Sökning: "Ab initio"

Visar resultat 26 - 30 av 330 avhandlingar innehållade orden Ab initio.

1. 26. Effects of disorder in metallic systems from First-Principles calculations

   Författare :Christian Asker; Igor Abrikosov; Jörg Neugebauer; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Iron; Nickel; Magnesium; Manganese; Molybdenum; Zirconium; Elastic Constants; High pressure; Earth s core; Density-functional theory; Ab-initio; First-Principles; Core-level shifts; Molecular Dynamics; Phonons; Dynamical Instability; Condensed matter physics; Kondenserade materiens fysik; Computational physics; Beräkningsfysik;

   Sammanfattning : In this thesis, quantum-mechanical calculations within density-functional theory on metallic systems are presented. The overarching goal has been to investigate effects of disorder. In particular, one of the properties investigated is the bindingenergy shifts for core electrons in binary alloys using different theoretical methods. LÄS MER

3. 27. Stacking fault energy and deformation behaviour of austenitic stainless steels: a joint theoretical-experimental study

   Författare :Dávid Sándor Molnár; Levente Vitos; Göran Engberg; Guocai Chai; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; austenitic stainless steel; deformation properties; stacking fault energy; electron backscatter diffraction; ab initio; Teknisk materialvetenskap; Materials Science and Engineering; Steel Forming and Surface Engineering;

   Sammanfattning : Austenitiska rostfria stål är främst kända för sin exceptionella korrosionsbeständighet. De har en ytcentrerad kubisk (FCC) struktur som stabiliseras genom att nickel, mangan eller kväve tillsätts till Fe-Cr legeringen. Fe-Cr-Ni-systemet kan utökas ytterligare genom tillsats av andra element såsom Mo, Cu, Ti, C, etc. LÄS MER

4. 28. Mechanisms of Anion Reactions from the lab to ionospheres

   Författare :Fredrik Lindén; Wolf D. Geppert; Henrik Cederquist; Henning Zettergren; Einar Uggerud; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ab initio; anion; complex molecules; cross section; electron transfer; heavy ions; ionosphere; nitriles; quantum chemistry; spectroscopy; kemisk fysik; Chemical Physics;

   Sammanfattning : A multitude of heavy neutral and ionic molecules have been discovered by the Cassini Plasma Spectrometer in the ionosphere of Saturn's largest moon Titan. However, only three cyano anions were explicitly identified there, namely CN-, C3N- and C5N-. LÄS MER

5. 29. Thermodynamic and Kinetic Investigation of the Fe-Cr-Ni System Driven by Engineering Applications

   Författare :Wei Xiong; Malin Selleby; John Ågren; Byeong-Joo Lee; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; phase transformation; magnetism; spinodal decomposition; stainless steel; low temperature CALPHAD; phase field; ab initio; atom probe tomography; calorimetry; SRA - E-vetenskap SeRC ; SRA - E-Science SeRC ; SRA - Energy; SRA - Energi;

   Sammanfattning : This work is a thermodynamic and kinetic study of the Fe-Cr-Ni system as the core of stainless steels. The Fe-Cr, Fe-Ni and Cr-Ni systems were studied intensively using both computational and experimental techniques, including CALPHAD (CALculation of PHAse Diagrams), phase field simulation, ab initio modeling, calorimetry, and atom probe tomography. LÄS MER

7. 30. Excitation and Ground-State Properties of Natural and Modified Nucleic Acid Bases

   Författare :Anders Holmén; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ab initio; linear dichroism; DFT; transition moment; tautomerism; structure; IR; spectra; DNA bases;

   Sammanfattning : The nucleic acid bases are the carriers of genetic information in DNA and RNA. They are also the main chromophores of nucleic acids and determine their optical properties and sensitivity to UV radiation. LÄS MER