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Resonance mechanism of flapping wing based on fluid structure interaction simulation

Chinese Journal of Aeronautics 2024年第5期37卷 243-262页

作者： Yueyang GUO Wenqing YANG Yuanbo dong dong XUE National Key Laboratory of Science and Technology on Aerodynamic Design and Research School of AeronauticsNorthwestern Polytechnical UniversityXi'an 710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China Yangtze River Delta Research Institute of Northwestern Polytechnical University Taicang 215400China

Certain insect species have been observed to exploit the resonance mechanism of their *** order to achieve resonance and optimize aerodynamic performance,the conventional approach is to set the flapping frequency of flexible wings based on the Traditional Structural Modal(TSM)***,there exists controversy among researchers regarding the relationship between frequency and aerodynamic *** that the structural response of wings can be influenced by the surrounding air vibrations,an analysis known as Acoustic Structure Interaction Modal(ASIM)is introduced to calculate the resonant *** this study,Fluid Structure Interaction(FSI)simulations are employed to investigate the aerodynamic performance of flapping wings at modal frequencies derived from both TSM and ASIM *** performance is evaluated for various mass ratios and frequency ratios,and the findings indicate that the deformation and changes in vortex structure exhibit similarities at mass ratios that yield the highest aerodynamic ***,the flapping frequency associated with the maximum time-averaged vertical force coefficient at each mass ratio closely aligns with the ASIM frequency,as does the frequency corresponding to maximum ***,the ASIM analysis can provide an effective means for predicting the optimal flapping frequency for flexible ***,it enables the prediction that flexible wings with varying mass ratios will exhibit similar deformation and vortex structure *** paper offers a fresh perspective on the ongoing debate concerning the resonance mechanism of Flexible Flapping Wings(FFWs)and proposes an effective methodology for predicting their aerodynamic performance.

关键词： Flexible Flapping Wing(FFW) Acoustic Structure Interaction Modal(ASIM) Fluid Structure Interaction(FSI) Resonance mechanism Aerodynamic performance

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SSL协议的初步研究和应用

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仪器仪表与分析监测 2010年第2期 15-20页

作者：董智鹏中国科学院文献情报中心北京100190

分析研究SSL协议的原理和工作流程,给出SSL协议应用的两个实例:一是在Web服务器上配置SSL协议以实现浏览器和Web服务器间的安全通信;二是设计和实现一个基于SSL协议的简单的网络聊天程序Demo。

关键词：安全套接层 Java安全套接字扩展 OPENSSL 网络安全

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Finite-time Prescribed Performance Time-Varying Formation Control for Second-Order Multi-Agent Systems With Non-Strict Feedback Based on a Neural Network Observer

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 1039-1050页

作者： Chi Ma Dianbiao dong the School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an 710072China

This paper studies the problem of time-varying formation control with finite-time prescribed performance for nonstrict feedback second-order multi-agent systems with unmeasured states and unknown *** eliminate nonlinearities,neural networks are applied to approximate the inherent dynamics of the *** addition,due to the limitations of the actual working conditions,each follower agent can only obtain the locally measurable partial state information of the leader *** address this problem,a neural network state observer based on the leader state information is ***,a finite-time prescribed performance adaptive output feedback control strategy is proposed by restricting the sliding mode surface to a prescribed region,which ensures that the closed-loop system has practical finite-time stability and that formation errors of the multi-agent systems converge to the prescribed performance bound in finite ***,a numerical simulation is provided to demonstrate the practicality and effectiveness of the developed algorithm.

关键词： Finite-time control multi-agent systems neural network prescribed performance control time-varying formation control

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Decision and Coordination in a Closed-Loop Supply Chain with Product Recycling Under Different Low-Carbon Regulations

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Journal of the Operations Research Society of China 2024年第3期12卷 695-728页

作者： Qian-dong dong Hai-Wen Xu School of Management and Engineering Nanjing UniversityNanjing210093JiangsuChina School of Science Civil Aviation Flight University of ChinaGuanghan618307SichuanChina

The implementation of recycling activity is of great significance to closed-loop supply chain ***’environmental awareness and governmental subsidy are considered in the two-echelon closed-loop supply *** types of decision-making structures are proposed under different carbon emission *** subsidy sharing mechanism is designed to resolve the channel members’conflict caused by double *** paper provides insight into the effect of environmental awareness and government subsidy under different low-carbon regulations on the supply chain benefit and social welfare via the game *** analysis results display that the government subsidy and subsidy sharing mechanism are profitably beneficial to the whole supply chain and social ***,a noteworthy result reveals that social welfare is not always directly proportional to consumers’environmental *** welfare decreases slightly with the increase in consumers’environmental awareness when consumers’environmental awareness is ***,social welfare will be significantly improved when consumers’environmental awareness increases beyond a certain threshold.

关键词： Closed-loop supply chain Recycling Coordination Social welfare Game theory Carbon emissions

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Copper slag assisted coke reduction of phosphogypsum for sulphur dioxide preparation

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Chinese Journal of Chemical Engineering 2024年第1期65卷 43-53页

作者： dong Ma Qinhui Wang State Key Laboratory of Clean Energy Utilization Institute for Thermal Power EngineeringZhejiang UniversityHangzhou 310027China

The reduction of phosphogypsum(PG)to lime slag and SO_(2)using coke can effectively alleviate the environmental problems caused by ***,the PG decomposition temperature remains high and the product yield remains *** adding additives,the decomposition temperature can be further reduced and PG decomposition rate and product yield can be ***,the use of current additives such as Fe_(2)O_(3)and SiO_(2)brings the problem of increasing economic ***,it is proposed to use solid waste copper slag(CS)as a new additive to reduce PG to prepare SO2,which can reduce the cost and meet the environmental benefits at the same *** effects of proportion,temperature and thermostatic time on PG decomposition are investigated by experimental and kinetic analysis combined with FactSage thermodynamic calculations to optimize the roasting ***,the reaction mechanism is *** is found that adding CS to the coke and PG system can increase the rate of PG decomposition and SO_(2)yield while lowering the PG decomposition *** example,when the CS/PG mass ratio increases from 0 to 1,PG decomposition rate increases from 83.38%to 99.35%,SO_(2)yield increases from 78.62%to 96.81%,and PG decomposition temperature decreases from 992.4℃to 949.6℃.The optimal reaction parameters are CS/PG mass ratio of 1,Coke/PG mass ratio of 0.06 at 1100℃for 20 min with 99.35%PG decomposition rate and 96.81%SO_(2) *** process proceeds according to the following reactions:2CaSO_(4)+ 0.7C + 0.8Fe_(2)SiO_(4)→0.8Ca_(2)SiO_(4)+ 0.2Ca_(2)Fe_(2)O_(5)+ 0.4Fe_(3)O_(4)+2SO_(2)+ 0.7CO_(2)Finally,a process for decomposing PG with coke and CS is proposed.

关键词： Phosphogypsum Sulfur dioxide Copper slag Fluidized-bed Reduction Waste treatment

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Resilient control of flexible hypersonic vehicles against unmatched distributed faults

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Chinese Journal of Aeronautics 2024年第5期37卷 60-70页

作者： dong ZHAO Wenjing REN School of Artificial Intelligence Anhui UniversityHefei 230601China Key Laboratory of System Control and Information Processing Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009China

This paper studies a robust fault compensation and vibration suppression problem of flexible hypersonic *** controlled plant is represented by a cascade system composed of a nonlinear Ordinary Differential Equation(ODE)and an Euler-Bernoulli Beam Equation(EBBE),in which the vibration dynamics is coupled with the rigid dynamics and suffers from distributed faults.A state differential transformation is introduced to transfer distributed faults to an EBBE boundary and a longitudinal dynamics is refined by utilizing T-S fuzzy IF-THEN rules.A novel T-S fuzzy based fault-tolerant control algorithm is developed and related stability conditions are *** robust exponential stability and well-posedness are proved by using the modified l_(0)-semigroup based Lyapunov direct approach.A simulation study on the longitudinal dynamics of flexible hypersonic vehicles effectively verifies the validity of the developed theoretical results.

关键词： Flexible hypersonic vehicles ODE-EBBE cascade Robust exponential stability Unmatched distributed fault compensation Vibration suppression

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Modeling urban scale human mobility through big data analysis and machinelearning

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Building Simulation 2024年第1期17卷 3-21页

作者： Yapan Liu Bing dong Department of Mechanical&Aerospace Engineering Syracuse University263 Link HallSyracuseNY 13244USA

In the United States,the buildings sector consumes about 76%of electricity use and 40% of all primary energy use and associated greenhouse gas *** behavior has drawn increasing research interests due to its impacts on the building energy ***,occupant behavior study at urban scale remains a challenge,and very limited studies have been *** an effort to couple big data analysis with human mobility modeling,this study has explored urban scale human mobility utilizing three months Global Positioning System(GPS)data of 93,o00 users at Phoenix Metropolitan *** research extracted stay points from raw data,and identified users'home,work,and other locations by Density-Based Spatial Clustering ***,daily mobility patterns were constructed using different types of *** propose a novel approach to predict urban scale daily human mobility patterns with 12-hour prediction horizon,using Long Short-Term Memory(LSTM)neural network *** shows the developed models achieved around 85%average accuracy and about 86%mean *** developed models can be further applied to analyze urban scale occupant behavior,building energy demand and flexibility,and contributed to urban planning.

关键词： urban human mobility big data analysis urban scale occupant behavior recurrent neural networks

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高碳铬轴承钢网状碳化物评价标准的对比分析

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金属热处理 2021年第6期46卷 27-30页

作者：庄权王雨田董智鹏瓦房店轴承集团有限责任公司辽宁瓦房店116300

对网状碳化物评价标准GB/T 18254-2016、SEP 1520-1998进行了对比,分析两者评级放大倍数、评级图片谱系以及评级原则等差异对质量判定的影响。结果表明,与GB/T 18254-2016标准相比,SEP 1520-1998标准的图谱设置、检测及评价方法更全面... 详细信息

对网状碳化物评价标准GB/T 18254-2016、SEP 1520-1998进行了对比,分析两者评级放大倍数、评级图片谱系以及评级原则等差异对质量判定的影响。结果表明,与GB/T 18254-2016标准相比,SEP 1520-1998标准的图谱设置、检测及评价方法更全面反映整体实物水平、更具有可操作性。大型轴承零件由于表层和心部冷却速度差异,应根据有效厚度对表层和心部网状碳化物级别应分别提出控制要求。

关键词：高碳铬轴承钢网状碳化物评定标准对比分析

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基于卷积神经网络的高分辨率遥感影像目标检测方法研究

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测绘学报 2023年第9期52卷 1613-1613页

作者：董志鹏自然资源部第一海洋研究所山东青岛266061

高分辨率遥感影像目标检测作为高分对地观测系统中影像信息自动提取及分析理解的重要内容,对高分对地观测系统应用价值的发挥具有重要影响。卷积神经网络作为最热门的深度学习模型,由于其可以根据海量数据和标注自行进行有效图像特征提... 详细信息

高分辨率遥感影像目标检测作为高分对地观测系统中影像信息自动提取及分析理解的重要内容,对高分对地观测系统应用价值的发挥具有重要影响。卷积神经网络作为最热门的深度学习模型,由于其可以根据海量数据和标注自行进行有效图像特征提取和学习,在训练数据充足的情况下,模型具有良好的泛化能力,能够在复杂多变的条件下依然保持良好的稳健性和普适性。因此,基于卷积神经网络的目标检测架构被相继提出,但现有网络架构多是针对自然图像设计的,相对于自然图像,高分辨率遥感影像存在背景更加复杂、目标尺度更小、同类目标尺度变化更大和影像尺寸更大等特点;将这些网络架构直接用于高分辨率遥感影像目标检测会存在网络目标建议框尺度不匹配,待检影像相对于网络输入过大,以及缺乏训练数据等问题。针对上述问题,论文系统性地开展基于卷积神经网络的高分辨遥感影像目标检测方法研究。主要研究内容如下。

关键词：卷积神经网络高分辨率遥感影像对地观测系统海量数据网络架构图像特征提取目标检测信息自动提取

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Web3.0文化数字资产监管:域外模式与中国路径

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南京社会科学 2024年第5期 131-143,154页

作者：臧志彭董美孝同济大学人文学院上海200092 北京大学文化产业研究院北京100091

人类社会正在从以移动互联网为主体的Web2.0向以区块链技术为支撑、以数字资产为价值基础的Web3.0加速转型升级。为了有效应对Web3.0文化数字资产领域近几年来出现的诸多乱象,妥善保护创作者和消费者的合法权益,推动文化数字资产在数字... 详细信息

人类社会正在从以移动互联网为主体的Web2.0向以区块链技术为支撑、以数字资产为价值基础的Web3.0加速转型升级。为了有效应对Web3.0文化数字资产领域近几年来出现的诸多乱象,妥善保护创作者和消费者的合法权益,推动文化数字资产在数字经济中的健康发展,亟需构建适应Web3.0未来产业的文化数字资产监管体系。基于对域外数字资产的监管框架研究发现,各国对于数字资产目前主要采取审慎型、分类型与协同型三种类型监管模式。中国Web3.0文化数字资产监管框架的建立,应秉持包容审慎的态度,精确把握文化数字资产监管的关键环节,从厘清文化数字资产交易平台分级分类准入标准、明确监管部门职责分配与协作机制以及文化数字资产交易平台双重自律义务等方面着力,为数字文化内容创作者营造有利的发展环境,从而促进文化数字资产的健康可持续发展和文化新质生产力的形成。

关键词： Web3.0 文化数字资产 NFT 监管

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