2,211 research outputs found
The linear and nonlinear Jaynes-Cummings model for the multiphoton transition
With the Jaynes-Cummings model, we have studied the atom and light field
quantum entanglement of multiphoton transition, and researched the effect of
initial state superposition coefficient , the transition photon number
, the quantum discord and the nonlinear coefficient on the
quantum entanglement degrees. We have given the quantum entanglement degrees
curves with time evolution, and obtained some results, which should have been
used in quantum computing and quantum information.Comment: arXiv admin note: text overlap with arXiv:1404.0821, arXiv:1205.0979
by other author
Gait performance and prefrontal cortex activation during single and dual task walking in older adults with different cognitive levels
BackgroundGrowing evidence shows the cognitive function influences the motor performance. The prefrontal cortex (PFC) as a part of the executive locomotor pathway is also important for cognitive function. This study investigated the differences in motor function and brain activity among older adults with different cognitive levels, and examined the significance of cognition on motor functions.MethodsNormal control (NC), individuals with mild cognitive impairment (MCI) or mild dementia (MD) were enrolled in this study. All participants received a comprehensive assessment including cognitive function, motor function, PFC activity during walking, and fear of fall. The assessment of cognitive function included general cognition, attention, executive function, memory, and visuo-spatial. The assessment of motor function included timed up and go (TUG) test, single walking (SW), and cognitive dual task walking (CDW).ResultsIndividuals with MD had worse SW, CDW and TUG performance as compared to individuals with MCI and NC. These gait and balance performance did not differ significantly between MCI and NC. Motor functions all correlated with general cognition, attention, executive function, memory, and visuo-spatial ability. Attention ability measured by trail making test A (TMT-A) was the best predictor for TUG and gait velocity. There were no significant differences in PFC activity among three groups. Nevertheless, the PFC activated more during CDW as compared with SW in individuals with MCI (p = 0.000), which was not demonstrated in the other two groups.ConclusionMD demonstrated worse motor function as compared to NC and MCI. The greater PFC activity during CDW in MCI may be considered as a compensatory strategy for maintaining the gait performance. Motor function was related to the cognitive function, and the TMT A was the best predictor for the gait related performance in present study among older adults
Stochastic Heterostructures in B/N-Doped Carbon Nanotubes
Carbon nanotubes are one-dimensional and very narrow. These obvious facts
imply that under doping with boron and nitrogen, microscopic doping
inhomogeneity is much more important than for bulk semiconductors. We consider
the possibility of exploiting such fluctuations to create interesting devices.
Using self-consistent tight-binding (SCTB), we study heavily doped highly
compensated nanotubes, revealing the spontaneous formation of structures
resembling chains of random quantum dots, or nano-scale diode-like elements in
series. We also consider truly isolated impurities, revealing simple scaling
properties of bound state sizes and energies.Comment: 4 pages RevTeX, 4 PostScript figure
Effect of Te on selective oxidation of propane to acrolein over MoPO/SiO2 catalyst
Effect of To on the catalytic performance of the MOPO/SiO2 catalyst for the selective oxidation of propane to acrolein was investigated. The MoPO/SiO2 catalyst exhibited high selectivity for propene, which was a possible intermediate for the formation of acrolein. The addition of To to the catalyst enhanced the conversion of propene to acrolein. The catalysts MoPO/SiO2 and MoPTeO/SiO2 were comparatively characterized by N-2 adsorption, XRD, Raman spectroscopy, XPS, H-2-TPR, pulse reaction of propane, NH3-TPD and Py-IR. The results showed that the addition of To to the catalyst reduced the surface area, but it enhanced the specific surface acidity and improved the reducibility of the supported catalyst, and the performance of the catalyst for propane conversion was improved at the same time. To might be favorable to alpha-H abstraction of propene and/or oxygen insertion into allylic species
Pairing symmetry and properties of iron-based high temperature superconductors
Pairing symmetry is important to indentify the pairing mechanism. The
analysis becomes particularly timely and important for the newly discovered
iron-based multi-orbital superconductors. From group theory point of view we
classified all pairing matrices (in the orbital space) that carry irreducible
representations of the system. The quasiparticle gap falls into three
categories: full, nodal and gapless. The nodal-gap states show conventional
Volovik effect even for on-site pairing. The gapless states are odd in orbital
space, have a negative superfluid density and are therefore unstable. In
connection to experiments we proposed possible pairing states and implications
for the pairing mechanism.Comment: 4 pages, 1 table, 2 figures, polished versio
The Atacama Large Millimeter/submillimeter Array (ALMA) Band-1 Receiver
The Atacama Large Millimeter/submillimeter Array(ALMA) Band 1 receiver covers
the 35-50 GHz frequency band. Development of prototype receivers, including the
key components and subsystems has been completed and two sets of prototype
receivers were fully tested. We will provide an overview of the ALMA Band 1
science goals, and its requirements and design for use on the ALMA. The
receiver development status will also be discussed and the infrastructure,
integration, evaluation of fully-assembled band 1 receiver system will be
covered. Finally, a discussion of the technical and management challenges
encountered will be presented
Pterostilbene, a Methoxylated Resveratrol Derivative, Efficiently Eradicates Planktonic, Biofilm, and Intracellular MRSA by Topical Application
Pterostilbene is a methoxylated derivative of resveratrol originated from natural sources. We investigated the antibacterial activity of pterostilbene against drug-resistant Staphylococcus aureus and the feasibility of using it to treat cutaneous bacteria. The antimicrobial effect was evaluated using an in vitro culture model and an in vivo mouse model of cutaneous infection. The minimum inhibitory concentration (MIC) assay demonstrated a superior biocidal activity of pterostilbene compared to resveratrol (8~16-fold) against methicillin-resistant S. aureus (MRSA) and clinically isolated vancomycin-intermediate S. aureus (VISA). Pterostilbene was found to reduce MRSA biofilm thickness from 18 to 10 μm as detected by confocal microscopy. Pterostilbene showed minimal toxicity to THP-1 cells and was readily engulfed by the macrophages, facilitating the eradication of intracellular MRSA. Pterostilbene exhibited increased skin absorption over resveratrol by 6-fold. Topical pterostilbene application improved the abscess formation produced by MRSA by reducing the bacterial burden and ameliorating the skin architecture. The potent anti-MRSA capability of pterostilbene was related to bacterial membrane leakage, chaperone protein downregulation, and ribosomal protein upregulation. This mechanism of action was different from that of resveratrol according to proteomic analysis and molecular docking. Pterostilbene has the potential to serve as a novel class of topically applied agents for treating MRSA infection in the skin while demonstrating less toxicity to mammalian cells
Measurement of the Forward-Backward Asymmetry in the B -> K(*) mu+ mu- Decay and First Observation of the Bs -> phi mu+ mu- Decay
We reconstruct the rare decays , , and in a data sample
corresponding to collected in collisions at
by the CDF II detector at the Fermilab Tevatron
Collider. Using and decays we report the branching ratios. In addition, we report
the measurement of the differential branching ratio and the muon
forward-backward asymmetry in the and decay modes, and the
longitudinal polarization in the decay mode with respect to the squared
dimuon mass. These are consistent with the theoretical prediction from the
standard model, and most recent determinations from other experiments and of
comparable accuracy. We also report the first observation of the {\mathcal{B}}(B^0_s \to
\phi\mu^+\mu^-) = [1.44 \pm 0.33 \pm 0.46] \times 10^{-6}27 \pm 6B^0_s$ decay observed.Comment: 7 pages, 2 figures, 3 tables. Submitted to Phys. Rev. Let
- …