1,071 research outputs found

    Ensuring Readability and Data-fidelity using Head-modifier Templates in Deep Type Description Generation

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    A type description is a succinct noun compound which helps human and machines to quickly grasp the informative and distinctive information of an entity. Entities in most knowledge graphs (KGs) still lack such descriptions, thus calling for automatic methods to supplement such information. However, existing generative methods either overlook the grammatical structure or make factual mistakes in generated texts. To solve these problems, we propose a head-modifier template-based method to ensure the readability and data fidelity of generated type descriptions. We also propose a new dataset and two automatic metrics for this task. Experiments show that our method improves substantially compared with baselines and achieves state-of-the-art performance on both datasets.Comment: ACL 201

    Interferences effects in polarized nonlinear Breit-Wheeler process

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    The creation of polarized electron-positron pairs by the nonlinear Breit-Wheeler process in short laser pulses is investigated using the Baier-Katkov semiclassical method beyond local-constant-field approximation (LCFA), which allows for identifying the interferences effects in the positron polarization. When the laser intensity is in the intermediate %multiphoton regime, the interferences of pair production in different formation lengths induce an enhancement of pair production probability for spin-down positrons, which significantly affects the polarization of created positrons. The polarization features are distinct from that obtained with LCFA, revealing the invalidity of LCFA in this regime. Meanwhile, the angular distribution for different spin states varies, resulting in an angular-dependent polarization of positrons. The average polarization of positrons at beam center is highly sensitive to the laser's carrier-envelope phase (CEP), which provides a potential alternative way of determining the CEP of strong lasers. The verification of the observed interference phenomenon is possible for the upcoming experiments

    Mechanism and Prevention Technologies of Reservoir Gas Disaster in Abandoned Oil Well of Coal Mine

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    AbstractThe reservoir gas disaster has distinct characteristics and is a key factor that threatens the safe and green mining of coal mines in the costorage area of coal and petroleum resources. In order to solve the problem of prevention and control of reservoir gas disasters in coal mines, the characteristics of oil-bed gas disasters in abandoned oil wells in coal mines were analyzed, and the oil-bed gas disaster mechanism of abandoned oil wells without isolation coal pillars was revealed to study the scope of gas disasters around oil wells under the influence of production. The research shows that: (1) abandoned oil well reservoir gas disasters have the characteristics of high gas pressure, high concentration, large lateral influence area, wide vertical sweep range, and frequent disasters, which seriously threaten the safety and green mining of coal mines; (2) divide the reservoir gas disaster of abandoned oil wells into the high-pressure gas disaster in the well and the disaster in the surrounding oil-bed gas enrichment area; (3) according to the numerical simulation results that the maximum damage depth of the coal seam mining floor is 38.6 m and the seepage height of high-pressure oil-bed gas is 40 m, the safety factor k is introduced, and the reservoir gas sweeping range of the abandoned oil well is determined to be 95.4 m below the coal seam to the surface; (4) the comprehensive prevention and control technical scheme of oil-bed gas for controlling high-pressure oil-bed gas in wells by ground plugging and downhole injection and injection of diluent to control enriched areas was proposed, which successfully solved the problem of safe and efficient exploitation of Shuangma coal mine in Ningdong coalfield by abandoned oil wells. The research results provide effective solutions for the realization of green mining in many coal mines in the costorage area of coal and oil resources in China and have important application value for the prevention and control of dynamic disasters in the costorage area of resources

    Origin and Evolution of the Ore-Forming Fluids in the Liyuan Gold Deposit, Central North China Craton: Constraints from Fluid Inclusions and H-O-C Isotopic Compositions

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    The Liyuan gold deposit is hosted within Archean basement metamorphic rocks and controlled by the NNE-trending faults in the central North China Craton. The ore-forming processes can be divided into three stages (early, middle, and late). Three types of primary fluid inclusions (FIs) are identified in the Liyuan, including pure carbonic, carbonic-aqueous, and aqueous inclusions. The primary FIs of three stages are mainly homogenized at temperatures of 318–408°C, 201–329°C, and 136–229°C, with salinities of 2.1–8.9, 0.5–12.4, and 0.4–6.3 wt.% NaCl equivalent, respectively. The main Au mineralization is related to the middle stage, and water-rock interaction caused rapid precipitation of gold in this stage. The initial ore-forming fluids were likely magmatic water or metamorphic fluid and mixed with meteoric water at later stages. Due to the lack of granite body at the present mining levels, we speculate that it was magmatic water that might have been exsolved from a concealed granite body at greater depth or it was metamorphic fluid that was directly transported from depth via deep faults. Based on all the available geological and geochemical evidence, we suggest that the Liyuan deposit belongs to orogenic gold deposit that located in the interior North China Craton
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