Sökning: "atomic substitution"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden atomic substitution.

  1. 1. Raman scattering investigations of phonons in ceramic high-T superconductors

    Författare :Mikael Käll; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; charge distribution; Raman spectroscopy; high-Tc superconductors; ceramics; phonons; atomic substitution;

    Sammanfattning : .... LÄS MER

  3. 2. Atomic-scale modelling of interfaces in cemented carbides: wetting and strength

    Författare :Martin Gren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; adhesion; density functional theory; hardmetals; cemented carbides; WC-Co; surfaces; interfaces; grain boundaries; wetting; phase boundaries;

    Sammanfattning : Cemented carbides are composite materials of great technological and industrial importance. They have a unique combination of hardness and toughness and are therefore used widely as tool materials in applications where both high hardness and toughness are demanded. These applications include among others: mining, turning, cutting and milling. LÄS MER

  4. 3. Quantum Chemical Studies of Radical Cation Rearrangement, Radical Carbonylation, and Homolytic Substitution Reactions

    Författare :Daniel Norberg; Nessima Salhi-Benachenhou; Sten Lunell; Tim Clark; Uppsala universitet; []
    Nyckelord :Quantum chemistry; quantum chemistry; coupled-cluster; density functional theory; meta-GGA; reaction mechanism; potential energy surface; isomerization; fragmentation; dissociation; condensation; addition; SH2; hydrogen abstraction; iodine atom transfer; complex; weakly interacting system; hyperfine coupling constant; Kvantkemi;

    Sammanfattning : Quantum chemical calculations have been performed to investigate radical cation rearrangement, radical carbonylation, and homolytic substitution reactions of organic molecules. The rearrangement of the bicyclopropylidiene radical cation to the tetramethyleneethane radical cation is predicted to proceed with stepwise disrotatory opening of the two rings. LÄS MER

  5. 4. The use of metal substitution in characterizing the catalytic mechanism of glyoxalase I

    Författare :Siv Sellin; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Glyoxalase I, a zinc enzyme, has been purified from human erythrocytes. The aim of this investigation was to examine the active center of this enzyme and its catalytic mechanism by applying different spectroscopic methods to the study of metal-substituted glyoxalase I. LÄS MER

  7. 5. Computational Studies of Chemical Interactions: Molecules, Surfaces and Copper Corrosion

    Författare :Joakim Halldin Stenlid; Tore Brinck; Thomas Bligaard; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; computational chemistry; density functional theory; chemical interactions; reactivity descriptors; copper corrosion; surface and materials science; nucleophilic substitution reactions; heterogeneous catalysis; transition metal oxides; nanotechnology; beräkningskemi; täthetsfunktionalteori; kemiska interaktioner; reaktivitetsdeskriptorer; kopparkorrosion; yt- och materialvetenskap; nukleofila substitutionsreaktioner; heterogen katalys; överångsmetalloxider; nanoteknologi; Kemi; Chemistry;

    Sammanfattning : The chemical bond – a corner stone in science and a prerequisite for life – is the focus of this thesis. Fundamental and applied aspects of chemical bonding are covered including the development of new computational methods for the characterization and rationalization of chemical interactions. LÄS MER