Browsing B6 – LU institūti un aģentūras / Institutes and agencies of the UL by Title
Now showing items 948-967 of 1020
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Untangling the controversy on Ce3+luminescence in LaAlO3crystals
(Royal Society of Chemistry, 2022)Aluminum perovskites represent an important group of promising scintillation materials with excellent proportionality and energy resolution, but due to difficulties in crystal growth not much attention has been paid to ... -
Unveiling Molecular Changes in Water by Small Luminescent Nanoparticles
(Wiley-VCH Verlag, 2017)Nowadays a large variety of applications are based on solid nanoparticles dispersed in liquids—so called nanofluids. The interaction between the fluid and the nanoparticles plays a decisive role in the physical properties ... -
Up-conversion luminescence of GdVO4:Nd3+/Er3+ and GdVO4:Nd3+/Ho3+ T phosphors under 808 nm excitation
(Elsevier B.V., 2018)In recent years, there exists a tendency in research of up-conversion materials to shift excitation from 980 nm to shorter wavelengths. Here, in order to produce up-conversion luminescence emission of GdVO4-based materials ... -
Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4
(Elsevier, 2019)Transparent oxyfluoride glass ceramics containing hexagonal NaErF4 nanocrystals were synthesized by a heat treatment of a precursor glass obtained by the melt quenching technique. Combined X-ray diffraction (XRD) and ... -
Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4
(Elsevier B.V., 2019)Transparent oxyfluoride glass ceramics containing hexagonal NaErF4 nanocrystals were synthesized by a heat treatment of a precursor glass obtained by the melt quenching technique. Combined X-ray diffraction (XRD) and ... -
Upconversion luminescence of a transparent glass ceramics with hexagonal Na(Gd,Lu)F4 nanocrystals
(Elsevier B.V., 2017)Novel Er3+ doped transparent glass ceramics containing hexagonal Na(Gd,Lu)F4 nanocrystals were prepared from oxyfluoride glasses. The distribution of rare earth ions in the crystalline and glassy phase has been analyzed ... -
Upconversion luminescence of Er3 +/Yb3 + and their role in the stabilization of cubic NaLaF4 nanocrystals in transparent oxyfluoride glass ceramics
(Elsevier B.V., 2018)Novel Er3 + and Yb3 + doped transparent oxyfluoride glass ceramics containing NaLaF4 nanocrystals were prepared from oxyfluoride glasses with general composition of Na2O-NaF-LaF3-Al2O3-SiO2. The crystallization processes, ... -
Use of site symmetry in supercell models of defective crystals: Polarons in CeO2
(Royal Society of Chemistry, 2017)In supercell calculations of defective crystals, it is common to place a point defect or vacancy in the atomic position with the highest possible point symmetry. Then, the initial atomic structure is often arbitrary distorted ... -
Using 2-colorings in the theory of uniquely Hamiltonian graphs
(2019-02)We use the concept of 2-coloring in analyzing UH3 graphs and building exact specifications of functions to find new UH3 graphs by Hamiltonian cycle edge extractions -
UV light induced processes in pure and doped AlN ceramics
(Elsevier, 2021)AlN ceramics samples, pure and doped with Y2O3, Eu2O3 and GaN, and produced from the same AlN powder, were studied for photoelectric effect, photoluminescence spectra and kinetics and thermoluminescence under irradiation ... -
Uzņēmumu ārtelpas reklāminformācija ģeosemiotikas kontekstā
(LU Latviešu valodas institūts, 2018)Rakstā uzmanība ir pievērsta ārtelpas reklāminformācijas izpētes teorētiskajiem un metodoloģiskajiem jautājumiem, un tam ir četri savstarpēji saistīti mērķi: 1) definēt, kas ir semiotiskā ainava un kādi ir tās analīzes ... -
Über die Bestimmung von zwei speziellen Klassen von Eilinien
(Mathematische Zeitschrift, 1937) -
Vacancy defects in Ga2O3: First-principles calculations of electronic structure
(Multidisciplinary Digital Publishing Institute (MDPI), 2021)First-principles density functional theory (DFT) is employed to study the electronic structure of oxygen and gallium vacancies in monoclinic bulk β-Ga2 O3 crystals. Hybrid exchange– correlation functional B3LYP within the ... -
Vai pasaule var būt pieredzes priekšmets?
(LU FSI, 2018-02)Jautājuma “Vai pasaule var būt pieredzes priekšmets?” atbilde ir atkarīga no tā, vai varam pasaulē saskatīt fenomenu vai jēdzienu. Vērstība uz pasauli it kā ir tik acīmredzama, tomēr tai nav nekāda īpaša satura, taču tas ... -
Values as a hobby: the transformation and survival of cultural ritual values in the process of desecration
(Latvijas Universitātes Filozofijas un socioloģijas institūts, 2023)The paper examines how values lose their sacred or protected significance and turn into values as a hobby. Using an excerpt from Arundhati Roy's novel “The God of Small Things”, a trend of transformation of values is ... -
Variation of Nonlinear Refraction and Three-Photon Absorption of Indium–Tin Oxide Quantum Dot Thin Films and Solutions in Near Infrared Range
(MDPI, 2023)We characterize the nonlinear optical properties of indium–tin oxide (ITO) quantum dots (QDs) in the IR range using the Z-scan method. We present results of three-photon absorption (3PA), third harmonic generation (3HG), ... -
Vibrational analysis of paraelectric–ferroelectric transition of linbo3: An ab-initio quantum mechanical treatment
(MDPI, 2021)The phase transitions between paraelectric (PE) and ferroelectric (FE) isomorph phases of LiNbO3 have been investigated quantum mechanically by using a Gaussian-type basis set, the B3LYP hybrid functional and the CRYSTAL17 ... -
Vide un cilvēks: jaunākie pētījumi par neolīta periodu Austrumbaltijā: LU 82. starptautiskās zinātniskās konferences sekcijas programma un tēzes
(Latvijas Universitātes Latvijas vēstures institūts, 2024-03)Sekcija ir veltīta vienam no interesantākajiem periodiem aizvēsturē – neolītam un tajā notiekošajiem procesiem, īpašu uzmanību pievēršot vides faktoru un cilvēka mijiedarbībai. Vides apstākļi un tajā pieejamie resursi ... -
Viskrievijas arheoloģijas kongress Rīgā un tā ieguldījums Latvijas arheoloģijas attīstībā
(Latvijas Vēstures institūts, 2016)