Effective generation of Ising interaction and cluster states in coupled microcavities

We propose a scheme for realizing the Ising spin-spin interaction and atomic cluster states utilizing trapped atoms in coupled microcavities. It is shown that the atoms can interact with each other via the exchange of virtual photons of the cavities. Through suitably tuning the parameters, an effective Ising spin-spin interaction can be generated in this optical system, which is used to produce the cluster states. This scheme does not need the preparation of initial states of atoms and cavity modes, and is insensitive to cavity decay.Comment: 11pages, 2 figures, Revtex

Evaluating distribution of foveal avascular zone parameters corrected by lateral magnification and their associations with retinal thickness

Purpose To examine the distribution of foveal avascular zone (FAZ) parameters, with and without correction for lateral magnification, in a large cohort of healthy young adults. Design Cross-sectional, observational cohort study. Participants A total of 504 healthy adults, 27 to 30 years of age. Methods Participants underwent a comprehensive ophthalmic examination including axial length measurement and OCT angiography (OCTA) imaging of the macula. OCT angiography images of combined superficial and deep retinal vessel plexuses were processed via a custom software to extract foveal avascular zone area (FAZA) and foveal density-300 (FD-300), the vessel density in a 300-μm wide annulus surrounding the FAZ, with and without correction for lateral magnification. Bland–Altman analyses were performed to examine the effect of lateral magnification on FAZA and FD-300, as well as to evaluate the interocular agreement in both parameters. Linear mixed-effects models were used to examine the relationship between retinal thicknesses and OCTA parameters. Main Outcome Measures The FAZA and FD-300, corrected for lateral magnification. Results The mean (standard deviation [SD]) of laterally corrected FAZA and FD-300 was 0.22 mm2 (0.10 mm2) and 51.9% (3.2%), respectively. Relative to uncorrected data, 55.6% of corrected FAZA showed a relative change > 5%, whereas all FD-300 changes were within 5%. There was good interocular symmetry (mean right eye–left eye difference, 95% limits of agreement [LoA]) in both FAZA (0.006 mm2, -0.05 mm2, to 0.07 mm2) and FD-300 (-0.05%, -5.39%, to 5.30%). There were significant negative associations between central retinal thickness and FAZA (β = -0.0029), as well as between central retinal thickness and FD-300 (β = -0.044), with the relationships driven by inner, not outer, retina. Conclusions We reported lateral magnification adjusted normative values for FAZA and FD-300 in a large cohort of young, healthy eyes. Clinicians should strongly consider accounting for lateral magnification when evaluating FAZA. Good interocular agreement in FAZA and FD-300 suggests the contralateral eye can be used as control data

Metallurgical and corrosion characterization of warring states period bronzes excavated from Pujiang, Chengdu, China

Located in Pujiang, Chengdu, China, more than four hundred artifacts were unearthed during the excavation of the Warring States (the Warring States period lasts from 475 to 221 BC) ship-shaped graves in 2016. The compositional and metallurgical feature of the unearthed vessels are still unclear. Archaeologists and conservators are puzzled by such problems that need to be answered by systematic scientific studies. Fifty one samples, either from the matrix (26 samples), or from the corrosion part (25 samples) of 25 unearthed bronze vessels, were carefully collected from the fallen part of the bronze vessels for analysis. Technical methods, such as OM, SEM-EDS, XRD and Raman Spectroscopy were adopted for compositional and metallurgical characterization of the bronzes, as well as identification of the corrosion products. The bronzes are Cu–Sn–Pb trinary alloys with typical casting microstructure. The proportion of Sn are in accordance with excavated bronze vessels in surrounding areas. Recycling isn’t involved with the production of such vessels. Layered structure of the corrosion products was observed. Different corrosion products were identified as Cu2CO3(OH)2, Cu2O, CuSO4·5H2O SnO2, PbSO4 and PbCO3. The findings help us gain insights into the bronze manufacturing in Bashu district, as well as the corrosion behavior in certain condition.Introduction Archaeological context Material and methods - Material - Methods -- Microscopic analysis -- Metallographic analysis -- Compositional analysis Results and discussion - Analysis of the matrix - Analysis of the corrosion products Conclusio

eta_c production at the Large Hadron Collider

We have studied the production of the 1S_0 charmonium state, eta_c, at the Large Hadron Collider (LHC) in the framework of Non-Relativistic Quantum Chromodynamics (NRQCD) using heavy-quark symmetry. We find that NRQCD predicts a large production cross-section for this resonance at the LHC even after taking account the small branching ratio of eta_c into two photons. We show that it will be possible to test NRQCD through its predictions for eta_c, with the statistics that will be achieved at the early stage of the LHC, running at a center of mass energy of 7 TeV with an integrated luminosity of 100 pb^{-1}Comment: 8 pages, 2 figure

The Holographic Model of Dark Energy and Thermodynamics of Non-Flat Accelerated Expanding Universe

Motivated by recent results on non-vanishing spatial curvature \cite{curve} we employ the holographic model of dark energy to investigate the validity of first and second laws of thermodynamics in non-flat (closed) universe enclosed by apparent horizon $R_A$ and the event horizon measured from the sphere of horizon named $L$. We show that for the apparent horizon the first law is roughly respected for different epochs while the second laws of thermodynamics is respected while for $L$ as the system's IR cut-off first law is broken down and second law is respected for special range of deceleration parameter. It is also shown that at late-time universe $L$ is equal to $R_A$ and the thermodynamic laws are hold, when the universe has non-vanishing curvature. Defining the fluid temperature to be proportional to horizon temperature the range for coefficient of proportionality is obtained provided that the generalized second law of thermodynamics is hold.Comment: 12 pages, no figure, abstract and text extended, references added, accepted for publication in JCA