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Visar resultat 11 - 15 av 630 avhandlingar som matchar ovanstående sökkriterier.

1. 11. Carbenes: The Gathering : Photophysics of Transition Metal Carbene Complexes

   Författare :Nidhi Kaul; Leif Hammarström; James K. McCusker; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; photophysics; time-resolved spectroscopy; transition-metal complexes; Kemi med inriktning mot kemisk fysik; Chemistry with specialization in Chemical Physics;

   Sammanfattning : This thesis explores the photophysics of some transition-metal complexes (TMCs) which utilize N-heterocyclic carbenes as ligands. After a historical interlude which traces the development of the broader field of transition metal complexes and their photophysical investigations, there is an overview of theoretical concepts and the spectroscopic methods employed. LÄS MER

3. 12. Thermodynamic investigations of transition metal systems containing coabon and nitrogen

   Författare :Lidong Teng; Seshadri Seetharaman; Tooru Matsumiya; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; thermodynamic activity; galvanic cell technique; transition metal carbides; transition metal nitrides; phase equilibrium; Materialvetenskap; Materials science; Teknisk materialvetenskap;

   Sammanfattning : In view of the important applications of carbides and carbo-nitrides of transition metals in the heat-resistant and hard materials industries, the thermodynamic activities of Cr and Mn in the Cr-C, Fe-Cr-C, Mn-Ni-C and Mn-Ni-C-N systems have been studied in the present work by the use of the galvanic cell technique. CaF2single crystals were used as the solid electrolyte. LÄS MER

4. 13. Toughness enhancement in transition metal nitrides

   Författare :Davide Giuseppe Sangiovanni; Valeriu Chirita; Lars Hultman; Sergey Simak; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cubic; transition metal nitrides; mechanical properties; ab initio; dft; toughness; ductility; electronic structure; Condensed matter physics; Kondenserade materiens fysik;

   Sammanfattning : Toughness enhancements can be induced in cubic-B1 transition metal nitride alloys by an increased occupation of the d-t2g metallic states. In this Licentiate Thesis I use density functional theory to investigate the mechanical properties of TiN and VN and of the ternaries obtained by replacing 50% of Ti and V atoms with M (M = V, Nb, Ta, Mo, and W) to form ordered structures with minimum number of inter-metallic bonds. LÄS MER

5. 14. Tunable Magnetic Properties of Transition Metal Compounds

   Författare :Solveig Felton; Per Nordblad; Peter Svedlindh; John Chapman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetic properties; Transition metal compounds; Magnetic structure; Domain structure; SQUID-magnetometry; MFM; Magnetism; Magnetism;

   Sammanfattning : The magnetic properties of transition metal compounds have been studied using SQUID-magnetometry, magnetic force microscopy and Lorentz transmission electron microscopy. New magnetic materials have been found and their magnetic properties have been determined. How the magnetic properties of a material can be changed through e.g. LÄS MER

7. 15. The metal-to-nonmetal transition

   Författare :C. G. Greger Lindell; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : What distinguishes a metal from an insulator? The macroscopic differences are apparent: we immediately note the distinction between the shiny metal which conducts electricity and the colored, sometimes transparent appearance of the insulator. But which are the microscopic criteria that tell us to which of these two macroscopic classes a certain material should belong? An answer to this question must involve an understanding, at least qualitatively of the nature of the electronic system in question. LÄS MER