3,657 research outputs found

    Extended Quark Potential Model from Random Phase Approximation

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    The quark potential model is extended to include the sea quark excitation using the random phase approximation (RPA). The effective quark interaction preserves the important Quantum Chromodynamics (QCD) properties -- chiral symmetry and confinement simultaneously. A primary qualitive analysis shows that the π\pi meson as a well-known typical Goldstone boson and the other mesons made up of valence qqˉq\bar{q} quark pair such as the ρ\rho meson can also be described in this extended quark potential model

    Planar Object Tracking in the Wild: A Benchmark

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    Planar object tracking is an actively studied problem in vision-based robotic applications. While several benchmarks have been constructed for evaluating state-of-the-art algorithms, there is a lack of video sequences captured in the wild rather than in constrained laboratory environment. In this paper, we present a carefully designed planar object tracking benchmark containing 210 videos of 30 planar objects sampled in the natural environment. In particular, for each object, we shoot seven videos involving various challenging factors, namely scale change, rotation, perspective distortion, motion blur, occlusion, out-of-view, and unconstrained. The ground truth is carefully annotated semi-manually to ensure the quality. Moreover, eleven state-of-the-art algorithms are evaluated on the benchmark using two evaluation metrics, with detailed analysis provided for the evaluation results. We expect the proposed benchmark to benefit future studies on planar object tracking.Comment: Accepted by ICRA 201

    Reproductive health and access to services among rural-to-urban migrants in China

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    Reproductive health, including maternal health, is an important issue for China´s migrant population. This paper briefly reviews the reproductive health situation, including reproductive health knowledge and status, health service use, and interventions among rural-to-urban migrants. By analysing three data sets, the authors assess the reproductive health status of migrants, focusing particularly on the self-reported reproductive health of migrant women; maternal health and service utilization of migrant women; and contraceptive use among migrant men. Their three surveys found the following common themes in terms of migrant reproductive health services: migrants were found to have limited access to health service or poor health-seeking behaviour in some aspects of reproductive health; they often have relatively limited sources of service compared to local residence; and their knowledge and information about reproductive health service is not adequate. There have been some improvements over time, in some cases through project intervention. Further research is needed to assess the impact of policy change and other variety of efforts to improve migrants´ reproductive health

    Atomically Resolved Observation of Continuous Interfaces between As-grown MoS2 Monolayer and WS2/MoS2 Heterobilayer on SiO2

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    Van der Waals (vdW) heterostructures synthesized through the chemical vapor deposition (CVD) method allow creation and tuning of intriguing electronic and optical properties of two- dimensional (2D) materials, the knowledge of which is critical for a wide range of potential applications. Here we report our scanning tunneling microscopy/spectroscopy (STM/STS) study of as-grown MoS2 monolayer and WS2/MoS2 heterobilayer on SiO2. The heterobilayer appears smoother than the MoS2 monolayer, with root mean square (RMS) roughness of 0.230 +- 0.021 nm in the former and 0.329 +- 0.033 nm in the latter. For the first time, to our knowledge, we directly observed a continuous interface between the MoS2 monolayer and the top layer of the heterobilayer with atomic resolution. This finding contrasts to the previously reported open edges in the top layer of the heterobilayer. Our STS results and density functional theory (DFT) calculations revealed the band gaps of the heterobilayer and the MoS2 monolayer
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