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27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019

作者： Liu, Hang Huang, Haojie Lai, Jianyong Pan, Liangming Li, Yi Zhou, Wenxiong Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610041 China Nanjing Research Institute of El ectronics Technology Nanjing210000 China Department of Nuclear Engineering Chongqing University Chongqing400044 China

ISBN: (纸本)9784888983051

Interfacial area concentration is one of the most critical parameters in two-phase flow and reflects the interfacial area of mass, momentum and energy transfer. The prediction of interfacial area concentration is also essential to close the interfacial transfer terms in the two-fluid model. The calculation of interfacial area concentration has been well developed from bubbly flow to churn flow, including interfacial area correlations and two-group interfacial area transport equation. While seldom researchers focus on that for annular flow or annular mist flow. This paper proposed the one-dimensional interfacial area correlation for annular flow in vertical pipes based on the averaged liquid film thickness model for annular flow. The effects of the droplets in pipes were also considered in the model. The new model has been evaluated against the existing experimental data. The results indicate that the new model can provide the excellent prediction of the interfacial area concentration for annular flow in vertical pipes. Copyright © 2018-2019 by JSME

关键词： Two phase flow

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Ca-Doped La0.5Ba0.5FeO3-δAs an Efficient Cathode Material for Proton-Conducting Direct Ammonia Fuel Cells

ACS Electrochemistry

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ACS Electrochemistry 2024年第1期1卷 63-72页

作者： Shenglin Liu Menglin Wu Chaozhong Wang Yihang Li Tong Liu Jiupai Ni John Irvine Chengsheng Ni College of Resources and Environment Southwest University Chongqing 400715 China；Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and Environment Southeast University Nanjing 211189 Jiangsu China College of Resources and Environment Southwest University Chongqing 400715 China；Institute of Energy Hefei Comprehensive National Science Center Hefei Anhui 230031 P. R. China College of Resources and Environment Southwest University Chongqing 400715 China Interdisciplinary Research Center of Smart Sensors Academy of Advanced Interdisciplinary Research Xidian University Xi’an 710071 P. R. China Key Laboratory of Green Chemical Process of Ministry of Education Key Laboratory of Novel Reactor and Green Chemical Technology of Hubei Province School of Chemical Engineering and Pharmacy Wuhan Institute of Technology Wuhan 430205 China College of Resources and Environment Southwest University Chongqing 400715 China；School of Chemistry University of St Andrews St Andrews KY16 9ST United Kingdom

Sr or Ca doping on the Ba site of layered perovskites is reported to increase oxygen reduction reaction catalytic activity, but the underlying mechanism of this phenomenon for the protonic cell is not clear. In this research, Ca containing La0.5(Ba0.5–xCax)FeO3-δ(0≤x≤0.3) perovskites are explored as cathodes for proton-conducting direct ammonia fuel cells. La0.5Ba0.5FeO3-δ(LBF) has mixed cubic and tetragonal phases with cation ordering, and the Ca doping generally increases the oxide-ion conductivity because it could increase the stability of random cation distribution on the A site and facilitate the formation of oxide ion vacancy in the layer according to the density-function theory (DFT) calculation. The surface exchange coefficient (2.00 × 10–5cm s–1) and the chemical diffusion coefficient (4.01 × 10-10cm2s–1) are enhanced to 8.56 × 10–5cm s–1and 7.37 × 10–9cm2s–1, respectively, when the Ca content increased from 0 to 30%. For electrochemical tests, the single cell with a cathode of cubic La0.5(Ba0.45Ca0.05)FeO3−δbased on BaZr0.1Ce0.7Y0.2O3(BZCY) electrolyte shows a polarization resistance of 0.058 Ω cm2at 700 °C, imparting a peak power density of 682 mW cm–2under NH3fuel. The Ca2+doping abovex= 0.05 would decrease the cell output or stability for continuous operation in fuel-cell mode because of the decreased protonic conductivity that could localize the site for water production. This research highlights the effect of isovalent Ca2+doping on the Ba2+site and demonstrates the possibility for a proton conducting cathode for direct ammonia fuel cell.

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designing light-element materials with large effective spin-orbit coupling

arXiv

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arXiv 2021年

作者： Li, Jiayu Yao, Qiushi Wu, Lin Hu, Zongxiang Gao, Boya Wan, Xiangang Liu, Qihang Department of Physics Southern University of Science and Technology Shenzhen518055 China National Laboratory of Solid State Microstructures School of Physics Nanjing University Nanjing210093 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing210093 China Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices Southern University of Science and Technology Shenzhen518055 China Guangdong Provincial Key Laboratory for Computational Science and Material Design Southern University of Science and Technology Shenzhen518055 China

Spin-orbit coupling (SOC), which is the core of many condensed-matter phenomena such as nontrivial band gap and magnetocrystalline anisotropy, is generally considered appreciable only in heavy elements. This is detrimental to the synthesis and application of functional materials. Therefore, amplifying the SOC effect in light elements is crucial. Herein, focusing on 3d and 4d systems, we demonstrate that the interplay between crystal symmetry and electron correlation can significantly enhance the SOC effect in certain partially occupied orbital multiplets through the self-consistently reinforced orbital polarization as a pivot. Thereafter, we provide design principles and comprehensive databases, where we list all the Wyckoff positions and site symmetries in all two-dimensional (2D) and three-dimensional crystals that could have enhanced SOC effect. Additionally, we predict nine material candidates from our selected 2D material pool as high-temperature quantum anomalous Hall insulators with large nontrivial band gaps of hundreds of meV. Our study provides an efficient and straightforward way for predicting promising SOC-active materials, relieving the use of heavy elements for next-generation spin-orbitronic materials and devices. © 2021, CC BY.

关键词： Chemical elements

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Numerical Simulation of Damage to Submarine Pipe-in-Pipe Systems Impacted by Falling Objects

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ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering 2025年第3期11卷

作者： Zhao, Wenhao Yang, Jiayan Zhang, Chunhui Wang, Le Hou, Zhechen Tian, Yinghui Hebei Prov. Technol. Innov. Ctr. for Disaster Prev. and Mitigation of Geotechnical and Struct. Syst. Hebei Univ. of Science and Technology Shijiazhuang050018 China Research and Design Dept. China Harbour Engineering Company Ltd. Beijing100027 China State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin Univ. 92 Weijin Rd. Tianjin300072 China Oceans Graduate School The Univ. of Western Australia 35 Stirling Hwy. CrawleyWA6009 Australia Dept. of Infrastructure Engineering Faculty of Engineering and Information Technology The Univ. of Melbourne MelbourneVIC3010 Australia

Subsea pipe-in-pipe systems frequently encounter challenges from impact loads caused by falling objects, resulting in dents and damages that lead to oil and gas leakage. This study conducted a comprehensive analysis using a nonlinear explicit dynamic finite-element model, considering 108 parameter scenarios, to study the damage pattern of the inner pipe. An economic benefit analysis was done for the steel consumption of the pipe. Research revealed that the impact position of falling objects and the gap between the centralizer and the outer pipe are critical factors in determining the extent of damage to the inner pipe. To mitigate inner pipe damage, optimal measures include increasing the outer pipe wall thickness, enhancing the grade of steel pipes, and maintaining the gap between the centralizer and the outer pipe 40 mm. This study contributes to a deeper understanding of the structural response of falling objects impacting subsea pipe-in-pipe systems, providing valuable insights for the design and operation of such systems. © 2025 American Society of Civil Engineers.

关键词： Offshore technology

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Electrically switchable quantum anomalous and spin Hall states in two-dimensional honeycomb lattices with non-Dirac bands

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Physical Review B 2025年第23期111卷 235414-235414页

作者： Sihui Wu Jiahui Qian Xunkai Duan Xianzhang Chen Zhou Cui Jiayong Zhang Chunlan Ma Tong Zhou Key Laboratory of Efficient Low-carbon Energy Conversion and Utilization of Jiangsu Provincial Higher Education Institutions School of Physical Science and Technology Suzhou University of Science and Technology Suzhou 215009 China Eastern Institute for Advanced Study Eastern Institute of Technology Ningbo Zhejiang 315200 China School of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China International Center for Quantum Design of Functional Materials (ICQD) and Hefei National Laboratory University of Science and Technology of China Hefei 230026 China

Two-dimensional (2D) honeycomb lattices provide a versatile platform for realizing topologically nontrivial states. In this work, we uncover the coexistence and electrical tunability of quantum anomalous Hall (QAH) and quantum spin Hall (QSH) states in 2D honeycomb lattices characterized by non-Dirac band structures. Employing a tight-binding model, we demonstrate that px and py orbitals lead to quadratic non-Dirac band degeneracies at the Γ point and linear Dirac band degeneracies at the K and K′ points. The introduction of a magnetic exchange field and atomic spin-orbit coupling can induce distinct QAH and QSH gaps at separate energy levels within the same system. First-principles calculations validate these findings in a ferromagnetic monolayer of functionalized plumbene (Pb2BrO), predicting sizable QAH (175.4 meV) and QSH (187.8 meV) gaps. Notably, the Fermi energy of monolayer Pb2BrO resides in the QAH gap but can be electrically gated into the QSH gap, enabling reversible transitions between these two topologically nontrivial states. These results provide a theoretical foundation for the design of electrically tunable topological materials and establish 2D honeycomb lattices with non-Dirac bands as a promising platform for multifunctional quantum applications.

关键词： Crystal lattices

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Spatial-temporal characteristics and the importance of environmental factors in relation to algal blooms in coastal seas

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science of the Total Environment 2024年 957卷 177686页

作者： Tong, Yanbin Lei, Kun Wang, Li Li, Yuanyi Lan, Wenlu Cheng, Yuming Deng, Zeng'an Zhai, Jingsheng Huang, Zhe School of Marine Science and Technology Tianjin University Tianjin300072 China Chinses Research Academy of Environmental Sciences Beijing100012 China Shanghai East Sea Marine Engineering Survey and Design Institute Co. Ltd. Shanghai200137 China Beibu Gulf Marine Ecological Environment Field Observation and Research Station of Guangxi Marine Environmental Monitoring Centre of Guangxi Beihai536000 China State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin University Tianjin China

In the prediction of algal blooms with the artificial intelligence (AI) technology, the proper selection of the indices is crucial to the quality of the results. Although eutrophication and climate change have been identified as the main contributors to algal blooms, limited knowledge of the relationships among environmental factors hinders the accurate and correct AI prediction. To explore the importance of environmental factors in the occurrence of algal blooms in coastal seas and facilitate the selection of inputs for the prediction model, this study examines observed water quality data and analyzes their relationship using machine learning methods. It was found that nutrients, water temperature, and salinity play important roles in controlling algal blooms in coastal seas, and their influence varies depending on locations. The high-risk cases of algal bloom mainly occur in environments with medium salinity (22–28 psu), particularly in open estuaries with high nutrient levels. According to the feature importance analysis, water temperature presented the most significant impact on algal bloom risk compared to other environmental factors. The variations of water temperature and Chl-a concentration are synchronous when the water temperature is below 32 °C. Additionally, the relationships between inorganic nutrients (NO3−-NO2− and Ortho-P) and Chl-a exhibit asynchronous across multi-temporal scales. The uptake of inorganic nutrients occurs in large quantities within the 24 h prior to the boom in Chl-a concentration. This demonstrates that variations in concentration of inorganic nutrients can be considered as crucial factors in algal bloom predictions, and their significant decrease can be served as an important signal of an impending algal bloom. This study enhances our understanding of the mechanisms behind algal blooms and facilitates their management and prediction strategies in coastal seas. © 2024

关键词： Prediction models

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Effect of pore shape on uniaxial compressive behaviour of porous rock-like materials: DEM simulation

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Case Studies in Construction Materials 2025年 23卷

作者： Chuanfeng Fang Tieyong Zhao Weijian Yu Ping Wang Zizheng Zhang Baifu An Genshui Wu Shunkai Liu School of Resources Environment and Safety Engineering Hunan University of Science and Technology Xiangtan 411201 China Tongchuang Engineering Design Co. LTD. Shaoxing 312000 China Hunan Key Laboratory of Safe Mining Techniques of Coal Mines Hunan University of Science and Technology Xiangtan 411201 China School of Civil Engineering Hunan University of Science and Technology Xiangtan 411201 China

The pore shapes of porous rock-like materials are not circular but complex and diverse，constituting a critical factor influencing their mechanical properties and failure characteristics. In this study, the effects of pore angularity and aspect ratio on the mechanical behaviour of porous rock-like materials under uniaxial compression were quantitatively analyzed using the Discrete Element Method (DEM). Numerical models containing pores of various shapes were constructed as Voronoi polygon aggregates to more realistically simulate material fracture. The results show that with increasing angularity or aspect ratio, both the uniaxial compressive strength and elastic modulus decrease in distinct patterns, while Poisson's ratio remains unchanged. Moreover, higher angularity or aspect ratio not only leads to cracks initiation at sharp corners and causes the crack paths to deviate from the axial loading direction, but also results in an increase in both the total crack length and the number of fragments. Finally, the evolution of the microstructure, including contact forces and the spatial distribution of stress, was analyzed to assess the influence of pore shape on microscopic characteristics.

关键词： Pore shape Mechanical properties Failure characteristics DEM simulation Uniaxial compression

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Experimental Simulations Of Effects of Surface Roughness Level of Tbc on Overall Effectiveness of Film Cooling Model

SSRN

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SSRN 2022年

作者： Pu, Jian Zhang, Tiao Shuai, Xu Wang, Jian-Hua Chen, Yun Wu, Wei-Long CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Thermal Science and Energy Engineering University of Science and Technology of China No. 96 Jinzhai Road Anhui Hefei230027 China Shenyang Aero-engine Institute of Aero Engine Corporation of China No. 1 Wanlian Road Liaoning Shenyang110015 China

It is unknown about the selection of surface roughness level of thermal barrier coatings (TBCs) at turbine vanes with film cooling (FC). In this work, the universal turbine vane flow environment was characterized by the proper combinations of different wall curvatures and streamwise pressure gradients. To achieve the direct measurements of overall effectiveness, a conjugate FC model with simulated TBCs was established by matching the hot-side Biot numbers of actual materials. The surface roughness levels were set in a range for TBC design stage. The measurements displayed the detailed trends in overall effectiveness of metal and TBC with the surface roughness level, wall curvature, streamwise pressure gradient, and cooling air flowrate. The roughness effect on overall effectiveness was complicated by the wall curvature, due to generating different jet-mechanisms. When the engine Ra changes from 0.2μm to 14μm, the variations of metal overall effectiveness can be controlled below 15% at different walls. Overall, to improve the protection ability to metal, the smoother TBC is suggested to spray at the flat wall;while at the convex and concave walls, the proper roughness of TBC can be considered in the near-hole region, when the stress level of material is met. © 2022, The Authors. All rights reserved.

关键词： Surface roughness

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Customer Enrollment and Participation in Building Demand Management Programs: A Review of Key Factors

SSRN

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SSRN 2024年

作者： Langevin, Jared Cetin, Kristen Willems, Sara Kang, Jeonga Mahmud, Roohany Christensen, Toke Haunstrup Li, Rongling Knotzer, Armin Olawale, Opeoluwa Wonuola Saelens, Dirk O'Connell, Sarah Building Technology and Urban Systems Department Lawrence Berkeley National Laboratory BerkeleyCA United States College of Engineering Michigan State University East LansingMI United States Building Physics and Sustainable Design KU Leuven Leuven Belgium Department of Civil and Mechanical Engineering Technical University of Denmark Kongens Lyngby Denmark Department of the Built Environment Aalborg University Copenhagen Denmark AEE–Institute for Sustainable Technologies Gleisdorf Austria National Renewable Energy Laboratory GoldenCO United States Energyville Genk Belgium College of Science Engineering and Food Science University College Cork Cork Ireland

Increasing the efficiency and flexibility of electricity demand is necessary for ensuring a cost-effective and reliable transition to zero-carbon electricity systems. Such demand-side management (DSM) resources have been procured by utilities for decades via energy efficiency and demand response programs;however, the key drivers of program enrollment and customer participation levels remain poorly understood - even as governments and grid planners seek to scale up the deployment of DSM assets to meet climate targets. Here we systematically review the evidence on multiple factors that may influence customer enrollment and participation in DSM programs. We examine the contexts in which relationships between DSM factors and outcomes are most often explored and with which methods;we also score the strength, direction, and internal consistency of each factor's reported impact on the enrollment and participation outcomes. We find that studies most commonly assess the effects of economic incentives for load flexibility on program participation levels, often using simulation-based methods in lieu of measured data. Few studies focus on program enrollment outcomes or regulatory drivers of either enrollment or participation, and gaps are also evident in the coverage of emerging DSM opportunities like load electrification. Removal of structural barriers (e.g., the lack of controls infrastructure) and the use of third party services (e.g., load aggregators) are the factors with the largest positive impacts on DSM outcomes, but no single factor emerges as clearly most impactful. For a given factor, the range of reported impacts typically varies widely across the relevant studies reviewed. Our findings provide a snapshot of the state of knowledge about DSM and customer decision-making and expose key gaps in understanding that must be filled if DSM is to expand as a critical resource for operating clean power grids. © 2024, The Authors. All rights reserved.

关键词： Energy efficiency

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KADEL: Knowledge-Aware Denoising Learning for Commit Message Generation

arXiv

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arXiv 2024年

作者： Tao, Wei Zhou, Yucheng Wang, Yanlin Zhang, Hongyu Wang, Haofen Zhang, Wenqiang Shanghai Engineering Research Center of AI and Robotics Academy for Engineering and Technology Fudan University Shanghai China State Key Laboratory of Internet of Things for Smart City Department of Computer and Information Science University of Macau China School of Software Engineering Sun Yat-sen University Guangdong Zhuhai519082 China School of Big Data and Software Engineering Chongqing University Chongqing China College of Design and Innovation Tongji University Shanghai China Engineering Research Center of AI and Robotics Ministry of Education Academy for Engineering and Technology Shanghai Key Lab of Intelligent Information Processing School of Computer Science Fudan University 220 Handan Road Shanghai200433 China

Commit messages are natural language descriptions of code changes, which are important for software evolution such as code understanding and maintenance. However, previous methods are trained on the entire dataset without considering the fact that a portion of commit messages adhere to good practice (i.e., good-practice commits), while the rest do not. On the basis of our empirical study, we discover that training on good-practice commits significantly contributes to the commit message generation. Motivated by this finding, we propose a novel knowledge-aware denoising learning method called KADEL. Considering that good-practice commits constitute only a small proportion of the dataset, we align the remaining training samples with these good-practice commits. To achieve this, we propose a model that learns the commit knowledge by training on good-practice commits. This knowledge model enables supplementing more information for training samples that do not conform to good practice. However, since the supplementary information may contain noise or prediction errors, we propose a dynamic denoising training method. This method composes a distribution-aware confidence function and a dynamic distribution list, which enhances the effectiveness of the training process. Experimental results on the whole MCMD dataset demonstrate that our method overall achieves state-of-the-art performance compared with previous methods. © 2024, CC BY.

关键词： Sampling

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