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Ultrafast growth of wafer-scale fold-free bilayer graphene

Nano Research 2023年第7期16卷 10684-10689页

作者： Jilin Tang Yuechen Wang Yuwei Ma Xiaoyin Gao Xin Gao Ning Li Yani Wang Shishu Zhang Liming Zheng Bing Deng Rui Yan Yisen Cao Ronghua Zhang Lianming Tong Jin Zhang Peng Gao Zhongfan Liu Xiaoding Wei Hongtao Liu Hailin Peng Center for Nanochemistry Beijing Science and Engineering Centre for NanocarbonsBeijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China Beijing Graphene Institute Beijing 100095China State Key Laboratory for Turbulence and Complex System Department of Mechanics and Engineering ScienceCollege of EngineeringBeijing Innovation Center for Engineering Science and Advanced TechnologyPeking UniversityBeijing 100871China Electron Microscopy Laboratory School of PhysicsInternational Center for Quantum MaterialsPeking UniversityBeijing 100871China

Bilayer graphene provides a versatile platform for exploring a variety of intriguing phenomena and shows much promise for applications in electronics,optoelectronics,*** growth of large-area bilayer graphene is therefore highly desired yet still suffers from a slow growth rate and poor layer ***,graphene wrinkles,including folds and ripples,form during cooling due to the thermal contraction mismatch between graphene and the metal substrates,and have been far from suppressed or eliminated,especially in bilayer graphene,which would greatly degrade the extraordinary properties of *** we report the ultrafast growth of wafer-scale fold-free bilayer graphene by chemical vapor *** well-tuning the alloy thickness and strain regulation of the single-crystal CuNi(111)/sapphire,the full coverage of a 2-inch fold-free bilayer graphene wafer via mainly isothermal segregation has been achieved as fast as 30 *** tensile-strained CuNi(111)film reduces the thermal contraction mismatch and suppresses the formation of graphene folds during cooling,which is directly observed through in situ optical *** ultraflat bilayer graphene exhibits wafer-scale uniformity in electrical performance and enhanced mechanical property comparable to the exfoliated *** results offer a promising route for largescale production of bilayer graphene and enable its various applications.

关键词： bilayer graphene graphene wrinkles ultrafast growth in situ optical microscopy single crystal wafer

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Exploring the nonlinear piezoresistive effect of 4HSiC and developing MEMS pressure sensors for extreme environments

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Microsystems & Nanoengineering 2023年第2期9卷 59-76页

作者： Chen Wu Xudong Fang Qiang Kang Ziyan Fang Junxia Wu Hongtao He Dong Zhang Libo Zha Bian Tian Ryutaro Maedai Zhuangde Jjang State Key Laboratory for Manufacturing Systems Engineering International Joint Laboratory for Micro/Nano Manufacturing and Measurement TechnologiesXian Jiaotong UniversityXian 710049China School of Mechanical Engineering Xian Jiaotong UniversityXi'an 710049China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 265503China Xi'an Jiaotong University(Yantai)Research Institute for Intelligent Sensing Technology and System Xi'an Jiaotong UniversityXianChina HeBei Semiconductor Research Institute Shjiazhuang 050051China

Microelectromechanical system(MEMS)pressure sensors based on silicon are widely used and offer the benefits of miniaturization and high ***,they cannot easily withstand high temperatures exceeding 150 ℃ because of intrinsic material ***,we proposed and executed a systematic and full-process study of Sic-based MEMS pressure sensors that operate stably from-50 to 300 ℃.First,to explore the nonlinear piezoresistive effect,the temperature coefficient of resistance(TCR)values of 4H-SiC piezoresistors were obtained from-50 to 500 ℃.A conductivity variation model based on scattering theory was established to reveal the nonlinear variation ***,a piezoresistive pressure sensor based on 4H-SiC was designed and *** sensor shows good output sensitivity(3.38 mVN/MPa),accuracy(0.56%FS)and low temperature coefficient of sensitivity(TCS)(-0.067%FS/℃)in the range of-50 to 300 ℃.In addition,the survivability of the sensor chip in extreme environments was demonstrated by its anti-corrosion capability in H_(2)SO_(4) and NaOH solutions and its radiation tolerance under 5 W ***,the sensor developed in this work has high potential to measure pressure in high-temperature and extreme environments such as are faced in geothermal energy extraction,deep well dilling,aeroengines and gas turbines.

关键词： environments extreme nonlinear

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Design and Experimental Evaluation of WLR-III

Design and Experimental Evaluation of WLR-III

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IEEE International Conference on robotics and Biomimetics

作者： Xu Li Yili Fu State Key Laboratory of Robotics and System Harbin Institute of Technology and State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University Intelligent Robot Research Center Zhejiang Laboratory and State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

This paper introduces the design and experimental evaluation of WLR-III, which stands for the third-generation hydraulic wheel-legged robot. WLR-III is expected to be applied to disaster scenarios where the mobility, adaptability and manipulation capability are required. Based on the development of the previous two generations of wheel-legged robots, this work continuously optimizes the design to achieve higher mobility and stronger adaptability by reducing weight & inertia. The hydraulic power transmission system adopts a hose-less design method to ensure the robustness of the system. What's more prominent is that the successful development of hydraulic power unit (HPU) enables WLR-III to realize hydraulic power autonomy. In addition, to accomplish all kinds of operational tasks in the rescue scene, the electro-hydraulic hybrid drives anthropomorphic arms with heavy load grippers were developed. Finally, the effectiveness and reliability of design optimization have been evaluated through a series of experiments, including grassland movement, load bearing, obstacle-stepping and tool-operating. To the authors' best knowledge, this is the first time that a hydraulic powered autonomous wheel-legged humanoid robot with the ability to operate simple tools has been developed.

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Design of a Novel Autonomous Docking system With a Supporting robotic Fish

Design of a Novel Autonomous Docking System With a Supportin...

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2023 IEEE International Conference on Real-Time Computing and robotics, RCAR 2023

作者： Dong, Huijie Zhao, Chunyang Qiao, Tiezhu Wang, Jian Chen, Di Meng, Yan Yu, Junzhi Taiyuan University of Technology Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan030024 China Chinese Academy of Sciences Laboratory of Cognitive and Decision Intelligence for Complex System Institute of Automation Beijing100190 China Peking University State Key Laboratory for Turbulence and Complex Systems Department of Advanced Manufacturing and Robotics College of Engineering Beijing100871 China Guangdong Ocean University College of Electronics and Information Engineering Zhanjiang524088 China

ISBN: (纸本)9798350327182

Underwater supporting robots serving as a relay of energy supplements and communication for other underwater equipment are promising for ocean exploration, development, and protection. This paper proposes a novel autonomous docking system centered on a designed supporting robotic fish named 'CourierFish'. Specifically, CourierFish is capable of docking with a surface dock station for supplying itself and docking with a seafloor platform for supporting equipment in the platform. A visual navigation scheme integrating LED and ArUco markers is presented for accurate localization. The control approach for docking motion is also illustrated. Simulations and aquatic experiments are performed to verify the feasibility of the proposed docking system. The obtained results lay a solid foundation for the construction of various underwater equipment and robot networks. © 2023 IEEE.

关键词： Fish

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Impact of Perturbation Schemes on the Ensemble Prediction in a Coupled Lorenz Model

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Advances in Atmospheric Sciences 2023年第3期40卷 501-513页

作者： Qian ZOU Quanjia ZHONG Jiangyu MAO Ruiqiang DING Deyu LU Jianping LI Xuan LI State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth Science University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Frontiers Science Center for Deep Ocean Multispheres and Earth System(FDOMES)/Key Laboratory of Physical Oceanography/Institute for Advanced Ocean Studies Ocean University of ChinaQingdao 266100China Laboratory for Ocean Dynamics and Climate Pilot Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China

Based on a simple coupled Lorenz model,we investigate how to assess a suitable initial perturbation scheme for ensemble forecasting in a multiscale system involving slow dynamics and fast *** initial perturbation approaches are used in the ensemble forecasting experiments:the random perturbation(RP),the bred vector(BV),the ensemble transform Kalman filter(ETKF),and the nonlinear local Lyapunov vector(NLLV)*** show that,regardless of the method used,the ensemble averages behave indistinguishably from the control forecasts during the first few time *** to different error growth in different time-scale systems,the ensemble averages perform better than the control forecast after very short lead times in a fast subsystem but after a relatively long period of time in a slow *** to the coupled dynamic processes,the addition of perturbations to fast variables or to slow variables can contribute to an improvement in the forecasting skill for fast variables and slow *** the initial perturbation approaches,the NLLVs show higher forecasting skill than the BVs or RPs *** NLLVs and ETKFs had nearly equivalent prediction skill,but NLLVs performed best by a narrow *** particular,when adding perturbations to slow variables,the independent perturbations(NLLVs and ETKFs)perform much better in ensemble *** results are simply implied in a real coupled air–sea *** the prediction of oceanic variables,using independent perturbations(NLLVs)and adding perturbations to oceanic variables are expected to result in better performance in the ensemble prediction.

关键词： ensemble prediction nonlinear local Lyapunov vector(NLLV) ensemble transform Kalman filter(ETKF) coupled air-sea models

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OFDR system with broadened frequency sweep range assisted by dual electro-optic frequency comb 27

OFDR system with broadened frequency sweep range assisted by...

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27th International Conference on Optical Fiber Sensors, OFS 2022

作者： Zhu, Yidai Fan, Xinyu Zhang, Zhaopeng Yuan, Zhengchao Xu, Bingxin He, Zuyuan State Key Laboratory of Advanced Optical Communication System and Networks Shanghai Jiao Tong University Shanghai200240 China Peng Cheng Laboratory Guangdong Shenzhen518055 China

We propose an OFDR system with the assistance of dual electro-optic frequency comb (EOFC). Rayleigh backscattering signals collected by multiple comb lines are synthesized to broaden the frequency sweep range for the ... 详细信息

ISBN: (纸本)9781957171142

关键词： Effective refractive index Frequency combs Optical amplification Optical amplifiers Spatial resolution Swept sources

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Research on the Process-based Generation Method of Multi-ships Collision Avoidance Test Scenarios Database for Maritime Autonomous Surface Ships 33rd

Research on the Process-based Generation Method of Multi-shi...

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33rd International Ocean and Polar Engineering Conference, ISOPE 2023

作者： Wang, Xinyu Wang, Yihang Bian, Hui Ma, Jilin Zhao, Xuan Qinhuangdao Branch China Classification Society Hebei China School of Mechanical Engineering Yanshan University Hebei China Parallel Robot and Mechatronic System Laboratory Hebei Province Hebei China Key Laboratory of Advanced Forging & Stamping Technology and Science Hebei China Science & Technology Innovation and Test Center Beijing China

ISBN: (纸本)9781880653807

This paper proposes a process-based method for generating virtual test scenarios for near-shore maritime autonomous surface ships (MASS) collision avoidance tests. The method includes a scenario complexity index to provide different difficulty levels of virtual test scenarios for different test requirements, reducing the test volume while ensuring coverage and reliability requirements. The scenario database generated by this method reflects the frequency of real-world scenarios and meets the requirements of virtual test realism. This method can improve the efficiency and reliability of MASS testing, with potential future improvements in the complexity evaluation matrix and statistical analysis of vessel maneuvering ability. © 2023 by the International Society of Offshore and Polar Engineers (ISOPE).

关键词： Ships

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Power Transformer Health state Prediction Based on Multi-attention Coupling Learning 6

Power Transformer Health State Prediction Based on Multi-att...

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6th IEEE International Electrical and Energy Conference, CIEEC 2023

作者： Zhang, Peng Gan, Jinrui Wu, Chunpeng Wu, Peng Qi, Bo Zhou, Fei State Grid Smart Grid Research Institute Co. Ltd. State Grid Laboratory of Grid Advanced Computing and Applications Beijing102209 China North China Electric Power University State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources Beijing102206 China

ISBN: (纸本)9798350346671

Transformer is the key apparatus of the power system, and its operational reliability is directly related to the stability of the power grid. Accurately predicting the future health state of transformers can reserve enough time for formulating outage maintenance and power dispatching plans. The existing transformer health state prediction methods are based on the structure of 'predict-diagnose', which is the superposition of two local optimal methods, with error superposition. To fill this gap, a transformer health state prediction method based on multi-attention coupling learning is proposed in this paper. The 'situational quantity' integrating the transformer operation state change relationship, the correlation relationship between state quantities, the mapping relationship between the state quantity and the state, the fuzzy relationship between the evaluation result and the actual state, and the traditional expert experience is proposed. Then, the structural optimization attention (SOA) model applicable to 'situational quantity' is proposed, and various relationships are treated as individual attention. All kinds of attention are coupled and constrained in the SOA to realize the unification of the prediction process and diagnosis process, obtain the global optimization of prediction and diagnosis, and the problem of error superposition is solved. The actual fault case verification results show that the accuracy of the proposed SOA prediction model can reach 96.33%, which is significantly better than the traditional methods. © 2023 IEEE.

关键词： Global optimization

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Integrated terahertz vortex beam emitter for rotating target detection

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advanced Photonics 2023年第6期5卷 37-46页

作者： Jingya Xie Jun Qian Tengjiao Wang Linjie Zhou Xiaofei Zang Lin Chen Yiming Zhu Songlin Zhuang University of Shanghai for Science and Technology Terahertz Technology Innovation Research InstituteShanghai Key Laboratory of Modern Optical SystemShanghaiChina Shanghai Jiao Tong University State Key Laboratory of Advanced Optical Communication Systems and NetworksDepartment of Electronic EngineeringShanghaiChina

We propose a terahertz(THz)vortex emitter that utilizes a high-resistance silicon resonator to generate vortex beams with various topological *** the challenge of double circular polarization superposition resulting from the high refractive index contrast,we regulate the transverse spin state through a newly designed second-order grating partially etched on the waveguide’s top *** reflected wave can be received directly by a linearly polarized antenna,simplifying the *** from the tuning feature,a joint detection method involving positive and negative topological charges identifies and detects rotational Doppler effects amid robust micro-Doppler interference *** emitter can be used for the rotational velocity measurement of an on-axis spinning object,achieving an impressive maximum speed error rate of∼2%.This approach holds promise for the future development of THz vortex beam applications in radar target detection and countermeasure systems,given its low cost and potential for mass production.

关键词： vortex beam emitter terahertz rotational Doppler detection

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Effect of variable-angle trajectory structure on mechanical performance of CF/PEEK laminates made by robotic fiber placement

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Chinese Journal of Aeronautics 2022年第12期35卷 336-356页

作者： Shouzheng SUN Haiyang MEI Yang WANG Jiahai ZHANG Zhenyu HAN Jinglan GUO State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China Wuhu Robot Technology Research Institute Harbin Institute of TechnologyWuhu 241000China Shanghai Spaceflight Precision Machinery Institute Shanghai 201600China School of Mechanical and Power Engineering Harbin University of Science and TechnologyHarbin 150080China

In comparison to the traditional fixed-angle trajectory,the variable-angle trajectory has a greater design ***,it is a challenge to determine which common design curve structure is the most effective for improving mechanical *** work explores the effects of various design curves such as fixed-angle curve,linear curve,arc curve,sine curve,Bezier curve,and cubic polynomial curve trajectories on mechanical performance of laminates,including vibration modal performance and buckling *** algorithm and improved NSGA-II algorithm are then used to optimize various curve *** results are confirmed utilizing thermoplastic Carbon Fiber(CF)/Polyether-Ether-Ketone(PEEK)laminates made by robotic fiber placement *** relationship model between different mechanical performance and curve design variables is *** optimization of variable-angle structure with mechanical properties as input variables is ***,a full-process angle-variable laying software platform from trajectory planning(CAD),trajectory optimization to manufacturing(CAM)is developed for facilitating the fiber placement application.

关键词： Fiber reinforced plastics Mechanical properties robotic fiber placement Thermoplastics Trajectory design Variable-angle laminate

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