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西南山区道路汽车安全预警系统研究与开发

时代汽车 2024年第8期 187-189页

作者：王茂辉张攀锋重庆工商职业学院智能制造与汽车学院重庆市401520

文章主要对西南山区危险的坡路建模采集信息后储存在路侧装置中,研究对象为汽车在山区道路上的安全行驶预警系统,梳理出了影响西南山区道路交通安全因素。通过总结和研究交通事故预警的基本理论。反复查阅文献和研究相关理论,构建山区... 详细信息

文章主要对西南山区危险的坡路建模采集信息后储存在路侧装置中,研究对象为汽车在山区道路上的安全行驶预警系统,梳理出了影响西南山区道路交通安全因素。通过总结和研究交通事故预警的基本理论。反复查阅文献和研究相关理论,构建山区道路安全行驶预警系统和规则。并设计预警系统硬件系统、软件系统,并不断修正提高系统的稳定性和可靠性。

关键词：预警系统可靠性西南山区汽车安全

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Review of zero-net-mass-flux jet and its application in separation flow control

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Science China(Technological Sciences) 2008年第9期51卷 1315-1344页

作者： zhang panfeng WANG JinJun FENG LiHao Institute of Fluid Mechanics Beijing University of Aeronautics and AstronauticsBeijing 100191China

Since the zero-net-mass-flux (ZNMF) jet was first used as a laboratory flow control method in 1990's, it has attracted much attention. The ZNMF jet has unique features such as compact actuator, no requirement for external air supply, complex piping, etc., and becomes a hot topic research subject in fluid mechanics. This review introduces the state of the art in the development of ZNMF jet in the quiescent fluid, the interaction of the ZNMF jet with the cross flow and its application in the separation flow control. The evolution of the vortex ring/pair and the spacial flow structure of the ZNMF in quicent fluid or cross flow are presented, as well as the key parameter effects. At last, the applications of ZNMF jet in the wake control of the circular cylinder, the separation control on the airfoil and the aerodynamic force or moment control on MAV/UAV are presented.

关键词： zero-net-mass-flux jet quiescent fluid cross flow separation control

Experimental investigation on the flow structure over a simplified Papilio Ulysses model

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Chinese Science Bulletin 2009年第6期54卷 1026-1031页

作者： HU Ye WANG JinJun zhang panfeng zhang Cao Fluid Mechanics Institute Beijing University of Aeronautics and Astronautics Beijing 100191 China Corresponding author (email: jjwang@***)

The aerodynamic characteristics of butterflies, especially those which can migrate overseas, have received a great deal of attention because they have larger-scale wingspans and lower flapping frequencies than other insects such as drosophilae and bees. The objective of this work is to investi-gate the flow structures over a simplified model of Papilio Ulysses, one kind of migratory butterflies, through hydrogen bubble visualizations, and leading-edge vortices, wing-tip vortices, separation bub-bles and horseshoe vortex wake are observed. Moreover, the variations of these structures with the angle of attack are discussed in detail. A new type of leading-edge vortices which resembles the inversed Chinese character "八" is observed in the experiment.

关键词：流场结构凤蝶模型实验空气动力特性流动结构可视化马蹄涡

Extreme Temperature Change of the Last 110 Years in Changchun,Northeast China

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Advances in Atmospheric Sciences 2020年第4期37卷 347-358,I0002-I0006页

作者： Xiujing YU Guoyu REN panfeng zhang Jingbiao HU Ning LIU Jianping LI Chenchen zhang Jilin Climate Center Changchun 130062China Department of Atmospheric Science School of Environmental StudiesChina University of GeosciencesWuhan 430074China Laboratory for Climate Studies National Climate CenterChina Meteorological AdministrationBeijing 100081China Jilin Province Weather Modification Office Changchun 130062China Institute of Meteorological Sciences of Jilin Province Changchun 130062China

In China and East Asia,the long-term continuous observational data at daily resolution are insufficient,and thus there is a lack of good understanding of the extreme climate variation over the last 100 years *** this study,the extreme temperature indices defined by ETCCDI(Expert Team on Climate Change Detection and Indices)and local meteorological administrations were analyzed for Changchun City,Northeast China,by using the daily maximum temperature(Tmax)and daily minimum temperature(Tmin)over 1909?*** results showed that extreme cold events,such as cold days,cold nights,frost days,icing days,and low temperature days,decreased significantly at rates of?0.41 d(10 yr)^?1,?1.45 d(10 yr)^?1,?2.28 d(10 yr)^?1,?1.16 d(10 yr)?1 and?1.90 d(10 yr)^?1,*** nights increased significantly at a rate of 1.71 d(10 yr)^?1,but warm days decreased slightly and the number of high temperature days decreased at a rate of?0.20 d(10 yr)?*** frequency of cold surge events increased significantly at a rate of 0.25 d(10 yr)^?1,occurring mainly from the mid-1950s to *** average Tmax,average Tmin and extreme Tmin increased at rates of 0.09℃(10 yr)^?1,0.36℃(10 yr)^?1 and 0.54℃(10 yr)^?1,respectively;and extreme Tmax decreased significantly at a rate of?0.17℃(10 yr)^?*** 1909?2018,1951?2018 and 1979?2018,the indices related to cold events decreased,while the trends of the indices related to warm events were different for different periods.

关键词： extreme temperature climate change long-term series observation Changchun Northeast China

Game theory based finite-time formation control using artificial potentials for tethered space net robot

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Chinese Journal of Aeronautics 2024年第8期37卷 358-372页

作者： Yifeng MA Yizhai zhang panfeng HUANG Ya LIU Fan zhang The Research Center for Intelligent Robotics School of AstronauticsNorthwestern Polytechnical UniversityXi’an 710072China School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The Tethered Space Net Robot(TSNR)is an innovative solution for active space debris capture and *** large envelope and simple capture method make it an attractive option for this ***,capturing maneuverable debris with the flexible and elastic underactuated net poses significant *** address this,a novel formation control method for the TSNR is proposed through the integration of differential game theory and robust adaptive control in this ***,the trajectory of the TSNR is obtained through the solution of a real-time feedback pursuit-evasion game with a dynamic target,where the primary condition is to ensure the stability of the ***,to minimize tracking errors and maintain a specific configuration,a robust adaptive formation control scheme with Artificial Potential Field(APF)based on a Finite-Time Convergent Extended State Observer(FTCESO)is *** proposed control method has a key advantage in suppressing complex oscillations by a new adaptive law,thus precisely maintaining the ***,numerical simulations are performed to demonstrate the effectiveness of the proposed scheme.

关键词： Game theory Formation control Artificial potential field Relative distance constraint Tethered space net robot(TSNR)

Lift enhancement method by synthetic jet circulation control

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Science China(Technological Sciences) 2012年第9期55卷 2585-2592页

作者： zhang panfeng YAN Bo DAI ChenFeng State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Institute of Fluid Mechanics Beijing University of Aeronautic and AstronauticsBeijing 100191China Key Laboratory of Fluid Mechanics Ministry of EducationBeijing 100191China

A novel circulation control technique is proposed to overcome the shortcomings of blowing jet circulation control, which uses the synthetic jet as the actuator and avoids the limitation about air supply requirement. The effectiveness of synthetic jet circulation control to enhance lift of NCCR1510-7067N airfoil is confirmed by solving the 2-D unsteady Reynolds-averaged Na- vier-Stokes equations. The aerodynamic characteristics and the flow structure （especially close to the trailing edge） of NCCR 1510-7067N airfoil at zero angle of attack are also presented to discuss the mechanism of lift enhancement of the airfoil with synthetic jet circulation control. The results indicate that the synthetic jet can effectively delay the separation point on the airfoil trailing edge and increase the circulation and lift of the airfoil by Coanda effect. The numerical simulation results demonstrate that the lift augmentation efficiency with synthetic jet circulation control reaches △C1/Cμ,=114 in the present study, which is much higher than the value 12.1 in the case with steady blowing jet circulation control.

关键词： synthetic jet circulation control numerical simulation lift enhancement

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北疆地区城市化对地面气温趋势的影响

沙漠与绿洲气象 2024年第5期18卷 99-105页

作者：张爱英任国玉薛晓颖索南看卓张盼峰张思齐北京市气象服务中心北京100089 中国气象局气候研究开放实验室/国家气候中心北京100081 中国地质大学(武汉)环境学院大气科学系湖北武汉430074 中国气象科学研究院灾害天气国家重点实验室北京100081 青海大学高原生态与农业国家重点实验室青海西宁810000 吉林师范大学地理科学与旅游学院吉林四平136000

基于前期研究发展的气温参考站数据和分析方法,对北疆地区国家基准气候站、国家基本气象站和4个代表性城镇站记录的地面气温序列趋势变化特征进行对比分析,探讨造成北疆地区城镇站气温序列中城市化影响特殊性的可能原因。研究表明:北疆... 详细信息

基于前期研究发展的气温参考站数据和分析方法,对北疆地区国家基准气候站、国家基本气象站和4个代表性城镇站记录的地面气温序列趋势变化特征进行对比分析,探讨造成北疆地区城镇站气温序列中城市化影响特殊性的可能原因。研究表明:北疆地区城镇站和基准、基本站与全国其他地区相比,其城市化影响表现为明显的气温负趋势,基准、基本站年平均城市化影响达到-0.05℃/10 a,城市化贡献率为-14.1%,春、夏和秋季城市化影响均为显著的负趋势,秋季最明显,冬季城市化影响表现出不显著的正趋势;乌苏、石河子、克拉玛依和乌鲁木齐4个城镇站年平均城市化影响为-0.19~-0.07℃/10 a,城市化贡献率为-100%~-23.3%。

关键词：城市化影响城镇站北疆凉岛效应绿洲化

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Dynamic Update Scheme of Spectrum Information Based on Spectrum Opportunity Incentive in the Database-Assisted Dynamic Spectrum Management

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China Communications 2024年第3期21卷 75-90页

作者： zhang Yu Chen Yong He panfeng Cai Yueming Sixty-third Research Institute National University of Defense TechnologyNanjing 210007China College of Communications Engineering Army of Engineering UniversityNanjing 210007China

To solve the problem of delayed update of spectrum information(SI) in the database assisted dynamic spectrum management(DB-DSM), this paper studies a novel dynamic update scheme of SI in DB-DSM. Firstly, a dynamic update mechanism of SI based on spectrum opportunity incentive is established, in which spectrum users are encouraged to actively assist the database to update SI in real time. Secondly, the information update contribution(IUC) of spectrum opportunity is defined to describe the cost of accessing spectrum opportunity for heterogeneous spectrum users, and the profit of SI update obtained by the database from spectrum allocation. The process that the database determines the IUC of spectrum opportunity and spectrum user selects spectrum opportunity is mapped to a Hotelling model. Thirdly, the process of determining the IUC of spectrum opportunities is further modelled as a Stackelberg game by establishing multiple virtual spectrum resource providers(VSRPs) in the database. It is proved that there is a Nash Equilibrium in the game of determining the IUC of spectrum opportunities by VSRPs. Finally, an algorithm of determining the IUC based on a genetic algorithm is designed to achieve the optimal IUC. The-oretical analysis and simulation results show that the proposed method can quickly find the optimal solution of the IUC, and ensure that the spectrum resource provider can obtain the optimal profit of SI update.

关键词： database-assisted dynamic spectrum management Hotelling information updating contribution spectrum information updating Stackelberg

The effect of actuation frequency on the plasma synthetic jet

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Science China(Technological Sciences) 2011年第11期54卷 2945-2950页

作者： zhang panfeng DAI ChenFeng LIU AiBing WANG JinJun Institute of Fluid Mechanics Beijing University of Aeronautics and Astronautics Beijing 100191 China Key Laboratory of Fluid Mechanics Ministry of Education Beijing 100191 China

The flow induced by plasma synthetic jet actuator was simulated through solving the Reynolds-averaged Navier-Stokes equations augmented by body force phenomenological plasma *** effect of actuation frequency on the plasma synthetic jet was examined by case *** numerical results present that with the actuation frequency increasing,the stream-wise distance of the adjacent vortex pairs induced by the actuator decreases monotonically,which is the same as the situation of the velocity fluctuations field caused by the vortex *** the actuation frequency is 60 Hz,the vortex pairs formed during the adjacent actuation periods merge together quickly,and the flow structure in the downstream region is more close to that of the steady *** actuation frequency has no visible influence on the time-averaged flow field of plasma synthetic ***,when the actuation frequency is relatively low(f<40 Hz),the momentum flux close to the actuator increases with the actuation frequency increasing,which is contrary to the situation in the far field from the wall.

关键词： plasma actuator synthetic jet numerical simulation actuation frequency