Sökning: "isotope shifts"

Visar resultat 1 - 5 av 33 avhandlingar innehållade orden isotope shifts.

  1. 1. Holocene climate and atmospheric circulation changes in northern Fennoscandia : Interpretations from lacustrine oxygen isotope records

    Författare :Christina E. Jonsson; Gunhild Rosqvist; Jan Seibert; Philip Barker; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; oxygen isotope; diatom silica; lake sediment; atmospheric circulation; North Atlantic Oscillation; northern Fennoscandia; The Holocene; Little Ice Age; Physical geography; Naturgeografi; Physical Geography; naturgeografi;

    Sammanfattning : This thesis investigates how variations in the oxygen isotopic composition of lake waters in northern Fennoscandia are recorded in lake sediment archives, especially diatoms, and how these variations can be used to infer past changes in climate and atmospheric circulation. Results from analyses of the oxygen isotopic composition of lake water samples (δ18Olakew) collected between 2001 and 2006 show that δ18O of northern Fennoscandian lakes is mainly controlled by the isotopic composition of the precipitation (δ18Op). LÄS MER

  3. 2. Hubble Space Telescope Spectroscopy of Eta Carinae and Chi Lupi

    Författare :Torgil Zethson; Partikel- och kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic and optical properties; supraconductors; electrical; Rymdteknik; kosmisk kemi; Condensed matter:electronic structure; rymdvetenskap; Astronomi; cosmic chemistry; space research; Astronomy; boron; isotope shifts; Chi Lupi; fluorescence; element abundances; emission lines; GHRS; strontium; STIS; Eta Carinae; spectroscopy; Hubble Space Telescope; supraledare; magnetiska och optiska ; magnetisk resonans; Space technology; spektroskopi; relaxation; magnetic resonance; egenskaper elektriska ; Kondenserade materiens egenskaper:elektronstruktur;

    Sammanfattning : Eta Carinae is a super-massive, super-luminous star. It is surrounded by a bipolar nebula, the "Homunculus", and several blobs of ejected gas which are the source of a complex emission-line spectrum. LÄS MER

  4. 3. Computational Atomic Structures Toward Heavy Element Research

    Författare :Sacha Schiffmann; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atoms; electron correlation; relativity; Quantum mechanics; calculations; natural orbitals; isotope shifts; hyperfine structures; transition parameters; Landé g factor; Fysicumarkivet A:2021:Schiffmann;

    Sammanfattning : We are interested in complex electronic structures of various atomic and ionics systems. We use an ab initioapproach, the multiconfigurational Dirac-Hartree-Fock (MCDHF), to compute atomic structures and properties. LÄS MER

  5. 4. Towards understanding stable isotope signatures in stressed systems

    Författare :Caroline Ek; Elena Gorokhova; Katrine Borgå; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Stable isotope analysis; trophic position; chemical exposure; oxidative stress; Daphnia magna; Gammarus spp.; Limecola balthica; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : Stable isotope analysis (SIA) is a valuable tool in ecotoxicology because δ13C and δ15N may provide insights into the trophic transfer of contaminants in a food web. The relationship between a species’ trophic position (TP, determined from δ15N) and internal concentration of biomagnifying contaminants can be established and used for regulatory purposes. LÄS MER

  7. 5. Hyperfine structure, isotope shifts and transition probabilities in singly charged atoms : laser - ion beam studies

    Författare :Petrine Villemoes; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER