9,107 research outputs found
Coherent output of photons from coupled superconducting transmission line resonators controlled by charge qubits
We study the coherent control of microwave photons propagating in a
superconducting waveguide consisting of coupled transmission line resonators,
each of which is connected to a tunable charge qubit. While these coupled line
resonators form an artificial photonic crystal with an engineered photonic band
structure, the charge qubits collectively behave as spin waves in the low
excitation limit, which modify the band-gap structure to slow and stop the
microwave propagation. The conceptual exploration here suggests an
electromagnetically controlled quantum device based on the on-chip circuit QED
for the coherent manipulation of photons, such as the dynamic creation of
laser-like output from the waveguide by pumping the artificial atoms for
population inversion.Comment: 8 pages, 3 figure
Simulation of valveless micropump and mode analysis
In this work, a 3-D simulation is performed to study for the solid-fluid
coupling effect driven by piezoelectric materials and utilizes asymmetric
obstacles to control the flow direction. The result of simulation is also
verified. For a micropump, it is crucial to find the optimal working frequency
which produce maximum net flow rate. The PZT plate vibrates under the first
mode, which is symmetric. Adjusting the working frequency, the maximum flow
rate can be obtained. For the micrpump we studied, the optimal working
frequency is 3.2K Hz. At higher working frequency, say 20K Hz, the fluid-solid
membrane may come out a intermediate mode, which is different from the first
mode and the second mode. It is observed that the center of the mode drifts.
Meanwhile, the result shows that a phase shift lagging when the excitation
force exists in the vibration response. Finally, at even higher working
frequency, say 30K Hz, a second vibration mode is observed.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
Efficient two-step entanglement concentration for arbitrary W states
We present two two-step practical entanglement concentration protocols (ECPs)
for concentrating an arbitrary three-particle less-entangled W state into a
maximally entangled W state assisted with single photons. The first protocol
uses the linear optics and the second protocol adopts the cross-Kerr
nonlinearity to perform the protocol. In the first protocol, based on the
post-selection principle, three parties say Alice, Bob and Charlie in different
distant locations can obtain the maximally entangled W state from the arbitrary
less-entangled W state with a certain success probability. In the second
protocol, it dose not require the parties to posses the sophisticated
single-photon detectors and the concentrated photon pair can be retained after
performing this protocol successfully. Moreover, the second protocol can be
repeated to get a higher success probability. Both protocols may be useful in
practical quantum information applications.Comment: 10 pages, 4 figure
Realistic interpretation of a superposition state does not imply a mixture
Contrary to previous claims, it is shown that, for an ensemble of either
single-particle systems or multi-particle systems, the realistic interpretation
of a superposition state that mathematically describes the ensemble does not
imply that the ensemble is a mixture. Therefore it cannot be argued that the
realistic interpretation is wrong on the basis that some predictions derived
from the mixture are different from the corresponding predictions derived from
the superposition state
Hadronic Rapidity Spectra in Heavy Ion Collisions at SPS and AGS energies in a Quark Combination Model
The quark combination mechanism of hadron production is applied to
nucleus-nucleus collisions at the CERN Super Proton Synchrotron (SPS) and BNL
Alternating Gradient Synchrotron (AGS). The rapidity spectra of identified
hadrons and their spectrum widths are studied. The data of ,
, , , , , and
at 80 and 40 AGeV, in particular at 30 and 20 AGeV where the onset of
deconfinement is suggested to happen, are consistently described by the quark
combination model. However at AGS 11.6 AGeV below the onset the spectra of
, and can not be simultaneously explained,
indicating the disappearance of intrinsic correlation of their production in
the constituent quark level. The collision-energy dependence of the rapidity
spectrum widths of constituent quarks and the strangeness of the hot and dense
quark matter produced in heavy ion collisions are obtained and discussed.Comment: 7 pages, 5 figure
The Effect of Pre-fermentative Freezing Treatment on the Sensory Quality of ‘Meili’ Rosé Wine
In this study, the effect of a pre-fermentative freezing treatment on quality attributes of ‘Meili’ rosé wine was assessed. Prior to fermentation, ‘Meili’ grapes (berries and must) were subjected to a freezing treatment considering factors of freezing temperatures, freezing time, and thawing method. Colour-related indices were measured by spectral methods. Wine aroma characteristics and sensory attributes were assessed by trained panellists. The results revealed that lower freezing temperature and longer freezing time had positive effects on wine quality attributes. The treatment of frozen berries might help extract colour-related compounds. Microwave thawing improved wine colour, but decreased taste quality. In the work, the MF-10°C/6 h treatment (microwave-thawed berries that had been frozen at -10°C for 6 h) contributed to the best colour characteristics, whereas the NP-20°C/4 h treatment (naturally-thawed must that had been frozen at -20°C for 4 h) contributed to the best taste attributes
Current status and future trends of precision agricultural aviation technologies
Modern technologies and information tools can be used to maximize agricultural aviation productivity allowing for precision application of agrochemical products. This paper reviews and summarizes the state-of-the-art in precision agricultural aviation technology highlighting remote sensing, aerial spraying and ground verification technologies. Further, the authors forecast the future of precision agricultural aviation technology with key development directions in precision agricultural aviation technologies, such as real-time image processing, variable-rate spraying, multi-sensor data fusion and RTK differential positioning, and other supporting technologies for UAV-based aerial spraying. This review is expected to provide references for peers by summarizing the history and achievements, and encourage further development of precision agricultural aviation technologies
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