Search results for "Optical"
showing 10 items of 7671 documents
Heterovalent BiIII/PbII ionic substitution in one-dimensional trimethylsulfoxonium halide pseudo-perovskites (X = I, Br)
2021
We report on the synthesis and characterization of novel lead and bismuth hybrid (organic-inorganic) iodide and bromide pseudo-perovskites (ABX3) containing the trimethylsulfoxonium cation (CH3)3SO+ (TMSO) in the A site, Pb/Bi in the B site, and Br or I as X anions. All of these compounds are isomorphic and crystallize in the orthorhombic Pnma space group. Lead-based pseudo-perovskites consist of one-dimensional (1D) chains of face-sharing [PbX6] octahedra, while in the bismuth-based ones, the chains of [BiX6] are interrupted, with one vacancy every third site, leading to a zero-dimensional (0D) local structure based on separated [Bi2I9]3- dimers. Five solid solutions for the iodide with di…
Photoconductivity & photoelectron emission of LiGaO2 crystal excited in intrinsic absorption range
2019
This research is funded by the Latvian Council of Science, project “Research of luminescence mechanisms and dosimeter properties in prospective nitrides and oxides using TL and OSL methods], project No. lzp-2018/0361.
Linear and nonlinear optical properties of a series of Ni-dithiolene derivatives
2009
Some linear and nonlinear optical (NLO) properties of Ni(SCH)4 and several of its derivatives have been computed by employing a series of basis sets and a hierarchy of methods (e.g., HF, DFT, coupled cluster, and multiconfigurational techniques). The electronic structure of Ni(SCH)4 has been also analyzed by using CASSCF/CASPT2, ab initio valence bond, and DFT methods. In particular we discuss how the diradicaloid character (DC) of Ni(SCH)4 significantly affects its NLO properties. The quasidegeneracy of the two lowest-energy singlet states 1 mathg and 1 math1u, the clear DC nature of the former, and the very large number of low-lying states enhance the NLO properties values. These particul…
Graph-based analysis of ethylene glycol decomposition on a palladium cluster
2017
The ethylene glycol, CH2OH-CH2OH, decomposition mechanism, occurring on a subnanometric palladium cluster shaped by 12 atoms, was investigated by means of density functional theory. Different reaction routes were identified leading to H2 and CO. The whole reaction network was analyzed, framing the results within the graph theory. The possible decomposition pathways were discussed and compared, allowing one to draw a whole picture of all the parallel, possibly competitive, routes that starting from CH2OH-CH2OH originate H2 and CO.
New Quasi-Atomic Nanoheterostructures: Superatoms and Excitonic Quasi-Molecules
2016
In this review, the state-of-the-art of research of artificial atoms (superatoms or quasi-atomic nanoheterostructures) and more complex nanostructures based on them—synthetic molecules is discussed, a new model of an artificial atom, which satisfactorily explains its electronic properties, is proposed, and the prospects for development of the new scientific trend are mentioned. В этом обзоре обсуждается современное состояние исследований искусственных атомов (сверхатомов или квазиатомных наногетероструктур) и более сложных наноструктур на их основе — синтетических молекул, предложена новая модель искусственного атома, удовлетворительно объясняющая его электронные свойства, а также указаны п…
A comparison among different kinds of stator lamination in tubular linear machines
2016
In this paper the authors perform a comparison among three different stator structures for a Tubular Permanent Magnet Linear Machine. Each structure is characterized by its own lamination which is expected to contribute to the overall performance of the machine. A detailed analysis of the main figures of merit of the three configurations has been carried out in order to identify the configuration with the best characteristics. Significant data such as flux distribution, rated voltage and current, force on the moved and power losses have been compared. The results show that the choice of a mixed stator lamination allows to improve the performance of these machines.
Biomimetic oxidation of pyrene and related aromatic hydrocarbons. Unexpected electron accepting abilities of pyrenequinones
2014
We present a mild catalytic method to oxidize PAHs and, in particular, pyrene. The pyrenediones are much better electron acceptors than benzoquinone in the gas phase and present similar accepting abilities in solution.
A method for eluting DNA in a wide range of molecular weights from agarose gels
1991
We have developed a simple and rapid method for recovering DNAs of a wide range of molecular weights from agarose gels. A DNA-containing gel slice is placed on a Parafilm sheet in the center of a circular (positive) electrode and covered with a drop of buffer, while a linear (negative) electrode is placed on the top of the gel and driven about 1 mm into the gel itself. When a continuous current is applied, the DNA migrates into the buffer toward the circular electrode. We have obtained almost total recovery of DNAs up to 10 kb in size. Our method may also be used, under appropriate conditions, for higher molecular weight DNAs. The yield and all the biological assays performed on the DNAs ob…
Ettringite surface chemistry: Interplay of electrostatic and ion specificity
2011
International audience; This paper presents a detailed experimental study combined with Monte Carlo (MC) simulations within the primitive model of the physical chemistry at the ettringite-water interface over a wide range of pH and bulk conditions for which ettringite exists thanks to its solubility in aqueous solutions. Ettringite, which is an important phase in hydrated cement-based systems, bears a permanent and positive structural charge. In contrast with previous studies, electrokinetic measurements together with the careful chemical analysis of the equilibrium solutions of the dispersions have brought strong support to designate sulfate as being the ion determining the potential. Simu…
Personalization of Fast Conduction Purkinje System in Eikonal-Based Electrophysiological Models with Optical Mapping Data
2010
We present a pipeline for the personalization of model-based Purkinje fast conduction system using fast electrophysiological models and optical mapping data acquired from ex-vivo porcine hearts. The regional density of the Purkinje terminals as well as the latest endocardial activation time were the parameters personalized in an iterative procedure maximizing the similarity between the outcome of the electrophysiological simulations and measurements obtained from optical mapping data. We used a fast wave-front Eikonal-based electrophysiological model that generated the depolarization time maps that were subsequently compared with measurements at each iteration of the optimization stage. The…