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Large eddy simulation study of 3D wind field in a complex mountainous area under different boundary conditions

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第7期25卷 541-556页

作者： yan LI Lei yan xuhui HE School of Civil Engineering Central South UniversityChangsha410075China National Engineering Research Center for High-speed Railway Construction Changsha410075China Hunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structures Changsha410075China

Large eddy simulations generally are used to predict 3D wind field characteristics in complex mountainous *** simulation boundary conditions,such as the height and length of the computational domain or the characteristics of inflow turbulence,can significantly impact the quality of *** this study,we examined these boundary conditions within the context of the mountainous terrain around a long-span cable-stayed bridge using a wind tunnel *** sizes of computational domains and turbulent incoming wind velocities were used in large eddy *** results show that when the height of the computational domain is five times greater than the height of the terrain model,there is minimal influence from the top wall on the wind field characteristics in this complex mountainous *** the length of the wake region of the computational domain has negligible effects on the wind *** in the inlet boundary reduces the length of the wake region on a leeward hill with a low slope,but has less impact on the mean wind velocity of steep hills.

关键词： Large eddy simulation(LES) Spectral representation method Recycling method High mountainous canyon Wind characteristics Atmospheric boundary layer Computational domain

Multi-field Coupled Inverse Hall–Petch Relations for Ferroelectric Nanocrystals

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Acta Mechanica Solida Sinica 2024年第1期37卷 139-147页

作者： Xiaodong Zhang Wei yan xuhui Lou Yujun Chen Zhihong Zhou Qingyuan Wang Lianhua Ma Xiaobao Tian Non-Destructive Testing Laboratory School of Quality and Technical SupervisionHebei UniversityBaoding 071002China AVIC Huiyang Aviation Propeller Co. LtdBaoding 071051China Department of Mechanics and Engineering Sichuan UniversityChengdu 610065China Yibin Institute of Industrial Technology Sichuan University Yibin ParkYibin 644000China Research Institute of Interdisciplinary Sciences(RISE) Dongguan University of TechnologyDongguan 523808China School of Materials Science and Engineering Dongguan University of TechnologyDongguan 523808China

Tailoring grain size can improve the strength of polycrystals by regulating the proportion of grains to grain boundaries and the interaction *** the grain size decreases to the nanoscale,the deformation mechanism in polycrystals shifts from being primarily mediated by dislocations to deformation occurring within the grains and grain ***,the mechanism responsible for fine-grain strengthening in ferroelectric materials remains unclear,primarily due to the complex multi-field coupling effect arising from spontaneous *** molecular dynamics simulations,we investigate the strengthening mechanism of barium titanate(BaTiO3),with extremely fine-grain *** material exhibits an inverse Hall–Petch relationship between grain size and strength,rooting in the inhomogeneous concentration of atomic strain and grain ***,we present a theoretical model to predict the transition from the inverse Hall–Petch stage to the Hall–Petch stage based on strength variations with size,which aligns well with the simulation *** has been found that the piezoelectric properties of the BaTiO3 are affected by polarization domain switching at various grain *** study enhances our understanding of the atomic-scale mechanisms that contribute to the performance evolution of fine-grain nano-ferroelectric *** also provides valuable insights into the design of extremely small-scale ferroelectric components.

关键词： Ferroelectrics Multi-field coupling Molecular dynamics Fine-grain reinforcement Inverse Hall-Petch effect

A framework for stochastic estimation of electric vehicle charging behavior for risk assessment of distribution networks

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Frontiers in Energy 2020年第2期14卷 298-317页

作者： Salman HABIB Muhammad Mansoor KHAN Farukh ABBAS Muhammad NUMAN Yaqoob ALI Houjun TANG xuhui yan Key Laboratory of Control of Power Transmission and Transformation of the Ministry of Education School of ElectronicInformation and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Electrical Engineering University of Engineering and TechnologyLahore 54890Pakistan State Grid Liyang Power Supply Company Liyang 213300China

Power systems are being transformed to enhance the *** paper contributes to the knowledge regarding the operational process of future power networks by developing a realistic and stochastic charging model of electric vehicles(EVs).Large-scale integration of EVs into residential distribution networks(RDNs)is an evolving issue of paramount significance for utility *** voltages prevent effective and reliable operation of *** EV loads require a stochastic approach to predict EVs charging demand,consequently,a probabilistic model is developed to account several realistic aspects comprising charging time,battery capacity,driving mileage,state-of-charge,traveling frequency,charging power,and time-of-use mechanism under peak and off-peak charging *** attempt is made to examine risks associated with RDNs by applying a stochastic model of EVs charging *** output of EV stochastic model obtained from Monte-Carlo simulations is utilized to evaluate the power quality parameters of *** equipment capability of RDNs must be evaluated to determine the potential *** specifications of RDNs including voltage unbalance factor,voltage behavior,domestic transformer limits and feeder losses are assessed in context to EV charging scenarios with various charging power levels at different penetration ***,the impact assessment of EVs on RDNs is found to majorly rely on the type and location of a power network.

关键词： electric vehicles(EVs) residential distribution networks(RDNs) voltage unbalance factor(VUF) state-of charge(SOC) time-of-use(TOU)

Clinical management of a rare melanoma case arising from congenital melanocytic nevus

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Genes & Diseases 2024年第3期11卷 79-82页

作者： Ruixin Jiang yan Wang xuhui Ma Xinyang Xuanyuan yanjie Zhang Bin Jiang Weizhen Zhang Hanlin Zeng Department of Oncology Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 201900China Department of Oncology The Third People's Hospital of ZhengzhouZhengzhouHenan 450000China Department of Oral&Maxillofacial-Head and Neck Oncology Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 200125China Shanghai Institute of Precision Medicine Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai200125China Department of Dermatology Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 200000China

Congenital melanocytic nevi(CMNs)are skin lesions characterized by benign melanocytic proliferations and present at birth or shortly *** and giant CMNs,with a projected adult size≥20 cm and 40 cm in diameter respectively,are more likely to develop into malignant *** most cases,melanoma arising from congenital melanocytic nevus(CMN)is particularly aggressive.

关键词： melanoma congenital melan

基于同构思想的模型方法研究——从科学哲学视野看

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科技管理研究 2009年第6期29卷 548-550页

作者：闫旭晖华南师范大学公共管理学院广东广州510006

模型方法是一种基于数学同构映射思想建立起来的分析方法,它在科学理论与现实原型之间充当一个认知的桥梁。文章在研究模型方法的逻辑本质和理论基础上,对模型方法在科学理论的建构及其对现代科学跨学科认知活动的作用和意义进行了研究。

关键词：模型方法同构科学理论跨学科

复杂性科学视野下的组织管理本质研究——基于复杂系统演变的分析

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科技管理研究 2009年第7期29卷 310-313页

作者：闫旭晖华南师范大学系统科学与系统管理研究中心广东广州510006

在复杂系统演变过程中存在着三种演变规律:一是封闭式系统向无序演进的熵增定律;二是开放式系统向有序演进的自组织与进化机制;三是混沌系统向不确定演进的规律。通过分析这三种演变规律的作用机理和内在联系,从复杂性科学的角度进一步... 详细信息

在复杂系统演变过程中存在着三种演变规律:一是封闭式系统向无序演进的熵增定律;二是开放式系统向有序演进的自组织与进化机制;三是混沌系统向不确定演进的规律。通过分析这三种演变规律的作用机理和内在联系,从复杂性科学的角度进一步阐明现代组织管理的本质意义。

关键词：复杂系统演变规律管理本质

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企业核心竞争力的难以模仿性的系统分析

科技管理研究 2007年第9期27卷 203-204,192页

作者：闫旭晖华南师范大学公共管理学院广东广州510631

企业核心竞争力难以模仿性的研究是许多企业家所关注的复杂性问题。本文用系统思想从"突现与层级"、"通讯与控制"和"进化与自组织"三个原理对核心竞争力形成和作用过程的机理和条件作了分析,指出核心竞争力形成和作用过程的复杂性、非... 详细信息

企业核心竞争力难以模仿性的研究是许多企业家所关注的复杂性问题。本文用系统思想从"突现与层级"、"通讯与控制"和"进化与自组织"三个原理对核心竞争力形成和作用过程的机理和条件作了分析,指出核心竞争力形成和作用过程的复杂性、非线性和不可还原性是核心竞争力难以模仿的原因。

关键词：系统思想企业核心竞争力难以模仿性复杂性问题

基于系统思想方法论创造性地解决组织复杂性问题的研究

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科技管理研究 2008年第7期28卷 461-463,504页

作者：闫旭晖华南师范大学公共管理学院广东广州510631

系统思想方法论是帮助组织管理者有效解决现实问题环境为目的的一套方法体系,不同系统方法论根据其所属的社会范式都有一定局限性。创造性整体论采用了社会范式理论、批判思想意识和多元主义系统观把不同系统方法论创造性地统一到同一... 详细信息

系统思想方法论是帮助组织管理者有效解决现实问题环境为目的的一套方法体系,不同系统方法论根据其所属的社会范式都有一定局限性。创造性整体论采用了社会范式理论、批判思想意识和多元主义系统观把不同系统方法论创造性地统一到同一理论框架下,它使组织管理者较容易地把握和运用各种系统方法论来解决复杂的组织问题。本文阐述创造性整体论在解决组织中复杂问题环境的作用和意义,并探索该理论在解决现实复杂问题环境中的应用。

关键词：系统思想方法论创造性解决复杂性问题

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现代企业发展信息共享战略的软系统思考

科技管理研究 2011年第6期31卷 38-41页

作者：闫朝晖闫旭晖广东金融学院继续教育学院广东广州510521 华南师范大学公共管理学院广东广州510630

信息时代下企业面临的信息不仅无处不在,同时还具有丰富的内涵。信息的丰富内涵与人们所处的社会和文化背景紧密相关,它体现在现实世界中人们所具有的多元世界观和价值观。从社会和文化的视野考察了信息与传统组织理论的内在联系,指出传... 详细信息

信息时代下企业面临的信息不仅无处不在,同时还具有丰富的内涵。信息的丰富内涵与人们所处的社会和文化背景紧密相关,它体现在现实世界中人们所具有的多元世界观和价值观。从社会和文化的视野考察了信息与传统组织理论的内在联系,指出传统"目标导向"管理范式不足以应对信息丰富的社会和文化意义,企业在构建信息共享的机制设计中必须引入"关系维护"管理范式,据此探讨了以软系统方法论为指导思想发展企业信息共享平台的研究进路,该进路提出建模、比较和讨论是实现理解信息和共享信息三项关键活动。

关键词：信息共享关系维护软系统方法论