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"Identification of mixed bromidochloridotellurate anions in disordered crystal structures of (bdmim)2[TeX2Y4] (X, Y = Br, Cl; bdmim = 1-butyl-2,3-dim…
2013
Abstract The discrete mixed [TeBrxCl6−x]2− anions in their disordered crystal structures have been identified by using the phases prepared by the reaction of 1-butyl-2,3-dimethylimidazolium halogenides (bdmim)X with tellurium tetrahalogenides TeX4 (X = Cl, Br) as examples. Homoleptic (bdmim)2[TeX6] [X = Cl (1), Br (2)] and mixed (bdmim)2[TeBr2Cl4] (3), and (bdmim)2[TeBr4Cl2] (4) are formed depending on the choice of the reagents, and their crystal structures have been determined by single-crystal X-ray diffraction. The coordination environments of tellurium in all hexahalogenidotellurates are almost octahedral. Because of the crystallographic disorder, the mixed [TeBr2Cl4]2− and [TeBr4Cl2]2…
Should TiO2 nanostructures doped with Li+ be used as photoanodes for photoelectrochemical water splitting applications?
2017
[EN] Different TiO2 nanostructures, nanotubes and nanosponges, were obtained by anodization of Ti under stagnant and hydrodynamic conditions. Samples were doped with Li+ before and after annealing at 450 degrees C during 1 h. The nanostructures were characterized by different microscopy techniques: Field Emission Scanning Electron Microscopy (FE-SEM) and Raman Confocal Laser Microscopy. Additionally, Incident Photon-to-electron Conversion Efficiency (IPCE), photoelectrochemical water splitting and stability measurements were also performed. According to the results, TiO2 nanostructures doped before annealing present the worst photocurrent response, even if compared with undoped samples. On …
Lateral Fusion of Chemical Vapor Deposited N = 5 Armchair Graphene Nanoribbons
2017
Bottom-up synthesis of low-bandgap graphene nanoribbons with various widths is of great importance for their applications in electronic and optoelectronic devices. Here we demonstrate a synthesis of N = 5 armchair graphene nanoribbons (5-AGNRs) and their lateral fusion into wider AGNRs, by a chemical vapor deposition method. The efficient formation of 10- and 15- AGNRs is revealed by a combination of different spectroscopic methods, including Raman and UV−visnear-infrared spectroscopy as well as by scanning tunneling microscopy. The degree of fusion and thus the optical and electronic properties of the resulting GNRs can be controlled by the annealing temperature, providing GNR films with o…
High photodegradation and antibacterial activity of BN–Ag/TiO 2 composite nanofibers under visible light
2018
To develop material with good photocatalytic properties for organic compound degradation and bacterial removal, we produced Ag/TiO2 and BN–Ag/TiO2 composite nanofibers that included controlled amounts of boron nitride (BN) nanosheets and silver (Ag). After annealing at 500 °C under air, we used scanning electron microscopy, transmission electron microscopy, Brunauer–Emmet–Teller analysis, X-ray diffraction, energy-dispersive X-ray spectroscopy, Raman spectroscopy, UV-visible reflectance spectroscopy and room temperature photoluminescence to investigate the morphological, structural and optical properties of all samples. The photocatalytic tests using methylene blue under visible light, in r…
Exact non-Markovian dynamics of Gaussian quantum channels: Finite-time and asymptotic regimes
2018
We investigate the Markovian and non-Markovian dynamics of Gaussian quantum channels, exploiting a recently introduced necessary and sufficient criterion and the ensuing measure of non-Markovianity based on the violation of the divisibility property of the dynamical map. We compare the paradigmatic instances of Quantum Brownian motion (QBM) and Pure Damping (PD) channels, and for the former we find that the exact dynamical evolution is always non-Markovian in the finite-time as well as in the asymptotic regimes, for any nonvanishing value of the non-Markovianity parameter. If one resorts to the rotating wave approximated (RWA) form of the QBM, that neglects the anomalous diffusion contribut…
Diffusion Acceleration in Randomly Switching Sawtooth Potential
2005
We investigate an overdamped Brownian motion in symmetric sawtooth periodic potential switched by Markovian dichotomous noise between two configurations. The two configurations differ each other by a translation of half of period. The calculation of the effective diffusion coefficient is reduced to the mean first‐passage time problem, and we obtain the exact expression valid for arbitrary mean rate of switchings and arbitrary intensity of white Gaussian noise. We find the area at parameters plane where acceleration of diffusion in comparison with the free diffusion case takes place.
Plant Sterols and Antioxidant Parameters in Enriched Beverages: Storage Stability
2012
Plant sterols (PS) stability, antioxidant parameters, and color were studied during 6 months of storage at 4, 24, and 37 °C in three PS-enriched functional beverages. Beverages were skimmed milk with fruit juice and PS (MFJPS), fruit juice and PS (FJPS), and skimmed milk with PS (MPS). No loss in total PS content occurred during storage observing the same values at any given storage time point. Total carotenoids decreased 36% with storage at two months and then remained stable. Total polyphenols showed fluctuations throughout the storage, remaining stable at 6 months and reaching initial values. The antioxidant capacity (TEAC method) increased 18% at 6 months, and there was an increase in c…
Sixfold improved single particle measurement of the magnetic moment of the antiproton
2017
Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement gp/2=2.7928473…
Reference values of fetal aortic flow velocity waveforms and associated intra-observer reliability in normal pregnancies
2001
Objectives It was the aim of the present study to calculate new Doppler reference ranges for blood flow velocities (Vmax, Vmean, Vmin) and resistance indices (PI, RI) for the fetal descending aorta by automatic waveform analysis. Design Cross-sectional prospective study. Subjects Nine hundred and twenty-six low-risk pregnancies at 18–41 weeks' gestation. Methods Aortic blood flow velocities were derived with pulsed-wave color Doppler. Measurements were carried out at the level of the diaphragm. Reference ranges for the individual measuring parameters were constructed based on a growth function from a four-parameter class of monotonic continuous functions according to the smallest square pri…
Generalized hypergeometric functions and the evaluation of scalar one-loop integrals in Feynman diagrams
2000
Present and future high-precision tests of the Standard Model and beyond for the fundamental constituents and interactions in Nature are demanding complex perturbative calculations involving multi-leg and multi-loop Feynman diagrams. Currently, large effort is devoted to the search for closed expressions of loop integrals, written whenever possible in terms of known - often hypergeometric-type - functions. In this work, the scalar three-point function is re-evaluated by means of generalized hypergeometric functions of two variables. Finally, use is made of the connection between such Appell functions and dilogarithms coming from a previous investigation, to recover well-known results.