Search results for "XAS"

Comparative Experimental and Theoretical Study of the Fe L-2,L-3-Edges X-ray Absorption Spectroscopy in Three Highly Popular, Low-Spin Organoiron Com…

2019

The occupied and unoccupied electronic structures of three highly popular, closed shell organoiron complexes ([Fe(CO)(5)], [(eta(5)-C5H5 )Fe(CO)(mu-CO)](2), and [(eta(5)-C5H5)(2)Fe]) have been theoretically investigated by taking advantage of density functional theory (DFT) calculations coupled to the isolobal analogy (Elian et al. Inorg. Chem. 1976, 15, 1148). The adopted approach allowed us to look into the relative role played by the ligand -> Fe donation and the Fe -> ligand back-donation in title molecules, as well as to investigate how CO- (terminal or bridging) and [(eta(5)-C5H5)](-)-based pi* orbitals compete when these two ligands are simultaneously present as in [(eta(5)-C5H…

Structural characterization of 2,2-di-n-butyl-4-methyl-1,3,2-dioxastannolane isolated from supercritical CO2 conditions

2009

The title compound has been isolated as single crystals from the synthesis of propylene carbonate from racemic 1,2-propanediol and carbon dioxide using n-Bu2SnO as a catalyst precursor. The X-ray crystallographic structure analysis revealed the self-assembly of di-n-butyltin(IV) 1,2-propanediolate units, linked together through long-distance Sn-O interactions leading to a one-dimensional polymeric architecture organized in a syndiotactic arrangement. The coordination geometry around the tin atoms can be described as an unusual faced-capped trigonal bipyramidal environment.

The complementary structural studies of the double metal cyanide type catalysts for the ring opening polymerization of the oxiranes

2016

Przeprowadzono badania strukturalne katalizatorów dimetalocyjankowych (DMC) z dwoma rodzajami ligandów organicznych. Zaproponowano wyjaśnienie etapów przebiegu krzywych otrzymanych metodą analizy termograwimetrycznej i różnicowej kalorymetrii skaningowej (TG/DSC) badanych katalizatorów. Wykazano obecność kilku stopni związania ligandów w kompleksach DMC. Na podstawie wyników badań z wykorzystaniem absorpcji rentgenowskiej (XAS) stwierdzono, że centrum aktywne katalizatora stanowi atom cynku. W bezpośrednim sąsiedztwie atomów Zn wykryto obecność atomów Cl, natomiast w najbliższych sferach koordynacyjnych atomu Zn nie wykryto atomów tlenu.

Hetero-Telechelic Dye-Labeled Polymer for Nanoparticle Decoration

2009

The synthesis of poly(methyl methacrylate) (PMMA) exhibiting one fluorescent dye (Texas Red) and one methyl disulfide end group is described. It is shown that the latter end group enabled the exchange of both oleic amine on gold nanoparticles (AuNP) and of oleic acid on CdSe/ZnS quantum dots (QD), allowing for a phase transfer of both types of nanoparticles (NP) from hexane into dimethylformamide due to the solubility provided by the PMMA chains. For AuNP, a fluorescence quenching of the dye was found due to fluorescence resonance energy transfer (FRET) from the dye to the AuNP, while QDs caused a fluorescence enhancement by FRET from the QD to the attached dyes. Due to the hetero-telecheli…

L'episteme e la sua giustificabilità razionale nella terza definizione del Teeteto: verso una teoria della responsabilità cognitiva

2010

Hazardous air pollutants and primary liver cancer in Texas.

2016

The incidence of hepatocellular carcinoma (HCC), the most common primary liver cancer, is increasing in the US and tripled during the past two decades. The reasons for such phenomenon remain poorly understood. Texas is among continental states with the highest incidence of liver cancer with an annual increment of 5.7%. Established risk factors for HCC include Hepatitis B and C (HBV, HCV) viral infection, alcohol, tobacco and suspected risk factors include obesity and diabetes. While distribution of these risk factors in the state of Texas is similar to the national data and homogeneous, the incidence of HCC in this state is exceptionally higher than the national average and appears to be di…

When the Grafting of Double Decker Phthalocyanines on Si(100)-2 × 1 Partly Affects the Molecular Electronic Structure

2016

International audience; A combined X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and density functional theory (DFT) study has been performed to characterize the adsorbate interaction of lutetium biphthalocyanine (LuPc2) molecules on the Si(100)-2 × 1 surface. Large molecule–substrate adsorption energies are computed and are found to compete with the molecule–molecule interactions of the double decker molecules. A particularly good matching between STM images and computed ones confirms the deformation of the molecule upon the absorption process. The comparison between DFT calculations and XP spectra reveals that the electronic distribution in the two plateaus …

Spēles ar nepilnīgu informāciju, Texas holdem spēles situāciju modelēšana

2020

Bakalaura darbā pētītas pretinieku modelēšanas metodes, risināti un analizēti spēlētāju stratēģiju veidi. Lai to paveiktu, ir nepieciešams iepazīties ar Spēļu teoriju. Skaidrākam kontekstam tiek aplūkoti spēļu teorijas jēdzieni, spēļu klasifikācija, tuvāk apskatītas spēles ar nepilnīgu informāciju, kas sevī iekļauj arī Beijesa formulas pielietošanu praktiski, kas nepieciešama, lai sekmīgi analizētu spēli. Kā pētāmā spēle izmantota pokera veids – Texas Hold’em, kuras noteikumi un izspēles gaita ir aprakstīta darbā. Spēlei ir izveidotas pretinieku modelēšanas metodes un aprēķinātas uzvaras varbūtības pie noteiktu izspēļu variantiem. Darba noslēgumā ir simulēta 2 spēlētāju spēle, lai praktiski…

Compression and load balancing for efficient sparse matrix-vector product on multicore processors and graphics processing units

2021

We contribute to the optimization of the sparse matrix-vector product by introducing a variant of the coordinate sparse matrix format that balances the workload distribution and compresses both the indexing arrays and the numerical information. Our approach is multi-platform, in the sense that the realizations for (general-purpose) multicore processors as well as graphics accelerators (GPUs) are built upon common principles, but differ in the implementation details, which are adapted to avoid thread divergence in the GPU case or maximize compression element-wise (i.e., for each matrix entry) for multicore architectures. Our evaluation on the two last generations of NVIDIA GPUs as well as In…