Search results for "reduced"
showing 10 items of 191 documents
Chirality asymptotic behavior and non-Markovianity in quantum walks on a line
2014
We investigate the time evolution of the chirality reduced density matrix for a discrete-time quantum walk on a one-dimensional lattice, which is obtained by tracing out the spatial degree of freedom. We analyze the standard case, without decoherence, and the situation where decoherence appears in the form of broken links in the lattice. By examining the trace distance for possible pairs of initial states as a function of time, we conclude that the evolution of the reduced density matrix is non-Markovian, in the sense defined in [H. P. Breuer, E. M. Laine, and J. Piilo, Phys. Rev. Lett. 103, 210401 (2009)]. As the level of noise increases, the dynamics approaches a Markovian process. The hi…
Validity of power functionals for a homogeneous electron gas in reduced-density-matrix-functional theory
2016
Physically valid and numerically efficient approximations for the exchange and correlation energy are critical for reduced density-matrix functional theory to become a widely used method in electronic structure calculations. Here we examine the physical limits of power functionals of the form $f(n,n')=(n n')^\alpha$ for the scaling function in the exchange-correlation energy. To this end we obtain numerically the minimizing momentum distributions for the three- and two-dimensional homogeneous electron gas, respectively. In particular, we examine the limiting values for the power $\alpha$ to yield physically sound solutions that satisfy the Lieb-Oxford lower bound for the exchange-correlatio…
C3N4/reduced graphene oxide photocatalysts loaded with Ag or Ag/Pt for H2 evolution from aqueous solution of triethanolamine
2023
Composites of C3N4/reduced graphene oxide have been used as photocatalysts for triethanolamine photo- reforming with H2 generation in aqueous solution. The rate of H2 production over the Ag loaded best per- forming photocatalyst reached 525 μmol⋅h
On the factors governing the pressure dependence of the viscosity of moderately concentrated polymer solutions
1982
Viscosity measurements were carried out as a function of pressure and temperature with solutions of polystyrene in eight (endothermal) θ-solvents at the respective critical composition by means of a Searle-type apparatus. A rolling-ball viscometer was used for the investigation of the pure solvents. In all cases the viscosity coefficient increases in a more or less exponential manner when the pressure is raised. For θ-conditions, the volumes of activation of the solutions exceed that of the pure solvent by typically 10–15%. The exact amount of this extra efffect stemming from the presence of the polymer and its variation with temperature can be qualitatively correlated with the heats of mix…
Effects of Commitment on Fear of Failure and Burnout in Teen Spanish Handball Players
2021
The raw data supporting the conclusions of this article will be made available by the authors if they are requested, and without undue reservation (jgonzalez@ugr.es).
Migration history and risk of psychosis: results from the multinational EU-GEI study.
2022
The European Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU-GEI) Project was funded by grant agreement Health-F2-2010-241909 (Project EU-GEI) from the European Community’s Seventh Framework programme.
Ion mobility spectrometry and high resolution mass-spectrometry as methodologies for rapid identification of the last generation of new psychoactive …
2018
A new drug trafficking trend has been observed in the last years by the introduction in the black market of new psychoactive substances (NPS) in order to difficult competent authority controls. In this study, ion mobility spectrometry (IMS) and high-resolution mass-spectrometry (HRMS) were proposed as vanguard and rearguard methodologies for the rapid identification of the last generation of NPS in seizures. The combined use of IMS and HRMS has been evaluated through the analysis of 24 NPS seized from 2016 to 2018 in Valencia (Spain) to demonstrate the utility of this approach. The characteristic reduced mobility (K0) values for seized NPS were determined and mass-mobility relationships wer…
Incommensurate phases of a bosonic two-leg ladder under a flux
2016
A boson two--leg ladder in the presence of a synthetic magnetic flux is investigated by means of bosonization techniques and Density Matrix Renormalization Group (DMRG). We follow the quantum phase transition from the commensurate Meissner to the incommensurate vortex phase with increasing flux at different fillings. When the applied flux is $\rho \pi$ and close to it, where $\rho$ is the filling per rung, we find a second incommensuration in the vortex state that affects physical observables such as the momentum distribution, the rung-rung correlation function and the spin-spin and charge-charge static structure factors.
Age-dependent regulation of antioxidant genes by p38α MAPK in the liver
2018
p38α is a redox sensitive MAPK activated by pro-inflammatory cytokines and environmental, genotoxic and endoplasmic reticulum stresses. The aim of this work was to assess whether p38α controls the antioxidant defense in the liver, and if so, to elucidate the mechanism(s) involved and the age-related changes. For this purpose, we used liver-specific p38α-deficient mice at two different ages: young-mice (4 months-old) and old-mice (24 months-old). The liver of young p38α knock-out mice exhibited a decrease in GSH levels and an increase in GSSG/GSH ratio and malondialdehyde levels. However, old mice deficient in p38α had higher hepatic GSH levels and lower GSSG/GSH ratio than young p38α knock-…
The lift computation for an oscillating flat plate in incompressible potential flow
1994
The initial aim of this work was the estimation of the lift acting on a flat plate performing small oscillations in a plane uniform stream by means of a simplified model based on one or at the most two lumped vortices, and the assessment of its results by comparison to those that were exact. The model was found to work well up to a reduced frequency of about 1 or 2, above which the results diverged from those that were correct. In order to improve the model, its behaviour at very high frequencies was then investigated, discovering: (i) that if the number of lumped vortices is greater than one the possibility to impose all boundary conditions is subject to certain geometrical constraints; (i…