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A Railway Fastener Inspection Method Based on Abnormal Sample Generation

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Computer Modeling in Engineering & sciences 2024年第4期139卷 565-592页

作者： Shubin Zheng Yue Wang Liming Li Xieqi Chen Lele Peng Zhanhao Shang Higher Vocational and Technical College Shanghai University of Engineering ScienceShanghai200437China School of Urban Railway Transportation Shanghai University of Engineering ScienceShanghai201620China shanghai Engineering research Centre of Vibration and Noise Control Technologies for Rail Transit Shanghai University of Engineering ScienceShanghai201620China

Regular fastener detection is necessary to ensure the safety of ***,the number of abnormal fasteners is significantly lower than the number of normal fasteners in real *** supervised inspectionmethods have insufficient detection ability in cases of imbalanced *** solve this problem,we propose an approach based on deep convolutional neural networks(DCNNs),which consists of three stages:fastener localization,abnormal fastener sample generation based on saliency detection,and fastener state ***,a lightweight YOLOv5s is designed to achieve fast and precise localization of fastener ***,the foreground clip region of a fastener image is extracted by the designed fastener saliency detection network(F-SDNet),combined with data augmentation to generate a large number of abnormal fastener samples and balance the number of abnormal and normal ***,a fastener inspection model called Fastener ResNet-8 is constructed by being trained with the augmented fastener *** show the effectiveness of our proposed method in solving the problem of sample imbalance in fastener *** and quantitative comparisons show that the proposed F-SDNet outperforms other state-of-the-art methods in clip region extraction,reaching MAE and max F-measure of 0.0215 and 0.9635,*** addition,the FPS of the fastener state inspection model reached 86.2,and the average accuracy reached 98.7%on 614 augmented fastener test sets and 99.9%on 7505 real fastener datasets.

关键词： Railway fastener sample generation inspection model deep learning

Enhancing SAEAs with unevaluated solutions:a case study of relation model for expensive optimization

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science China(Information sciences) 2024年第2期67卷 41-58页

作者： Hao HAO Xiaoqun ZHANG Aimin ZHOU Institute of Natural sciences Shanghai Jiao Tong University shanghai Frontiers science center of Molecule Intelligent Syntheses School of Computer science and Technology East China Normal University

Surrogate-assisted evolutionary algorithms(SAEAs) hold significant importance in resolving expensive optimization problems. Extensive efforts have been devoted to improving the efficiency of SAEAs through the development of proficient model-assisted solution selection methods, which, however, first requires generating high-quality solutions. The fundamental paradigm of evaluating a limited number of solutions in each generation within SAEAs reduces the variance of adjacent populations, thereby affecting the quality of offspring solutions. This is a frequently encountered issue yet receives little attention. To address the issue, this paper presents a framework using unevaluated solutions to enhance the efficiency of *** surrogate model is employed to identify high-quality solutions for the direct generation of new solutions without evaluation. To ensure dependable selection, we have introduced two tailored relation models to select the optimal solution and the unevaluated population. A comprehensive experimental analysis is performed on two test suites, which showcases the superiority of the relation model over regression and classification models in the solution selection phase. Furthermore, the surrogate-selected unevaluated solutions with high potential have been shown to enhance the efficiency of the algorithm significantly.

关键词： expensive optimization unevaluated solutions relation model surrogate-assisted evolutionary algorithm

Interaction mechanism between BaZrO_(3)/Y_(2)O_(3) refractory and Ti_(2)Ni alloy melts

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Journal of Iron and Steel research(International) 2024年第6期31卷 1376-1388页

作者： Xiao Hou Guang-yao Chen Jian Liu Ming-rui Lv Fei-hai Yu Qi-sheng Feng Rong-bin Li Xiong-gang Lu Chong-he Li State Key Laboratory of Advanced Special Steel and shanghai Key Laboratory of Advanced Ferromeallurgy and School of Materials science and Engineering Shanghai UniversityShanghai 200072China shanghai Special Casting Engineering Technology research center Shanghai 201605China Zhejiang Institute of Advanced Materials Shanghai UniversityJiashan 314100ZhejiangChina School of Materials science and Engineering Shanghai DianJi UniversityShanghai 201306China

The titanium alloys with highly chemical activity require stable crucible refractories that can withstand the erosion of alloy *** phase composition and microstructure are crucial factors that affect the stability of the refractory *** effect of Y_(2)O_(3) on the composition and microstructure of BaZrO_(3) crucible was systematically investigated,and the improved mechanism of the stability of BaZrO_(3)/Y_(2)O_(3) crucible was clarified in comparison with the BaZrO_(3) *** results showed that the erosion layer thickness of the BaZrO_(3)/Y_(2)O_(3) crucible was only 63μm,which was far less than that in the BaZrO_(3) crucible(485μm),and the erosion layer in the BaZrO_(3)/Y_(2)O_(3) crucible also exhibited a higher density than that in the BaZrO_(3) *** the sintering,Y_(2)O_(3) could improve the densification of the BaZrO_(3) crucible due to the solid solution effect between Y_(2)O_(3) and ZrO_(2),which also caused the evaporation of BaO,resulting in the generation of a Y_(2)O_(3)(ZrO_(2))film on the surface of the ***,the Y_(2)O_(3)(ZrO_(2))had higher thermodynamic stability than Y_(2)O_(3),confirming that the BaZrO_(3)/Y_(2)O_(3) crucible with high density exhibited a superior erosion resistance to titanium *** dual-phase structure provides a strategy to design a long-life and stable refractory for melting titanium alloys.

关键词： Barium zirconate Yttrium oxide Dual-phase refractory Titanium alloy Interaction

Broadband second-harmonic generation in thin-film lithium niobate microdisk via cyclic quasi-phase matching

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Chinese Optics Letters 2024年第3期22卷 118-122页

作者：朱杰夫丁婷婷孙雪芮倪枫超黎浩刘时杰郑远林陈险峰 State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China School of Electronic and Electrical Engineering Shanghai University of Engineering ScienceShanghai 201620China shanghai research center for Quantum sciences Shanghai 201315China Collaborative Innovation center of Light Manipulations and Applications Shandong Normal UniversityJinan 250358China

Whispering-gallery-mode(WGM)microresonators can greatly enhance light-matter interaction,making them indispensable units for frequency conversion in nonlinear *** nonlinear wave mixing in microresonators requires stringent simultaneous optical resonance and phase-matching ***,it is challenging to achieve efficient frequency conversion over a broad ***,we demonstrate broadband second-harmonic generation(SHG)in the x-cut thinfilm lithium niobate(TFLN)microdisk with a quality factor above 107by applying the cyclic quasi-phase-matching(CQPM)mechanism,which is intrinsically applicable for broadband *** SHG of continuous-wave laser with a maximum normalized conversion efficiency of~15%/m W is achieved with a bandwidth spanning over 100 nm in the telecommunication ***,broadband SHG of femtosecond lasers,supercontinuum lasers,and amplified spontaneous emission in the telecommunication band is also experimentally *** work is beneficial for integrated nonlinear photonics devices like frequency converters and optical frequency comb generator based on second-order nonlinearity on the TFLN platform.

关键词： lithium niobate whispering-gallery mode broadband second-harmonic generation cyclic quasi-phase matching

TCERG1L hypermethylation is a risk factor of diabetic retinopathy in Chinese children with type 1 diabetes

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International Journal of Ophthalmology(English edition) 2024年第3期17卷 537-544页

作者： Yu Qian Ying Xiao Qiu-Rong Lin Zhao-Yu Xiang Li-Pu Cui Jia-Qi Sun Si-Cong Li Xin-Ran Qin Hai-Dong Zou Chen-Hao Yang Pei-Yao Jin Department of Ophthalmology Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai First People’s HospitalShanghai 200080China shanghai Eye Diseases Prevention&Treatment center Shanghai Eye HospitalShanghai 200040China National Clinical research center for Eye Diseases Shanghai Clinical Research Center for Eye DiseasesShanghai Key Clinical SpecialtyShanghai Key Laboratory of Ocular Fundus DiseasesShanghai Engineering Center for Visual Science and PhotomedicineShanghai Engineering Center for Precise Diagnosis and Treatment of Eye DiseasesShanghai 200080China Department of Ophthalmology Children’s Hospital of Fudan UniversityShanghai 201102China

●AIM:To identify the differential methylation sites(DMS)and their according genes associated with diabetic retinopathy(DR)development in type 1 diabetes(T1DM)children.●METHODS:This study consists of two surveys.A total of 40 T1DM children was included in the first *** no participant has DR,retina thinning was used as a surrogate indicator for *** lowest 25%participants with the thinnest macular retinal thickness were included into the case group,and the others were *** DNA methylation status was assessed by the Illumina methylation 850K array BeadChip assay,and compared between the case and control *** DMS with a potential role in diabetes were *** second survey included 27 T1DM children,among which four had *** methylation patterns of the four DMS identified by 850K were compared between participants with and without DR by pyrosequencing.●RESULTS:In the first survey,the 850K array revealed 751 sites significantly and differentially methylated in the case group comparing with the controls(|Δβ|>0.1 and Adj.P0.05)between participants with and without DR.●CONCLUSION:The hypermethylation of the TCERG1L gene is a risk factor for DR development in Chinese children with T1DM.

关键词： DNA methylation 850K array pyrosequencing diabetic retinopathy type 1 diabetes children

In silico optimization of actuation performance in dielectric elastomercomposites via integrated finite element modeling and deep learning

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Theoretical & Applied Mechanics Letters 2024年第1期14卷 48-56页

作者： Jiaxuan Ma Sheng Sun Materials Genome Institute Shanghai UniversityShanghai 200444China Zhejiang Laboratory Hangzhou 311100China shanghai Frontier science center of Mechanoinformatics Shanghai UniversityShanghai 200444China

Dielectric elastomers(DEs)require balanced electric actuation performance and mechanical integrity under applied *** high dielectric particles as fillers provides extensive design space to optimize concentration,morphology,and distribution for improved actuation performance and material *** study presents an integrated framework combining finite element modeling(FEM)and deep learning to optimize the microstructure of DE *** first calculates actuation performance and the effective modulus across varied filler combinations,with these data used to train a convolutional neural network(CNN).Integrating the CNN into a multi-objective genetic algorithm generates designs with enhanced actuation performance and material modulus compared to the conventional optimization approach based on FEM approach within the same *** framework harnesses artificial intelligence to navigate vast design possibilities,enabling optimized microstructures for high-performance DE composites.

关键词： Dielectric elastomer composites Multi-objective optimization Finite element modeling Convolutional neural network

BL03HB: a Laue microdiffraction beamline for both protein crystallography and materials science at SSRF

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Nuclear science and Techniques 2024年第7期35卷 68-78页

作者： Zhi-Jun Wang Si-Sheng Wang Zheng-Huang Su Li Yu Yu-Zhu Wang Bo Sun Wen Wen Xing-Yu Gao shanghai Advanced research Institute Chinese Academy of SciencesShanghai201210China University of Chinese Academy of science Beijing100049China

A Laue microdiffraction beamline (BL03HB) was constructed at the shanghai SynchrotronRadiation Facility (SSRF). This beamline featu res two consecutive focusing points in twodifferent sectors within its end station, the first dedicated to protein crystallography and theother tailored to materials science applications. Based on a superbend dipole magnet with amagnetic field of 2.29 T, a two-stage focusing design was implemented with two sets of Kirkpatrick- Baez mirrors to achieve a micro white beam as small as 4.2 um X4.3 pμm at the firstsector and 09 pum X 1.3 pum at the second sector in the standard beamline operation mode at *** X-ray microbeam in the two sectors can be easily switched between monochromatic andwhite beams by moving a four-bounce monochromator in or out of the light path, respectively. Inthe protein crystallography sector, white-beam Laue microdifraction was dermonstrated tosuccessully determine the structure of protein crystals from only a few images of diffraction data .collected by a Pilatus 2 M area detector. In the materials science sector, the white -beam Lauediffraction was collected in a reflection geometry using another Pilatus 2 M area detector, whichcould map the microstructural distribution on the sample surface by scanning the samples. Ingeneral, the BL03HB beamline promotes the application of Laue microdiffraction in both proteincrystallgraphy and materials science. This paper presents a comprehensive overview of theBL03HB beamline, end station, and the first commission results.

关键词： Crystallography White-beam Laue microdiffraction Beamline Synchrotron

Modified dynamic event-triggered scaled formation control for multi-agent systems via a sparrow search algorithm based co-design algorithm

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Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 197-213页

作者： Yanping YANG Siyu MA Dawei LI Jinghui SUO College of Information science and Technology Donghua UniversityShanghai201620China Engineering research center of Digitized Textile&Apparel Technology Donghua UniversityShanghai201620China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Information Science and TechnologyDonghua UniversityShanghai201620China

This paper is concerned with the scaled formation control problem for multi-agent systems(MASs)over fixed and switching ***,a modified resilient dynamic event-triggered(DET)mechanism involving an auxiliary dynamic variable(ADV)based on sampled data is *** the proposed DET mechanism,a random variable obeying the Bernoulli distribution is introduced to express the idle and busy situations of communication ***,the operation of absolute value is introduced into the triggering condition to effectively reduce the formation ***,a scaled formation control protocol with the proposed resilient DET mechanism is designed over fixed and switching *** scaled formation error system is modeled as a time-varying delay ***,several sufficient stability criteria are derived by constructing appropriate Lyapunov-Krasovskii functionals(LKFs).A co-design algorithm based on the sparrow search algorithm(SSA)is presented to design the control gains and triggering parameters ***,numerical simulations of multiple unmanned aerial vehicles(UAVs)are presented to validate the designed control method.

关键词： Scaled consensus Formation control Dynamic event-triggered scheme Switching topology

Fundamental Understanding of Hydrogen Evolution Reaction on Zinc Anode Surface:A First‑Principles Study

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Nano-Micro Letters 2024年第6期16卷 180-191页

作者： Xiaoyu Liu Yiming Guo Fanghua Ning Yuyu Liu Siqi Shi Qian Li Jiujun Zhang Shigang Lu Jin Yi Institute for Sustainable Energy&Department of Chemistry Shanghai UniversityShanghai 200444People’s Republic of China School of Materials science and Engineering Shanghai UniversityShanghai 200444People’s Republic of China College of Materials science and Engineering National Engineering Research Center for Magnesium AlloysChongqing UniversityChongqing 400044People’s Republic of China

Hydrogen evolution reaction(HER)has become a key factor affecting the cycling stability of aqueous Zn-ion batteries,while the corresponding fundamental issues involving HER are still ***,the reaction mechanisms of HER on various crystalline surfaces have been investigated by first-principle calculations based on density functional *** is found that the Volmer step is the ratelimiting step of HER on the Zn(002)and(100)surfaces,while,the reaction rates of HER on the Zn(101),(102)and(103)surfaces are determined by the Tafel ***,the correlation between HER activity and the generalized coordination number(CN)of Zn at the surfaces has been *** relatively weaker HER activity on Zn(002)surface can be attributed to the higher CN of surface Zn *** atomically uneven Zn(002)surface shows significantly higher HER activity than the flat Zn(002)surface as the CN of the surface Zn atom is *** CN of surface Zn atom is proposed as a key descriptor of HER *** the CN of surface Zn atom would be a vital strategy to inhibit HER on the Zn anode surface based on the presented theoretical ***,this work provides a theoretical basis for the in-depth understanding of HER on the Zn surface.

关键词： Aqueous Zn-ion battery Zn anode Hydrogen evolution reaction Coordination number First-principles calculation