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An interval finite element method based on bilevel Kriging model

Chinese Journal of Aeronautics 2024年第12期37卷 1-11页

作者： Zhongyang YAO Shaohua WANG Pengge WU Bingyu NI Chao JIANG State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China Flight Automatic Control Research Institute of AVIC Xi’an 710065China Agriculture Equipment Institute of Hunan Hunan Academy of Agricultural SciencesChangsha 410125China

This study introduces a new approach utilizing an interval finite element method combined with a bilevel Kriging model to determine the bounds of structural responses in the presence of spatial uncertainties.A notable benefit of this approach is its ability to determine the response bounds across all degrees of freedom with a small sample size,which means that it has high ***,the spatially varying uncertain parameters are quantified using an interval field model,which is described by a series of standard interval variables within a truncated interval Karhunen-Loe`ve(K-L)series ***,considering that the bound of structural response is a function of spatial position with the property of continuity,a surrogate model for the response bound is constructed,namely the first-level Kriging *** training samples required for this surrogate model are obtained by establishing the second-level Kriging *** second-level Kriging model is established to describe the structural responses at particular locations relative to the interval variables so as to facilitate the upper and lower bounds of the node response required by the first-level Kriging ***,the accuracy and effectiveness of the method are verified through examples.

关键词： Interval field Spatial uncertainty Kriging model Interval finite element analysis Response bounds

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An experimental study of noise generated by tandem blades

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Chinese Journal of Aeronautics 2025年第2期38卷 143-160页

作者： Xiaolong TANG Fan TONG Chao WANG Jue DING Guangming LI Xiaoquan YANG Shanghai Institute of Applied Mathematics and Mechanics Shanghai Frontier Science Center of MechanoinformaticsShanghai Key Laboratory of Mechanics in Energy EngineeringSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Key Laboratory of Aerodynamic Noise Control China Aerodynamics Research and Development CenterMianyang 621000China Equipment Design and Testing Technology Research Institute China Aerodynamics Research and Development CenterMianyang 621000China

To facilitate the low-noise design of tandem lift bodies as applied in aeroengines and aircraft,the acoustic features of tandem blades are investigated by wind-tunnel *** is further specialized for the rotating blades applied in contra-rotating open rotors under the concept of frozen-rotor.A 70-channel phased microphone array and nine high-precision free-field microphones are *** beamforming method,enhanced by a source filtering technique,is employed to locate noise sources,providing insights into the source patterns of blade-blade interaction noise concerning flow speed,blade spacing,and aft blade *** results show the following:(A)Sources of tandem-blade noise exist in the form of concentrated source clusters,resulting in two major clusters:the mid-span interaction noise and the tip-induced noise.(B)These source clusters tend to separate as flow speed or blade spacing increases.(C)By increasing blade spacing,the band-pass filtered overall sound pressure level is reduced by 2.9 dB.(D)A two-phase noise suppression pattern is observed with blade clipping,resulting in a total reduction of 3.0 dB for the interaction noise through the removal of tip-induced noise sources and the replacement of mid-span noise *** on these findings,suggestions concerning blade spacing and clipping are discussed.

关键词： Tandem blades Contra-rotating open rotor Noise Beamforming Blade spacing and clipping Wind tunnel test

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Bond behavior of the interface between concrete and basalt fiber reinforced polymer bar after freeze–thaw cycles

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Frontiers of Structural and Civil engineering 2024年第4期18卷 630-641页

作者： Li HONG Mingming LI Congming DU Shenjiang HUANG Binggen ZHAN Qijun YU Department of Structural Engineering Hefei University of TechnologyHefei 230009China Key Laboratory of Performance Evolution and Control for Engineering Structures Tongji UniversityShanghai 200092China Engineering Research Center of Low-carbon Technology and Equipment for Cement-based Materials(Ministry of Education) Hefei University of TechnologyHefei 230009China Hefei Cement Research&Design Institute Corporation Ltd. Hefei 230051China

The shear bond of interface between concrete and basalt fiber reinforced polymer(BFRP)bars during freeze–thaw(F–T)cycles is crucial for the application of BFRP bar-reinforced concrete structures in cold *** this study,48 groups of pull-out specimens were designed to test the shear bond of the BFRP-concrete interface subjected to F–T *** effects of concrete strength,diameter,and embedment length of BFRP rebar were investigated under numerous F–T *** results showed that a larger diameter or longer embedment length of BFRP rebar resulted in lower interfacial shear bond behavior,such as interfacial bond strength,initial stiffness,and energy absorption,after the interface goes through F–T ***,higher concrete strength and fewer F–T cycles were beneficial for enhancing the interfacial bond ***,a three-dimensional(3D)interfacial model based on the finite element method was developed,and the interfacial bond behavior of the specimens was analyzed ***,a degradation bond strength subjected to F–T cycles was predicted by a proposed mechanical *** predictions were fully consistent with the tested *** model demonstrated accuracy in describing the shear bond behavior of the interface under numerous F–T cycles.

关键词： F-T cycle interface shear bond strength bond stress−slip curves bond degradation

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Geobacter sulfurreducens promoted the biosynthesis of reduced graphene oxide and coupled it for nitrobenzene reduction

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Journal of Environmental Sciences 2024年第4期138卷 458-469页

作者： Shoujuan Zhang Qi Liu Linrui Zhong Jianhong Jiang Xiaozhe Luo Xingxin Hu Qian Liu Yue Lu College of Environmental Science and Engineering Hunan UniversityChangsha 410082China Shenzhen Research Institute Hunan UniversityShenzhen 510082China Key Laboratory of Environment Biology and Pollution Control Hunan UniversityMinistry of EducationChangsha 410082China China Machinery International Engineering Design&Research Institute Co. LtdChangsha 410007China Hunan Engineering Research Center for Water Treatment Process&Equipment Changsha 410007China

In order to explore an efficient and green method to deal with nitrobenzene(NB)pollutant,reduced graphene oxide(r GO)as an electron shuttle was applied to enhance the extracellular electron transfer(EET)process of Geobacter sulfurreducens,which was a typical electrochemically active bacteria(EAB).In this study,r GO biosynthesis was achieved via the reduction of graphene oxide(GO)by *** PCA within 3 ***,the r GOPCA combining system completely reduced 50-200μmol/L of NB to aniline as end product within one *** characterization revealed that PCA cells were partly wrapped by rGO,and therefore the distance of electron transfer between strain PCA and r GO material was ***,the ID/IGof GO,r GO,and r GO-PCA combining system were 0.990,1.293 and 1.31,***,highest currents were observed in r GO-PCA-NB as 12.950μA/-12.560μA at -408 m V/156 m V,attributing to the faster electron transfer efficiency in EET ***,the NB reduction was mainly due to:(I)direct EET process from *** PCA to NB;(II)r GO served as electron shuttle and accelerated electron transfer to NB,which was the main degradation ***,the biosynthesis of r GO via GO reduction by Geobacter promoted the NB removal process,which provided a facile strategy to alleviate the problematic nitroaromatic pollution in the environment.

关键词： Reduced graphene oxide Geobacter Nitrobenzene Removal Extracellular electron transfer

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Tourmaline guiding the electric field and dechlorination pathway of 2,3-dichlorophenol by Desulfitobacterium hafniense

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Journal of Environmental Sciences 2024年第1期135卷 262-273页

作者： Yue Lu Fangyi Liang Fanzhi Qin Linrui Zhong Jianhong Jiang Qi Liu Shoujuan Zhang Ming Yan Changzheng Fan Haoran Dong College of Environmental Science and Engineering Hunan UniversityChangsha 410082China Shenzhen Research Institute Hunan UniverisyShenzhen 510082China Key Laboratory of Environment Biology and Pollution Control Hunan UniversityMinistry of EducationChangsha 410082China China Machinery International Engineering Design&Research Institute Co. Ltd.Changsha 410007China Hunan Engineering Research Center for Water Treatment Process&Equipment Changsha 410007China

The dehalogenation of organohalides has been a research hotspot in bioremediation field;however,the influence of tourmaline,a natural ore that can generate spontaneous electric field,on organohalide-respiring bacteria(OHRB)and their dechlorination process is not well *** this study,the effect and mechanism of tourmaline on the reductive dechlorination of 2,3-dichlorophenol(2,3-DCP)by Desulfitobacterium hafniense DCB-2Twere *** characterization results confirmed that tourmaline had good stability and the optimal dosage of tourmaline was 2.5 g/L,which shortened the total time required for dechlorination reaction to 72 ***,tourmaline amendment also increased the proportion of 2-chlorophenol(2-CP)from 18%to 30%of end products,while that of 3-CP decreased *** theoretical calculations showed that the bond charge of the orthosubstituted chlorine declined from-0.179 to-0.067,and that of meta-substituted chlorine increased from-0.111 to-0.129,which indicated that the spontaneous electric field of tourmaline affected the charge distribution of 2,3-DCP and was more conducive to the generation of ***,tourmaline with the spontaneous electric field affected the reductive dechlorination pathway of Desulfitobacterium,and the tourmaline-OHRB combining system might serve as a novel strategy for the bioremediation of environments polluted with chlorinated phenols.

关键词： Reductive dechlorination Desulfitobacterium hafniense Tourmaline Electric field 2 3-dichlorophenol

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Characteristics of Transition Layer at Soft Metal-Substrate Interface for Metal Seal

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稀有金属材料与工程 2025年第1期54卷 1-9页

作者： Zhang Dawei Zhang Xuekai Cao Zixuan Ge Ziyi Lv Shichang Li Zhijun Zhao Shengdun Hu Yanghu Xi'an Key Laboratory of Intelligent Equipment and Control School of Mechanical EngineeringXi'an Jiaotong UniversityXi'an 710049China Xi'an Aerospace Propulsion Institute Xi'an 710100China Light Alloy Research Institute Central South UniversityChangsha 410083China National Key Laboratory of Metal Forming Technology and Heavy Equipment Xi'an 710018China

The pressure-actuated metal seal with soft metal coating has been widely used in complex working conditions such as high temperature,low temperature and high *** investigation of the characteristics and binding strength of the transition layer between the soft metal coating and the superalloy substrate is important to improve the sealing performance and to model and simplify the working through-process of metal *** distribution characteristics of elements at soft metal-substrate interface and the binding strength between coating and substrate under different thicknesses and material combinations of coating layer were studied by experimental *** results indicate that the thickness of soft metal coating has little influence on the interface morphology of GH4169-Cu,GH4169-Ag and Cu-Ag,but has an influence on the thickness of transition layer between different metals,while this influence is weakened with increasing the coating thickness,and the thickness of transition layer is about 2μm when the coating thickness is more than 30μ*** cross-cut test shows that the Cu,Ag and Cu-Ag coatings are all well combined with nickel-based superalloy GH4169 *** materials of soft metal,*** coating materials,have significant influence on the characteristic of transition layer and the surface characteristics of coating after cross-cut test.

关键词： pressure-actuated metal seal nickel-based superalloy copper coating silver coating element transition layer

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Modulating Electromagnetic Genes Through Bi-Phase High-Entropy engineering Toward Temperature-Stable Ultra-Broadband Megahertz Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第7期 262-277页

作者： Xiaoji Liu Yuping Duan Nan Wu Guangming Li Yuan Guo Jiangyong Liu Ning Zhu Qiang Wang Lin Wang Zichen Xu Hao Wei Guojun Wang Zhijia Zhang Songsong Zhang Wenjun Zhou Teng Ma Tongmin Wang Qingdao Innovation and Development Base of Harbin Engineering University Harbin Engineering University Key Laboratory of Solidification Control and Digital Preparation Technology School of Materials Science and EngineeringDalian University of Technology National Key Laboratory of Electromagnetic Effect and Security On Marine Equipment China Ship Development and Design Center Wuhan Second Ship Design and Research Institute

Magnetic absorbers with high permeability have significant advantages in lowfrequency and broadband electromagnetic wave （EMW） ***,the insufficient magnetic loss and inherent high conductivity of existing magnetic absorbers limit the further expansion of EMW absorption ***,the spinel （FeCoNiCrCu）3O4high-entropy oxides （HEO） are successfully constructed on the surface of FeCoNiCr0.4Cu0.2high-entropy alloys （HEA） through low-temperature oxygen bath *** the one hand,HEO and HEA have different magnetocrystalline anisotropies,which is conducive to achieving continuous natural resonance to improve magnetic *** the other hand,HEO with low conductivity can serve as an impedance matching layer,achieving magneto-electric *** the thickness is 5 mm,the minimum reflection loss （RL） value and absorption bandwidth （RL<-5 d B） of bi-phase high-entropy composites （BPHEC） can reach-12.8 d B and 633 MHz,*** RCS reduction value of multilayer sample with impedance gradient characteristic can reach 18.34 d B *** addition,the BPHEC also exhibits temperaturestable EMW absorption performance,high Curie temperature,and oxidation *** absorption bandwidth maintains between 593 and 691 MHz from-50 to 150℃.This work offers a new and tunable strategy toward modulating the electromagnetic genes for temperature-stable ultra-broadband megahertz EMW absorption.

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Fault diagnosis for small samples based on VMR

Fault diagnosis for small samples based on VMR

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2024 China Automation Congress, CAC 2024

作者： Wu, Xuejin Wu, Yali Hu, Yanghu Department of Information and Control Engineering Xi'an University of Technology Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an710048 China State Key Laboratoiy of Metal Extrusion and Forging Equipment Technology China National Heavy Machinery Research Institute Co. Ltd Xi'an710016 China

ISBN: (纸本)9798350368604

The scarcity of fault samples presents a significant challenge for fault diagnosis in industrial processes. Conventional methods often fail to deliver satisfactory results when dealing with small sample sizes. In addressing the issue of small sample fault diagnosis in industrial processes, this paper utilizes the Variational Mode Reconstruction(VMR) algorithm to screen the best components decomposed by the Variational Mode Decomposition(VMD) through the envelope entropy then random weighting them and signal reconstruction to achieve data enhancement, to enrich the sample size and to prevent the model overfitting phenomenon due to the scarcity of samples. Meanwhile, this paper integrates Convolutional Neural Network (CNN) and Long Short-term Memory Neural Network (LSTM) to propose a network model of spatio-temporal feature fusion for feature extraction and classification. The experiments demonstrate that this model not only enhances data diversity but also ensures consistency before and after enhancement, effectively mitigating overfitting. Furthermore, it guarantees high recognition and generalization rates in fault diagnosis. © 2024 IEEE.

关键词： Convolutional neural networks

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Research on optimization of two-stage scheduling for aluminum extrusion machine manufacturing line

Research on optimization of two-stage scheduling for aluminu...

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2024 China Automation Congress, CAC 2024

作者： Zhou, Aoran Qiu, Lipeng Wu, Yali Department of Information and Control Engineering Xi'an University of Technology Shaan'xi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an710048 China State Key Laboratory of Metal Extrusion and Forging Equipment Technology China National Heavy Machinery Research Institute Co Ltd Xi'an710016 China

ISBN: (纸本)9798350368604

In view of the problems of high energy consumption, long inventory time and low production efficiency in the production process of traditional aluminum extrusion machine, this paper establishes an efficient two-stage parallel scheduling optimization model based on the integration of flexible job shop scheduling and assembly sequence planning (IFJSS-ASP). On this basis, an evolutionary algorithm combining strong dominance relationship and simple grouping method (SDREA-SGM) is proposed. The algorithm utilizes a two-stage hybrid chromosome encoding and decoding method to establish a rational mapping from the decision space to the solution space. Furthermore, in order to prevent the model from easily falling into local optima, an adaptive intra-class and inter-class pairing selection strategy has been adopted by the algorithm. This enhances global search and improves local search ***, the feasibility and effectiveness of the algorithm are verified by solving problems of different scales. © 2024 IEEE.

关键词： Job shop scheduling

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NO reduction by carbon-based gases based on coal gasification fractions:NO reduction intermediate identification and kinetic analysis

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Frontiers of Environmental Science & engineering 2025年第3期19卷 175-189页

作者： Xiang Zhang Jian Tian Tanghui Hu Guangyong Yue Xianlong Liu Wen Zhou Xiaohong Liu Xinye Wang Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials Hubei Engineering Research Center for Green Industrialization Technology of Industrial WasteSchool of Materials Science and EngineeringHubei UniversityWuhan 430062China Hubei Huda Tianshu New Energy Materials Industrial Research and Design Institute Co. Ltd.Wuhan 430062China Wuhan Tianshu Dust Removal Equipment Co. Ltd.Wuhan 430062China Engineering Laboratory for Energy System Process Conversion&Emission Control Technology of Jiangsu Province School of Energy and Mechanical EngineeringNanjing Normal UniversityNanjing 210042China

Combining pulverized coal gasifiers with cement kiln production is promising for application in low-cost and efficient NO *** paper presents a pulverized coal gasifier catalytic denitration technique and investigates the homogeneous reduction(by CO and CH_(4))and heterogeneous catalytic reduction(by coke,CaO,MgO,and Fe_(2)O_(3))of NO.A combination of Chemkin simulations and fixed-bed experiments is used to elucidate the reaction pathways and key intermediates of NO reduction by carbon-based *** addition,the activation energies for different catalyst combinations were analyzed via reaction *** results demonstrate that the presence of small amounts of O_(2) inhibits NO reduction by CO but promotes NO reduction by CH_(4).The NCO·radical is essential for the NO reduction process,and the generation of this radical depends on the CH_(4) cleavage intermediate and O·*** and Fe_(2)O_(3) exhibit more significant catalytic effects on NO reduction by carbon-based gases than the other catalysts *** presence of a small amount of O_(2) in the reacting gas mixtures facilitates the NO reduction *** activation energy is reduced to 1.02 kJ/mol,and the NO conversion reaches 99.80%when the catalyst is C+CaO+MgO+Fe_(2)O_(3) and the gas composition is CO+CH_(4)+O_(2).This work provides theoretical support and data recommendations for the use of pulverized coal gasifiers for the denitrification of cement kilns.

关键词： Carbon-based gas Catalytic denitration Coke Kinetic analysis Reaction mechanism

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