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Resonance mechanism of flapping wing based on fluid structure interaction simulation

Chinese Journal of Aeronautics 2024年第5期37卷 243-262页

作者： Yueyang GUO Wenqing YANG Yuanbo DONG Dong XUE National Key Laboratory of Science and Technology on Aerodynamic Design and Research School of AeronauticsNorthwestern Polytechnical UniversityXi'an 710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China Yangtze River Delta Research Institute of Northwestern Polytechnical University Taicang 215400China

Certain insect species have been observed to exploit the resonance mechanism of their *** order to achieve resonance and optimize aerodynamic performance,the conventional approach is to set the flapping frequency of flexible wings based on the Traditional Structural Modal(TSM)***,there exists controversy among researchers regarding the relationship between frequency and aerodynamic *** that the structural response of wings can be influenced by the surrounding air vibrations,an analysis known as Acoustic Structure Interaction Modal(ASIM)is introduced to calculate the resonant *** this study,Fluid Structure Interaction(FSI)simulations are employed to investigate the aerodynamic performance of flapping wings at modal frequencies derived from both TSM and ASIM *** performance is evaluated for various mass ratios and frequency ratios,and the findings indicate that the deformation and changes in vortex structure exhibit similarities at mass ratios that yield the highest aerodynamic ***,the flapping frequency associated with the maximum time-averaged vertical force coefficient at each mass ratio closely aligns with the ASIM frequency,as does the frequency corresponding to maximum ***,the ASIM analysis can provide an effective means for predicting the optimal flapping frequency for flexible ***,it enables the prediction that flexible wings with varying mass ratios will exhibit similar deformation and vortex structure *** paper offers a fresh perspective on the ongoing debate concerning the resonance mechanism of Flexible Flapping Wings(FFWs)and proposes an effective methodology for predicting their aerodynamic performance.

关键词： Flexible Flapping Wing(FFW) Acoustic Structure Interaction Modal(ASIM) Fluid Structure Interaction(FSI) Resonance mechanism Aerodynamic performance

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Application and Practice of Smart Education technology in Blended Teaching of Engineering Drawing Course 24

Application and Practice of Smart Education Technology in Bl...

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9th International Conference on Distance Education and Learning, ICDEL 2024

作者： Xu, Jinyou Tian, He Wang, Xiaofei Xue, Yahong Li, Ling Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin University of Technology China School of Environmental Science and Safety Engineering Tianjin University of Technology Tianjin China

ISBN: (纸本)9798400716805

The expeditious progress of information technology has encouraged the digital enhancement of the educational sector. To remedy the issues of the traditional teaching mode, a blended teaching mode of engineering drawing course has been developed with the use of smart education technology. Based on the Outcomes-based Education ( OBE ), the teaching objectives and teaching contents of the course are reconstructed by using the method of reverse design and forward implementation. By leveraging the synergy of online and offline, virtual and real, and quantitative and qualitative evaluation, a blended teaching approach that is both student-centered and teacher-guided is realized. A course knowledge graph has been built, offering fresh concepts for accomplishing personalized learning for students. The teaching practice shows that the blended teaching mode based on intelligent education has created a multi-dimensional autonomous learning space and personalized learning path for students, which effectively improves the enthusiasm and initiative of students to participate in teaching activities, and also improves the information level of teaching process and management, and promotes the organic integration of teaching and learning. © 2024 ACM.

关键词： Contrastive Learning

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Interface Characteristics and Evolution Mechanism of W/CuCrZr in Hot Melt Explosion Welding

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稀有金属材料与工程 2024年第11期53卷 3077-3083页

作者： Sun Yuling Liang Hanliang Zhu Jiansheng Ma Honghao Wang Luqing ZhangBingyuan Luo Ning Shen Zhaowu CAS Key Laboratory of Mechanical Behavior and Design of Materials University of Science and Technology of ChinaHefei 230026China PLA Army Academy of Artillery and Air Defense Hefei 230031China University of Science and Technology of China Hefei 230026China School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhou 221116China

Explosion welding was carried out on the basis of vacuum hot melt W/CuCrZr composite *** microscope,scanning electron microscope and energy dispersive X-ray spectroscope were used to observe the microscopic morphology of the bonding *** the same time,combined with finite element calculations,the evolution mechanism of the interface of the hot melt explosion welded W/CuCrZr composite plate was *** results show that the interface bonding of the hot melt explosion welded W/CuCrZr composite plate is good and there is a cross-melting zone with 3–8μm in thickness,but cracks are developed on the W *** numerical simulation reproduces the changes of pressure,stress,strain and internal energy at the bonding interface in the process of hot melt explosion *** location of the crack generated in the experiment coincides with the high stress position calculated by numerical *** high pressure and high temperature near the hot melt explosion welding interface further promote the bonding of the interface.

关键词： hot melt explosion welding W/CuCrZr interface characteristics numerical simulation evolution mechanisms

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Effect of SiC-coated diamond and its size on the relative density and thermal conductivity of diamond/W composites

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Ceramics International 2025年第15期51卷 19815-19827页

作者： Cao, Zhenya Xue, Yongsheng Jiang, Zhizhong Sun, Jialong Hefei Institutes of Physical Science Chinese Academy of Sciences Anhui Hefei230031 China Anhui Province Key Laboratory of Micro/Small Nuclear Reactor Technology Institute of Nuclear Energy Safety Technology Chinese Academy of Sciences Anhui Hefei230031 China North China University of Water Resources and Electric Power Zhengzhou450045 China Shanghai Radio Equipments Research Institute Shanghai201109 China

In this study, SiC coating was deposited on the diamond surfaces by magnetron sputtering, and SiC-coated diamonds with a diamond size of 100–400 μm were employed to prepared diamond(SiC)/W composite for improving the interface bonding and thermal conductivity. The effects of SiC coating and diamond size on the interfacial bonding, evolution of interfacial structure and thermal conductivity of composite were investigated. The results showed that a relatively homogeneous SiC coating was formed after 16h of deposition at a sputtering power of 150W. At a diamond size of 200 μm, when the diamond addition was lower than 40 vol%, through W-SiC interface reaction, SiC coating can improve the interface bonding, and increase the relative density and thermal conductivity of composites. As the diamond addition increased to 50-60 vol%, the enhanced degree of W-SiC reaction would lead to the broken and migration of WC-SiC layer under the action of sintering temperature, pressure and local Joule heat, causing an increase in interface defects and a decrease in thermal conductivity of composites. 40 vol%diamond(SiC)/W composite achieved the higher thermal conductivity of 152 W m−1 K−1. Increasing the diamond size would help increase the densification and heat transfer efficiency of composite, and 40 vol%diamond(SiC)/W composite with a diamond size of 400 μm possessed the maximum relative density and thermal conductivity, i.e. 96.78 % and 225 W m−1 K−1. © 2025

关键词： Sintering

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Dynamic response of the cell traction force to osmotic shock

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Microsystems & Nanoengineering 2023年第5期9卷 321-331页

作者： Yongman Liu Wenjie Wu Shuo Feng Ye Chen Xiaoping Wu Qingchuan Zhang Shangquan Wu School of Biomedical Engineering Anhui Medical University230032 HefeiChina CAS Key Laboratory of Mechanical Behavior and Design of Material Department of Modern MechanicsCAS Center for Excellence in Complex System MechanicsUniversity of Science and Technology of China230026 HefeiChina

Osmotic pressure is vital to many physiological activities,such as cell proliferation,wound healing and disease ***,how cells interact with the extracellular matrix(ECM)when subjected to osmotic shock remains ***,we visualize the mechanical interactions between cells and the ECM during osmotic shock by quantifying the dynamic evolution of the cell traction *** show that both hypertonic and hypotonic shocks induce continuous and large changes in cell traction ***,the traction force varies with cell volume:the traction force increases as cells shrink and decreases as cells ***,the direction of the traction force is independent of cell volume changes and is always toward the center of the cell-substrate ***,we reveal a mechanical mechanism in which the change in cortical tension caused by osmotic shock leads to the variation in traction force,which suggests a simple method for measuring changes in cell cortical *** findings provide new insights into the mechanical force response of cells to the external environment and may provide a deeper understanding of how the ECM regulates cell structure and function.

关键词： traction healing wound

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High-Performance in N-Type Pbte Thermoelectric Materials by Defects Management and Extraordinary Role of Cd Alloying

SSRN

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SSRN 2024年

作者： Chen, Zhiyu Li, Mancang Chen, Zhang Wang, Yu Zhou, Daijie Huang, Xueliang Zhang, Xinhu Guo, Rui Liu, Xianbo Wang, Zhengshang Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China Sichuan Research Center of New Materials Chengdu610000 China

The conventional multiple isovalent alloying is proved to be effective for enhancing n-type PbTe thermoelectrics. However, the introduction of various elements undeniably leads to potential stability concerns during material application. Here, we propose a straightforward strategy that leverages Cd alloying and defect management to enhance the TE performance of n-type PbTe. The Cd doping facilitates band gap widening, resulting in increased effective mass and Seebeck coefficient, especially at elevated temperatures due to the improved Cd solubility. Furthermore, the introduction of excess Pb atoms serves to occupy intrinsic Pb vacancies, consequently enhancing carrier mobility. As a result, the maximum power factor of Cd-alloyed Pb1.01Te samples reaches 31.5 μW cm-1 K-2, signifying a remarkable improvement of 69.3% in comparison to pristine PbTe. Additionally, the enlarged band gap induced by Cd alloying also effectively mitigates bipolar diffusion, combining with the enhanced phonon scattering due to CdTe secondary phase, yields a 34.3% decrease in thermal conductivity. By harnessing the multifaceted effects of Cd alloying and defect management, the ZT value of Pb1.01Te-2%Cd samples reaches 1.35 at 782 K. The present findings provide a novel perspective on the versatile utilization of single isovalent element alloying and the optimization of performance across other TE materials. © 2024, The Authors. All rights reserved.

关键词： Energy gap

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Computational homogenization of thermomechanical properties for Fully Ceramic Microencapsulated fuel with 3D printed SiC matrix

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Annals of Nuclear Energy 2025年 222卷

作者： Chen, Yiwen Lu, Qi Liu, Changwen Li, Wei Zhang, Dalin Su, G.H. State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi'an Jiaotong University Xi'an710049 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu61213 China State Key Laboratory for Strength and Vibration of Mechanical Structures Xi'an Jiaotong University Xi'an710049 China

Fully Ceramic Microencapsulated (FCM) fuel, fabricated using 3D printing technology, incorporates traditional Tristructural-Isotropic (TRISO) fuel particles embedded within a 3D-printed SiC matrix. This fuel type shows great potential for compact, high-temperature nuclear reactors. However, comprehensive performance analysis remains challenging due to the multilayered structure, complex material properties, and the irradiation behavior of numerous TRISO particles within the matrix. To address these challenges, this study aims to apply finite element (FE)-based computational homogenization to evaluate the fuel's thermomechanical properties. First, a detailed finite element analysis (FEA) of a single TRISO particle's performance was conducted, focusing primarily on the Buffer-IPyC gap size change during irradiation, a critical factor influencing the fuel's thermal performance. Second, the homogenization of a single TRISO particle was performed using FEA, accounting for the changes in the Buffer-IPyC gap size. Finally, homogenized TRISO particles were randomly distributed and perfectly bonded within a 3D-printed SiC matrix to form a Representative Volume Element (RVE). The FE homogenization of the RVE was then conducted to derive the effective thermomechanical properties of the FCM fuel. The packing fraction of TRISO particles in the matrix ranged from 10 % to 50 %, with temperature and burnup conditions spanning 800–1600 K and 0–16 % FIMA, respectively. Results show that irradiation significantly affects the effective properties of the fuel, though this impact diminishes as burnup increases. Additionally, the effective thermal conductivity of the FCM fuel decreases with increasing TRISO packing fraction, assuming the thermal conductivity of the SiC matrix exceeds that of TRISO particles. This study provides a valuable reference for the design and optimization of FCM fuel for future nuclear applications. © 2025 Elsevier Ltd

关键词： Thermal conductivity of solids

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Terahertz circularly polarized detection structures based on metasurfaces with high transmittance and extinction ratio 2

Terahertz circularly polarized detection structures based on...

引用

Advanced Optical Manufacturing Technologies and Applications 2022, AOMTA 2022 and 2nd International Forum of Young Scientists on Advanced Optical Manufacturing, YSAOM 2022

作者： Yang, Bowei Ouyang, Mingzhao Ren, Hang Zhang, Ziqiang Fu, Yuegang School of Optoelectronic Engineering Changchun University of Science and Technology Changchun130022 China Key Laboratory of Optoelectronic Measurement and Optical Information Transmission Technology Ministry of Education Changchun University of Science and Technology Changchun130022 China Key Laboratory of Advanced Optical System Design and Manufacturing Technology The Universities of Jilin Province Changchun130022 China

ISBN: (纸本)9781510661264

Circularly polarized light is widely used in wireless communications, polarized imaging and circular dichroism spectroscopy. The existing miniature circular polarization detection structure cannot guarantee high transmission efficiency and extinction ratio at the same time. In this paper, we propose a terahertz circularly polarized detection metasurface based on dielectric materials. The proposed structure can well distinguish the handedness of circularly polarized light. At 2.3Thz, the transmission efficiency is greater than 95% and the extinction ratio is greater than 250dB. I believe our design could facilitate the development of devices such as small biomedical imaging. © 2023 SPIE.

关键词： Circular polarization

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design of an All-Fiber Fabry-Perot Sensor for Strain Measurement in Radiative Environment

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Photonic Sensors 2022年第4期12卷 81-90页

作者： Tingting YANG Zengling RAN Xiu HE Lupeng GAN Zhengxi HE Jialiang ZHU Peng HE Zhuoyue LI Dong SUN Key Laboratory of Optical Fiber Sensing&Communications(Ministry of Education) University of Electronic Science and Technology of ChinaChengdu 611731China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

A length-matched micro Fabry-Perot(FP)interferometer is proposed for strain measurement under irradiation *** simulation shows that a well length-matched FP sensor can achieve a very low drift of the cavity length and strain sensitivity in irradiation *** experiment,such an FP cavity is realized by laser *** shows a low cavity length drift of−0.037μm and a strain sensitivity deviation of 0.52%,respectively,under gamma ***,the intensity of interference fringes is also *** a result,such a length-matched FP cavity is a very promising candidate for strain sensing in radiative environments.

关键词： Gamma radiation Fabry-Perot sensor radiation-induced compaction strain sensing

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Matthew effect:General design strategy of ultra-fluorogenic nanoprobes with amplified dark–bright states in aggregates

Aggregate

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Aggregate 2024年第2期5卷 482-492页

作者： Shinsuke Segawa Xinwen Ou Tianruo Shen Tomohiro Ryu Yuki Ishii Herman H.Y.Sung Ian D.Williams Ryan T.K.Kwok Ken Onda Kiyoshi Miyata Xuewen He Xiaogang Liu Ben Zhong Tang Translational and Advanced Bioimaging Laboratory Department of Chemical and Biological EngineeringSchool of EngineeringThe Hong Kong University of Science and TechnologyKowloonHong KongChina Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction and Institute for Advanced StudyThe Hong Kong University of Science and TechnologyKowloonHong KongChina Science Mathematics and Technology ClusterSingapore University of Technology and DesignSingaporeSingapore Department of Chemistry Graduate School of ScienceKyushu UniversityNishi-kuFukuokaJapan The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou College of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsuChina School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhenGuangdongChina

Fluorescence imaging,a key technique in biological research,frequently utilizes fluorogenic probes for precise imaging in living *** is an effective emission quencher in fluorogenic probe designs,which can be selectively damaged upon bioorthogonal click reactions,leading to considerable emission *** significant efforts to increase the emission enhancement ratio(I_(AC)/I_(BC))of tetrazine-functionalized fluorogenic probes,the influence of molecular aggregation on the emission properties has been largely overlooked in these probe *** this study,we reveal that an ultrahigh I_(AC)/I_(BC)can be realized in the aggregate system when tetrazine is paired with aggregation-induced emission(AIE)*** amplifies its quenching efficiency upon aggregation and drastically reduce background *** click reactions damage tetrazine and trigger significant AIE,leading to considerably enhanced I_(AC)/I_(BC).We further showcase the capability of these ultra-fluorogenic systems in selective imaging of multiple organelles in living *** term this unique fluorogenicity of AIE luminogen-quencher complexes with amplified dark-bright states as“Matthew effect”in aggregate emission,potentially providing a universal approach to attain ultrahigh I_(AC)/I_(BC)in diverse fluorogenic systems.

关键词： aggregation-induced emission bioorthogonal chemistry click chemistry fluorescence imaging tetrazine

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