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Experimental Research on Inlet Steady Swirl Distortion in an Axial Compressor with Non-Uniform Tip Clearance

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Journal of Thermal Science 2023年第1期32卷 286-296页

作者： XU Rong HU Jun WANG Xuegao JIANG Chao LI wenyu College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The inlet swirl distortion and non-uniform tip clearance have great effects on aero-engine performance and stall margin.In this paper,the effects of paired swirl distortion on the aerodynamic stability and stall inception of a single stage axial compressor with non-uniform tip clearance are quantitatively analyzed by using the swirl distortion descriptors.The experimental results show that the paired swirl distortion dominated by co-rotating swirl improves the stability of the axial compressor.For a single-stage axial compressor with eccentricity of 100%,the stall inception starts at the maximum tip clearance with clean inlet.The initial position of the stall inception is determined by the maximum tip clearance when the small intensity paired swirl distortion exists at the compressor inlet.As the swirl intensity increases,it shifts towards the position of the counter rotating swirl vortex core.The inlet swirl will not change the type of stall inception.

关键词： steady swirl distortion non-uniform tip clearance stall inception experiment research compressor performance

Review of reader antennas for UHF RFID systems

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The Journal of China Universities of Posts and Telecommunications 2023年第5期30卷 72-92页

作者： Niu Yaohui li Xiuping Zhao wenyu State Key Laboratory of Information Photonics and Optical Communications Beijing 100876China Key Laboratory of Universal Wireless Communications of Ministry of Education Beijing 100876China Beijing Key Laboratory of Work Safety Intelligent Monitoring Beijing 100876China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Radio-frequency identification(RFID)antennas are critical components in wireless communication networks for the Internet of things(IoT).The RFID systems make it possible to realize the dynamic interconnection of various things.To better summarize the operating principles of the RFID antennas and associate antennas with specific complex applications,a review of RFID systems and antennas is necessary.In this paper,a review of reader antennas for ultra-high frequency(UHF)RFID systems is presented,and the categories of RFID systems are summarized for the first time.The antennas are classified according to the reading region and operating principle.The reading region determines the most crucial performance that should be concentrated on when designing an antenna,while the operating principle affects the current distribution on the surface of the antenna,and further the electromagnetic radiation.By the summary of the RFID systems and antennas,the understanding of future researchers on the operating principles of the RFID antennas could be facilitated,which can be helpful in the advanced design and implementation of RFID antennas.In addition,taking engineering requirements into account,the future prospective of RFID applications is discussed,as well as the challenges to be addressed.

关键词： radio frequency identification(RFID) near-field antenna ultra-high frequency(UHF) RFID system

A dual-mode fiber-shaped flexible capacitive strain sensor fabricated by direct ink writing technology for wearable and implantable health monitoring applications

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Microsystems & Nanoengineering 2023年第6期9卷 321-331页

作者： Chi Zhang wenyu Ouyang Lei Zhang Dachao li State Key Laboratory of Precision Measuring Technology and Instruments Tianjin University300072 TianjinChina

Flexible fiber-shaped strain sensors show tremendous potential in wearable health monitoring and human‒machine interactions due to their compatibility with everyday clothing.However,the conductive and sensitive materials generated by traditional manufacturing methods to fabricate fiber-shaped strain sensors,including sequential coating and solution extrusion,exhibit limited stretchability,resulting in a limited stretch range and potential interface delamination.To address this issue,we fabricate a fiber-shaped flexible capacitive strain sensor(FSFCSS)by direct ink writing technology.Through this technology,we print parallel helical Ag electrodes on the surface of TPU tube fibers and encapsulate them with a high dielectric material BTO@Ecoflex,endowing FSFCSS with excellent dual-mode sensing performance.The FSFCSS can sense dual-model strain,namely,axial tensile strain and radial expansion strain.For axial tensile strain sensing,FSFCSS exhibits a wide detection range of 178%,a significant sensitivity of 0.924,a low detection limit of 0.6%,a low hysteresis coefficient of 1.44%,and outstanding mechanical stability.For radial expansion strain sensing,FSFCSS demonstrates a sensitivity of 0.00086 mmHg−1 and exhibits excellent responsiveness to static and dynamic expansion strain.Furthermore,FSFCSS was combined with a portable data acquisition circuit board for the acquisition of physiological signals and human‒machine interaction in a wearable wireless sensing system.To measure blood pressure and heart rate,FSFCSS was combined with a printed RF coil in series to fabricate a wireless hemodynamic sensor.This work enables simultaneous application in wearable and implantable health monitoring,thereby advancing the development of smart textiles.

关键词： wear strain shaped

Modification of Melting Combustion Kinetic Model of Fine Ash from Entrained-Flow Gasifier

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Journal of Thermal Science 2024年第1期33卷 300-310页

作者： WANG wenyu li Wei LU Yu REN Qiangqiang LYU Qinggang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory for Clean Energy Chinese Academy of SciencesDalian 116023China

Coal gasification technology is a prominent technology in the coal chemical industry and serves as the fundamental basis for various process industries,including coal-based chemicals,coal-based liquid fuels,Integrated Gasification Combined Cycle(IGCC) power generation,multi-generation systems,hydrogen production,and fuel cells.The gasification process generates significant quantities of ash residue,with annual emissions exceeding tens of millions of tons and accumulation reaching hundreds of millions of tons.Accordingly,there is an urgent need to investigate methods for its disposal.The combustion of gasified fine ash(GFA) was conducted in a tube furnace,and the conventional shrinking core model was modified to accurately predict the combustion behaviors at different temperatures(900℃-1500℃).We divided the reaction temperatures into three ranges,which is defined as unmelted combustion(TFT) and mixed combustion(DTFT),the surface ash of GFA grains fell off,and the residual carbon and gas-phase reactants were nearly no longer affected by the diffusion resistance,thus significantly accelerated the reaction of internal residual carbon.In order to predict the melt combustion process more accurately,the time term of the shrinkage core model(SCM) is modified,and the effective diffusion coefficient of T>FT is defined.

关键词： fine ash melting combustion kinetic model combustion characteristics

Self-Renewal Consortium Blockchain Based on Proof of Rest and Strong Smart Contracts

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Tsinghua Science and Technology 2022年第6期27卷 964-972页

作者： wenyu Shen Xuebing Huang Yunshan Fu Yongwei Hou li ling School of Information Science and Technology Fudan UniversityShanghai 200433China

Focusing on the business alliance scenario in blockchains,this paper proposes a new consensus mechanism named proof of rest(PoR)and strong smart contracts.The block structure and logic of PoR consensus are described.And a consortium blockchain system supporting strong smart contracts is designed.We modify the difficulty value algorithm based on proof of work(PoW)and add adjustable parameters.The longer a node rests after creating a block,the less difficult it is to create another new block,hence the term PoR.The penalty for slack nodes,the joining and quitting of nodes,and the adjustment of the expected block creation time can all be accomplished using the strong smart contracts,so the consortium blockchain can realize self-renewal.

关键词： blockchain consortium chain proof of rest(PoR) smart contract self-renewal

Efficient nitrite-to-ammonia electroreduction over Zr-Ni frustrated Lewis acid-base pairs

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Science China Chemistry 2024年第5期67卷 1707-1714页

作者： Ying Zhang Zhuohang li wenyu Du Kai Chen Ke Chu School of Materials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.

关键词： electrochemical nitrite-to-ammonia conversion frustrated Lewis acid-base pairs(FLPs) in situ spectroscopy theoretical computations

Wideband circular-polarized transmitarray for generating a high-purity vortex beam

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Frontiers of Information Technology & Electronic Engineering 2023年第6期24卷 927-934页

作者： liangjie QIU Xiuping li Zihang QI wenyu ZHAO Yuhan HUANG State Key Laboratory of Information Photonics and Optical Communications Beijing 100876China MOE Key Laboratory of Universal Wireless Communications Beijing 100876China Beijing Key Laboratory of Work Safety Intelligent Monitoring Beijing 100876China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Institute of Spacecraft System Engineering Beijing 100094China

In this correspondence,a wideband circular-polarized(CP)transmitarray(TA)in the Ka-band is presented for generating a high-purity vortex beam.The proposed element is composed of two identical combinations separated by an air layer.The subwavelength structure and double-resonance characteristics ensure the stable phase shift of the element within the 1-dB transmission bandwidth of 28.4%.A square aperture TA fed by a horn antenna is fabricated and measured.Owing to the honeycomb arrangement of elements,the mode purity of l=−1 is>0.93 in a wide band from 28.5 to 38 GHz.The measured peak gain is 22.3 dBic,and the 3-dB axial ratio bandwidth is 27.6%.The performance of the proposed antenna demonstrates its potential for high-capacity wireless communication and high-quality radar imaging.

关键词： antenna generating circular

A Causal Configuration Analysis of Payment Decision Drivers in Paid Q&A

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Journal of Data and Information Science 2021年第2期6卷 139-162页

作者： wenyu Chen Yan Cheng Jia li School of Business East China University of Science and TechnologyShanghai 200237China

Purpose:This paper examines factors of payment decision as well as the role each factor plays in casual configurations leading to high payment intention under systematic and heuristic information processing routes.Design/methodology/approach:Based on heuristic-systematic model(HSM),we propose a configurational analytic framework to investigate complex casual relationships between influencing factors and payment decision.In line with this approach,we use fuzzy-set qualitative comparative analysis(fsQCA)to analyze data crawled from Zhihu.com.Findings:The number of previous consultations is a necessary element in all five equivalent configurations which lead to high intention in payment decision.The heuristic processing route plays a core role while the systematic processing route plays a peripheral role in payment decision-making process.Research limitations:Research is limited in that moderating effect of professional fields has not been considered in the framework.Practical implications:Configurations in results can assist managers of knowledge communities and paid Q&A service providers in the management of information elements to motivate more payment decision.Originality/value:This paper is one of the few studies to apply HSM theory and fsQCA method with respect to the payment decision in paid Q&A.

关键词： Payment decision Paid Q&A Dual-process theory Configurational paradigm Fuzzy-set qualitative comparative analysis(fsQCA)

Automatic extraction method of force chain information and its application in the flow photoelastic experiment of granular matter

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Particuology 2023年第12期83卷 142-155页

作者： Qingfa Chen Enlin Long Wenjing Niu Jun liu wenyu Fan Hangyu li School of Civil Engineering and Architecture Key Laboratory of Disaster Prevention and Structural Safety of Ministry of EducationGuangxi UniversityNanning530004China School of Resources Environment and MaterialsGuangxi UniversityNanning530004China

The force chain is the core of the multi-scale analysis of granular matter.Accurately extracting the force chain information among particles is of great significance to the study of particle mechanics and geological hazards caused by particle flow.However,in the photoelastic experiment,the precise identification of the branching points of force chains has not been effectively realized.Therefore,this study proposes an automatic extraction method of force chain key information.First,based on the Hough transform and the Euclidean distance,a particle geometric information identification model is established and geometric information such as particle circle center coordinates,radius,contact point location,and contact angle is extracted.Then,a particle contact force information identification model is established following the color gradient mean square method.The model realizes the rapid calibration and extraction of a large number of particle media contact force information.Next,combined with the force chain composition criterion and its quasilinear feature,an automatic extraction method of force chain information is established,which solves the problem of the accurate identification of the force chain branch points.Finally,in the photoelastic experiment of ore drawing from a single drawpoint,the automatic extraction method of force chain information is verified.The results show that the macroscopic distribution of force chains during ore drawing from a single drawpoint is left–right symmetrical.Strong force chains are mostly located on the two sides of the model but in small numbers and they mainly develop vertically.Additionally,the ends are mostly in a combination of Y and inverted Y shapes,while the middle is mostly quasilinear.Weak force chains are abundant and mostly distributed in the middle of the model,and develop in different directions.The proposed extraction method accurately extracts the force chain network from the photoelastic experiment images and dynamically characterizes the force chains of granular

关键词： Granular matter Photoelastic experiment Digital image processing Force chain extraction method