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Frequency-domain analysis of fluid-structure interaction in aircraft hydraulic pipeline systems: numerical and experimental studies

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第8期25卷 605-617页

作者： Yang deng Zongxia JIAO Yuanzhi XU School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Research Institute for Frontier Science Beihang UniversityBeijing 100191China Key Laboratory of Advanced Airborne Systems Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315800China Tianmushan Laboratory Hangzhou 310023China

The fluid-structure interaction(FSI)in aircraft hydraulic pipeline systems is of great concern because of the damage it *** accurately predict the vibration characteristic of long hydraulic pipelines with curved segments,we studied the frequency-domain modeling and solution method for FSI in these pipeline *** partial differential equations(PDEs)are utilized to model the pipeline FSI,considering both frequency-dependent friction and bending-flexibility *** address the numerical instability encountered by the traditional transfer matrix method(TMM)in solving relatively complex pipelines,an improved TMM is proposed for solving the PDEs in the frequency domain,based on the matrix-stacking strategy and matrix representation of boundary *** proposed FSI model and improved solution method are validated by numerical cases and *** experimental rig of a practical hydraulic system,consisting of an aircraft engine-driven pump,a Z-shaped aero-hydraulic pipeline,and a throttle valve,was constructed for *** magnitude ratio of acceleration to pressure is introduced to evaluate the theoretical and experimental results,which indicate that the proposed model and solution method are effective in practical *** methodology presented in this paper can be used as an efficient approach for the vibrational design of aircraft hydraulic pipeline systems.

关键词： Fluid-structure interaction(FSI) Frequency-domain analysis Aircraft hydraulic pipeline Pipeline vibration Transfer matrix method(TMM)

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自由贸易账户与多账户体系比较研究

新金融 2019年第12期 21-25页

作者：邓志超景建国复旦大学新闻学院博士后流动站上海市经济学会金融开放研究院上海市金融学会

建立本外币一体化账户体系是上海自贸区建设的核心抓手,如何丰富和拓展现有的自由贸易账户功能是当前推进对外开放的一个重要议题。通过梳理前人关于自由贸易账户的观点,本文认为自由贸易账户对自贸区而言起到了"电子围网"的作用,同时... 详细信息

建立本外币一体化账户体系是上海自贸区建设的核心抓手,如何丰富和拓展现有的自由贸易账户功能是当前推进对外开放的一个重要议题。通过梳理前人关于自由贸易账户的观点,本文认为自由贸易账户对自贸区而言起到了"电子围网"的作用,同时阐释了金融开放与金融风险之间的关系,然后对自由贸易账户、离岸账户和NRA账户进行比较分析,最后提出了发展账户体系便利自由贸易的一些建议。

关键词：自贸区自由贸易账户离岸账户 NRA账户

Gait Recognition Under Different Clothing Conditions Via Deterministic Learning

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1530-1532页

作者： Muqing deng Cong Wang School of Automation Guangdong University of TechnologyGuangzhou 510006China School of Control Science and Engineering Shandong UniversityJinan 250100China

Dear Editor,This letter deals with the robustness problem of gait recognition method against maximum number of clothing *** selecting four kinds of time-varying silhouette features,gait dynamics underlying different individuals’gait features is effectively modeled by radial basis function(RBF)neural networks through deterministic *** kind of dynamics information has little sensitivity to the variance between gait patterns under different clothing *** order to eliminate the effect of clothing differences,the training patterns under different clothing conditions further constitute a uniform training dataset,containing all kinds of gait dynamics under different clothing conditions.A rapid recognition scheme is presented on published gait *** experiments demonstrate the efficacy of the proposed method.

关键词： networks neural individual

EAE-Net: effective and efficient X-ray joint detection

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Optoelectronics Letters 2024年第10期20卷 629-635页

作者： WU zhichao WAN Mingxuan BAI Haohao MA Jianxiong MA Xinlong School of Control Science and Engineering Tiangong University Orthopaedics Institute Tianjin Hospital Tianjin University

The detection and localization of bone joint regions in medical X-ray images are essential for contemporary medical diagnostics. Traditional methods rely on subjective interpretation by physicians, leading to variability and potential errors. Automated bone joint detection techniques have become feasible with advancements in general-purpose object detection. However, applying these algorithms to X-ray images faces challenges due to the domain gap. To overcome these challenges, a novel framework called effective and efficient network(EAE-Net) is proposed. It incorporates a context augment module(CAM) to leverage global structural information and a ghost bottleneck module(GBM) to reduce redundant features. The EAE-Net model achieves exceptional detection performance, striking a balance between accuracy and speed. This advancement improves efficiency, enabling clinicians to focus on critical aspects of diagnosis and treatment.

关键词： A

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Nano metal-photosensitizer based on Aza-BODIPY-Cu complex for CDT-enhanced dual phototherapy

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Chinese Chemical Letters 2024年第7期35卷 296-300页

作者： Wenjuan Jin Zelong Chen Yi Wang Jiaxuan Li Jiahui Li Yuxin Pei zhichao Pei College of Chemistry&Pharmacy Northwest A&F UniversityYangling 712100China

Chemodynamic therapy(CDT)combined with dual phototherapy(photothermal therapy(PTT)and photodynamic therapy(PDT))is an efficient way to synergistically improve anti-tumor ***,the combination of multiple modes often makes the composition of the system more complex,which is not conducive to clinical *** this study,a dual phototherapy ligand carboxyl-modified Aza-BODIPY(BOD-COOH)and metal active center Cu^(2+)were used to construct multiple-modes metalphotosensitizer nanoparticles(BOD-Cu NPs)via one-step coordination self-assembly for combination therapy of CDT/PDT/*** order to improve delivery efficiency,the targeted hydrophilic molecule pyridinemodified glucose derivative(G-Py)was synthesized and coated onto the BOD-Cu NPs to form a glycosylated nano metal-photosensitizer BOD-Cu@G by electrostatic *** Cu^(2+)in BOD-Cu@G could not only be used as a coordination node for metal-driven self-assembly but also consume intracellular glutathione(GSH),and then catalyze Fenton-like reaction to generate hydroxyl radical(·OH)for *** vitro and in vivo studies revealed that BOD-Cu@G could achieve excellent anti-tumor efficiency by CDTenhanced dual phototherapy.

关键词： Nano metal-photosensitizer Aza-BODIPY-Cu Coordination self-assembly Chemodynamic therapy Dual phototherapy

A Data Intrusion Tolerance Model Based on an Improved Evolutionary Game Theory for the Energy Internet

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Computers, Materials & Continua 2024年第6期79卷 3679-3697页

作者： Song deng Yiming Yuan Institute of Advanced Technology Nanjing University of Posts and TelecommunicationsNanjing210003China College of Automation Nanjing University of Posts and TelecommunicationsNanjing210003China

Malicious attacks against data are unavoidable in the interconnected,open and shared Energy Internet(EI),Intrusion tolerant techniques are critical to the data security of *** intrusion tolerant techniques suffered from problems such as low adaptability,policy lag,and difficulty in determining the degree of *** address these issues,we propose a novel adaptive intrusion tolerance model based on game theory that enjoys two-fold ideas:(1)it constructs an improved replica of the intrusion tolerance model of the dynamic equation evolution game to induce incentive weights;and (2)it combines a tournament competition model with incentive weights to obtain optimal strategies for each stage of the game *** experiments are conducted in the IEEE 39-bus system,whose results demonstrate the feasibility of the incentive weights,confirm the proposed strategy strengthens the system’s ability to tolerate aggression,and improves the dynamic adaptability and response efficiency of the aggression-tolerant system in the case of limited resources.

关键词： Energy Internet Intrusion tolerance game theory racial competition adaptive intrusion response

Rail-Pillar Net:A 3D Detection Network for Railway Foreign Object Based on LiDAR

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Computers, Materials & Continua 2024年第9期80卷 3819-3833页

作者： Fan Li Shuyao Zhang Jie Yang Zhicheng Feng zhichao Chen School of Electrical Engineering and Automation Jiangxi University of Science and TechnologyGanzhou341000China Jiangxi Provincial Key Laboratory of Maglev Technology Ganzhou341000China School of Information Engineering Jiangxi University of Science and TechnologyGanzhou341000China

Aiming at the limitations of the existing railway foreign object detection methods based on two-dimensional(2D)images,such as short detection distance,strong influence of environment and lack of distance information,we propose Rail-PillarNet,a three-dimensional(3D)LIDAR(Light Detection and Ranging)railway foreign object detection method based on the improvement of ***,the parallel attention pillar encoder(PAPE)is designed to fully extract the features of the pillars and alleviate the problem of local fine-grained information loss in PointPillars pillars ***,a fine backbone network is designed to improve the feature extraction capability of the network by combining the coding characteristics of LIDAR point cloud feature and residual ***,the initial weight parameters of the model were optimised by the transfer learning training method to further improve *** experimental results on the OSDaR23 dataset show that the average accuracy of Rail-PillarNet reaches 58.51%,which is higher than most mainstream models,and the number of parameters is 5.49 *** with PointPillars,the accuracy of each target is improved by 10.94%,3.53%,16.96%and 19.90%,respectively,and the number of parameters only increases by 0.64M,which achieves a balance between the number of parameters and accuracy.

关键词： Railway foreign object light detection and ranging(LiDAR) 3D object detection PointPillars parallel attention mechanism transfer learning

Comparison and Verification of Coherent Doppler Wind Lidar and Radiosonde Data in the Beijing Urban Area

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Advances in Atmospheric Sciences 2024年第11期41卷 2203-2214页

作者： Zexu LUO Xiaoquan SONG Jiaping YIN zhichao BU Yubao CHEN Yongtao YU Zhenlu ZHANG College of Marine Technology Faculty of Information Science and EngineeringOcean University of ChinaQingdao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQingdao 266237China Qingdao Leice Transient Technology Co.LTD Qingdao 266100China CMA Meteorological Observation Centre Beijing 100081China Beijing Municipal Meteorological Observation Center Beijing 102600China Qingdao Meteorological Comprehensive Support Center Qingdao 266003China

As a new type of wind field detection equipment, coherent Doppler wind lidar(CDWL) still needs more relevant observation experiments to compare and verify whether it can achieve the accuracy and precision of traditional observation equipment in urban areas. In this experiment, a self-developed CDWL provided four months of observations in the southern Beijing area. After the data acquisition time and height match, the wind profile data obtained based on a Doppler beam swinging(DBS) five-beam inversion algorithm were compared with radiosonde data released from the same location. The standard deviation(SD) of wind speed is 0.8 m s^(–1), and the coefficient of determination R~2 is 0.95. The SD of the wind direction is 17.7° with an R~2 of 0.96. Below the height of the roughness sublayer(about 400 m), the error in wind speed and wind direction is significantly greater than the error above the height of the boundary layer(about 1500 m). For the case of wind speeds less than 4 m s^(–1), the error of wind direction is more significant and is affected by the distribution of surrounding buildings. Averaging at different height levels using suitable time windows can effectively reduce the effects of turbulence and thus reduce the error caused by the different measurement methods of the two devices.

关键词： coherent Doppler wind lidar radiosonde wind measurement urban boundary layer

Tailored energy absorption for a novel auxetic honeycomb structure under large deformation

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 63-80页

作者： Xiuhui Hou Bin Wang Zichen deng School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710129China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical UniversityXi'an 710072China School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China

In comparison to conventional hexagonal honeycomb structures,auxetic metamaterials with re-entrant configurations have exhibited superior mechanical properties in terms of energy *** further enhance the energy absorption capacity of these materials,a novel re-entrant honeycomb configuration,named novel auxetic re-entrant honeycomb(NARH),is developed by incorporating“”-shaped cell walls into the conventional auxetic re-entrant honeycomb(ARH).Two analytical models for the plateau stress are formulated to consider the plastic deformation of NARH during quasi-static compression and the dynamic impact using the linear momentum ***-static compression tests on 3D printed NARH honeycomb specimens and finite element simulations are performed to verify the effectiveness of the theoretical *** exhibits higher plateau stresses compared with ARH during compression,which can be attributed to the presence of more plastic hinges formed in *** hinges,the embedded parts with inclined cell walls,not only improve stability by forming stable triangles during compression but also enhance the energy absorption capacity.A parametric study is conducted to analyze the effect of impact velocity,thickness,and incline angle of cell walls on *** simulations demonstrate higher sensitivity of the mechanical properties to impact velocity and cell wall *** ribs to the“”-shaped cell walls in NARH further reduces the initial peak force during dynamic crushing while maintaining high energy *** research provides valuable guidelines for the design of energy absorption metamaterials.

关键词： absorption walls shaped