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Behavior modeling on the PIM performance in connectors using FEA method and circuit simulation

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The Journal of China Universities of Posts and Telecommunications 2021年第1期28卷 87-93页

作者： Dun Shubo Jin Qiuyan Bi lingyu Wang Ziren Xie Jun The 54th Research Institute of CETC Shijiazhuang 050050China School of Information Science and Teehnology Southwest Jiaotong UniversityChengdu 614202China School of Electronie Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Coaxial connectors are generally regarded as a kind of potential passive non-linear source when magnetic materials are applied in the coating or under-plating, which may result in serious passive intermodulation(PIM) interference and degrade the communication quality. In this paper, the effect of connector coating materials on the PIM is theoretically studied using finite element analysis(FEA) and circuit simulations. Considering the material composition both in central and outer conductor, an FEA model of connector is proposed to identify the current density in magnetic material region. An equivalent circuit model expressing the nonlinearity in coating material is developed, coupled with the non-linear transfer model. The PIM product power of the connector with related material configuration is predicted by harmonic balance simulation. Intentionally design connector samples are used in PIM tests and the measurement results are consistent with the theoretical predictions. The PIM performance in coaxial connectors is demonstrated from the perspectives of both modeling analysis and experimental investigations.

关键词： passive intermodulation(PIM) finite element analysis(FEA) circuit model coaxial connector

Metal-Free Synthesis of β-Bromoalkenyl Sulfides via Deoxygenative Bromination/Olefination/Sulfenylation of Ketones with SulfonylHydrazides and Pyridinium Tribromide

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Chinese Journal of Chemistry 2018年第11期36卷 1063-1068页

作者： Yishu Bao lingyu Zhong Qiaodan Hou Qingfa Zhou Fulai Yang State Key Laboratory of Natural Medicines Department of Organic Chem- istry China Pharmaceutical University Nanjing Jiangsu 210009 China

A novel metal‐free method for synthesis of β‐bromoalkenyl sulfides via deoxygenative bromination/olefination/sulfenylation process using commercially available ketones, sulfonyl hydrazides and pyridinium tribromide as starting materials has been developed. In this reaction, pyridinium tribromide plays the role of oxidant and substrate, wherein water and molecular nitrogen are generated as environmentally benign by‐products. Preliminary investigation revealed that vinyl bromides were critical intermediate. Importantly, this protocol not only obviates the use of alkynes and traditional sulfenylating agents, but also reveals that ketones can be used as precursors of vinyl bromides.

关键词： ketones sulfonyl hydrazides deoxygenative β‐bromoalkenyl sulfides pyridinium tribromide

One-pot synthesis of Au@Pt star-like nanocrystals and their enhanced electrocatalytic performance for formic acid and ethanol oxidation

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Nano Research 2018年第6期11卷 3222-3232页

作者： Yi Peng Lidong Li Ran Tao lingyu Tan Mengna Qiu Lin Guo Key Laboratory of Bio-lnspired Smart Interfacial Science and Technology of Ministry of Education School of Chemistry and Environment Beihang University Beijing 100191 China Department of Chemistry and Biochemistry University of California 1156 High Street Santa Cruz California 95064 USA

The current bottleneck facing further developments in fuel cells is the lack of durable electrocatalysts with satisfactory activity. In this study, a simple and fast one-pot wet-chemical method is proposed to synthesize novel Au@Pt star-like bimetallic nanocrystals （Au@Pt SLNCs） with a low Pt/Au ratio of 1：4, which show great electrocatalytic properties and outstanding stability toward the electro-oxidation reactions commonly found in fuel cells. The star-like Au core （90±20 nm） is partially coated with 5 nm Pt nanocluster shells, a morphology which creates a large amount of boundaries and edges, thus tuning the surface electronic structure as demonstrated by X-ray photoelectron spectroscopy and CO-stripping measurements. This promotes excellent electrocatalytic performance towards the formic acid oxidation reaction in acidic media and the ethanol oxidation reaction in alkaline media, compared to commercial Pt or Au@Pt triangular nanoprisms, in which the Au core is fully coated by a Pt shell. Au@Pt SLNCs have the highest current density within the dehydrogenation potential range, needing the least potential to achieve a certain current density as well as the highest long-term stability. Because of the small amount of Pt usage, very fast synthesis, excellent electrocatalytic activity and durability, the proposed Au@Pt SLNCs have a promising practical application in fuel cells.

关键词： Au@Pt core-shell nanocrystals electrocatalyst formic acid ethanol oxidation

A Novel Evaluation Strategy to Artificial Neural Network Model Based on Bionics

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Journal of Bionic Engineering 2022年第1期19卷 224-239页

作者： Sen Tian Jin Zhang Xuanyu Shu lingyu Chen Xin Niu You Wang School of Mathematics and Statistics Hunan Normal UniversityChangsha410081China College of Information Science and Engineering Hunan Normal UniversityChangsha410081China School of Computer and Communication Engineering Changsha University of Science and TechnologyChangsha410114China Key Laboratory of Industrial Control Technology Zhejiang UniversityHangzhou310058China Science and Technology on Parallel and Distributed Laboratory College of ComputerNational University of Defense TechnologyChangsha410199China Key Laboratory of Industrial Control Technology Institute of Cyber Systems and ControlZhejiang UniversityHangzhou310027China

With the continuous deepening of Artificial Neural Network(ANN)research,ANN model structure and function are improving towards diversification and ***,the model is more evaluated from the pros and cons of the problem-solving results and the lack of evaluation from the biomimetic aspect of imitating neural networks is not inclusive ***,a new ANN models evaluation strategy is proposed from the perspective of bionics in response to this problem in the ***,four classical neural network models are illustrated:Back Propagation(BP)network,Deep Belief Network(DBN),LeNet5 network,and olfactory bionic model(KIII model),and the neuron transmission mode and equation,network structure,and weight updating principle of the models are analyzed *** analysis results show that the KIII model comes closer to the actual biological nervous system compared with other models,and the LeNet5 network simulates the nervous system in ***,evaluation indexes of ANN are constructed from the perspective of bionics in this paper:small-world,synchronous,and chaotic ***,the network model is quantitatively analyzed by evaluation indexes from the perspective of *** experimental results show that the DBN network,LeNet5 network,and BP network have synchronous *** the DBN network and LeNet5 network have certain chaotic characteristics,but there is still a certain distance between the three classical neural networks and actual biological neural *** KIII model has certain small-world characteristics in structure,and its network also exhibits synchronization characteristics and chaotic *** with the DBN network,LeNet5 network,and the BP network,the KIII model is closer to the real biological neural network.

关键词： Artificial neural network(ANN) Back Propagation(BP)network Deep Belief Network(DBN) LeNet5 network Olfactory bionic model(KIII model) Small world Chaos Synchronous

Application of Excitation Function to the Prediction of RI Level Caused by Corona Discharge

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Plasma Science and Technology 2012年第12期14卷 1091-1096页

作者： ZHU lingyu JI Shengchang HUI Sisi GUO Jun LI Yansong FU Chenzhao The State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong University Xi'an 710049 China Shanxi Electric Power Corporation Taiyuan 030001 China Electric Power Research Institute SMEPC Shanghai 200437 China

Radio interference （RI）, as an aftereffect of corona discharge, is an important research topic in the field of electromagnetic compatibility, where excitation function is applied broadly to the prediction of RI level. This paper presents the theory of excitation function method used in the RI level prediction. Then, some practical problems related to this method are discussed. The propagation procedure of corona current is solved by the phase-modal transformation, and the impedance matrix of multi transmission lines is calculated by a double logarithmic approximate model of Carson＇s Ground-Return impedance. At the same time, in order to calculate the RI level when total line corona is assumed, an analytical formula is deduced for integral operation. Based on the above solutions, an algorithm is presented and applied to the prediction of RI level of a practical overhead transmission line. Comparison of prediction and measurement results indicates that the algorithm proposed in this paper is effective and feasible.

关键词： radio interference excitation function modal propagation Ground-Return impedance

Expert Recommendation in Community Question Answering via Heterogeneous Content Network Embedding

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Computers, Materials & Continua 2023年第4期75卷 1687-1709页

作者： Hong Li Jianjun Li Guohui Li Rong Gao lingyu Yan School of Computer Science and Technology Huazhong University of Science and TechnologyWuhan 430074China College of Computer Science and Technology Hubei University of TechnologyWuhan 430068China

ExpertRecommendation(ER)aims to identify domain experts with high expertise and willingness to provide answers to questions in Community Question Answering(CQA)web *** to model questions and users in the heterogeneous content network is critical to this *** traditional methods focus on modeling questions and users based on the textual content left in the community while ignoring the structural properties of heterogeneous CQA networks and always suffering from textual data sparsity *** approaches take advantage of structural proximities between nodes and attempt to fuse the textual content of nodes for ***,they often fail to distinguish the nodes’personalized preferences and only consider the textual content of a part of the nodes in network embedding learning,while ignoring the semantic relevance of *** this paper,we propose a novel framework that jointly considers the structural proximity relations and textual semantic relevance to model users and questions more ***,we learn topology-based embeddings through a hierarchical attentive network learning strategy,in which the proximity information and the personalized preference of nodes are encoded and ***,we utilize the node’s textual content and the text correlation between adjacent nodes to build the content-based embedding through a meta-context-aware skip-gram *** addition,the user’s relative answer quality is incorporated to promote the ranking *** results show that our proposed framework consistently and significantly outperforms the state-of-the-art baselines on three real-world datasets by taking the deep semantic understanding and structural feature learning *** performance of the proposed work is analyzed in terms of MRR,P@K,and MAP and is proven to be more advanced than the existing methodologies.

关键词： Heterogeneous network learning expert recommendation semantic representation community question answering

Effect of surface modification of electrodes on charge injection and dielectric characteristics of propylene carbonate

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High Voltage 2020年第1期5卷 15-23页

作者： Shilin Wu Qing Yang Tao Shao Zhaotian Zhang lingyu Huang State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing UniversityShapingbaChongqing 400044People's Republic of China Chinese Academy of Sciences Institute of Electrical EngineeringBeijing 100190People's Republic of China

Space charge injected into a liquid dielectric by an electrode under an impulse voltage causes the electric field to be distorted,which affects the dielectric's insulation *** this study,the authors study the surface modification of three-electrode materials,namely aluminium,copper,and stainless steel,by sputtering of titanium dioxide(TiO2)based on magnetron *** breakdown voltage of propylene carbonate and the surface morphology of the electrodes before and after modification were ***,the distribution of the space charge injected into the propylene carbonate from the different electrode materials was also measured based on the Kerr electro-optic *** results indicate that the breakdown voltage of propylene carbonate increased by 7,4,and 9%after surface modification of aluminium,copper,and stainless steel,*** sputtering of TiO2,micro-grooves on the surface of the three-electrode materials became smooth,and the surface roughness decreased,which changed the barrier height of the solid–liquid *** space charge injection mode of the three-electrode materials before and after surface modification was bipolar injection;however,the space charge injection amounts were markedly lower for the modified electrodes.

关键词： injection carbonate charge

Bioinspired Adhesive and Antibacterial Microneedles for Versatile Transdermal Drug Delivery

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Research 2020年第1期2020卷 562-570页

作者： Xiaoxuan Zhang Guopu Chen Yunru Yu lingyu Sun Yuanjin Zhao Department of Rheumatology and Immunology The Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjing 210008China State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China

Microneedles have attracted increasing interest among various medical fields due to their painless,noninvasive,and efficient way of drug ***,practical applications of these microneedles in different epidermal locations and environments are still restricted by their low adhesion and poor antimicrobial ***,inspired by the antibacterial strategy of Paenibacillus polymyxa and adhesion mechanisms of mussel byssi and octopus tentacles,we develop hierarchical microneedles with multifunctional adhesive and antibacterial *** polydopamine hydrogel as the microneedle base and a loop of suctioncup-structured concave chambers encircling each microneedle,the generated microneedles can fit the skin well;keep strong adhesion in dry,moist,and wet environments;and realize self-repair after being split into two ***,as polymyxin is loaded into both the hydrogel tips and the polydopamine base,the microneedles are endowed with excellent ability to resist common bacteria during storage and *** have demonstrated that these microneedles not only showed excellent adhesion when applied to knuckles and ideal antibacterial activity but also performed well in drug-sustained release and treatment for the osteoarthritis rat *** results indicate that bioinspired multifunctional microneedles will break through the limitation of traditional methods and be ideal candidates for versatile transdermal drug delivery systems.

关键词： needle base sustained

Microfluidic Generation of Microsprings with Ionic Liquid Encapsulation for Flexible Electronics

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Research 2019年第1期2019卷 842-850页

作者： Yunru Yu Jiahui Guo lingyu Sun Xiaoxuan Zhang Yuanjin Zhao State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China

Inspired by helical or spiral veins,which endow plants with excellent fexibility and elasticity to withstand storms,we present novel hollow microsprings with ionic liquid encapsulation for fexible and stretchable *** microsprings were generated by using a coaxial capillary microfuidic device to consecutively spin poly(vinylidene fuoride)(PVDF)presolution and an ionic liquid,which formed laminar fows in the coaxial injection microfuidic *** fast phase inversion of PVDF helps to form the core-shell structure of a microfber and guarantees the in situ encapsulation of ionic *** hybrid microfber can then spiral and be further solidifed to maintain the helical structure with increasing fow rates of the injection *** of the feasible and precise control of the injection fuids during the microfuidic spinning,the resultant microsprings have controlled core-shell structures,helical pitches,and corresponding electromechanical *** further embedding them into stretchable flms,the simple paradigm of a fexible device shows great conductive performance in tensile tests and even motion cycles,which could be explored as a promising candidate in stretchable sensors,fexible electronics,and electronic skins.

关键词： properties rings helical