12,683 research outputs found

    Strain in epitaxial CoSi2 films on Si (111) and inference for pseudomorphic growth

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    The perpendicular x-ray strain of epitaxial CoSi2 films grown on Si(111) substrates at ~600 °C was measured at temperatures from 24 up to 650 °C. At 600 °C, the perpendicular x-ray strain is –0.86%, which is about the x-ray strain that a stress-free CoSi2 film on Si(111) would have at that temperature. This result shows that the stress in the epitaxial CoSi2 film is fully relaxed at the growth temperature. Strains in the film below the growth temperature are induced by the difference in the thermal expansion coefficient of CoSi2 and Si, alphaf–alphas=0.65×10^–5/°C. Within experimental error margins, the strain increases linearly with decreasing temperature at a rate of (1.3±0.1)×10^–5/C. The slope of the strain-temperature dependence, obtained by assuming that the density of misfit dislocations formed at the growth temperature remains unchanged, agrees with the measured slope if the unknown Poisson ratio of CoSi2 is assumed to be nuf=1/3. These observations support three rules postulated for epitaxial growth

    Existence problem of proton semi-bubble structure in the 21+2_1^+ state of 34^{34}Si

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    The fully self-consistent Hartree-Fock (HF) plus random phase approximation (RPA) based on Skyrme-type interaction is used to study the existence problem of proton semi-bubble structure in the 21+2_1^+ state of 34^{34}Si. The experimental excitation energy and the B(E2) strength of the 21+2_1^+ state in 34^{34}Si can be reproduced quite well. The tensor effect is also studied. It is shown that the tensor interaction has a notable impact on the excitation energy of the 21+2_1^+ state and a small effect on the B(E2) value. Besides, its effect on the density distributions in the ground and 21+2_1^+ state of 34^{34}Si is negligible. Our present results with T36 and T44 show that the 21+2_1^+ state of 34^{34}Si is mainly caused by proton transiton from π1d5/2\pi 1d_{5/2} orbit to π2s1/2\pi 2s_{1/2} orbit, and the existence of a proton semi-bubble structure in this state is very unlikely.Comment: 6 pages, 3 figures, 3 table

    Endoood: Uncertainty-Aware Out-of-Distribution Detection in Capsule Endoscopy Diagnosis

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    Wireless capsule endoscopy (WCE) is a non-invasive diagnostic procedure that enables visualization of the gastrointestinal (GI) tract. Deep learning-based methods have shown effectiveness in disease screening using WCE data, alleviating the burden on healthcare professionals. However, existing capsule endoscopy classification methods mostly rely on predefined categories, making it challenging to identify and classify out-of-distribution (OOD) data, such as undefined categories or anatomical landmarks. To address this issue, we propose the Endoscopy Out-Of-Distribution (EndoOOD) framework, which aims to effectively handle the OOD detection challenge in WCE diagnosis. The proposed framework focuses on improving the robustness and reliability of WCE diagnostic capabilities by incorporating uncertainty-aware mixup training and long-tailed in-distribution (ID) data calibration techniques. Additionally, virtual-logit matching is employed to accurately distinguish between OOD and ID data while minimizing information loss. To assess the performance of our proposed solution, we conduct evaluations and comparisons with 12 state-of-the-art (SOTA) methods using two publicly available datasets. The results demonstrate the effectiveness of the proposed framework in enhancing diagnostic accuracy and supporting clinical decision-making

    Multi-view urban scene reconstruction in non-uniform volume

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    This paper presents a new fully automatic approach for multi-view urban scene reconstruction. Our algorithm is based on the Manhattan-World assumption, which can provide compact models while preserving fidelity of synthetic architectures. Starting from a dense point cloud, we extract its main axes by global optimization, and construct a nonuniform volume based on them. A graph model is created from volume facets rather than voxels. Appropriate edge weights are defined to ensure the validity and quality of the surface reconstruction. Compared with the common pointcloud- to-model methods, the proposed methodology exploits image information to unveil the real structures of holes in the point cloud. Experiments demonstrate the encouraging performance of the algorithm. © 2013 SPIE

    Inelastic X-Ray Scattering Study of Exciton Properties in an Organic Molecular crystal

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    Excitons in a complex organic molecular crystal were studied by inelastic x-ray scattering (IXS) for the first time. The dynamic dielectric response function is measured over a large momentum transfer region, from which an exciton dispersion of 130 meV is observed. Semiempirical quantum chemical calculations reproduce well the momentum dependence of the measured dynamic dielectric responses, and thus unambiguously indicate that the lowest Frenkel exciton is confined within a fraction of the complex molecule. Our results demonstrate that IXS is a powerful tool for studying excitons in complex organic molecular systems. Besides the energy position, the IXS spectra provide a stringent test on the validity of the theoretically calculated exciton wave functions.Comment: 4 pages, 4 figure
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