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A robust compact least-squares reconstruction method for compressible turbulent flow simulations of complex configurations

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Chinese Journal of Aeronautics 2023年第12期36卷 113-138页

作者： Jia YAN Zhengyu NIU Xiaoquan YANG Jue DING Xiaolong TANG peifeng weng Shanghai Institute of Applied Mathematics and Mechanics Shanghai UniversityShanghai 200072China School of Mechanics and Engineering Science Shanghai UniversityShanghai 200072China Shanghai University of Electric Power Shanghai 200090China

For the second-order finite volume method,implicit schemes and reconstruction methods are two main algorithms which influence the robustness and efficiency of the numerical simulations of compressible turbulent flows.In this paper,a compact least-squares reconstruction method is proposed to calculate the gradients for the distribution of flow field variables approximation.The compactness of the new reconstruction method is reflected in the gradient calculation process.The geometries of the face-neighboring elements are no longer utilized,and the weighted average values at the centroid of the interfaces are used to calculate the gradients instead of the values at the centroid of the face-neighboring elements.Meanwhile,an exact Jacobian solving strategy is developed for implicit temporal discretization.The accurate processing of Jacobian matrix can extensively improve the invertibility of the Jacobian matrix and avoid introducing extra numerical errors.In addition,a modified Venkatakrishnan limiter is applied to deal with the shock which may appear in transonic flows and the applicability of the mentioned methods is enhanced further.The combination of the proposed methods makes the numerical simulations of turbulent flow converge rapidly and steadily with an adaptive increasing CFL number.The numerical results of several benchmarks indicate that the proposed methods perform well in terms of robustness,efficiency and accuracy,and have good application potential in turbulent flow simulations of complex configurations.

关键词： Compact least-squares reconstruction method Exact Jacobian matrix Finite volume method Implicit schemes Turbulent flow

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Integrated multi-scale approach combining global homogenization and local refinement for multi-field analysis of high-temperature superconducting composite magnets

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 747-762页

作者： Hanxiao GUO peifeng GAO Xingzhe WANG Key Laboratory of Mechanics on Western Disaster and Environment of Ministry of Education Key Laboratory of Special Function Materials and Structure Design of Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

Second-generation high-temperature superconducting(HTS)conductors,specifically rare earth-barium-copper-oxide(REBCO)coated conductor(CC)tapes,are promising candidates for high-energy and high-field superconducting applications.With respect to epoxy-impregnated REBCO composite magnets that comprise multilayer components,the thermomechanical characteristics of each component differ considerably under extremely low temperatures and strong electromagnetic fields.Traditional numerical models include homogenized orthotropic models,which simplify overall field calculation but miss detailed multi-physics aspects,and full refinement(FR)ones that are thorough but computationally demanding.Herein,we propose an extended multi-scale approach for analyzing the multi-field characteristics of an epoxy-impregnated composite magnet assembled by HTS pancake coils.This approach combines a global homogenization(GH)scheme based on the homogenized electromagnetic T-A model,a method for solving Maxwell's equations for superconducting materials based on the current vector potential T and the magnetic field vector potential A,and a homogenized orthotropic thermoelastic model to assess the electromagnetic and thermoelastic properties at the macroscopic scale.We then identify“dangerous regions”at the macroscopic scale and obtain finer details using a local refinement(LR)scheme to capture the responses of each component material in the HTS composite tapes at the mesoscopic scale.The results of the present GH-LR multi-scale approach agree well with those of the FR scheme and the experimental data in the literature,indicating that the present approach is accurate and efficient.The proposed GH-LR multi-scale approach can serve as a valuable tool for evaluating the risk of failure in large-scale HTS composite magnets.

关键词： epoxy-impregnated high-temperature superconducting(HTS)magnet multi-scale method global homogenization(GH) local refinement(LR) multi-field analysis

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Exploring the Core-shell Structure of BaTiO3-based Dielectric Ceramics Using Machine Learning Models and Interpretability Analysis

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 561-569页

作者：孙家乐 XIONG peifeng 郝华 LIU Hanxing State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Material Science and EngineeringInternational School of Material Science and EngineeringWuhan University of TechnologyWuhan 430070China Sanya Science and Education Innovation Park Wuhan University of TechnologySanya 572000China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen ValleyFoshan 528200China

A machine learning(ML)-based random forest(RF)classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO_(3)-based ceramics and their interpretability was analyzed by using Shapley additive explanations(SHAP).An F1-score changed from 0.8795 to 0.9310,accuracy from 0.8450 to 0.9070,precision from 0.8714 to 0.9000,recall from 0.8929 to 0.9643,and ROC/AUC value of 0.97±0.03 was achieved by the RF classification with the optimal set of features containing only 5 features,demonstrating the high accuracy of our model and its high robustness.During the interpretability analysis of the model,it was found that the electronegativity,melting point,and sintering temperature of the dopant contribute highly to the formation of the core-shell structure,and based on these characteristics,specific ranges were delineated and twelve elements were finally obtained that met all the requirements,namely Si,Sc,Mn,Fe,Co,Ni,Pd,Er,Tm,Lu,Pa,and Cm.In the process of exploring the structure of the core-shell,the doping elements can be effectively localized to be selected by choosing the range of features.

关键词： machine learning BaTiO_(3) core-shell structure random forest classifier

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The joint knowledge reasoning model based on knowledge representation learning for aviation assembly domain

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Science China(Technological Sciences) 2024年第1期67卷 143-156页

作者： LIU peifeng QIAN Lu LU Hu XUE Lei ZHAO XingWei TAO Bo State Key Laboratory of Digital Manufacturing Equipment and Technology Department of MechanicalHuazhong University of Science and TechnologyWuhan 430074China School of Transportation and Logistics Engineering Wuhan University of Technology(WHUT)Wuhan 430063China Shanghai Aircraft Manufacturing Co. Ltd.Shanghai 201324China

Knowledge graph technology is widely applied in the domain of general knowledge reasoning with an excellent performance.For fine-grained professional fields,professional knowledge graphs can provide more accurate information in practical industrial scenarios.Based on an aviation assembly domain-specific knowledge graph,the article constructs a joint knowledge reasoning model,which combines a named entity recognition model and a subgraph embedding learning model.When performing knowledge reasoning tasks,the two models vectorize entities,relationships and entity attributes in the same space,so as to share parameters and optimize learning efficiency.The knowledge reasoning model,which provides intelligent question answering services,is able to reduce the assembly error rate and improve the assembly efficiency.The system can accurately solve general knowledge reasoning problems in the assembly process in actual industrial scenarios of general assembly and component assembly under interference-free conditions.Finally,this paper compares the proposed knowledge reasoning model based on knowledge representation learning and the question-answering system based on large-scale pre-trained models.In the application scenario of system functional testing in general assembly,the joint model attains an accuracy rate of 95%,outperforming GPT with 78%accuracy and enhanced representation through knowledge integration with 71%accuracy.

关键词： intelligent manufacturing knowledge graph aviation assembly knowledge representation knowledge-based question an-swering

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Understanding Bridging Sites and Accelerating Quantum Efficiency for Photocatalytic CO_(2) Reduction

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Nano-Micro Letters 2024年第1期16卷 68-84页

作者： Kangwang Wang Zhuofeng Hu peifeng Yu Alina M.Balu Kuan Li Longfu Li Lingyong Zeng Chao Zhang Rafael Luque Kai Yan Huixia Luo School of Materials Science and Engineering State Key Laboratory of Optoelectronic Materials and TechnologiesGuangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesKey Lab of Polymer Composite and Functional MaterialsSun Yat-Sen UniversityNo.135Xingang Xi RoadGuangzhou 510275People’s Republic of China School of Environmental Science and Engineering Sun Yat-Sen UniversityNo.135Xingang Xi RoadGuangzhou 510275People’s Republic of China Departamento de Química Orgánica Universidad de CórdobaCampus Universitario de RabanalesEdificio Marie Curie(C3)14014 CórdobaSpain Center for Refining and Advanced Chemicals King Fahd University of Petroleum and Minerals31261 DhahranSaudi Arabia Universidad ECOTEC Km 13.5 SamborondónEC092302 SamborondónEcuador

We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in S_(v)–In_(2)S_(3)@2H–MoTe_(2).The X-ray absorption near-edge structure shows that the formation of S_(v)–In_(2)S_(3)@2H–MoTe_(2) adjusts the coordination environment via interface engineering and forms Mo–S polarized sites at the interface.The interfacial dynamics and catalytic behavior are clearly revealed by ultrafast femtosecond transient absorption,time-resolved,and in situ diffuse reflectance–Infrared Fourier transform spectroscopy.A tunable electronic structure through steric interaction of Mo–S bridging bonds induces a 1.7-fold enhancement in S_(v)–In_(2)S_(3)@2H–MoTe_(2)(5)photogenerated carrier concentration relative to pristine S_(v)–In_(2)S_(3).Benefiting from lower carrier transport activation energy,an internal quantum efficiency of 94.01%at 380 nm was used for photocatalytic CO_(2)RR.This study proposes a new strategy to design photocatalyst through bridging sites to adjust the selectivity of photocatalytic CO_(2)RR.

关键词： Quantum efficiency Electronic structure Steric interaction Bridging sites CO_(2)reduction

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所有权的自由意志奠基——论康德所有权理论的思路及其政治哲学意义

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复旦学报（社会科学版） 2024年第1期66卷 144-153,165页

作者：汤沛丰暨南大学法学院广州511443

格劳秀斯与洛克分别是现代所有权理论中的契约-先占理论模式和劳动理论模式的奠基人。康德曾是洛克劳动理论模式的追随者,但是在其成熟时期的法哲学著作中放弃了这一模式,转而采用了一种在表面上与格劳秀斯的契约-先占理论模式十分接近... 详细信息

格劳秀斯与洛克分别是现代所有权理论中的契约-先占理论模式和劳动理论模式的奠基人。康德曾是洛克劳动理论模式的追随者,但是在其成熟时期的法哲学著作中放弃了这一模式,转而采用了一种在表面上与格劳秀斯的契约-先占理论模式十分接近的所有权理论。事实上,康德是在与天赋观念论和经验主义立场的所有权理论的论争中阐发出他的学说的,在前述表面上的“接近”背后,隐藏着一个在自由意志之地基上对所有权理论进行重构的计划。据此,原本与各种后天因素纠缠不清的所有权观念,现在被纯化为先天平等的人际关系。基于这一视角,国家既不是福利的监护机构,也不是为了保障公民劳动果实而不得不存在的恶,而是为了使所有权概念得以落实而必须内在于此概念之中的结构性存在。这一共同体形式要求人们重视公民与国家之间的同一性,以及公共舆论对于这种同一性的形成的意义。因此,康德的理论重构计划为崭新的公民自由和共同体观念提供了坚实的哲学基础。

关键词：康德源始取得先占劳动现代国家

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行业比较优势的显现与维持——基于知识溢出和政策干预视角

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系统工程理论与实践 2024年第4期44卷 1129-1148页

作者：许永洪梁佩凤厦门大学经济学院厦门361005

新行业比较优势如何出现以及优势行业如何维持是探究经济增长路径的根本问题.本文使用2010–2020年各省133万家企业注册大数据研究了知识溢出和政策干预对比较优势显现和维持的影响,并从行业特征和省份特征层面进行了多种异质性探讨.研... 详细信息

新行业比较优势如何出现以及优势行业如何维持是探究经济增长路径的根本问题.本文使用2010–2020年各省133万家企业注册大数据研究了知识溢出和政策干预对比较优势显现和维持的影响,并从行业特征和省份特征层面进行了多种异质性探讨.研究发现,知识溢出促进了新行业比较优势的出现,但只有省份内部关联行业之间的知识溢出有利于已有比较优势的维持.全国层面的产业政策没有提升被扶持行业比较优势出现的概率,但增加了重点发展行业的份额.发展比较优势方面,高知识含量和高地理集中度的行业在知识溢出中得到的收益较低;中西部省份和专业化程度高的省份在行业发展时更依赖于省份间知识溢出.进一步分析发现,发达的公路系统有助于增强省份之间知识溢出对行业发展的促进作用,人口净流入高的省份充当知识外溢的角色.省份之间的知识溢出对重点行业发展政策的发挥有正向调节作用.本文的研究为提升行业多样性提供了经验证据.

关键词：发展比较优势维持比较优势知识溢出政策干预

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从工艺父权到漆艺家身份赋权的漆艺传承——基于福州民间新老漆艺聚落的考察

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民族艺术 2024年第3期 135-147页

作者：张培枫福建师范大学传播学院

福州脱胎漆器髹饰技艺是首批国家级非遗之一。通过近6年对福州漆艺从业者共103人的访谈并结合进入漆工坊参与式观察,可探寻福州民间新老漆艺聚落传承中的身份赋权变迁。传统漆艺传承主要在父权控制下。20世纪70年代后由于国有工厂的分... 详细信息

福州脱胎漆器髹饰技艺是首批国家级非遗之一。通过近6年对福州漆艺从业者共103人的访谈并结合进入漆工坊参与式观察,可探寻福州民间新老漆艺聚落传承中的身份赋权变迁。传统漆艺传承主要在父权控制下。20世纪70年代后由于国有工厂的分工需求,在乡村形成民间漆工的老聚落由工艺赋权而非工艺父权带来红利。老聚落衰弱,城乡接合部崛起的新聚落中,新一代从业者的职业规划路线与院校教育带来的漆艺家身份赋权密切相关,同时生存成本高且生存模式不稳定。应提升漆工匠的社会地位并保留漆村空间优势,使传承中的身份赋权多样,方可推动行业可持续发展。

关键词：漆艺传承人工艺身份赋权文化传承

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下肢穿戴式助行器结构设计与仿真分析

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机械传动 2024年第4期48卷 95-102页

作者：王新鄢沛峰华北理工大学轻工学院河北唐山063000 华北理工大学机械工程学院河北唐山063210

设计了一款下肢穿戴式助行器,主要作用是辅助脑卒中、偏瘫等有下肢运动障碍的患者进行日常行走活动。首先,在对下肢运动机制、关节结构以及自由度组成分析的基础上,建立了下肢穿戴式助行器的三维结构模型;应用三维红外动作捕捉系统采集... 详细信息

设计了一款下肢穿戴式助行器,主要作用是辅助脑卒中、偏瘫等有下肢运动障碍的患者进行日常行走活动。首先,在对下肢运动机制、关节结构以及自由度组成分析的基础上,建立了下肢穿戴式助行器的三维结构模型;应用三维红外动作捕捉系统采集正常人行走步态数据,拟合出对应关节角度曲线;建立助行器简化D-H模型,对助行器进行了运动学建模分析;将动作捕捉实验(简称动捕实验)采集的步态数据作为仿真驱动,对助行器进行了运动学仿真验证。结果表明,仿真得到的关节角度变化曲线与实验采集到的角度曲线基本一致,角速度变化曲线与踝关节质心位置变化曲线符合正常人体行走规律,验证了下肢穿戴式助行器的结构设计的合理性。

关键词：下肢穿戴式助行器下肢运动机制动作捕捉实验运动学建模运动学仿真

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冻融循环作用下不同含水率灰土的细微观结构与宏观力学性能

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材料导报 2024年第7期38卷 93-99页

作者：吕晶赵欢张金翼席培峰长安大学建筑工程学院西安710061

为了探明素土和灰土在不同含水率时细微观结构与宏观力学性能受冻融循环的影响规律,开展了素土和灰土在不同含水率时的冻融循环试验、抗压强度试验和核磁共振试验。结果表明,素土和灰土抗压强度均随含水率的提高而降低;素土和灰土抗压... 详细信息

为了探明素土和灰土在不同含水率时细微观结构与宏观力学性能受冻融循环的影响规律,开展了素土和灰土在不同含水率时的冻融循环试验、抗压强度试验和核磁共振试验。结果表明,素土和灰土抗压强度均随含水率的提高而降低;素土和灰土抗压强度在同一含水率时均随着冻融循环次数的增加而降低,冻融循环六次时降低率可达到12次时的80%左右;灰土T_(2)谱信号峰值大于素土,T_(2)谱信号峰值随着灰土比例的提高而增大;不同含水率时素土和灰土T_(2)谱面积在冻融循环次数由3次增大至6次的增长率均明显大于6次至12次。

关键词：土遗址灰土冻融循环含水率力学性能核磁共振

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