Search results for "Spectroscopy."
showing 10 items of 9110 documents
Addition of Ethylene or Hydrogen to a Main-Group Metal Cluster under Mild Conditions
2015
Reaction of the tin cluster Sn8(Arinline image)4 (Arinline image=C6H2-2,6-(C6H3-2,4,6-Me3)2) with excess ethylene or dihydrogen at 25 °C/1 atmosphere yielded two new clusters that incorporated ethylene or hydrogen. The reaction with ethylene yielded Sn4(Arinline image)4(C2H2)5 that contained five ethylene moieties bridging four aryl substituted tin atoms and one tin–tin bond. Reaction with H2 produced a cyclic tin species of formula (Sn(H)Arinline image)4, which could also be synthesized by the reaction of {(Arinline image)Sn(μ-Cl)}2 with DIBAL-H. These reactions represent the first instances of direct reactions of isolable main-group clusters with ethylene or hydrogen under mild conditions…
Extraordinary Performance of Carbon‐Coated Anatase TiO 2 as Sodium‐Ion Anode
2015
The synthesis of in situ polymer‐functionalized anatase TiO2 particles using an anchoring block copolymer with hydroxamate as coordinating species is reported, which yields nanoparticles (≈11 nm) in multigram scale. Thermal annealing converts the polymer brushes into a uniform and homogeneous carbon coating as proven by high resolution transmission electron microscopy and Raman spectroscopy. The strong impact of particle size as well as carbon coating on the electrochemical performance of anatase TiO2 is demonstrated. Downsizing the particles leads to higher reversible uptake/release of sodium cations per formula unit TiO2 (e.g., 0.72 eq. Na+ (11 nm) vs only 0.56 eq. Na+ (40 nm)) while the …
Revealing the local structure of CuMo1−xWxO4 solid solutions by multi-edge X-ray absorption spectroscopy
2022
I.P. and A.K. would like to thank the support of the Latvian Council of Science project No. lzp-2019/1-0071. I.P. acknowledges the L’OREAL Baltic “For Women In Science Program” with the support of the Latvian National Commission for UNESCO and the Latvian Academy of Sciences. The experiment at the Elettra synchrotron was performed within project No. 20150303. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.
The Gaia-ESO Public Spectroscopic Survey
2012
The Gaia-ESO Public Spectroscopic Survey has begun and will obtain high quality spectroscopy of some 100000 Milky Way stars, in the field and in open clusters, down to magnitude 19, systematically covering all the major components of the Milky Way. This survey will provide the first homogeneous overview of the distributions of kinematics and chemical element abundances in the Galaxy. The motivation, organisation and implementation of the Gaia-ESO Survey are described, emphasising the complementarity with the ESA Gaia mission. Spectra from the very first observing run of the survey are presented.
SCOPE-Based Emulators for Fast Generation of Synthetic Canopy Reflectance and Sun-Induced Fluorescence Spectra
2017
Progress in advanced radiative transfer models (RTMs) led to an improved understanding of reflectance (R) and sun-induced chlorophyll fluorescence (SIF) emission throughout the leaf and canopy. Among advanced canopy RTMs that have been recently modified to deliver SIF spectral outputs are the energy balance model SCOPE and the 3D models DART and FLIGHT. The downside of these RTMs is that they are computationally expensive, which makes them impractical in routine processing, such as scene generation and retrieval applications. To bypass their computational burden, a computationally effective technique has been proposed by only using a limited number of model runs, called emulation. The idea …
Thermodynamic and spectroscopic study of the binding of dimethyltin(IV) by citrate at 25°C
2006
Thermodynamic (potentiometric and calorimetric) and spectroscopic ( 1 H NMR, 119 Sn Mossbauer) studies were performed in aqueous solution in order to characterize the interaction of dimethyltin(IV) cation with citrate ligand. Six species {(CH 3 ) 2 Sn(cit) - ; [(CH 3 ) 2 Sn] 2 (cit) 2 2- ; (CH 3 ) 2 Sn(cit)H 0 ; (CH 3 ) 2 Sn(cit)OH 2- ; [(CH 3 ) 2 Sn] 2 (cit)OH 0 ; [(CH 3 ) 2 Sn] 2 (cit)(OH) 2 - } were found. All the species formed in this system are quite stable and formation percentages are fairly high. For example, at pH = 7.5 and C (CH3)2Sn = C cit = 10 mmol l -1 , E% for [(CH 3 ) 2 Sn] 2 (cit)(OH) 2 - and (CH 3 ) 2 Sn(cit)OH 2- species reaches 65%. Overall thermodynamic parameters obta…
A Decade of GRB Follow-Up by BOOTES in Spain (2003–2013)
2016
This article covers ten years of GRB follow-ups by the Spanish BOOTES stations: 71 follow-ups providing 23 detections. Follow-ups by BOOTES-1B from 2005 to 2008 were given in a previous article and are here reviewed and updated, and additional detection data points are included as the former article merely stated their existence. The all-sky cameras CASSANDRA have not yet detected any GRB optical afterglows, but limits are reported where available.
Pd2Au36(SR)(24) cluster: structure studies
2015
The location of the Pd atoms in Pd2Au36(SC2H4Ph)(24), is studied both experimentally and theoretically. X-ray photoelectron spectroscopy (XPS) indicates oxidized Pd atoms. Palladium K-edge extended X-ray absorption fine-structure (EXAFS) data clearly show Pd-S bonds, which is supported by far infrared spectroscopy and by comparing theoretical EXAFS spectra in R space and circular dichroism spectra of the staple, surface and core doped structures with experimental spectra.
Application of neural networks in diagnostics of chemical compounds based on their infrared spectra
2017
Abstract The paper presents possibilities of using the so-called „finger-print“ identification method and artificial neural network (ANN) for diagnosis of chemical compounds. The construction of a tool specifically developed for this purpose and the ANN, as well as the required conditions for its proper functioning were described. The identification of chemical compounds was tested in two different ways for proving correctness of the assumptions. First of all, initial studies were carried out with the objective to verify the proper functioning of the developed procedure for IR spectrum interpretation. The second research stage was to find out how the properties of artificial neural networks…
In-gas laser ionization and spectroscopy of actinium isotopes near the N=126 closed shell
2017
The in-gas laser ionization and spectroscopy (IGLIS) techniquewas applied on the $^{212–215}$Ac isotopes, produced at the Leuven Isotope Separator On-Line (LISOL) facility by using the in-gas-cell and the in-gas-jet methods. The first application under on-line conditions of the in-gas-jet laser spectroscopy method showed a superior performance in terms of selectivity, spectral resolution, and efficiency in comparison with the in-gas-cell method. Following the analysis of both experiments, the magnetic-dipole moments for the $^{212–215}$Ac isotopes, electric-quadrupole moments and nuclear spins for the $^{214,215}$Ac isotopes are presented and discussed. A good agreement is obtained with lar…