Search results for "GST"
showing 10 items of 874 documents
Akadēmiķis Pauls Valdens – Latvijas Augstskolas rektors
2017
Izcilākais zinātnieks, ķīmiķis un fiziķis, divu zinātnes apakšnozaru – dinamiskās stereoķīmijas un neūdens šķīdumu elektroķīmijas pamatlicējs, Rīgas Politehniskā institūta docētājs, profesors, Rīgas Politehniskā institūta direktors (1902-1905, 1917-1918), Baltijas Tehniskās augstskolas un Latvijas Augstskolas rektors (1919), Rostokas universitātes Ķīmijas institūta Neorganiskās un Farmaceitiskās nodaļas, Fizikāli ķīmiskās nodaļas vadītājs (1919-1934).
Latvijas Tautas frontes Augstākās Padomes frakcijas nostāja saimniecisko problēmu risināšanā (1991. gada janvāris - augusts)
2020
Maģistra darba mērķis ir raksturot Latvijas Tautas frontes Augstākās Padomes frakcijas darbību saimniecības jomā 1991. gadā no janvāra līdz augustam, izvērtējot, cik lielā mērā frakcija iesaistījās ekonomisko norišu virzībā, kādi bija frakcijas lēmumi un prioritātes un kādas bija frakcijas likumdošanas iniciatīvas ekonomikas jautājumos. Pētījumā aplūkots Latvijas vispārējais saimnieciskais stāvoklis 20. gadsimta 80. gadu otrajā pusē un 1991. gadā, sniegts ieskats Latvijas Tautas frontes Augstākās Padomes frakcijas izveidē un darbībā, raksturota frakcijas tautsaimniecības un ekonomikas stratēģija. Pamatojoties uz Latvijas Valsts arhīvā esošajiem frakcijas dokumentiem – pētīts, kā tajos atspo…
Latvijas Universitātes Raksti; 763 .sēj.
2011
Angst und Verzagtheit im . Eine Studie zum Wortschatz der Angst
2015
The Meier Helmbrecht, written by Wernher der Gärtner between 1250 and 1280, has often been object of study especially with regard to the protagonist’s extreme ambition and the disowning of his own origins and of his family heritage, but it also offers excellent opportunities for linguistic reflexions. Contrary to what is expected in a text, where the main character lives an immoral life and where his family is constantly concerned about his fate, there are few words to express fear or anxiety, but Wernher der Gärtner chooses the words used carefully, highlighting the different ways the characters perceive and reveal these emotions. The study of the vocabulary of fear in this work allows us …
Local atomic and electronic structure of tungsten ions in AWO4 crystals of scheelite and wolframite types
2001
Abstract X-ray absorption spectroscopy was used to study the local atomic and electronic structure of tungsten ions in polycrystalline scheelite CaWO4 and wolframite-type ZnWO4 and NiWO4. The W L1- and L3-edges X-ray absorption near edge structure (XANES) signals suggest tetrahedral coordination of tungsten ions in CaWO4 and strongly distorted octahedral coordination in ZnWO4 and NiWO4. Accurate analysis of the W L3-edge extended X-ray absorption fine structure (EXAFS) signals by the regularization procedure was performed to reconstruct the radial distribution functions within the first coordination shell around tungsten atoms in AWO4 crystals and polycrystalline WO3, which was utilized for…
<title>X-ray absorption spectroscopy study of the local environment around tungsten and molybdenum ions in tungsten-phosphate and molybdenum-ph…
1997
X-ray absorption spectroscopy (XAS) was used to study the local environment around tungsten and molybdenum ions in BaO-P2O5-WO3 and CaO-P2O5-MoO3 glasses having different composition of WO3 and MoO3 oxides. The W L1,3 and Mo K edges x-ray absorption spectra were measured in transmission mode at room temperature using the synchrotron radiation emitted by the ADONE and LURE DCI storage rings, respectively. The analysis of x-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) in glasses was performed in comparison with the results for a number of crystalline WO3, CaWO4, Na0.66WO3 alpha- MoO3, beta-MoO3 and amorphous a-WO3, a-MoO3 compounds. The resul…
XAS, XRD, AFM and Raman studies of nickel tungstate electrochromic thin films
2001
Abstract Systematic studies of nanocrystalline nickel tungstate, NiWO 4 , thin films were performed by several experimental techniques such as Ni K- and W L 1,3 -edges X-ray absorption spectroscopy, X-ray diffraction, Raman spectroscopy, atomic force microscopy and cyclic voltammetry measurements. We found that the NiWO 4 thin films exhibit electrochromic properties similar to that of amorphous tungsten trioxide films, but show better structural stability upon multiple colouring/bleaching cycling. It was observed that a nanocrystallinity of the thin films results in strong modifications of the NiO and WO interactions, which affect both local atomic and vibrational structures.
Sputtering deposition and characterization of Ru-doped WO3 thin films for electrochromic applications
2003
Mixed tungsten-ruthenium oxide thin films were prepared for the first time by dc magnetron co-sputtering technique and were studied by cyclic voltammetry, optical transmission measurements, Raman spectroscopy and the W L3 and Ru K edges X-ray absorption spectroscopy (XAS) in comparison with pure WO3 films. The Ru concentration was varied in the range from 0 to 28 at.%. XAS results suggest that the average local structure around both tungsten and ruthenium ions remains unchanged within experimental accuracy in all samples, moreover, for tungsten ions, it resembles that of pure WO3 films. However, the presence of the ruthenium ions affects the electrochemical and optical properties of the fil…
High-pressure x-ray absorption spectroscopy study of tin tungstates
2015
Room-temperature pressure-dependent (0-25 GPa) x-ray absorption spectroscopy at the W -edges of α-SnWO4 and β-SnWO4 was performed using a dispersive setup and a high-pressure nanodiamond anvil cell. The detailed analysis of experimental x-ray absorption near-edge structure and extended x-ray absorption fine structure data suggests that upon increasing pressure, a displacement of tungsten atoms by about 0.2 A toward the center of the WO6 octahedra occurs in α-SnWO4, whereas the coordination of tungsten atoms changes from tetrahedral to distorted octahedral in β-SnWO4.
Structure and composition of sputter-deposited nickel-tungsten oxide films
2011
Films of mixed nickel-tungsten oxide, denoted NixW1-x oxide, were prepared by reactive DC magnetron co-sputtering from metallic targets and were characterized by Rutherford backscattering spectrometry. X-ray photoelectron spectroscopy, X-ray diffractometry and Raman spectroscopy. A consistent picture of the structure and composition emerged, and at x<0.50 the films comprised a mixture of amorphous WO3 and nanosized NiWO4, at x = 0.50 the nanosized NiWO4 phase was dominating, and at x>0.50 the films contained nanosized NiO and NiWO4.