2,020 research outputs found

    Entanglement dynamics of photon pairs emitted from quantum dot

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    We present a model to derive the state of the photon pairs generated by the biexciton cascade decay of a self-assembled quantum dot, which agrees well with the experimental result. Furthermore we calculate the concurrence and entanglement sudden death is found in this system with temperature increasing, which prevents quantum dot emits entangled photon pairs at a high temperature. The relationship between the fine structure splitting and the sudden death temperature is provided too

    Phase Compensation Enhancement of Photon Pair Entanglement Generated from Biexciton Decays in Quantum Dots

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    Exciton fine-structure splittings within quantum dots introduce phase differences between the two biexciton decay paths that greatly reduce the entanglement of photon pairs generated via biexciton recombination. We analyze this problem in the frequency domain and propose a practicable method to compensate the phase difference by inserting a spatial light modulator, which substantially improves the entanglement of the photon pairs without any loss.Comment: 4 pages, 3 figure

    Preparation of a Counter Electrode with P

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    This study investigates the applicability of a counter electrode with a P-type semiconductor oxide (such as NiO) on a dye-sensitized solar cell (DSSC). The counter electrode is fabricated by depositing an NiO film on top of a Pt film, which has been deposited on a Fluorine-doped tin oxide (FTO) glass using an ion-sputtering coater (or E-beam evaporator), using a simple spin coating method. This study also examines the effect of the average thickness of TiO2 film deposited on a working electrode upon the power conversion efficiency of a DSSC. This study shows that the power conversion efficiency of a DSSC with a Pt(E)/NiO counter electrode (4.28%) substantially exceeds that of a conventional DSSC with a Pt(E) counter electrode (3.16%) on which a Pt film was deposited using an E-beam evaporator. This result is attributed to the fact that the NiO film coated on the Pt(E) counter electrode improves the electrocatalytic activity of the counter electrode

    Modeling Dynamic Heterogeneous Graph and Node Importance for Future Citation Prediction

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    Accurate citation count prediction of newly published papers could help editors and readers rapidly figure out the influential papers in the future. Though many approaches are proposed to predict a paper's future citation, most ignore the dynamic heterogeneous graph structure or node importance in academic networks. To cope with this problem, we propose a Dynamic heterogeneous Graph and Node Importance network (DGNI) learning framework, which fully leverages the dynamic heterogeneous graph and node importance information to predict future citation trends of newly published papers. First, a dynamic heterogeneous network embedding module is provided to capture the dynamic evolutionary trends of the whole academic network. Then, a node importance embedding module is proposed to capture the global consistency relationship to figure out each paper's node importance. Finally, the dynamic evolutionary trend embeddings and node importance embeddings calculated above are combined to jointly predict the future citation counts of each paper, by a log-normal distribution model according to multi-faced paper node representations. Extensive experiments on two large-scale datasets demonstrate that our model significantly improves all indicators compared to the SOTA models.Comment: Accepted by CIKM'202

    1-{4-[(1H-1,2,4-Triazol-1-yl)meth­yl]benz­yl}-1H-1,2,4-triazol-4-ium perchlorate

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    In the crystal structure of the title compound, C12H13N6 +·ClO4 −, the cation, located about an inversion center, is monoprotonated, and one H atom is disordered over two sites on N atoms of the two triazole rings, each with an occupancy factor of 0.5. The perchlorate anion has C 2 symmetry, the Cl atom and one O atom lying on the twofold rotation axis; the anion is thus disordered over two sites of equal occupancy. In the cation, the triazole ring makes a dihedral angle of 84.75 (7)° with the plane of the benzene ring. In the crystal, inter­molecular N—H⋯N hydrogen bonding between the triazole and triazolium rings links the cations into a wave-like supra­molecular chain. Weak inter­molecular C—H⋯N and C—H⋯O hydrogen bonding is also present

    The combined transarterial and transvenous onyx embolization of dural arteriovenous fistula of hypoglossal canal via the external jugular vein and facial vein: A case report

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    Dural arteriovenous fistulas of the hypoglossal canal (HCDAVFs) involving the anterior condylar confluence (ACC) and anterior condylar vein (ACV) are infrequent. Although transvenous embolization through the internal jugular vein (IJV) is the preferred treatment option for type I and II fistulas, it can be difficult if the IJV is unavailable. Here we report a rare case of HCDAVF in which the most common transvenous embolization access via IJV was not available. The patient underwent transarterial and transvenous onyx embolization. Transarterial embolization (TAE) aimed at controlling the arterial inflow and subsequently TVE was performed via the external jugular vein (EJV), the facial vein, the ophthalmic vein, the cavernous sinus, ACC, and ultimately to the fistula pouch. Complete obliteration of the HCDAVF was achieved without complications. We suggest that transvenous embolization (TVE) via the EJV and the facial vein can be effective in cases where trans-IJV is not possible

    Emulsion-directed liquid/liquid interfacial fabrication of lanthanide ion-doped block copolymer composite thin films

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    An emulsion-directed assembly and adsorption approach has been used to fabricate composite films of polystyrene-b-poly(acryl acid)-b-polystyrene (PS-b-PAA-b-PS) and Eu and La ions at the planar liquid/liquid interface of the polymer DMF/chloroform (1:1, v/v) mixed solution (lower phase) and aqueous solutions of the corresponding salts (upper phase). The lower phase gradually transformed to a water-in-oil (W/O) emulsion via spontaneous emulsification due to the "ouzo effect". Polymer molecules and the metal ions assembled around emulsion droplets that adsorbed at the planar liquid/liquid interface at last, resulting in formation of composite films. The film morphologies and structures depend on Ln ions: polymer/Eu composite films were foam films composed of microcapsules ranging in size from several hundreds of nanometers to micrometers, while polymer/La composite films were composed of hollow spheres several tens of nanometers in size. Fourier transform infrared (FTIR) spectra revealed that the coordination modes of carboxyl groups to Eu and La were bridging bidentate and ionic, respectively, in the two types of composites. These results indicate that stable microcapsules can be fabricated around droplets for polymer/Eu systems, while microcapsules of polymer/La are unstable. This leads to different film morphologies and structures. Compositions of these films were characterized using energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). In addition, foam films of polymer/Eu/2,2'-bipyridine (bpy) were fabricated using this approach, and their photoluminescence properties were investigated
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