Search results for "RATIO"
showing 10 items of 33258 documents
Aggregation of [Ln(12)(III)] clusters by the dianion of 3-formylsalicylic acid. Synthesis, crystal structures, magnetic and luminescence properties
2019
Three isostrucutral dodecanuclear clusters with the general formula [Ln(12)(fsa)(12)(mu f(3)-OH)(12)(DMF)(12)]center dot nDMF (fsa(2-) is the dianion of 3-formylsalicylic acid; Ln = Eu 1, Gd 2, Dy 3) have been obtained from the reaction of fromylsalicyclic acid (H(2)fsa), tetrabutylammonium hydroxide and Ln(NO3)(3)center dot 6H(2)O in methanol/DMF. Their structure consists of four vertex-sharing heterocubanes. Each heterocubane unit is assembled from four Ln(III) ions, three mu(3)-OH groups and one mu(3)-oxygen atom arising from the fsa(2-) carboxylato group. The photophysical properties of the europium derivative investigated at both 300 and 80 K sustain a relative intense emission obtaine…
Coexistence of superconductivity and spin-splitting fields in superconductor/ferromagnetic insulator bilayers of arbitrary thickness
2021
Ferromagnetic insulators (FI) can induce a strong exchange field in an adjacent superconductor (S) via the magnetic proximity effect. This manifests as spin splitting of the BCS density of states of the superconductor, an important ingredient for numerous superconducting spintronics applications and the realization of Majorana fermions. A crucial parameter that determines the magnitude of the induced spin splitting in FI/S bilayers is the thickness of the S layer d: In very thin samples, the superconductivity is suppressed by the strong magnetism. By contrast, in very thick samples, the spin splitting is absent at distances away from the interface. In this work, we calculate the density of …
Adaptación y validación en población española de la Escala de Expectativa de los hijos adolescentes sobre la reacción de sus padres frente al comport…
2014
El objetivo de esta investigación es presentar una adaptaciòn y validación en población española de la Escala de expectativa de los hijos adolescentes sobre la reacción de sus padres frente al comportamiento prosocial y antisocial,desarrollado por Wyatt y Carlo (2002). La muestra estuvo compuesta por 631 adolescentes españoles de entre 15 y 18 años de edad,de ambos sexos, de clase media. Se realizó un análisis factorial confirmatorio para estudiar la validez de constructo de la escala y se analizó la consistencia interna a través de del cálculo de alpha de Cronbach.Los resultados indican que la escala posee buenos índices de ajuste al modelo teórico propuesto por los autores en su versión o…
La forma de gobierno en la Constitución de Cádiz (reflexiones sobre la configuración de la Jefatura del Estado monárquica)
2012
A partir de las circunstancias históricas de las Cortes de Cádiz y de los precedentes de la monarquía española, el artículo analiza la posición de la Jefatura del Estado monárquica en la Constitución de 1812 caracterizada como una «Monarquía moderada» basada en los principios estructurales de soberanía nacional y división de poderes que determinan la configuración del Rey como poder constituido en la nueva forma de gobierno. La afirmación de la soberanía nacional impregna el conjunto del texto constitucional sin perjuicio de que coexista retóricamente con la antigua legitimidad monárquica. Por otra parte, la división de poderes supone la distinción entre la titularidad de la soberanía y su …
Use of Density Functional Based Tight Binding Methods in Vibrational Circular Dichroism.
2018
Vibrational circular dichroism (VCD) is a spectroscopic technique used to resolve the absolute configuration of chiral systems. Obtaining a theoretical VCD spectrum requires computing atomic polar and axial tensors on top of the computationally demanding construction of the force constant matrix. In this study we evaluated a VCD model in which all necessary quantities are obtained with density functional based tight binding (DFTB) theory. The analyzed DFTB parametrizations fail at providing accurate vibrational frequencies and electric dipole gradients but yield reasonable normal modes at a fraction of the computational cost of density functional theory (DFT). Thus, by applying DFTB in comp…
Energy transfer in LH2 of Rhodospirillum Molischianum, studied by subpicosecond spectroscopy and configuration interaction exciton calculations.
2001
Two color transient absorption measurements were performed on a LH2 complex from Rhodospirillum molischianum by using several excitation wavelengths (790, 800, 810, and 830 nm) and probing in the spectral region from 790 to 870 nm at room temperature. The observed energy transfer time of ∼1.0 ps from B800 to B850 at room temperature is longer than the corresponding rates in Rhodopseudomonas acidophila and Rhodobacter sphaeroides. We observed variations (0.9-1.2 ps) of B800-850 energy transfer times at different B800 excitation wavelengths, the fastest time (0.9 ps) was obtained with 800 nm excitation. At 830 nm excitation the energy transfer to the B850 ring takes place within 0.5 ps. The m…
Existence of fixed point for GP(Λ;Θ)-contractive mappings in GP-metric spaces
2017
We combine some classes of functions with a notion of hybrid $GP_{(\Lambda,\Theta )}$ - $H$ - $F$ - contractive mapping for establishing some fixed point results in the setting of $GP$-metric spaces. An illustrative example supports the new theory.
Removing the saturation assumption in Bank-Weiser error estimator analysis in dimension three
2020
International audience; We provide a new argument proving the reliability of the Bank-Weiser estimator for Lagrange piecewise linear finite elements in both dimension two and three. The extension to dimension three constitutes the main novelty of our study. In addition, we present a numerical comparison of the Bank-Weiser and residual estimators for a three-dimensional test case.
Adjusting the Knox test by accounting for spatio-temporal crime risk heterogeneity to analyse near-repeats
2020
The near-repeat phenomenon usually occurs with any crime. Hence, to implement preventive measures, it is of great interest to figure out at which spatio-temporal scale crimes are more likely to be repeated by offenders. The Knox test is the most used statistical tool for evaluating the presence of the near-repeat phenomenon given a dataset of crimes that are located in space and time. The classic version of this test assumes that crime risk is homogeneous in both space and time, although this assumption rarely holds in reality. Therefore, the main goal of this article is to highlight the necessity of adjusting the standard version of the Knox test, including spatial and temporal effects th…
Adjacency matrices of random digraphs: singularity and anti-concentration
2017
Let ${\mathcal D}_{n,d}$ be the set of all $d$-regular directed graphs on $n$ vertices. Let $G$ be a graph chosen uniformly at random from ${\mathcal D}_{n,d}$ and $M$ be its adjacency matrix. We show that $M$ is invertible with probability at least $1-C\ln^{3} d/\sqrt{d}$ for $C\leq d\leq cn/\ln^2 n$, where $c, C$ are positive absolute constants. To this end, we establish a few properties of $d$-regular directed graphs. One of them, a Littlewood-Offord type anti-concentration property, is of independent interest. Let $J$ be a subset of vertices of $G$ with $|J|\approx n/d$. Let $\delta_i$ be the indicator of the event that the vertex $i$ is connected to $J$ and define $\delta = (\delta_1, …