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On-ramp merging strategy for connected and automated vehicles based on complete information static game

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Journal of Traffic and Transportation Engineering(English Edition) 2021年第4期8卷 582-595页

作者： Haigen Min yukun Fang Xia wu Guoyuan wu Xiangmo Zhao School of Information Engineering Chang'an UniversityXi'an 710064China Department of Electrical and Computer EngineeringUniversity of CaliforniaRiversideCA 92521USA

Improper handling of vehicle on-ramp merging may hinder traffic flow and contribute to lower fuel economy,while also increasing the risk of collisions.Cooperative control for connected and automated vehicles(CAVs)has the potential to significantly reduce negative environmental impact while also improve driving safety and traffic efficiency.Therefore,in this paper,we focus on the scenario of CAVs on-ramp merging and propose a centralized control method.Merging sequence(MS)allocation and motion planning are two key issues in this process.To deal with these problems,we first propose an MS allocation method based on a complete information static game whereby the mixed-strategy Nash equilibrium is calculated for an individual vehicle to select its strategy.The on-ramp merging problem is then formulated as a bi-objective(total fuel consumption and total travel time)optimization problem,to which optimal control based on Pontryagin's minimum principle(PMP)is applied to solve the motion planning issue.To determine the proper parameters in the bi-objective optimization problem,a varying-scale grid search method is proposed to explore possible solutions at different scales.In this method,an improved quicksort algorithm is designed to search for the Pareto front,and the(approximately)unbiased Pareto solution for the bi-objective optimization problem is finally determined as the optimal solution.The proposed on-ramp merging strategy is validated via numerical simulation,and comparison with other strategies demonstrates its effectiveness in terms of fuel economy and traffic efficiency.

关键词： Connected and automated vehicles On-ramp merging Complete information static game Optimal control Varying-scale grid search

Atomically dispersed Fe-Ni dual sites in heteroatom doped carbon tyres for efficient oxygen electrocatalysis in rechargeable Zn-Air battery

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能源化学:英文版 2023年第8期83卷 264-274,I0008页

作者： Zili Wang Caiyun Li yukun Liu Yu wu Sen Zhang Chao Deng Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationCollege of chemistry and chemical engineeringHarbin Normal UniversityHarbin 150025HeilongjiangChina College of Material Science and Chemical Engineering Harbin Engineering UniversityHarbin 150001HeilongjiangChina

The electronic and functional synergies between the twin metal centers make dual single-atom catalysts(DACs) attractive for oxygen electrocatalysis. The catalytic activities of DACs are largely decided by their surrounding micro-environment and supporting substrates. Modulating the micro-environment as well as engineering the efficient support is challenging tasks. Moreover, both are critical to optimizing the performance of DACs. Herein, a novel bio-cooperative strategy is developed to synthesize Fe Ni-DAC wherein Fe-Ni dual-atom sites are embedded in the N, P codoped tyre shaped carbon matrix. The configuration matching of Fe-Ni dual centers together with the local electronic engineering of N, P heteroatoms synergistically boost the catalytic activity on the oxygen reaction. Furthermore, the central-hollow highlyporous carbon matrix not only gives rise to a large amount of active sites, but also facilitates fast kinetics.Taking advantage of both the DAC and the substrate, the Fe Ni-NPC hollow tyre(HT) catalyst scores high in both oxygen reduction and evolution reactions, which exhibits the narrow potential difference and excellent durability. The aqueous Zn-air full battery(ZAB) integrating the Fe Ni-NPC HT air cathode has a high power density and a good stability over long-term cycling. Moreover, the flexible solid-state ZAB assembled with the polymer electrolyte obtains the high reliability over a wide range of temperatures or under diverse outside deformations. Therefore, this work offers a new green approach to prepare highly efficient DACs with built-in modulated micro-environment and tailor-made substrates. Moreover,it also paves a new way to develop highly-pliable power source for flexible electronics.

关键词： FeNi dual sites P,N codoped carbon Bio-assisted stategy Zn-air battery

Optimizing impedance matching by a dual-carbon Co-regulation strategy of Co_(3)O_(4)@rGO/celery stalks derived carbon composites for excellent microwave absorption

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Journal of Materials Science & Technology 2023年第2期133卷 1-11页

作者： Xiubo Xie yukun Wang Xueqin Sun Heshan Wang Ronghai Yu Wei Du Hongjing wu School of Environmental and Material Engineering Yantai UniversityYantai 264005China MOE Key Laboratory of Material Physics and Chemistry under Extraordinary School of Physical Science and TechnologyNorthwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Aerospace Materials and Performance(Ministry of Education) School of Materials Science and EngineeringBeihang UniversityBeijing 100191China

Both macroscopic composition and microstructure should be considered for reasonable microwave ab-sorbent designing.In this study,Co_(3)O_(4)@reduced graphene oxide(rGO)/Celery stalks derived carbon(CDC)was prepared by loading Co_(3)O_(4) particles into rGO and biomass-derived carbon mixture through oxidation precipitation.By changing the mass ratio of rGO to CDC,the dielectric and impedance matching proper-ties of the composites can be easily regulated.The RL min value of Co_(3)O_(4)@rGO/CDC_(13) composite(weight ratio for rGO:CDC is 1:3)reaches-84.3 dB with a thickness of 4.6 mm,and the widest effective band-width can be obtained at 4.5 GHz with a matching thickness of 2.8 mm.The Co_(3)O_(4)@rGO/CDC_(13) compos-ite with multiple components(Co_(3)O_(4),CDC,rGO)and 3D net structure produces magnetic/dielectric loss combinations,interfacial polarization,and multiple reflections and scattering,and the CDC with half tube and half sheet structure is conducive to the optimization of impedance matching.The strategy of co-regulating dielectric properties of materials with double carbon provides a novel pathway for the prepa-ration of lightweight,low-cost,and high-performance absorbers.

关键词： Microwave absorption Graphene Co_(3)O_(4) Biomass carbon Impedance matching

Estimation of particle depth from two defocused images using the Fourier transform

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Particuology 2020年第2期18卷 48-54页

作者： wu Zhou Xu Luo Benting Chen yukun Zhang Xiaoshu Cai School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093China

Depth from defocus is one technology for depth estimation.We estimate particle depth information from two defocused images captured simultaneously by two coaxial cameras with different imaging distances.The images are processed with the Fourier transform to obtain the characteristic parameter(i.e.,the standard deviation of the relative blur kernel of these two defocused images).First,we theoretically analyze the functional relationship between the object depth and the standard deviation or variation of the relative blur kernel.Then,we verify the relationship experimentally.We analyze the influence of particle size,window size and image noise on the calibration curves using both numerical simulations and experiments.We obtain the depth range and accuracy of this measurement system experimentally.For the verification experiments,we use a sample of glass microbeads and the irregularly-shaped dust particles on a microscope slide.Both of these experiments present a suitable depth measurement result.Finally,we apply the measuring system to the depth estimation of drops from a small anti-fogging spray.The results show that our system and image processing algorithm are robust for different types of particles,facilitating the in-line three-dimensional positioning of particles.

关键词： Depth from two defocused images Fourier transform Standard deviation of relative blur kernel Drops depth measurement Sensitivity and accuracy analysis

A Bulky Pyridinylfluorene/Triphenylamine Hybrid Used as Host Material for Heavily-Doped Blue Electrophosphorescent Devices

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Chinese Journal of Chemistry 2016年第4期34卷 397-402页

作者： Xianghua Zhao Yukun Wu Li Zhou Nana wu Lin Tang Yi Zhao Xiaosheng Li Dongxue Ding Hui Xu College of Chemistry and Chemical Engineering Xinyang Normal University Xinyang 464000 Henan China State Key Laboratory on Integrated Optoelectronics College of Electronics Science and Engineering Jilin University Changchun Jilin 130012 China Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education Heilongjiang University Harbin Heilongfiang 150080 China

In this work, a novel molecule pyridinylfluorene/triphenylamine hybrid （TPyFTPA） with bulky steric hindrance effects has been synthesized successfully by substituting 9-（pyridine-2-yl）-fluoren-9-yl with triphenylamine （TPA） via Friedel-Crafts reaction, which possesses good thermal stability and triplet energy （ET） of 420 ℃ with 5% weight loss and 2.86 eV, respectively. Moreover, the bulky steric hindrance material shows high stable morphology by heating to 200 ℃ without finding melting phenomena and crystallization that is demonstrated by differential scanning calorimetry （DSC） curve. The bulky pyridinylfluorene end-capped TPA has been used as host material for blue phosphorescent organic light-emitting diodes （PhOLEDs） with maximum external quantum efficiencies （EQEs） of 2.7%, 3.7%, and 3.5%, at the doping ratios of 10%, 30%, and 40%, respectively. The performances of TPyFTPA-based blue PhOLEDs own wide concentration ranging from 10% to 40%, which indicates the bulky TPyFTPA might be a potential candidate for inexpensive products with simplifying process for the applications in full-color display and solid state lighting.

关键词： steric hindrance triphenylamine PhOLEDs high doping concentration

High Performance Top-Emitting Organic Light-Emitting Diodes for Super Video Graphics Array Monochromatic Microdisplays Application

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Chinese Journal of Chemistry 2015年第8期33卷 897-901页

作者： Yukun Wu Zhensong Zhang Shouzhen Yue Ran Huang Huan Du Yi Zhao State Key Laboratory on Integrated Optoelectronics College of Electronics Science and Engineering Jilin University Changchun Jilin 130012 China Institute of Microelectronics Chinese Academy of Sciences Beijing 100029 China

We have demonstrated a high perlbrmance top-emitting organic light-emitting diode （TEOLED） achieving a brightness of 1000 cd/m^2 at a low voltage of 3.4 V, a power efficiency of 55.2 lm/W at a brightness of 611cd/m^2. and a low efficiency roll-off 5.1% calculated from the maximum efficiency value to that of 5000 cd/m^2. Such im- proved properties are controlled by electron injection from 7-diphenyl-1,10-phenanthroline （BPhen） into and trans- port by the 2,4,6-tris[3＇-（pyridin-3-yl）biphenyl-3-yl]-l,3,5-triazine （TmPPPyTz） layer along with hole injection from 4,4＇,4＂-tris（N-carbazolyl）diphenylamine （TcTa） directly into the fac-tris（2-phenylpyridine）iridium [lr（ppy）3] highest occupied molecular level （HOMO）, leading to direct carrier recombination and excitons formation on the phosphor dopants. Eventually we integrated our high performance TEOLEDs on complementary metal oxide semi- conductor （CMOS） substrates to realize super video graphics array （SVGA） OLED microdisplays.

关键词： top-emitting organic light-emitting diodes organic light-emitting diodes microdisplay super video graphics array

A 16-QAM 45-Gbps 7-m Wireless Link Using InP HEMT LNA and GaAs SBD Mixers at 220-GHz-Band

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China Communications 2021年第5期18卷 255-262页

作者： yukun Li Yong Zhang Chengkai wu Jianhan Cui Huali Zhu Bo Yan School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

This paper presents a 220-GHz-band 7-m wireless link with a 45-Gbps transmission data rate by using 16 quadrature amplitude modulation(16-QAM).Super-heterodyne transceiver modules are developed for transmission and reception of the modulated signals,which consist of a Schottky barrier diodes(SBD)based sub-harmonic mixer(SHM),an InP HEMT low noise amplifier(LNA),a waveguide band-pass filter(BPF),and a 108-GHz local oscillator(LO)multiplier chain.The transmitter features a peak transmit power of 1.41 dBm,and the IF frequency varies from 5 GHz to 20 GHz.Besides,the receiver features a conversion gain of 9.3 dB in average and a noise temperature of 3052.8 K.The measured results indicate that the transceiver modules enable data transmission of a 45-Gbps 16-QAM signal with Signal-Noise-Ratio(SNR)from 11.59 dB to 15.36 dB in a 7-m line-of-sight channel.

关键词： wireless link 16 quadrature amplitude modulation(16-QAM) super-heterodyne transceiver modules sub-harmonic mixer(SHM)

Architectural Model of a Dryland Gravel Braided River,based on 3D UAV Oblique Photogrammetric Data:A Case Study of West Dalongkou River in Eastern Xinjiang,China

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Acta Geologica Sinica(English Edition) 2023年第1期97卷 269-285页

作者： YIN Senlin ZHU Baiyu GUO Haiping XU Zhenhua LI Xiaoshan wu Xiaojun CHEN yukun JIANG Zhibin Institute of Mud-Logging Technology and Engineering Yangtze UniversityJingzhouHubei 434023China Research Institute of Exploration and Development PetroChina Xinjiang Oilfield CompanyKaramayXinjiang 834000China School of GeoSciences Yangtze UniversityWuhan 430100China

Three-dimensional unmanned aerial vehicle(UAV)oblique photogrammetric data were used to infer mountainous gravel braided river lithofacies,lithofacies associations and architectural elements.Hierarchical architecture and lithofacies associations with detailed lithofacies characterizations were comprehensively described to document the architectural model,architectural element scale and gravel particle scale.(1)Nine lithofacies(i.e.,Gmm,Gcm,Gcc,Gci,Gcl,Ss,Sm,Fsm and Fl)were identified and classified as gravel,sand and fine matrix deposits.These are typical depositional features of a mountainous dryland gravel-braided river.(2)Three architectural elements were identified,including channel(CH),gravel bar(GB)and overbank(OB).CH can be further divided into flow channel and abandoned channel,while GB consists of Central Gravel bar(CGB)and Margin Gravel bar(MGB).(3)The gravel bar is the key architectural element of the gravel braided river,with its geological attributes.The dimensions of GBs and their particles are various,but exhibit good relationships with each other.The grain size of GB decreases downstream,but the dimensions of GB do not.The bank erosion affects the GB dimensions,whereas channel incision and water flow velocity influence the grain size of GB.The conclusions can be applied to the dryland gravel braided river studies in tectonically active areas.

关键词： three-dimensional UAV oblique photogrammetry gravel braided river architecture modern deposits West Dalongkou River

Analysis of micro-tubular SOFC stability under ambient and operating temperatures

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Journal of Materials Science & Technology 2018年第8期34卷 1436-1440页

作者： Wei Kong Wenxuan Zhang Hongyan Huang yukun Zhang Jie wu Yu Xu School of Energy and Power Jiangsu University of Science and Technology

The stability of micro-tubular solid oxide fuel cell （MT-SOFC） is predicted at ambient and operating temperatures via simulation method. The results reveal that as long as the anode failure probability satisfies the failure criterion of 1E-6 at ambient temperature, the anode will retain its structural integrity at operating temperature. For the electrolyte or cathode, the stress strength ratio at operating temperature is significantly higher than that at ambient temperature. For an inappropriate component thickness, the cathode maybe fractures at operating temperature. In order to ensure the stability of MT-SOFC, the cathode thickness must be smaller than the maximum cathode thickness （tmax-cathode）, which is derived from. tmax-cathode = 5.49 ＋ 5.54 te

关键词： Micro-tubular solid oxide fuel cell （MT-SOFC） Stress Stability Thickness Failure probability