2,240 research outputs found

    Analysis of the Spatial Separation Effects of Thorium/Uranium Fuels in Block‐Type HTRs

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    With the rapid development of nuclear energy, thorium has been gaining attention because of its abundant reserves and excellent physical properties. Compared with light-water reactors, block-type high temperature gas cooled reactors (HTRs) are a better choice for thorium-based fuel for higher burnup and harder neutron spectrum. When using thorium in block-type HTRs, the composition and spatial distribution of thorium/uranium fuels are two determined factors of nuclear performance. Four spatial separation levels of thorium/uranium fuels, no separation level, TRISO level, channel level, and block level, are defined for the block-type thorium-fueled HTRs. A two-step calculation scheme was used to obtain the neutronic performance, including the initial inventory of U-235, effective multiplication factor, and average conversion ratio. Based on these data, the fuel cycle cost of different spatial separation levels can be calculated by the levelized lifetime cost method as a function of thorium content. The fuel cycle cost changes with the same trend as the initial inventory of U-235 in the reactor cores because the latter determines 70% of the total cost. When the thorium content is constant, the initial inventory of U-235 decreases with the increase of the spatial separation level because spatial self-shielding effect is strengthened by the latter

    Molecular docking via quantum approximate optimization algorithm

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    Molecular docking plays a pivotal role in drug discovery and precision medicine, enabling us to understand protein functions and advance novel therapeutics. Here, we introduce a potential alternative solution to this problem, the digitized-counterdiabatic quantum approximate optimization algorithm (DC-QAOA), which utilizes counterdiabatic driving and QAOA on a quantum computer. Our method was applied to analyze diverse biological systems, including the SARS-CoV-2 Mpro complex with PM-2-020B, the DPP-4 complex with piperidine fused imidazopyridine 34, and the HIV-1 gp120 complex with JP-III-048. The DC-QAOA exhibits superior performance, providing more accurate and biologically relevant docking results, especially for larger molecular docking problems. Moreover, QAOA-based algorithms demonstrate enhanced hardware compatibility in the noisy intermediate-scale quantum era, indicating their potential for efficient implementation under practical docking scenarios. Our findings underscore quantum computing's potential in drug discovery and offer valuable insights for optimizing protein-ligand docking processes.Comment: 10 pages, 5 figures, All comments are welcom

    Effect of state-dependent time delay on dynamics of trimming of thin walled structures

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    Acknowledgments This work was supported by the National Key R&D Program of China (2020YFA0714900), National Natural Science Foundation of China (52075205, 92160207, 52090054, 52188102).Peer reviewedPostprin

    Continual Graph Convolutional Network for Text Classification

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    Graph convolutional network (GCN) has been successfully applied to capture global non-consecutive and long-distance semantic information for text classification. However, while GCN-based methods have shown promising results in offline evaluations, they commonly follow a seen-token-seen-document paradigm by constructing a fixed document-token graph and cannot make inferences on new documents. It is a challenge to deploy them in online systems to infer steaming text data. In this work, we present a continual GCN model (ContGCN) to generalize inferences from observed documents to unobserved documents. Concretely, we propose a new all-token-any-document paradigm to dynamically update the document-token graph in every batch during both the training and testing phases of an online system. Moreover, we design an occurrence memory module and a self-supervised contrastive learning objective to update ContGCN in a label-free manner. A 3-month A/B test on Huawei public opinion analysis system shows ContGCN achieves 8.86% performance gain compared with state-of-the-art methods. Offline experiments on five public datasets also show ContGCN can improve inference quality. The source code will be released at https://github.com/Jyonn/ContGCN.Comment: 9 pages, 4 figures, AAAI 2023 accepted pape
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