An integration of attachment theory and reinforcement sensitivity theory

This thesis examined how relationship experiences shape people\u27s sensitivity to detect threat and reward in romantic relationships and substance use scenarios. Findings indicated that anxious individuals experienced difficulty in distinguishing between threat and reward. In contrast, avoidant individuals were quick to detect threat either fleeing or confronting the problem aggressively

Electronic structure of PbSnS₃ and PbGeS₃ semiconductor compounds with the mixed cation coordination

The self-consistent band structure calculation of PbSnS₃ and PbGeS₃ ternary compounds with the mixed cation coordination was performed using the ab initio density functional theory method. It has been found that both compounds are indirect-gap semiconductors. The calculated band-gap widths are Egi = 0.75 eV for PbSnS₃ and Egi = 1.96 eV for PbGeS₃. It was performed the analysis of partial contributions to the total density of electronic states, which allowed to identify the genetic nature of valence and conduction bands. The feature of the structure of occupied energy bands in these compounds is the presence of isolated quasi-core d-band of lead atoms and the contribution of Pb6s-states of lone-electron pair to the top of valence band as well as to the second occupied subband. The electron density maps in the different planes have been analyzed. They clearly demonstrate presence of covalent-ionic bond character within the infinite chains and ribbons with prevailing charge concentration on Ge–S, Sn–S, Pb–S bonds, and a weak van der Waals bond component with participation of lone-electron pair of lead between layers as well as ribbons

Effect of the sapphire substrate on spectral emission features of LEDs based on InGaN/AlGaN/GaN heterostructures

Luminescence spectra of blue and green LEDs based on InxGa₁₋xN/AlyGa₁₋yN/GaN heterostructures with many quantum wells in the current range 0.1 to 10 mA have been studied besides the main electroluminescence band. In the emission spectra of blue LEDs, the energy maximum position is shifted with changing the current (hn max = 2.62 - 2.63 eV). A weak doublet of R-lines 692.8 and 694.3 nm conditioned by the re-emission of single Cr³⁺ ions in a sapphire substrate has been fixed. The use of substrates from heavy doped ruby for making white LEDs based on nitride heterostructures has been proposed. The expediency of using blue and green LEDs as sources of photoluminescence excitation in the range of R- and N-lines of sapphire substrates and heavy doped ruby has been shown

Influence of intrinsic point defects and substitutional impurities (Cl, I-S) on the electronic structure of 2H-SnS2

It was performed the systematic investigation of chemical modification regularities of electronic structure at the composition changes of “ideal” 2H-SnS 2 crystal by using the self-consistent density functional theory method in the supercell model. It were analyzed the phases obtained during doping the sulfur sublattice by substitutional impurity Y-S (Y = Cl, I) as well as during changing tin disulfide structure due to the appearance of atomic vacancies in cation and anion sublattices (non-stoichiometry effects)