidization; TGGE; Beringia;

    Sammanfattning : Polyploidization has occurred many times during the evolution of angiosperms. Allopolyploidization is believed to be the process behind many of these genome duplications, and has resulted in a genetically diverse angiosperm flora. LÄS MER