415 research outputs found

    Joint Adversarial Domain Adaptation

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    Domain adaptation aims to transfer the enriched label knowledge from large amounts of source data to unlabeled target data. It has raised significant interest in multimedia analysis. Existing researches mainly focus on learning domain-wise transferable representations via statistical moment matching or adversarial adaptation techniques, while ignoring the class-wise mismatch across domains, resulting in inaccurate distribution alignment. To address this issue, we propose a Joint Adversarial Domain Adaptation (JADA) approach to simultaneously align domain-wise and class-wise distributions across source and target in a unified adversarial learning process. Specifically, JADA attempts to solve two complementary minimax problems jointly. The feature generator aims to not only fool the well-trained domain discriminator to learn domain-invariant features, but also minimize the disagreement between two distinct task-specific classifiers' predictions to synthesize target features near the support of source class-wisely. As a result, the learned transferable features will be equipped with more discriminative structures, and effectively avoid mode collapse. Additionally, JADA enables an efficient end-to-end training manner via a simple back-propagation scheme. Extensive experiments on several real-world cross-domain benchmarks, including VisDA-2017, ImageCLEF, Office-31 and digits, verify that JADA can gain remarkable improvements over other state-of-the-art deep domain adaptation approaches

    The recent progress and future of oxygen reduction reaction catalysis: A review

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    © 2016 Elsevier Ltd Proton Exchange Membrane Fuel Cell (PEMFC) technology is an exciting alternative energy prospect, especially in the field of transportation. PEMFCs are three times as efficient as internal combustion (IC) engines and emit only water as a byproduct. The latter point is especially important in a day and age when climate change is upon us. However, platinum required to catalyze the sluggish oxygen reduction reaction (ORR) which takes place on the cathode of the PEMFC has rendered fuel cell automobiles economically unviable until now. Therefore, the pursuit of an inexpensive replacement for platinum has become an active research area. This review covers the promising progress made in this field since 2011. Some of the more promising catalysts reviewed include alloys such as Pt/Pd nanotubes which outperform their platinum counterpart by nine fold and a Pt/Ni alloy which improves upon Pt activity by 16 times. Platinum-free catalysts such as iron carbide and modified graphene which rival Pt activity are also reviewed

    Corrigendum to: The TianQin project: current progress on science and technology

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    In the originally published version, this manuscript included an error related to indicating the corresponding author within the author list. This has now been corrected online to reflect the fact that author Jun Luo is the corresponding author of the article

    Measurement of the cross section of e+eΞΞˉ+e^+e^-\rightarrow\Xi^{-}\bar\Xi^{+} at center-of-mass energies between 3.510 and 4.843 GeV

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    Using e+ee^+e^- collision data corresponding to a total integrated luminosity of 12.9 fb1fb^{-1} collected with the BESIII detector at the BEPCII collider, the exclusive Born cross sections and the effective form factors of the reaction e+eΞΞˉ+e^+e^-\rightarrow\Xi^{-}\bar\Xi^{+} are measured via the single baryon-tag method at 23 center-of-mass energies between 3.510 and 4.843 GeV. Evidence for the decay ψ(3770)ΞΞˉ+\psi(3770)\rightarrow\Xi^{-}\bar\Xi^{+} is observed with a significance of 4.5σ\sigma by analyzing the measured cross sections together with earlier BESIII results. For the other charmonium(-like) states ψ(4040)\psi(4040), ψ(4160)\psi(4160), Y(4230)Y(4230), Y(4360)Y(4360), ψ(4415)\psi(4415), and Y(4660)Y(4660), no significant signal of their decay to ΞΞˉ+\Xi^-\bar \Xi^+ is found. For these states, upper limits of the products of the branching fraction and the electronic partial width at the 90% confidence level are provided.Comment: 18 pages, 10 pages, 4 table

    First Observation of a Three-Resonance Structure in e+ee^+e^-\rightarrow{non-open} Charm Hadrons

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    We report the measurement of the cross sections for e+ee^+e^-\rightarrow{nOCH} (nOCH stands for non-open charm hadrons) with improved precision at center-of-mass energies from 3.645 to 3.871 GeV. We observe for the first time a three-resonance structure in the energy-dependent lineshape of the cross sections, which are R(3760)\mathcal R(3760), R(3780)\mathcal R(3780) and R(3810)\mathcal R(3810) with significances of 9.4σ9.4\sigma, 15.7σ15.7\sigma, and 9.8σ9.8\sigma, respectively. The R(3810)\mathcal R(3810) is observed for the first time. We found two solutions in analysis of the cross sections. For solution I [solution II], we measure the mass, the total width and the product of electronic width and nOCH decay branching fraction to be (3805.8±1.1±2.7)(3805.8 \pm 1.1 \pm 2.7) [(3805.8±1.1±2.7)(3805.8 \pm 1.1 \pm 2.7)] MeV/c2c^2, (11.6±2.6±1.9)(11.6 \pm 2.6 \pm 1.9) [(11.5±2.5±1.8)(11.5 \pm 2.5 \pm 1.8)] MeV, and (10.8±3.2±2.3)(10.8\pm 3.2\pm 2.3) [(11.0±2.9±2.4)(11.0\pm 2.9\pm 2.4)] eV for the R(3810)\mathcal R(3810), respectively. In addition, we measure the branching fractions B(R(3760){\mathcal B}({\mathcal R}(3760)\rightarrow{nOCH})=(24.5±13.4±27.4)%[(6.8±5.4±7.6)%])=(24.5 \pm 13.4 \pm 27.4)\% [(6.8 \pm 5.4 \pm 7.6)\%] for the first time, and B(R(3780){\mathcal B}(\mathcal R(3780)\rightarrow{nOCH})=(11.6±5.8±7.8)%[(10.3±4.5±6.9)%])=(11.6 \pm 5.8 \pm 7.8)\% [(10.3 \pm 4.5 \pm 6.9)\%]. Moreover, we determine the open-charm (OC) branching fraction B(R{\mathcal B}({\mathcal R}(3760)(3760)\rightarrow{OC})=(75.5±13.4±27.4)%[(93.2±5.4±7.6)%])=(75.5 \pm 13.4 \pm 27.4)\% [(93.2 \pm 5.4 \pm 7.6)\%], which supports the interpretation of R(3760)\mathcal R(3760) as an OC pair molecular state, but contained a simple four-quark state component. The first uncertainties are from fits to the cross sections, and the second are systematic

    Amplitude analysis and branching fraction measurement of the decay D+KS0π+π0π0D^{+} \to K_S^0\pi^+\pi^0\pi^0

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    Using 2.93 fb1\rm{fb}^{-1} of e+ee^+e^- collision data collected with the BESIII detector at the center-of-mass energy 3.773\,GeV, we perform the first amplitude analysis of the decay D+KS0π+π0π0D^+\to K_S^0\pi^+\pi^0\pi^0 and determine the relative magnitudes and phases of different intermediate processes. The absolute branching fraction of D+KS0π+π0π0D^+\to K_S^0\pi^+\pi^0\pi^0 is measured to be (2.888±0.058stat.±0.069syst.)%(2.888\pm0.058_{\rm stat.}\pm0.069_{\rm syst.})\%. The dominant intermediate processes are D+KS0a1(1260)+(ρ+π0)D^+\to K_S^0a_1(1260)^+(\to \rho^+\pi^0) and D+Kˉ0ρ+D^+\to \bar{K}^{*0}\rho^+, with branching fractions of (8.66±1.04stat.±1.39syst.) ⁣× ⁣103(8.66\pm1.04_{\rm stat.}\pm1.39_{\rm syst.})\!\times \!10^{-3} and (9.70±0.81stat.±0.53syst.) ⁣× ⁣103(9.70\pm0.81_{\rm stat.}\pm0.53_{\rm syst.})\!\times \!10^{-3}, respectively
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