Sökning: "atomic and molecular physics"

Visar resultat 11 - 15 av 391 avhandlingar innehållade orden atomic and molecular physics.

  1. 11. The effect of surface steps and oxides on the catalytic activity on model Pd and Rh catalysts

    Författare :Chu Zhang; Synkrotronljusfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Surface X-ray diffraction SXRD ; X-ray photonelectron spectroscopy; Catalytic activity; Oxide; Single Crystal surface; surface structure; vicinal surface; CO oxidation; stepped surface; Fysicumarkivet A:2018:Zhang;

    Sammanfattning : A catalyst is a substance that can speed up the rate of a chemical reaction without itself being consumed. Catalysts are crucial for chemical production industries, where about 90% of all chemicals are produced using catalysts. LÄS MER

  2. 12. Hydrodynamics of Binary Bose-Einstein Condensates and Hydro-elasticity of the Inner Crust of Neutron Stars

    Författare :Dmitry Kobyakov; Emil Lundh; Vitaly Bychkov; Mattias Marklund; Achim Schwenk; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Binary Bose-Einstein condensates in ultracold gases; hydrodynamics; quantum turbulence; neutron stars; the inner crust; nuclear astrophysics; fysik; Physics;

    Sammanfattning : In the present thesis, “Hydrodynamics of Binary Bose-Einstein Condensates and Hydro-elasticity of the Inner Crust of Neutron Stars”, the hydrodynamic effects, instabilities and superfluid turbulence in binary immiscible ultracold gases, and hydro-elastic macroscopic coupled modes and microscopic structure of the inner layers of the crust of neutron stars, are studied. The ultracold gas dynamics can be realized in the laboratory. LÄS MER

  3. 13. Effect of Substrate on Bottom-Up Fabrication and Electronic Properties of Graphene Nanoribbons

    Författare :Konstantin Simonov; Olof Karis; Nils Mårtensson; Alexei Preobrajenski; Alessandro Baraldi; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; graphene nanoribbons; bottom-up; substrate; metal contact; electronic structure; electron doping; PES; ARPES; NEXAFS; STM; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Taking into account the technological demand for the controlled preparation of atomically precise graphene nanoribbons (GNRs) with well-defined properties, the present thesis is focused on the investigation of the role of the underlying metal substrate in the process of building GNRs using bottom-up strategy and on the changes in the electronic structure of GNRs induced by the GNR-metal interaction. The combination of surface sensitive synchrotron-radiation-based spectroscopic techniques and scanning tunneling microscopy with in situ sample preparation allowed to trace evolution of the structural and electronic properties of the investigated systems. LÄS MER

  4. 14. The Penning trap mass spectrometer SMILETRAP II and evaporative cooling of highly-charged ions

    Författare :Matthias Hobein; Reinhold Schuch; David Lunney; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Penning trap; Precision mass spectrometry; Atomic mass; Highly-charged ions; Evaporative cooling; Coherent oscillation; Ion beam emittance; Atomic physics; Atomfysik; fysik; Physics;

    Sammanfattning : Accurate mass values have wide-ranging applications in physics and metrology, allowing, for example, to test quantum electrodynamics and fundamental symmetries, to determine fundamental constants, and to establish weight standards. This thesis describes the new high-precision double-Penning trap mass spectrometer SMILETRAP II which aims at relative uncertainties in the mass determination of 10-10 and below. LÄS MER

  5. 15. Optical Memories and Processing in Time- and Frequency Domain

    Författare :Baozhu Luo; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optical storage; photon echo; spectral hole burning; nonlinear optics; fiber amplifier; logical operation; phase retrieval; polarization holographic recording and retrieval; optical processing; Atomic and molecular physics; Atom- och molekylärfysik; Fysicumarkivet A:1998:Luo;

    Sammanfattning : Spectral hole burning and photon echoes are the techniques for frequency-selective optical memories, which have the potential to increase areal data storage density by a factor 10**7. They also have the capability to perform in-memory data processing. LÄS MER