1,424 research outputs found

    1-(2,4-Dichloro­benz­yl)pyridinium bis­(2-sulfanyl­idene-1,3-dithiole-4,5-dithiol­ato-κ2 S,S′)nickelate(III)

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    In the title compound, (C12H10Cl2N)[Ni(C3S5)2], the NiIII atom is chelated by two bidentate 2-sulfanyl­idene-1,3-dithiole-4,5-dithiol­ate (dmit) dianions and shows a distorted square-planar geometry. The two dmit ligands are twisted with respect to each other by 3.21 (2)°. In the cation, the two aromatic groups linked by the methyl­ene bridging group form a dihedral angle of 68.09 (2)°. S⋯S [3.6212 (11) and 3.5573 (9) Å] and Ni⋯S [3.566 (2)Å] inter­actions influence the arrangement of the anions in the crystal

    Vacancy expansion in alpha-Ti under tensile loads at different strain rates with MD simulation

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    In order to analyze the effect of strain rate under tensile load on microcrack growth in Alpha Titanium, molecular dynamics simulation was used to analyze the results of atomic location, dislocation distribution, lattice phase transition, potential energy distribution and volume strain distribution. It was found that the cracks gradually evolved into holes after unstable propagation, and the holes were occupied by clusters on both sides of the material in the later stage under the necking of the material. The higher the tensile strain rate, the earlier the crack initiation and the larger the evolution of the through-hole. When the same strain value is reached, the lattice transformation ratio is higher under high strain rate loading. HCP is transformed into amorphous structure, BCC lattice type and a small amount of FCC type. Moreover, the larger the strain rate, the less the compatible deformation ability of the lattice is, and the more twins are produced. In addition, it is found that there are volumetric strain wave emission and diffusion in the model at the moment of void birth, and voids play a role in dividing the energy absorption region. Dislocation emission occurs at the crack tip and energy competition exists between dislocation and crack propagation

    Fast Lithium Ion Diffusion in Brownmillerite LixSr2Co2O5\mathrm{Li}_{x}\mathrm{{Sr}_{2}{Co}_{2}{O}_{5}}

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    Ionic conductors have great potential for interesting tunable physical properties via ionic liquid gating and novel energy storage applications such as all-solid-state lithium batteries. In particular, low migration barriers and high hopping attempt frequency are the keys to achieve fast ion diffusion in solids. Taking advantage of the oxygen-vacancy channel in LixSr2Co2O5\mathrm{Li}_{x}\mathrm{{Sr}_{2}{Co}_{2}{O}_{5}}, we show that migration barriers of lithium ion are as small as 0.28~0.17eV depending on the lithium concentration rates. Our first-principles calculation also investigated hopping attempt frequency and concluded the room temperature ionic diffusivity and ion conductivity is high as 107106 cm2 s1{10}^{-7}\sim{10}^{-6}~\mathrm{{cm}^{2}~s^{-1}} and 103102 Scm1{10}^{-3}\sim{10}^{-2}~\mathrm{S\cdot{cm}^{-1}} respectively, which outperform most of perovskite-type, garnet-type and sulfide Li-ion solid-state electrolytes. This work proves LixSr2Co2O5\mathrm{Li}_{x}\mathrm{{Sr}_{2}{Co}_{2}{O}_{5}} as a promising solid-state electrolyte.Comment: 6 pages, 7 figure

    Research on a Model of Extracting Persons\u27 Information Based on Statistic Method and Conceptual Knowledge

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    PACLIC 21 / Seoul National University, Seoul, Korea / November 1-3, 200

    Facing Unknown: Open-World Encrypted Traffic Classification Based on Contrastive Pre-Training

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    Traditional Encrypted Traffic Classification (ETC) methods face a significant challenge in classifying large volumes of encrypted traffic in the open-world assumption, i.e., simultaneously classifying the known applications and detecting unknown applications. We propose a novel Open-World Contrastive Pre-training (OWCP) framework for this. OWCP performs contrastive pre-training to obtain a robust feature representation. Based on this, we determine the spherical mapping space to find the marginal flows for each known class, which are used to train GANs to synthesize new flows similar to the known parts but do not belong to any class. These synthetic flows are assigned to Softmax's unknown node to modify the classifier, effectively enhancing sensitivity towards known flows and significantly suppressing unknown ones. Extensive experiments on three datasets show that OWCP significantly outperforms existing ETC and generic open-world classification methods. Furthermore, we conduct comprehensive ablation studies and sensitivity analyses to validate each integral component of OWCP.Comment: Accepted by 2023 IEEE ISCC, 6 pages, 5 figure

    Numerical simulation analysis of large eddy simulation for T-tube based on solid-liquid two-phase abrasive flow

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    As a kind of nano machining technology, abrasive flow polishing technology plays an important role in precision machining region. As an important numerical simulation method in fluid mechanics, large eddy numerical simulation method has become an important method for many scholars to study abrasive grain polishing technology. In this paper, the use of fluid mechanics software FLUENT and selected Mixture mixed model. Based on the theory of solid-liquid two-phase flow dynamics, the large-eddy numerical simulation method was used to study the polishing process of T-tube abrasive flow, and the micro-machining mechanism of abrasive-polished workpiece was discussed. The influence of the different inlet velocities on the polishing effect of the abrasive grains was discussed by analyzing the numerical simulation results of the different inlet velocities of the abrasive grains during the processing of the T-tube
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