Sökning: "jessen"

Hittade 4 avhandlingar innehållade ordet jessen.

  1. 1. The Ups and Downs of the Holocene: Exploring Relationships between Global CO2 and Climate Variability in the North Atlantic Region

    Författare :Catherine Jessen; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marklära; geomorfologi; climatology; klimatologi; rapid climate change; Holocene climate; atmospheric CO2 concentrations; geochemical proxy indicators; Paleobotanik; palynology; Geology; palynologi; fylogeni; geomorphology; fysisk geografi; Geologi; physical geography; kartografi; pedology; cartography; phylogeny; Palaeobotany; stomatal frequency; lake sediments;

    Sammanfattning : This thesis aimed to examine the relationship between climate and atmospheric CO2 concentrations through rapid climate changes during the Holocene. Climate was reconstructed using high-resolution, radiocarbon dated, lake sediment geochemical proxies (magnetic susceptibility, loss-on-ignition, total carbon/nitrogen/sulphur determinations and biogenic silica), vegetational reconstruction (pollen analysis) and stomatal frequency based CO2 reconstructions. LÄS MER

  3. 2. Schultergürtel und Pectoralflosse bei Actinopterygiern

    Författare :Hans Jessen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : .... LÄS MER

  4. 3. Experimental Investigation of Three-Dimensional Single and Double optical Lattices

    Författare :Harald Ellmann; Poul Jessen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : A complete laser cooling setup was built, with focus on threedimensional near-resonant optical lattices for cesium. These consist of regularly ordered micropotentials, created by the interference of four laser beams. One key feature of optical lattices is an inherent ”Sisyphus cooling” process. LÄS MER

  5. 4. The braincase of Youngolepis, a Lower Devonian crossopterygian from Yunnan, south-western China

    Författare :Mee-mann Chang; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fiskar; Paleozoologi;

    Sammanfattning : The endocranium and skull roof of Youngolepis, a Lower Devonian crossopterygian from south-western China, is described based on some 40 specimens of which one was investigated by serial grinding. In cranial structure Youngolepis Chang et Yu, 1981, shows affinity to Powichthys Jessen, 1975, from the Lower Devonian of the Canadian Arctic. LÄS MER