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Structurally coupled characteristics of rotor blade geometrically exact formulation

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Chinese Journal of Aeronautics 2022年第6期35卷 186-197页

作者： Jie WU Yijiang MA Zhidong WANG zhihao yu School of Naval Architecture & Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In rotor dynamics,blades are normally modelled as a slender beam,in which elastic deformations are coupled with each *** identify these coupling effects,new rigid-flexible structural model for helicopter rotor system is proposed in this *** rotations of the whole blade(on flapwise,lagwise,and torsional)are described as three global rigid degrees of *** nonlinear deformation geometrics of the beam is built on geometrically exact beam *** expressions for blade strain energy,kinetic energy,and virtual work of various kinds of external forces are derived as functions of finite rotations and elastic *** quantify the coupling characteristics,following the definition of coupling factor in electromagnetics,a new coupling factor between two modal components on each mode is introduced in modal *** show that the new structural model is highly capable of solving static and dynamic problems in rotor system and the maximum deformation that moderate deformation beam theory can predict might be 15%of beam *** the new coupling factor is applied to study structurally coupled characteristics of rotor blade,it can be concluded that closeness of natural frequencies likely indicates considerable coupling between corresponding DOFs in structure.

关键词： Computational geometry Flexible couplings Helicopter rotors Modal analysis Structural dynamics

Electrical contacts to two-dimensional transition-metal dichalcogenides

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Journal of Semiconductors 2018年第12期39卷 60-67页

作者： Shuxian Wanga zhihao yu Xinran Wang Kansas Academy of Mathematics and Science Fort Hays State University600ark StreetHaysKansas 67601-4099USA National Laboratory of Solid State Microstructures School of Electronic Science and Engineeringand Collaborate Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

Two-dimensional(2D) transition-metal dichalcogenides(TMDCs) have attracted enormous interests as the novel channel materials for atomically thin transistors. Despite considerable progress in recent years, the transistor performance is largely limited by the excessive contact resistance at the source/drain interface. In this review, a summary of recent progress on improving electrical contact to TMDC transistors is presented. Several important strategies including topology of contacts, choice of metals and interface engineering are discussed.

关键词： two-dimension channel materials Fin-FET

Modeling and assessment of fve-frequency BDS precise point positioning

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Satellite Navigation 2022年第1期3卷 114-127,I0004页

作者： Zhiyuan Wu Qianxin Wang Chao Hu zhihao yu Wei Wu School of Environment and Surveying and Mapping China University of Mining and Technology1 Daxue RoadXuzhou 221100China School of Spatial Information and Surveying Engineering Anhui University of Science and Technology168 Taifeng StreetHuainan 232001China Guangzhou Hi-Target Navigation Tech Co. Ltd555 Panyu StreetGuangzhou 510000China

Since its full operation in 2020,BeiDou Satellite Navigation System(BDS)has provided global services with highly precise Positioning,Navigation,and Timing(PNT)as well as unique short-message *** and more academics focus on multi-frequency Precise Point Positioning(PPP)models,but few on BDS fve-frequency PPP ***,this study using the uncombined and Ionospheric-Free(IF)observations develops fve BDS fve-frequency PPP models and compares them with the traditional dual-frequency model,known as Dual-frequency IF(DF)*** biases such as Inter-Frequency Biases(IFB)and Diferential Code Bias(DCB)are also *** the data collected from 20 stations,the BDS dual-and fve-frequency PPP models are comprehensively evaluated in terms of the static and simulated kinematic positioning ***,the study also analyzes some by-product estimated parameters in fve-frequency PPP models such as Zenith Troposphere Delay(ZTD).The results of experiment show that fve-frequency PPP models have diferent levels of improvement compared with the DF *** the static mode,the one single Five-Frequency IF combination(FF5)model has the best positioning consequent,especially in the up direction,and in the simulated kinematic mode,the Three Dual-frequency IF combinations(FF3)model has the largest improvement in convergence time.

关键词： BDS-3 Five-frequency PPP IFB DCB ZTD

From lab to fab: path forward for 2D material electronics

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Science China(Information Sciences) 2023年第6期66卷 115-121页

作者： Hongkai NING zhihao yu Taotao LI Haoliang SHEN Gen LONG Yi SHI Xinran WANG National Laboratory of Solid State Microstructures School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced MicrostructuresNanjing University School of Integrated Circuits Nanjing University College of Integrated Circuit Science and Engineering Nanjing University of Posts and Telecommunications Suzhou Laboratory

The increasing demand for computation requires the development of energy-efficient logic devices with reduced dimensions. Owing to their atomic thickness, 2D semiconductors are expected to provide possible solutions at the sub-1 nm technology node. Furthermore, taking advantage of the van der Waals nature, the low-temperature back-end of line integration with silicon may occur in the near future. In this perspective, vital progress in material synthesis, device engineering, and integration technologies toward integrated circuits based on 2D materials is reviewed. The challenges and important milestones on the roadmap for the next decade toward the fab adoption of 2D materials are outlined. Particularly, performance,power, area, cost, and equipment for further technology development in this area are proposed as key metrics and enablers.

关键词： two-dimensional materials transition-metaldichalcogenides equipment integrated circuits roadmap

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Agglomeration and Firm Export

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2018年第1期13卷 116-132页

作者： Churen Sun zhihao yu Tao Zhang Department of Economics Southwestern University of Finance and Economics Chendu 611130 China Department of Economics Carleton University Ottawa Ontario K1S 5B6 Canada International Business School Shanghai University of International Business and EconomicsShanghai 201620 China

Using Chinese manufacturing data between 1998 and 2007, this paper in- vestigates the impact of agglomeration on firm＇s export behavior. It is found that the agglomeration of manufacturing industries in China over this period increases firm＇s export probability as well as its export volume, and the impact is larger for more ef- ficient firms. However, the impact on firm＇s export volume depends on the degree of agglomeration. When the degree of agglomeration is low, an increase in agglomera- tion would expand firm＇s export volume but the impact will be diminishing and even turns negative if the degree of agglomeration is already very high.

关键词： agglomeration firm export

Numerical study of rapid cyclogenesis over sea

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Acta Oceanologica Sinica 1989年第1期8卷 51-62页

作者： Du Jun and yu zhihao Department of Atmospheric Sciences, Nanjing University, Nanjing, China China

A five-layer primitive equation model was used in the study of rapid cyclogenesis over sea. The numerical simulations show that'the Tibetan Plateau, large-scale baroclinicity and heat flux from the sea surface are the three important agents to produce cyclonic vorticity along the east coast of China. The diagnostic computation of a 24 h control simulation indicates that the nonlinear vorticity advec-tion, baroclinicity and diabatic heating are also responsible for the development of the extratropical cyclones over seas.

关键词： Numerical study of rapid cyclogenesis over sea over

Modifying the Power and Performance of 2-Dimensional MoS_(2)Field Effect Transistors

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Research 2023年第3期2023卷 741-756页

作者： Fulin Zhuo Jie Wu Binhong Li Moyang Li Chee Leong Tan Zhongzhong Luo Huabin Sun Yong Xu zhihao yu College of Integrated Circuit Science and Engineering Nanjing University of Posts and TelecommunicationsNanjing 210023China Guangdong Greater Bay Area Institute of Integrated Circuit and System Guangzhou 510535China Institute of Microelectronics Chinese Academy of SciencesBeijing 100029China College of Electronic and Optical Engineering and College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China

Over the past 60 years,the semiconductor industry has been the core driver for the development of information technology,contributing to the birth of integrated circuits,Internet,artificial intelligence,and Internet of *** technology has been evolving in structure and material with co-optimization of performance–power–area–cost until the state-of-the-art sub-5-nm ***-dimensional(2D)semiconductors are recognized by the industry and academia as a hopeful solution to break through the quantum confinement for the future technology *** the recent 10 years,the key issues on 2D semiconductors regarding material,processing,and integration have been overcome in sequence,making 2D semiconductors already on the verge of *** this paper,the evolution of transistors is reviewed by outlining the potential of 2D semiconductors as a technological option beyond the scaled metal oxide semiconductor field-effect *** mainly focus on the optimization strategies of mobility(μ),equivalent oxide thickness(EOT),and contact resistance(RC),which enables high ON current(Ion)with reduced driving voltage(Vdd).Finally,we prospect the semiconductor technology roadmap by summarizing the technological development of 2D semiconductors over the past decade.

关键词： overcome driving enable

Preparation of crab-shell-based N,O co-doped graded porous carbon for supercapacitors using the confined nanospace deposition

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Waste Disposal and Sustainable Energy 2024年第2期6卷 173-183页

作者： Yiming Li zhihao yu Mengyan Guo Ming Zhang Jian Xiong Yina Qiao Rui Zhang Xuebin Lu School of Environmental Science and Engineering Tianjin UniversityTianjin 30000China School of Ecology and Environment Tibet UniversityLhasa 850000China School of Environment and Safety Engineering North University of ChinaTaiyuan 030051China School of Environmental and Municipal Engineering Tianjin Chengjian UniversityTianjin 300384China

Biomass-based carbon materials with hierarchical porous structures have attracted attention for their ability to provide more channels and shorten ion transport ***,we developed a simple method based on confined nanospace ***-ing high-temperature treatment,the mesoporous silica layer wrapped around the outside of the crab shells acted as a closed nanospace and effectively suppressed the severe deformation of the crab shell structure by shrinking *** prepared carbon material has a layered porous structure with abundant and stable N and O co-doping(N 7.32%,O 3.69%).The specific capacitance of the three-electrode system was 134.3 F/g at a current density of 0.5 A/g in a 6 mol/L KOH electrolyte,and the assembled aqueous symmetric supercapacitors exhibited an excellent cycling stability of 98.81%even after 5000 cycles.

关键词： Supercapacitor Confined nanospace deposition Biomass-based carbon materials Crab shell

Ultra-low power IGZO optoelectronic synaptic transistors for neuromorphic computing

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Science China(Information Sciences) 2024年第12期67卷 281-290页

作者： Li ZHU Sixian LI Junchen LIN yuanfeng ZHAO Xiang WAN Huabin SUN Shancheng YAN Yong XU zhihao yu Chee Leong TAN Gang HE College of Integrated Circuit Science and Engineering Nanjing University of Posts and Telecommunications School of Materials Science and Engineering Anhui University

Inspired by biological visual systems, optoelectronic synapses with image perception, memory retention, and preprocessing capabilities offer a promising pathway for developing high-performance artificial perceptual vision computing systems. Among these, oxide-based optoelectronic synaptic transistors are wellknown for their enduring photoconductive properties and ease of integration, which hold substantial potential in this regard. In this study, we utilized indium gallium zinc oxide as a semiconductor layer and high-k ZrAlOxas a gate dielectric layer to engineer low-power high-performance synaptic transistors with photonic *** biological synaptic functions, including excitatory postsynaptic currents, paired-pulse facilitation,and the transition from short-term to long-term plasticity, were replicated via optical pulse *** simulation was sustained even at an operating voltage as low as 0.0001 V, exhibiting a conspicuous photonic synaptic response with energy consumption as low as 0.0845 fJ per synaptic event. Furthermore,an optoelectronic synaptic device was employed to model “learn-forget-relearn” behavior similar to that exhibited by the human brain, as well as Morse code encoding. Finally, a 3 × 3 device array was constructed to demonstrate its advantages in image recognition and storage. This study provides an effective strategy for developing readily integrable, ultralow-power optoelectronic synapses with substantial potential in the domains of morphological visual systems, biomimetic robotics, and artificial intelligence.

关键词： IGZO optoelectronic synaptic devices persistent photoconductivity ultra-low power neuromorphic computing

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