1,396 research outputs found
How to prepare quantum states that follow classical paths
We present an alternative quantization procedure for the one-dimensional
non-relativistic quantum mechanics. We show that, for the case of a free
particle and a particle in a box, the complete classical and quantum
correspondence can be obtained using this formulation. The resulting wave
packets do not disperse and strongly peak on the classical paths. Moreover, for
the case of the free particle, they satisfy minimum uncertainty relation.Comment: 10 pages, 3 figures, to appear in Europhysics Letter
Policy recommendations for promoting touristic attractivity from local government perspective in innovative environments
The COVID-19 pandemic situation has had unprecedented negative consequences in the tourism sector, especially in the hotel industry, which has
implied negative shocks directly and indirectly in city revenues, employment and economy. Recent research has indicated that technology is becoming central in finding solutions for tourism recovery through the development of newor improved ICT-enabled tourism services, which could help to achieving a higher attraction of tourists and other sources of foreign investments to cities. This paper therefore seeks to analyse the impact of blockchain technologies (BCT) on the tourism business for attracting new customers to cities with the aim at gaining insights regarding public policies to be taken by local governments for improving tourism business in their city. To achieve this aim, this paper provides an empirical research on the impact of BCT on both lowering prices and improving service quality of lodging accommodations by a sample of lodging accommodations in different Italian cities, providing insights to know if the implementation of BCT on hospitality business, can help city governments to improve smart living into the urban space, deriving some recommendations for city government to take public policies to favour the implementation of these technologies into the hospitality industry
Time-resolved broadband analysis of slow-light propagation and superluminal transmission of electromagnetic waves in three-dimensional photonic crystals
A time-resolved analysis of the amplitude and phase of THz pulses propagating through three-dimensional photonic crystals is presented. Single-cycle pulses of THz radiation allow measurements over a wide frequency range, spanning more than an octave below, at and above the bandgap of strongly dispersive photonic crystals. Transmission data provide evidence for slow group velocities at the photonic band edges and for superluminal transmission at frequencies in the gap. Our experimental results are in good agreement with finite-difference-time-domain simulations
Enhanced fano resonance of organic material films deposited on arrays of asymmetric split-ring resonators (A-SRRs)
Depositing very thin organic films on the surface of arrays of asymmetric split-ring resonators (A-SRRs) produces a shift in their resonance spectra that can be utilized for sensitive analyte detection. Here we show that when poly-methyl-methacrylate (PMMA) is used as an organic probe (analyte) on top of the A-SRR array, the phase and amplitude of a characteristic molecular Fano resonance associated with a carbonyl bond changes according to the spectral positions of the trapped mode resonance of the A-SRRs and their plasmonic reflection peaks. Furthermore, we localize blocks of PMMA at different locations on the A-SRR array to determine the effectiveness of detection of very small amounts of non-uniformly distributed analyte
Time-resolved broadband analysis of slow-light propagation and superluminal transmission of electromagnetic waves in three-dimensional photonic crystals
A time-resolved analysis of the amplitude and phase of THz pulses propagating
through three-dimensional photonic crystals is presented. Single-cycle pulses
of THz radiation allow measurements over a wide frequency range, spanning more
than an octave below, at and above the bandgap of strongly dispersive photonic
crystals. Transmission data provide evidence for slow group velocities at the
photonic band edges and for superluminal transmission at frequencies in the
gap. Our experimental results are in good agreement with
finite-difference-time-domain simulations.Comment: 7 pages, 11 figure
Wigner phase space distribution as a wave function
We demonstrate that the Wigner function of a pure quantum state is a wave
function in a specially tuned Dirac bra-ket formalism and argue that the Wigner
function is in fact a probability amplitude for the quantum particle to be at a
certain point of the classical phase space. Additionally, we establish that in
the classical limit, the Wigner function transforms into a classical
Koopman-von Neumann wave function rather than into a classical probability
distribution. Since probability amplitude need not be positive, our findings
provide an alternative outlook on the Wigner function's negativity.Comment: 6 pages and 2 figure
Enhanced hydrogenation catalyst synthesized by Desulfovibrio desulfuricans exposed to a radio frequency magnetic field
EPSRC (EP/I007806/1; EP/D05768X/1), BBSRC (BB/
C516128/1), NERC (NE/L014076/1), The Royal Society
(Industrial Fellowship) and Spanish Government Sistema
Nacional de Garantia Juvenil grant PEJ-2014-P-00391.This work was supported by EPSRC (grants No EP/
I007806/1 and EP/D05768X/1), BBSRC (grant No BB/
C516128/1), NERC (grant NE/L014076/1) and by a
Royal Society Industrial Fellowship to LEM for secondment
into C-Tech Innovation Ltd., who provided the
bespoke apparatus used in this work. We acknowledge
the invaluable contributions of the late Dr Ruth Wroe of
C-Tech Innovation Ltd. into useful discussions and the
kind permission of Drs S. Megit, C. Berry and A. Morby
(University of Cardiff, UK) to show their unpublished
work in Supplementary Information. This work was partially
supported by the Spanish Government Sistema
Nacional de Garantia Juvenil Grant PEJ-2014-P- 00391
(Promocion de Empleo Joven e Implantacion de la
Garantia Juvenil 2014, MINECO) with a scholarship to
JGB. We also thank the EM Centre at U. Granada for
access to high-resolution electron microscopy (in Fig. S2
and S3). All authors declare no competing interests.Desulfovibrio desulfuricans reduces Pd(II) to Pd(0)-nanoparticles (Pd-NPs) which are catalytically active in 2-pentyne hydrogenation. To make Pd-NPs, resting cells are challenged with Pd(II) ions (uptake), followed by addition of electron donor to promote bioreduction of cell-bound Pd(II) to Pd(0) (bio-Pd). Application of radiofrequency (RF) radiation to prepared 5 wt% bio-Pd catalyst (60 W power, 60 min) increased the hydrogenation rate by 70% with no adverse impact on selectivity to cis-2-pentene. Such treatment of a 5 wt% Pd/carbon commercial catalyst did not affect the conversion rate but reduced the selectivity. Lower-dose RF radiation (2-8 W power, 20 min) was applied to the bacteria at various stages before and during synthesis of the bio-scaffolded Pd-NPs. The reaction rate (mu mol 2-pentyne converted s(-1)) was increased by similar to threefold by treatment during bacterial catalyst synthesis. Application of RF radiation (2 or 4 W power) to resting cells prior to Pd(II) exposure affected the catalyst made subsequently, increasing the reaction rate by 50% as compared to untreated cells, while nearly doubling selectivity for cis 2-pentene. The results are discussed with respect to published and related work which shows altered dispersion of the Pd-NPs made following or during RF exposure.UK Research & Innovation (UKRI)
Engineering & Physical Sciences Research Council (EPSRC) EP/I007806/1
EP/D05768X/1UK Research & Innovation (UKRI)
Biotechnology and Biological Sciences Research Council (BBSRC) BB/C516128/1UK Research & Innovation (UKRI)Natural Environment Research Council (NERC) NE/L014076/1Royal Society of London
European CommissionSpanish Government Sistema Nacional de Garantia Juvenil grant PEJ-2014-P-0039
Stability of stationary solutions of the Schrodinger-Langevin equation
The stability properties of a class of dissipative quantum mechanical systems
are investigated. The nonlinear stability and asymptotic stability of
stationary states (with zero and nonzero dissipation respectively) is
investigated by Liapunov's direct method. The results are demonstrated by
numerical calculations on the example of the damped harmonic oscillator.Comment: revised, 12 pages, 7 figure
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