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Noise and detectivity limits in organic shortwave infrared photodiodes with low disorder

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npj Flexible Electronics 2020年第1期4卷 58-65页

作者： Zhenghui Wu ning Li Naresh Eedugurala Jason DAzoulay Dong-Seok Leem Tse nga ng Department of Electrical and Computer Engineering University of California San Diego9500 Gilman DriveLa JollaCA 92093-0407USA Department of Electrical and Electronic Engineering Southern University of Science and Technology1088 Xueyuan AvenueShenzhenGuangdong 518023China Center for Optoelectronic Materials and Devices School of Polymer Science and EngineeringUniversity of Southern Mississippi118 College Drive#5050HattiesburgMS 39406USA Samsung Advanced Institute of Technology(SAIT) Samsung ElectronicsCo.Ltd.130 Samsung-roYeongtong-guSuwon-siGyeonggi-do 443-803South Korea

To achieve high detectivity in infrared detectors,it is critical to reduce the device ***,for non-crystalline semiconductors,an essential framework is missing to understand and predict the effects of disorder on the dark *** report presents experimental and modeling studies on the noise current in exemplar organic bulk heterojunction photodiodes,with 10 donor-acceptor combinations spanning wavelength between 800 and 1600 nm.A significant reduction of the noise and higher detectivity were found in devices using non-fullerene acceptors(NFAs)in comparison to those using fullerene *** low noise in NFA blends was attributed to a sharp drop off in the distribution of bandtail states,as revealed by variable-temperature density-of-states *** disorder into account,we developed a general physical model to explain the dependence of thermal noise on the effective bandgap and bandtail *** model provides theoretical targets for the maximum detectivity that can be obtained at different detection wavelengths in inherently disordered infrared photodiodes.

关键词： heterojunction noise donor

METASTABLE PHASES IN RAPIDLy-SOLIDIFIED ALUMINIUMRICH Al-Sm ALLOyS

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Acta Metallurgica Sinica(English Letters) 1998年第4期11卷 301-306页

作者： y.T.ning (Institute of Precious Metals, Kunming 650221, China) Inst of Precious Metals Kunming China

The splat foils of Al-Sm alloys with 0.04-0.06mm in thickness were made by hammeranvil technique. The estimated cooling rute was 106K/ order of magnitude. The extended solid solubility of Sm in α-Al reached 0.5at. % Sm. The intermediate phase in the rapidlysolidified Al-Sm alloys is Al11Sm3 phase, which is stable only at temperatures above 1339K in equilibrium state and retained to ambient temperature as a metastable phase, whereas the equlibrium intermediate phase, Al3Sm, was restricted to occur.

关键词： Al-Sm alloy rapid solidification metastable phase

Numerical simulations of cellular detonation diffraction in a stable gaseous mixture

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Propulsion and Power Research 2016年第3期5卷 177-183页

作者： Jian Li Jianguo ning Charles B.Kiyanda Hoi Dick ng State Key Laboratory of Explosion Science&Technology Beijing Institute of TechnologyBeijing 100081China Department of Mechanical and Industrial Engineering Concordia UniversityMontréalQCH3G 1M8Canada

In this paper,the diffraction phenomenon of gaseous cellular detonations emerging from a confined tube into a sudden open space is simulated using the reactive Euler equations with a two-step Arrhenius chemistry *** two-dimensional and axisymmetric configurations are used for modeling cylindrical and spherical expansions,*** chemical parameters are chosen for a stable gaseous explosive mixture in which the cellular detonation structure is highly *** mesh refinement(AMR)is used to resolve the detonation wave structure and its evolution during the *** numerical results show that the critical channel width and critical diameter over the detonation cell size are about 1371 and 2571,*** numerical findings are comparable with the experimental observation and confirm again that the critical channel width and critical diameter differ essentially by a factor close to 2,equal to the geometrical scaling based on front curvature *** unstable mixtures where instabilities manifested in the detonation front structure play a significant role during the transmission,the present numerical results and the observed geometrical scaling provide again evidence that the failure of detonation diffraction in stable mixtures with a regular detonation cellular pattern is dominantly caused by the global curvature due to the wave divergence resulting in the global decoupling of the reaction zone with the expanding shock front.

关键词： Detonations Diffraction Pulse detonation engine Stable mixture Adaptive mesh refinement(AMR)

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多无人机协同规划研究综述

计算机工程与应用 2025年第1期61卷 42-58页

作者：宁聪范菁孙书魁云南民族大学电气信息工程学院昆明650500 云南民族大学云南省高校信息与通信安全灾备重点实验室昆明650500 云南民族大学云南省无人自主系统重点实验室昆明650500

无人机在各行各业中发挥重要作用,多无人机之间的合作已成为研究热点。针对任务分配与路径规划两个核心问题,整理和分析了多无人机协同规划两个关键问题之间的复杂性,以及子问题间的信息耦合因素,并重点探讨了解耦策略;从数学模型方面... 详细信息

无人机在各行各业中发挥重要作用,多无人机之间的合作已成为研究热点。针对任务分配与路径规划两个核心问题,整理和分析了多无人机协同规划两个关键问题之间的复杂性,以及子问题间的信息耦合因素,并重点探讨了解耦策略;从数学模型方面对多无人机协同规划问题的通用模型进行描述,整理归纳出常见环境建模方法和多目标优化求解的约束条件;综述了基于集中式控制和分布式控制的任务规划方法,以及启发式算法在多无人机协同规划中的应用和研究进展,并重点介绍了多无人机协同规划问题面临实时性要求下的协同规划方法;结合典型研究,讨论了多无人机协同规划问题的未来研究方法与挑战,展望多无人机协同规划的发展。

关键词：无人机解耦策略智能算法任务分配路径规划

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Constitutive modeling of ultra?fine?grained titanium flow stress for machining temperature prediction

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Bio-Design and Manufacturing 2019年第3期2卷 153-160页

作者： Jinqiang ning Vinh nguyen y.ng Huang Karl T.Hartwig Steven y.Liang George W.Woodruff School of Mechanical Engineering Georgia Institute of Technology801 Ferst DriveAtlantaGA 30332USA Department of Mechanical and Aerospace Engineering University of Florida231 MAE-AP.O.Box 116250GainesvilleFL 32611USA Department of Mechanical Engineering Texas A&M University3123 TAMUCollege StationTX 77843?3123USA

This work investigates the machining temperatures of ultra-fine-grained titanium(UFG Ti),prepared by equal channel angular extrusion,through analytical *** Ti has great usefulness in biomedical applications because of its high mechanical strength,sufficient manufacturability,and high *** temperatures were predicted using a physics-based predictive model based on material constitutive relation and mechanics of the orthogonal cutting *** minimization between the stress calculated using Johnson–Cook constitutive model and the same stress calculated using mechanics model yields the estimation of machining temperatures at two deformation *** agreements are observed upon validation to the values reported in the *** machinability of UFG Ti is investigated by comparing its machining temperature to that of Ti–6Al–4V alloy under the same cutting *** lower temperatures are observed in machining UFG *** computational efficiency of the presented model is investigated by comparing its average computational time(~0.5 s)to that of a widely used modified chip formation model(8900 s)with comparable prediction *** work extends the applicability of the presented temperature model to a broader class of materials,specifically ultra-fine-grained *** high computational efficiency allows the in situ temperature prediction and optimization of temperature condition with process parameters planning.

关键词： Ultra-fine-grained titanium Analytical modeling High computational efficiency Johnson–Cook model Cutting mechanics

Intelligent resource allocation in mobile blockchain for privacy and security transactions: a deep reinforcement learning based approach

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Science China(Information Sciences) 2021年第6期64卷 172-187页

作者： Zhaolong ning Shouming SUN Xiaojie WAng Lei GUO Guoyin WAng Xinbo GAO Ricky y.K.KWOK School of Communication and Information Engineering Chongqing University of Posts and Telecommunications School of Software Dalian University of Technology State Key Laboratory of Industrial Control Technology Zhejiang University Chongqing Key Laboratory of Computational Intelligence Chongqing University of Posts and Telecommunications Chongqing Key Laboratory of Image Cognition Chongqing University of Posts and Telecommunications Department of Electrical and Electronic Engineering University of Hong Kong

In order to protect the privacy and data security of mobile devices during the transactions in the industrial Internet of Things(IIoT), we propose a mobile edge computing(MEC)-based mobile blockchain framework by considering the limited bandwidth and computing power of small base stations(SBSs). First,we formulate a joint bandwidth and computing resource allocation problem to maximize the long-term utility of all mobile devices, and take into account the mobility of devices as well as the blockchain throughput. We decompose the formulated problem into two subproblems to decrease the dimension of action space. Then,we propose a deep reinforcement learning additional particle swarm optimization(DRPO) algorithm to solve the two subproblems, in which a particle swarm optimization algorithm is leveraged to avoid the unnecessary search of a deep deterministic policy gradient approach. Simulation results demonstrate the effectiveness of our method from various aspects.

关键词： mobile blockchain deep reinforcement learning mobile edge computing power allocation bandwidth allocation

Group relational privacy protection on time-constrained point of interests

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Frontiers of Computer Science 2023年第3期17卷 239-241页

作者： Bo ning Xiaonan LI Fan y.ng yunhao SUN Guanyu LI George y.yUAN Faculty of Information Science and Technology Dalian Maritime UniversityDalian 116026China Faculty of Software Dalian University of Foreign LanguagesDalian 116044China Thinvent Digital Technology Co. Ltd.Nanchang 330029China

1 Introduction With the rapid development of mobile networks,locationbased services has become popular in the daily lives of *** service providers can recommend the profitable services to persons through mining the frequent interests or places of ***,one aspect is that the historical data on Internet can easily cause the leakage of user-relationship privacy,another aspect is that the historical interests of person are always bound to ***,this paper devotes to study a privacy protection method on time-constrained point of interests(PoIs)based on the group relationships of users.

关键词： services relational constrained

Facilely prepared layer-by-layer graphene membrane-based pressure sensor with high sensitivity and stability for smart wearable devices

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Journal of Materials Science & Technology 2020年第10期42卷 241-247页

作者： Tao Liu Caizhen Zhu Wei Wu Kai-ning Liao Xianjing Gong Qijun Sun Robert K.y.Li Department of Materials Science and Engineering City University of Hong KongTat Chee AvenueKowloonHong KongChina Institute of Low-dimensional Materials Genome Initiative College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen518060China National Engineering Research Center of Novel Equipment for Polymer Processing Key Laboratory of Polymer Processing Engineering of Ministry of EducationSchool of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou510640China State Key Laboratory of Organic-Inorganic Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029China

With the prosperous development of artificial intelligence,medical diagnosis and electronic skins,wearable electronic devices have drawn much attention in our daily *** pressure sensors based on carbon materials with ultrahigh sensitivity,especially in a large pressure range regime are highly required in wearable *** this work,graphene membrane with a layer-by-layer structure has been successfully fabricated via a facile self-assembly and air-dry.ng(SAAD)*** the SAAD process,air-dry.ng the self-assembled graphene hydrogels contributes to the uniform and compact layer structure in the obtained *** to the excellent mechanical and electrical properties of graphene,the pressure sensor constructed by several layers of membranes exhibits high sensitivity(52.36 kPa……-1)and repeatability(short response and recovery time)in the loading pressure range of 0–50 *** with most reported graphene-related pressure sensors,our device shows better sensitivity and wider applied pressure ***’s more,we demonstrate it shows desired results in wearable applications for pulse monitoring,breathing detection as well as different intense motion recording such as walk,run and ***’s hoped that the facilely prepared layer-by-layer graphene membrane-based pressure sensors will have more potential to be used for smart wearable devices in the future.

关键词： Graphene membrane Self-assembly High sensitivity Wearable devices Human motions

Influence of baffle position on liquid sloshing during braking and turning of a tank truck

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第5期11卷 317-324页

作者： ning KAng Kui LIU School of Transportation Science and Engineering University of A eronautics and Asttvnautics Beijing 100191 China

The influence of baffle position on liquid sloshing during the braking and turning of a tank truck was studied using a volume of fluid (VOF) model. The forces,their positions and weight distribution during braking and the forces and rolling moment during turning were calculated. The reliability of the calculation method was validated by comparisons with experimental results. The results showed that during braking,liquid splashes in the tank and the maximum forces and G (the ratio of weight acting on the front axle to the rear axle) are large when A (the ratio of the arch area above the baffle to the area of cross section)≤0.1. When A≥0.2,as the position of the baffle is lowered,the maximum of Fx (the force in direction x) first decreases then increases,and the maximum of Fy (the force in direction y) and G increase. During turning,liquid splashes in the tank and the maximum forces and M (the rolling moment) are large when D (the ratio of the arch area above the baffle to the area of cross section)≤0.2. When D≥0.3,as the position of the baffle is lowered,the maximums of Fy,Fz (the force in direction z) and M increase.

关键词： Tank truck Volume of fluid (VOF) method Liquid sloshing Two phase flow Baffle