Sökning: "Lattice inversion method"

Hittade 5 avhandlingar innehållade orden Lattice inversion method.

1. 1. Atomistic simulation and experimental studies of transition metal systems involving carbon and nitrogen

   Författare :Jiaying Xie; Seshadri Seetharaman; Oleg Ostrovski; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transition metal carbides; Transition metal nitrides; Transition metal carbo-nitrides; Lattice inversion method; Interatomic potential; Atomistic simulation; Metallurgical process engineering; Metallurgisk processteknik;

   Sammanfattning : The present work was initiated to investigate the stability, structural and thermodynamic properties of transition metal carbides, nitrides and carbo-nitrides by atomistic simulations and experimentations. The interatomic pair potentials of Cr-Cr, Mn-Mn, Fe-Fe, C-C, Cr-C, Mn-C, Fe-C, Cr-Fe, Cr-N and Mn-N were inverted by the lattice inversion method and ab initio cohesive energies, and then employed to investigate the properties of Cr-, Mn- and Fe-carbides by atomistic simulations in this work. LÄS MER

3. 2. Quantum computing with naturally trapped sub-nanometre-spaced ions

   Författare :Lars Rippe; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Laserteknik; Laser technology; Atom- och molekylärfysik; Atomic and molecular physics; akustik; optik; Elektromagnetism; optics; acoustics; Electromagnetism; Fysik; Physics; entanglement; spectroscopy; rare-earth-metal-ion-doped crystals spectral hole-burning; inversion; excitation; laser stabilization; quantum computation; quantum gate;

   Sammanfattning : The main aim of this work, was to lay the foundations for the experimental realisation of a quantum mechanical controlled NOT gate in rare-earth-metal-ion-doped crystals. Small amounts of rare-earth elements, added during the growth of some inorganic crystals, will become substituted into the crystal lattice as trivalent ions. LÄS MER

4. 3. On the Ising problem and some matrix operations

   Författare :Daniel Andrén; Roland Häggkvist; Henrik Eriksson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ising problem; phase tansition; matrix multiplicatoin; matrix inversion; Discrete mathematics; Diskret matematik;

   Sammanfattning : The first part of the dissertation concerns the Ising problem proposed to Ernst Ising by his supervisor Wilhelm Lenz in the early 20s. The Ising model, or perhaps more correctly the Lenz-Ising model, tries to capture the behaviour of phase transitions, i.e. how local rules of engagement can produce large scale behaviour. LÄS MER

5. 4. Molecular Structure, Interfacial Chain Topology, Electronic Structure and Fracture Toughness of Polyethylene: A Multiscale Computational Study

   Författare :Ali Moyassari Sardehaei; Ulf W. Gedde; Gregory C. Rutledge; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The structure of semicrystalline polyethylene (PE) strongly affects its properties. Two important structural features, namely the concentrations of tie chains and entanglements cannot be directly assessed using experimental techniques. LÄS MER

7. 5. Computer Simulations of Polymer Gels : Structure, Dynamics, and Deformation

   Författare :Natasha Kamerlin; Christer Elvingson; Jan Forsman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; computer simulations; Brownian dynamics; polymer gel; microgel; spherical boundary conditions; hypersphere; core-shell; deswelling; mechanical properties; uniaxial elongation;

   Sammanfattning : This thesis presents the results of computer simulation studies of the structure, dynamics, and deformation of cross-linked polymer gels. Obtaining a fundamental understanding of the interrelation between the detailed structure and the properties of polymer gels is a challenge and a key issue towards designing materials for specific purposes. LÄS MER