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Electrically focus-tuneable ultrathin lens for high-resolution square subpixels

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Light(Science & Applications) 2020年第1期9卷 1066-1078页

作者： Sehong Park Gilho Lee Byeongho Park Youngho Seo Chae bin Park Young Tea Chun Chulmin Joo Junsuk Rho Jong Min Kim James Hone Seong Chan Jun School of Mechanical engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul 03722Republic of Korea Electrical engineering Division Engineering DepartmentUniversity of Cambridge9 JJ Thomson AvenueCambridge CB3 OFAUK department of Electronic Material engineering Korea Maritime and Ocean UniversityBusan 49112Republic of Korea department of Mechanical engineering Pohang University of Science and Technology(POSTECH)77 Cheongam-roNam-guPohang 37673Republic of Korea department of Chemical engineering Pohang University of Science and Technology(POSTECH)77 Cheongam-roNam-guPohang 37673Republic of Korea Institute for Convergence Research and Education in Advanced Technology Yonsei University50 Yonsei-roSeodaemun-guSeoul 03722Republic of Korea department of Mechanical engineering Columbia University500 West 120th StreetMudd 220New YorkNY 10027USA

Owing to the tremendous demands for high-resolution pixel-scale thin lenses in displays,we developed a graphenebased ultrathin square subpixel lens(USSL)capable of electrically tuneable focusing(ETF)with a performance competitive with that of a typical mechanical refractive *** fringe field due to a voltage bias in the graphene proves that our ETF-USSL can focus light onto a single point regardless of the wavelength of the visible light—by controlling the carriers at the Dirac point using radially patterned graphene layers,the focal length of the planar structure can be adjusted without changing the curvature or position of the lens.A high focusing efficiency of over 60% at a visible wavelength of 405 nm was achieved with a lens thickness of design is first presented as an ETF-USSL that can be controlled in pixel units of flat panel displays for visible *** can be easily applied as an add-on to high resolution,slim displays and provides a new direction for the application of multifunctional autostereoscopic displays.

关键词： visible driving competitive

Virtual manufacturing in Industry 4.0:A review

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Data Science and Management 2024年第1期7卷 47-63页

作者： Mohsen Soori Behrooz Arezoo Roza Dastres department of Aeronautical engineering University of KyreniaKyreniaNorth CyprusVia Mersin 10Turkey CAD/CAPP/CAM Research Center Department of Mechanical EngineeringAmirkabir University of Technology(Tehran Polytechnic)Tehran15875-4413Iran department of Computer engineering Cyprus International UniversityNorth CyprusVia Mersin 10Turkey

Virtual manufacturing is one of the key components of Industry 4.0,the fourth industrial revolution,in improving manufacturing *** manufacturing enables manufacturers to optimize their production processes using real-time data from sensors and other connected devices in Industry ***-based virtual manufacturing platforms are a critical component of Industry 4.0,enabling manufacturers to design,test,and optimize their processes collaboratively and *** Industry 4.0,radio frequency identification(RFID)technology is used to provide real-time visibility and control of the supply chain as well as to enable the automation of various manufacturing *** data analytics can be used in conjunction with virtual manufacturing to provide valuable insights and optimize production processes in Industry *** intelligence(AI)and virtual manufacturing have the potential to enhance the effectiveness,consistency,and adaptability of manufacturing processes,resulting in faster production cycles,better-quality products,and lower *** developments in the application of virtual manufacturing systems to digital manufacturing platforms from different perspectives,such as the Internet of things,big data analytics,additive manufacturing,autonomous robots,cybersecurity,and RFID technology in Industry 4.0,are discussed in this study to analyze and develop the part manufacturing process in Industry *** limitations and advantages of virtual manufacturing systems in Industry 4.0 are discussed,and future research projects are also ***,productivity in the part manufacturing process can be enhanced by reviewing and analyzing the applications of virtual manufacturing in Industry 4.0.

关键词： Virtual manufacturing Industry 4.0

design and Pilot Programs of Marine Exposure Station of A Sea-crossing Bridge

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武汉理工大学学报 2010年第17期32卷 131-136页

作者： QIN M Q WANG C J TU L Q ZHANG G Z SUN T X Wuhan Harbour engineering design and Research Co. Ltd. Wuhan 430071China Key Lab of Large-span Bridge Construction Technology Ministry of CommunicationsWuhan 430071China Zhejiang Province Zhoushan Island Linking Construction Commanding department Zhoushan 316032China School of Materials Science and engineering Wuhan University of TechnologyWuhan 430070China

This paper presents the Location,the structural design as well as the anti-corrosion and the pilot programs of the marine exposure station of Zhoushan Archipelago seas sea-crossing bridges. Subjected to the marine environment,the concrete structures in serve with different mixing proportions,cover thickness,additional anti-corrosion measures such as rust-preventing agent,coating,penetration crystalline waterproof material,silicone and permeable fabric were studied. Those results obtained provide important information for the maintenance of marine concrete and the structural design of sea-crossing bridges in the above sea area.

关键词： exposure station sea-crossing bridge marine concrete durability design

Variable scale-convex-peak method for weak signal detection

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Science China(Technological Sciences) 2021年第2期64卷 331-340页

作者： TIAN RuiLan ZHAO ZhiJie XU Yong State Key Laboratory of Mechanical Behavior and System Safety of Traffic engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China department of engineering Mechanics Shijiazhuang Tiedao UniversityShijiazhuang 050043China department of Applied Mathematics Northwestern Polytechnical UniversityXi’an 710072China

Avariable scale-convex-peak method is constructed to identify the frequency of weak harmonic signal. The key of this method is to find a set of optimal identification coefficients to make the transition of dynamic behavior topologically persistent. By the stochastic Melnikov method, the lower bound of the chaotic threshold continuous function is obtained in the mean-square *** intermediate value theorem is applied to detect the optimal identification coefficients. For the designated identification system, there is a valuable co-frequency-convex-peak in bifurcation diagram, which indicates the state transition of chaosperiod-chaos. With the change of the weak signal amplitude and external noise intensity in a certain range, the convex peak phenomenon is still maintained, which leads to the identification of frequency. Furthermore, the proposition of the existence of reversible scaling transformation is introduced to detect the frequency of the harmonic signal in engineering. The feasibility of constructing the hardware and software platforms of the variable scale-convex-peak method is verified by the experimental results of circuit design and the results of early fault diagnosis of actual bearings, respectively.

关键词： variable-scale Duffing system stochastic Melnikov method scale transformation circuit experiment fault diagnosis

High-throughput screening of single-atom catalysts confined in monolayer black phosphorus for efficient nitrogen reduction reaction

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Nano Research 2024年第4期17卷 2360-2367页

作者： Xiao-Yan Li Manyi Duan Pengfei Ou department of Electrical and Computer engineering University of TorontoTorontoOntario M5S 1A4Canada School of Physics and Electronic engineering Sichuan Normal UniversityChengdu 610101China department of Chemistry Northwestern UniversityEvanstonIL 60208USA

The discovery of metal-nitrogen centers as the active sites for electrolysis has aroused significant interest in utilizing single-atom catalysts for nitrogen reduction reaction(NRR).Properly designed nanostructured catalysts that strongly interact with nitrogen molecules(N_(2))can promote adsorption and activation,thereby resulting in efficient catalysts with high stability,activity,and *** this study,using density functional theory calculations,we selected monolayer black phosphorus(BP)as the substrate and screened a series of single-atom transition metals confined in tri-coordinated and tetra-coordinated active centers(without and with N dopants)to electro-catalyze *** a result,we have identified two promising candidates(Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4)),which exhibit not only low overpotentials of 0.56 and 0.49 V but also high thermodynamic and electrochemical stability,as well as good selectivity towards NRR over the competing hydrogen evolution *** also demonstrate the ability of Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4) to activate and hydrogenate N_(2) by donating electrons and regulating charge *** study not only predicts new BP-based promising catalysts but also provides guidance for the rational design of high-performance NRR electrocatalysts under ambient conditions.

关键词： N_(2) electroreduction reaction single-atom catalysts black phosphorus density functional theory high-throughput calculations

A Piezoelectric and Electromagnetic Dual Mechanism Multimodal Linear Actuator for Generating Macro- and Nanomotion

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Research 2019年第1期2019卷 177-185页

作者： Xiangyu Gao Zhanmiao Li Jingen Wu Xudong Xin Xinyi Shen Xiaoting Yuan Jikun Yang Zhaoqiang Chu Shuxiang Dong department of Materials Science&engineering College of EngineeringPeking UniversityBeijing 100871China Beijing Key Laboratory for Magnetoeletric Materials and Devices Beijing 100871China

Fast actuation with nanoprecision over a large range has been a challenge in advanced intelligent manufacturing like lithography mask *** stacked stage method works effectively only in a local,limited range,and vibration coupling is also ***,we design a dual mechanism multimodal linear actuator(DMMLA)consisted of piezoelectric and electromagnetic costator and coslider for producing macro-,micro-,and nanomotion,respectively.A DMMLA prototype is fabricated,and each working mode is validated separately,confirming its fast motion(0~50 mm/s)in macromotion mode,micromotion(0~135μm/s)and nanomotion(minimum step:0~2 nm)in piezoelectric step and servomotion *** proposed dual mechanism design and multimodal motion method pave the way for next generation high-precision actuator development.

关键词： Dual motion piezoelectric

Micromechanism study on electronic and magnetic properties of silicene regulated by oxygen

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Journal of Materials Science & Technology 2019年第8期35卷 1803-1808页

作者： Li-Ping Ding Peng Shao Lin-Tai Yang Wei Guo Sun Fang-Hui Zhang Cheng Lu College of Elecrical & Information engineering Shaanxi University of Science & Technology Xi’an 710021 China department of Physics Nanyang Normal University Nanyang 473061 China department of Physics and High Pressure Science and engineering Center University of Nevada Las Vegas NV 89154 United States

Silicene, a two-dimensional(2D) silicon counterpart of graphene with attractive electronic properties, has attracted increasing attention. Understanding of its interaction with oxygen is of fundamental importance for nano-electronics in silicon-based technology. Here, we have systematically studied the structural,electronic and magnetic properties of silicene with oxygen atoms adsorption by using an unbiased structure search method coupled with First-principles calculations. The results show that the most favorable oxygen adsorption site on silicene surface is bridge site and oxygen atoms tend to chemisorb on silicene.A detailed analysis of the electronic band structure and density of state(DOS) suggests that there is a band gap opening near Fermi level after oxygen adsorption, which lead to pristine silicene changing from a gapless semiconductor to a direct or indirect bandgap semiconductor. The important finding is that two and six oxygen atoms adsorbed silicene are more advantageous due to the relatively large direct band gaps at the K point. The calculated magnetic moments and spin density isosurfaces reveal that the total magnetic moments are mostly localized on silicene sheet. This finding provides new insights for further materials design based on two-dimensional silicon systems.

关键词： Silicene CALYPSO method Band gap Oxygen adsorption

Impact of the Presence of the Loop at Different Location on Fabric Width and Areal Density of a Weft Knitted Structure

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Journal of Textile Science and Technology 2021年第1期7卷 55-65页

作者： Zubair Bin Sayed Nusrat Jahan Shabrina Kabir department of Textile engineering Port City International University Chittagong Bangladesh department of Textile engineering Ahsanullah University of Science and Technology Dhaka Bangladesh department of Textile Machinery design and Maintenance Bangladesh University of Textile Dhaka Bangladesh

Knitted structures are progressively built up from row after row of knitted intermeshed loops known as knitted loops. Apart from this knitted loops, tuck or miss loops may be produced by varying the timing of the intermeshing sequence of the old loop and new loops. These loops are main and prominent part of the design of the weft knitted structures. Structures having float or miss loop exhibits many noticeable characteristics. The fabrics renders better surface appearance or color pattern. Dimensional stability is significantly improved. Fabric width is reduced and areal density is also increased considerably due to the presence of float loops in the structure. Therefore, the dimensional and physical features of different knitted structures having knit-miss loops may be studied carefully to find the influence of float stitch or loop on fabric width and areal density. In this project work, such an attempt has been made to specify some specific single jersey structures, which will be ensured as an effective tool for product research and development as well as for meeting up customer’s quality requirements of high class products.

关键词： Course Per Inch Count GSM (Gram Per M2) Shrinkage Wales Per Inch Weft Knitting

Study on Position Control System with Programmable Logic Controller

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Journal of China University of Mining and Technology 2003年第1期13卷 108-112页

作者：唐海燕卢仁军郝云鹏 College of Mechanical and Architecture and Civil engineering CUMT Automatic Research Room Chongqing Irion Design Lnstitate department of Mechanical engineering in Anshan Normal University

To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a mathematical model of position control is set up. The experiments show that using a modified machine, PLC makes little welding positional error and can meet the product requirements.

关键词： elliptical tracking position control mathematical model PLC