17,419 research outputs found

    Cross-lingual Entity Alignment via Joint Attribute-Preserving Embedding

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    Entity alignment is the task of finding entities in two knowledge bases (KBs) that represent the same real-world object. When facing KBs in different natural languages, conventional cross-lingual entity alignment methods rely on machine translation to eliminate the language barriers. These approaches often suffer from the uneven quality of translations between languages. While recent embedding-based techniques encode entities and relationships in KBs and do not need machine translation for cross-lingual entity alignment, a significant number of attributes remain largely unexplored. In this paper, we propose a joint attribute-preserving embedding model for cross-lingual entity alignment. It jointly embeds the structures of two KBs into a unified vector space and further refines it by leveraging attribute correlations in the KBs. Our experimental results on real-world datasets show that this approach significantly outperforms the state-of-the-art embedding approaches for cross-lingual entity alignment and could be complemented with methods based on machine translation

    Phase separation in the trapped spinor gases with anisotropic spin-spin interaction

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    We investigate the effect of the anisotropic spin-spin interaction on the ground state density distribution of the one dimensional spin-1 bosonic gases within a modified Gross-Pitaevskii theory both in the weakly interaction regime and in the Tonks-Girardeau (TG) regime. We find that for ferromagnetic spinor gas the phase separation occurs even for weak anisotropy of the spin-spin interaction, which becomes more and more obvious and the component of mF=0m_F=0 diminishes as the anisotropy increases. However, no phase separation is found for anti-ferromagnetic spinor gas in both regimes.Comment: 5pages, 4 figure

    The electrorheology of suspensions consisting of Na-Fluorohectorite synthetic clay particles in silicon oil

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    Under application of an electric field greater than a triggering electric field Ec∼0.4E_c \sim 0.4 kV/mm, suspensions obtained by dispersing particles of the synthetic clay fluoro-hectorite in a silicon oil, aggregate into chain- and/or column-like structures parallel to the applied electric field. This micro-structuring results in a transition in the suspensions' rheological behavior, from a Newtonian-like behavior to a shear-thinning rheology with a significant yield stress. This behavior is studied as a function of particle volume fraction and strength of the applied electric field, EE. The steady shear flow curves are observed to scale onto a master curve with respect to EE, in a manner similar to what was recently found for suspensions of laponite clay [42]. In the case of Na-fluorohectorite, the corresponding dynamic yield stress is demonstrated to scale with respect to EE as a power law with an exponent α∼1.93\alpha \sim 1.93, while the static yield stress inferred from constant shear stress tests exhibits a similar behavior with α∼1.58\alpha \sim 1.58. The suspensions are also studied in the framework of thixotropic fluids: the bifurcation in the rheology behavior when letting the system flow and evolve under a constant applied shear stress is characterized, and a bifurcation yield stress, estimated as the applied shear stress at which viscosity bifurcation occurs, is measured to scale as EαE^\alpha with α∼0.5\alpha \sim 0.5 to 0.6. All measured yield stresses increase with the particle fraction Φ\Phi of the suspension. For the static yield stress, a scaling law Φβ\Phi^\beta, with β=0.54\beta = 0.54, is found. The results are found to be reasonably consistent with each other. Their similarities with-, and discrepancies to- results obtained on laponite-oil suspensions are discussed

    Simulating aerosol–radiation–cloud feedbacks on meteorology and air quality over eastern China under severe haze conditionsin winter

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    The aerosol-radiation-cloud feedbacks on meteorology and air quality over eastern China under severe winter haze conditions in January 2013 are simulated using the fully coupled online Weather Research and Forecasting/Chemistry (WRF-Chem) model. Three simulation scenarios including different aerosol configurations are undertaken to distinguish the aerosol's radiative (direct and semi-direct) and indirect effects. Simulated spatial and temporal variations of PM2.5 are generally consistent with surface observations, with a mean bias of −18.9 μg m−3 (−15.0%) averaged over 71 big cities in China. Comparisons between different scenarios reveal that aerosol radiative effects (direct effect and semi-direct effects) result in reductions of downward shortwave flux at the surface, 2 m temperature, 10 m wind speed and planetary boundary layer (PBL) height by up to 84.0 W m−2, 3.2°C, 0.8 m s−1, and 268 m, respectively. The simulated impact of the aerosol indirect effects is comparatively smaller. Through reducing the PBL height and stabilizing lower atmosphere, the aerosol effects lead to increases in surface concentrations of primary pollutants (CO and SO2). Surface O3 mixing ratio is reduced by up to 6.9 ppb (parts per billion) due to reduced incoming solar radiation and lower temperature, while the aerosol feedbacks on PM2.5 mass concentrations show some spatial variations. Comparisons of model results with observations show that inclusion of aerosol feedbacks in the model significantly improves model performance in simulating meteorological variables and improves simulations of PM2.5 temporal distributions over the North China Plain, the Yangtze River delta, the Pearl River delta, and central China. Although the aerosol–radiation–cloud feedbacks on aerosol mass concentrations are subject to uncertainties, this work demonstrates the significance of aerosol–radiation–cloud feedbacks for real-time air quality forecasting under haze conditions

    Phenomenological theory of a scalar electronic order: application to skutterudite PrFe4P12

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    By phenomenological Landau analysis, it is shown that a scalar order parameter with the point-group symmetry Γ1g\Gamma_{1g} explains most properties associated with the phase transition in PrFe4_4P12_{12} at 6.5 K. The scalar-order model reproduces magnetic and elastic properties in PrFe4_4P12_{12} consistently such as (i) the anomaly of the magnetic susceptibility and elastic constant at the transition temperature, (ii) anisotropy of the magnetic susceptibility in the presence of uniaxial pressure, and (iii) the anomaly in the elastic constant in magnetic field. An Ehrenfest relation is derived which relates the anomaly of the magnetic susceptibility to that of the elastic constant at the transition.Comment: 16 pages, 9 figure

    Evolution of spin-wave excitations in ferromagnetic metallic manganites

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    Neutron scattering results are presented for spin-wave excitations of three ferromagnetic metallic A1−xAx′A_{1-x}A^{\prime}_{x}MnO3_3 manganites (where AA and A′A^\prime are rare- and alkaline-earth ions), which when combined with previous work elucidate systematics of the interactions as a function of carrier concentration xx, on-site disorder, and strength of the lattice distortion. The long wavelength spin dynamics show only a very weak dependence across the series. The ratio of fourth to first neighbor exchange (J4/J1J_4/J_1) that controls the zone boundary magnon softening changes systematically with xx, but does not depend on the other parameters. None of the prevailing models can account for these behaviors.Comment: Submitted to Phys. Rev. Let

    Interactions of energetic electrons with ULF waves triggered by interplanetary shock: Van Allen Probes observations in the magnetotail

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    Abstract We present in situ observations of a shock-induced substorm-like event on 13 April 2013 observed by the newly launched Van Allen twin probes. Substorm-like electron injections with energy of 30-500 keV were observed in the region from L∼5.2 to 5.5 immediately after the shock arrival (followed by energetic electron drift echoes). Meanwhile, the electron flux was clearly and strongly varying on the ULF wave time scale. It is found that both toroidal and poloidal mode ULF waves with a period of 150 s emerged following the magnetotail magnetic field reconfiguration after the interplanetary (IP) shock passage. The poloidal mode is more intense than the toroidal mode. The 90 phase shift between the poloidal mode Br and Ea suggests the standing poloidal waves in the Northern Hemisphere. Furthermore, the energetic electron flux modulations indicate that the azimuthal wave number is ∼14. Direct evidence of drift resonance between the injected electrons and the excited poloidal ULF wave has been obtained. The resonant energy is estimated to be between 150 keV and 230 keV. Two possible scenaria on ULF wave triggering are discussed: vortex-like flow structure-driven field line resonance and ULF wave growth through drift resonance. It is found that the IP shock may trigger intense ULF wave and energetic electron behavior at L∼3 to 6 on the nightside, while the time profile of the wave is different from dayside cases

    Signature of Magnetic Phase Separation in the Ground State of Pr1-xCaxMnO3

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    Neutron scattering has been used to investigate the evolution of the long- and short-range charge-ordered (CO), ferromagnetic (FM), and antiferromagnetic (AF) correlations in single crystals of Pr1-xCaxMnO3. The existence and population of spin clusters as refected by short-range correlations are found to drastically depend on the doping (x) and temperature (T). Concentrated spin clusters coexist with long-range canted AF order in a wide temperature range in x = 0.3 while clusters do not appear in x = 0.4 crystal. In contrast, both CO and AF order parameters in the x = 0.35 crystal show a precipitous decrease below ~ 35 K where spin clusters form. These results provide direct evidence of magnetic phase separation and indicate that there is a critical doping x_c (close to x = 0.35) that divides the phase-separated site-centered from the homogeneous bond-centered or charge-disproportionated CO ground state.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Letter
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