Browsing B6 – LU institūti un aģentūras / Institutes and agencies of the UL by Title
Now showing items 189-208 of 1020
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Dielectric behaviour of nitrogen doped perovskite SrTiO3dNd films
(Royal Society of Chemistry, 2023)Technologically important high-permittivity dielectrics are often achieved using cationic engineering of ABO3-type perovskite para(ferro)electrics. Here, we experimentally and theoretically explore the potential of less ... -
Dielectric properties and ac conductivities of Bi 1− x Sm x FeO 3 ceramics
(Taylor and Francis Ltd., 2019)Dielectric permittivity, dielectric losses and ac-conductivity of polycrystalline Bi1−xSmxFeO3 (x = 0; 0.05; 0.1; 0.15; 0.2) are measured in the frequency range 1 kHz–10 MHz and in the temperature range 25–600 °C. Anomalies ... -
Dielectric response of BaTiO electronic states under AC fields via microsecond time-resolved X-ray absorption spectroscopy
(Elsevier, 2021)For the first time, the dielectric response of a BaTiO thin film under an AC electric field is investigated using microsecond time-resolved X-ray absorption spectroscopy at the Ti K-edge in order to clarify correlated ... -
Different approaches in sulfonated poly (ether ether ketone) conductivity measurements
(Institute of Physics Publishing, 2019)Ion conductivity of sulfonated poly (ether ether ketone) (SPEEK) membranes with various degree of sulfonation (DS) was investigated using impedance analysis with different measuring cell configuration and ion conductivity ... -
Differently substituted benzonitriles for non-doped OLEDs
(Elsevier Ltd, 2020)Towards highly efficient doping-free organic light-emitting diodes, five benzonitrile-based emitters with different substitution pattern were designed exploiting symmetrical donor-acceptor-donor and asymmetrical ... -
Diphenylsulfone-based hosts for electroluminescent devices: Effect of donor substituents
(Elsevier Ltd, 2020)In this work, we report on a series of diphenylsulfone derivatives substituted by 2-(trifluoromethyl)-phenothiazinyl, 10,11-dihydro-5H-dibenz[b,f]azepinyl, 5H-dibenz[b,f]azepinyl, 4-methoxy-carbazolyl and 1,2,3,4-tetrahy ... -
Direct and indirect determination of electrocaloric effect in Na0.5Bi0.5TiO3
(AIP Publishing, 2017)Direct and indirect studies of the electrocaloric effect were carried out in poled and depoled Na0.5Bi0.5TiO3. For this purpose, polarization and electrocaloric effect temperature change measurements were made at different ... -
Discovery of new boron-rich chalcogenides: orthorhombic B6X (X=S, Se)
(Scientific Reports, 2020)New boron-rich sulfde B6S and selenide B6Se have been discovered by combination of high pressure – high temperature synthesis and ab initio evolutionary crystal structure prediction, and studied by synchrotron X-ray ... -
Distinctive features of diffusion-controlled radiation defect recombination in stoichiometric magnesium aluminate spinel single crystals and transparent polycrystalline ceramics
(2020)MgAl2O4 spinel is important optical material for harsh radiation environment and other important applications. The kinetics of thermal annealing of the basic electron (F, F+) and hole (V) centers in stoichiometric MgAl2O4 ... -
Donor and acceptor substituted triphenylamines exhibiting bipolar charge-transporting and NLO properties
(Elsevier Ltd, 2017)Donor-acceptor type triphenylamine-based malonodinitriles were synthesized and their thermal, optical, photophysical, electrochemical and nonlinear optical properties were studied. The synthesized compounds formed glasses ... -
Dopant solubility in ceria: alloy thermodynamics combined with the DFT+U calculations
(Elsevier B.V., 2018)Tb-doped CeO2 (ceria) is a promising mixed conductor for oxygen permeation membranes and reversible oxygen sorbents. To predict solubility of Tb ions in ceria for a wide range of concentrations, density functional theory ... -
Doped zirconia phase and luminescence dependence on the nature of charge compensation
(Nature Publishing Group, 2017)Zirconia is a relatively new material with many promising practical applications in medical imaging, biolabeling, sensors, and other fields. In this study we have investigated lanthanide and niobium doped zirconia by ... -
The double-incompleteness theorem
(Stiinca, Kishinev, 1976)Let T be a strong enough theory, and M - its metatheory, both are consistent. Then there is a closed arithmetical formula H that is undecidable in T, but one cannot prove in M neither that H is T-unprovable, nor that H is ... -
The double-incompleteness theorem
(Latvia State University, 1975)Let T be a theory, Q - a metatheory of T. Under certain conditions there exist T-undecidable sentences for which this undecidability cannot be proved in Q. For English translation and proof, see K. Podnieks What is ... -
Dundaga parish oronyms (hill names) of Livonian origin in Juris Plāķis’ Latvian toponym publication
(University of Tartu Press, 2014) -
Durability of Advanced Polymer Composites: Book of abstracts
(2021-02-16) -
Dynamics of Singlet Oxygen Molecule Trapped in Silica Glass, Studied by Luminescence Polarization Anisotropy and Density Functional Theory
(American Chemical Society, 2020)The lowest excited electronic state of the O2 molecule, a1Δg, the "singlet oxygen", is of utmost importance for photochemistry and photobiology. For O2 trapped in silica glass, the lifetime of this state and the associated ... -
Dzīvās izstādes Latvijā 19. gs. otrajā pusē: avoti un to izpētes iespējas
(Latvijas Universitātes Latvijas vēstures institūts, 2022)Tēžu publikācija referātam “Dzīvās izstādes Latvijā 19. gs. otrajā pusē: avoti un to izpētes iespējas”, kas 2022. gada 27. janvārī nolasīts Daugavpils Universitātes Humanitārās fakultātes 32. Zinātniskajos lasījumos, sekcijā ... -
Dzīvo organismu bioloģiskie pētījumi pilsētas, lauku un ūdens ekosistēmās: Raksti
(Latvijas Universitātes Bioloģijas institūts, 2019-02-16)