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Effect of Laser Remelting on the Microstructure and Corrosion Resistance of Plasma Sprayed Fe-based Coating

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Journal of Wuhan University of Technology(Materials Science) 2015年第4期30卷 804-807页

作者：姜超平 wang junxing HAN Jianjun LU Yuan XING Yazhe CHEN Yongnan SONG Xuding School of Materials Science and Engineering Chang'an University Key Laboratory of Road Construction Technology and Equipment MOE Chang'an University Xi'an Special Equipment Inspection Institute

Fe-based amorphous and nanocrystalline coatings were fabricated by air plasma spraying. The coatings were further treated by laser remelting process to improve their microstructure and properties. The corrosion resistance of the as-sprayed and laser-remelted coatings in 3.5wt% NaC1 and 1 mol/L HCI solutions was evaluated by electrochemical polarization analysis. It was found that laser-remelted coating appeared much denser than the as-sprayed coating. However, laser-remelted coating contains much more nanocrystalline grains than the as-sprayed coatings, resulting from the lower cooling rate in laser remelting process compared with plasma spraying process. Electrochemical polarization results indicated that the laser-remelted coating has great corrosion resistance than the as-sprayed coating because of its dense structure.

关键词： plasma spraying coating laser remelting corrosion

CASIA-Iris-Africa:A Large-scale African Iris Image Database

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Machine Intelligence Research 2024年第2期21卷 383-399页

作者： Jawad Muhammad Yunlong wang junxing Hu Kunbo Zhang Zhenan Sun School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China Center for Research on Intelligent Perception and Computing National Laboratory of Pattern RecognitionInstitute of AutomationChinese Academy of SciencesBeijing 100190China

Iris biometrics is a phenotypic biometric trait that has proven to be agnostic to human natural physiological *** on iris biometrics has progressed tremendously,partly due to publicly available iris *** databases have been available to researchers that address pressing iris biometric challenges such as constraint,mobile,multispectral,synthetics,long-distance,contact lenses,liveness detection,***,these databases mostly contain subjects of Caucasian and Asian docents with very few *** many investigative studies on racial bias in face biometrics,very few studies on iris biometrics have been published,mainly due to the lack of racially diverse large-scale databases containing sufficient iris samples of Africans in the public ***,most of these databases contain a relatively small number of subjects and labelled *** paper proposes a large-scale African database named Chinese Academy of Sciences Institute of Automation(CASIA)-Iris-Africa that can be used as a complementary database for the iris recognition community to mediate the effect of racial biases on *** database contains 28717 images of 1023 African subjects(2046 iris classes)with age,gender,and ethnicity attributes that can be useful in demographically sensitive studies of *** of specific application protocols are incorporated with the database to ensure the database’s variability and *** results of some open-source state-of-the-art(SOTA)algorithms on the database are presented,which will serve as baseline *** relatively poor performances of the baseline algorithms on the proposed database despite better performance on other databases prove that racial biases exist in these iris recognition algorithms.

关键词： African iris recognition racial bias iris image database biometrics iris recognition

Masked Autoencoders as Single Object Tracking Learners

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Computers, Materials & Continua 2024年第7期80卷 1105-1122页

作者： Chunjuan Bo XinChen junxing Zhang School of Information and Communication Engineering Dalian Minzu UniversityDalian116600China School of Information and Communication Engineering Dalian University of TechnologyDalian116024China

Significant advancements have beenwitnessed in visual tracking applications leveragingViT in recent years,mainly due to the formidablemodeling capabilities of Vision Transformer(ViT).However,the strong performance of such trackers heavily relies on ViT models pretrained for long periods,limitingmore flexible model designs for tracking *** address this issue,we propose an efficient unsupervised ViT pretraining method for the tracking task based on masked autoencoders,called *** pretraining,we employ two shared-parameter ViTs,serving as the appearance encoder and motion encoder,*** appearance encoder encodes randomly masked image data,while the motion encoder encodes randomly masked pairs of video ***,an appearance decoder and a motion decoder separately reconstruct the original image data and video frame data at the pixel *** this way,ViT learns to understand both the appearance of images and the motion between video frames *** results demonstrate that ViT-Base and ViT-Large models,pretrained with TrackMAE and combined with a simple tracking head,achieve state-of-the-art(SOTA)performance without additional ***,compared to the currently popular MAE pretraining methods,TrackMAE consumes only 1/5 of the training time,which will facilitate the customization of diverse models for *** instance,we additionally customize a lightweight ViT-XS,which achieves SOTA efficient tracking performance.

关键词： Visual object tracking vision transformer masked autoencoder visual representation learning

Stress sensitivity analysis for a wide-chord fan blade using an adjoint method

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Chinese Journal of Aeronautics 2024年第10期37卷 103-117页

作者： Han YANG Shoujia GONG Yi LI junxing TANG Dingxi wang Sheng HUANG Shenren XU School of Power and Energy Northwestern Polytechnical UniversityXi’an 710129China

High-performance compressor design is best achieved with a good trade-off between aerodynamic and structural considerations,which requires efficient and accurate multidisciplinary design and optimization *** advanced compressors are defined with a large design space,their optimization is most efficiently achieved using a gradient-based approach,where the gradient can be computed using an adjoint method,at a cost nearly independent of the dimension of the design *** the adjoint method has been widely used for aerodynamic shape optimization,its use for structural shape optimizations of compressor blades has not been as well *** paper discussed a discrete adjoint solver for structural sensitivity analysis developed within the opensource Computational Structural Mechanics(CSM)software CalculiX,and proposed an efficient stress sensitivity analysis method based on the Finite Element Method(FEM)using *** proposed method is applied to compute the stress sensitivity of a wide-chord fan blade in a highbypass-ratio *** accuracy of the adjoint-based stress sensitivity is verified against central finite *** terms of computational efficiency,the adjoint approach is about 4.5 times more efficient than the conventional approach using finite *** works marks an important step towards fluid-structural coupled adjoint optimization of wide-chord fan blades.

关键词： Adjoint method Multidisciplinary optimization Stress sensitivity analysis Finite element method Shape optimization

Vitamin A regulates mitochondrial biogenesis and function through p38 MAPK‑PGC‑1α signaling pathway and alters the muscle fiber composition of sheep

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Journal of Animal Science and Biotechnology 2024年第2期15卷 898-910页

作者： Pengkang Song Jiamin Zhao Fanqinyu Li Xiaoyi Zhao Jinxin Feng Yuan Su Bo wang junxing Zhao College of Animal Science Shanxi Agricultural UniversityTaiguShanxi 030801People’s Republic of China State Key Laboratory of Animal Nutrition and Feeding Department of Animal Nutrition and Feed ScienceCollege of Animal Science and TechnologyChina Agricultural UniversityBeijing 100193People’s Republic of China

Background Vitamin A(VA)and its metabolite,retinoic acid(RA),are of great interest for their wide range of physiological ***,the regulatory contribution of VA to mitochondrial and muscle fiber composition in sheep has not been *** Lambs were injected with 0(control)or 7,500 IU VA palmitate into the biceps femoris muscle on d 2 after *** the age of 3 and 32 weeks,longissimus dorsi(LD)muscle samples were obtained to explore the effect of VA on myofiber type *** vitro,we investigated the effects of RA on myofiber type composition and intrinsic *** The proportion of type I myofiber was greatly increased in VA-treated sheep in LD muscle at *** greatly promoted mitochondrial biogenesis and function in LD muscle of *** exploration revealed that VA elevated PGC-1αmRNA and protein contents,and enhanced the level of p38 MAPK phosphorylation in LD muscle of *** addition,the number of type I myofibers with RA treatment was significantly increased,and type IIx myofibers was significantly decreased in primary *** with in vivo experiment,RA significantly improved mitochondrial biogenesis and function in primary myoblasts of *** then used si-PGC-1αto inhibit PGC-1αexpression and found that si-PGC-1αsignificantly abrogated RA-induced the formation of type I myofibers,mitochondrial biogenesis,MitoTracker staining intensity,UQCRC1 and ATP5A1 expression,SDH activity,and enhanced the level of type IIx muscle *** data suggested that RA improved mitochondrial biogenesis and function by promoting PGC-1αexpression,and increased type I *** order to prove that the effect of RA on the level of PGC-1αis caused by p38 MAPK signaling,we inhibited the p38 MAPK signaling using a p38 MAPK inhibitor,which significantly reduced RA-induced PGC-1αand MyHC I *** VA promoted PGC-1αexpression through the p38 MAPK signaling pathway,improved mitochondrial biogenesis,and altered

关键词： Mitochondria Muscle fiber type PGC-1α p38 MAPK Retinoic acid Vitamin A

基于非线性规划的岩质边坡有限元塑性极限分析下限法研究

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岩石力学与工程学报 2007年第4期26卷 747-753页

作者：李泽王均星武汉大学水资源与水电工程科学国家重点实验室湖北武汉430072

结合塑性极限分析下限法理论、有限元离散技术以及非线性数学规划手段,将有限元塑性极限分析法运用于岩质边坡的稳定性分析。基于非线性Mohr-Coulomb屈服条件、平衡条件、边界条件以及间断面应力连续条件,提出塑性极限分析中无厚度节理... 详细信息

结合塑性极限分析下限法理论、有限元离散技术以及非线性数学规划手段,将有限元塑性极限分析法运用于岩质边坡的稳定性分析。基于非线性Mohr-Coulomb屈服条件、平衡条件、边界条件以及间断面应力连续条件,提出塑性极限分析中无厚度节理单元、等厚度节理单元的有限元模式,建立带节理单元的有限元塑性极限分析非线性数学规划模型,并提出非线性规划的求解策略。最后对3个岩质边坡的稳定性进行分析,验证该方法的可行性。

关键词：边坡工程塑性极限分析岩质边坡节理有限元非线性规划

Intracerebral malignant melanoma presenting as an Arteriovenous Malformation: case report and literature review

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Chinese Neurosurgical Journal 2017年第3期3卷 179-183页

作者： Yajuan Tang Yong Hou Bruhaspaty Prasad Wuyang Yang junxing wang Department of Neurosurgery The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou Zhejiang Province 310009 China Department of Neurosurgery Taizhou Hospital of Zhejiang Province Taizhou Zhejiang Province China Department of Neurosurgery Johns Hopkins School of Medicine Baltimore MD USA

Background: The authors introduced a rare case of intracranial malignant melanoma. Case presentation: A 32 year-old male patient presented to the hospital with signs and symptoms commonly seen in the presentation of a hemorrhagic stroke. The patient was diagnosed as having an Arteriovenous Malformation (AVM) after a thorough history, physical examination and radiographic imaging were performed and assessed. However, intraoperative findings and postoperative histopathology findings revealed that the supposed AVM was in fact a malignant melanoma, appearing as an AVM of the brain, on radiographic imaging. Conclusion: After reviewing related literature, our team realized that it was a rare finding for a melanoma pretending as a brain AVM.

关键词： Malignant Melanoma (MM) Brain metastasis Arteriovenous Malformation (AVM)

基于改进粒子群优化算法和极限学习机的混凝土坝变形预测

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天津大学学报（自然科学与工程技术版） 2019年第11期52卷 1136-1144页

作者：李明军王均星王亚洲武汉大学水资源与水电工程科学国家重点实验室

混凝土坝变形预测是评价大坝运行状态和预测大坝行为的重要方法.但是,混凝土坝的随机荷载和强非线性变形限制了传统多元线性回归模型的应用.而人工神经网络模型则对复杂和高度非线性行为具有良好适应性.针对基于梯度下降法的常规神经网... 详细信息

混凝土坝变形预测是评价大坝运行状态和预测大坝行为的重要方法.但是,混凝土坝的随机荷载和强非线性变形限制了传统多元线性回归模型的应用.而人工神经网络模型则对复杂和高度非线性行为具有良好适应性.针对基于梯度下降法的常规神经网络模型收敛速度慢和过度拟合等问题,提出了一种基于改进型粒子群优化算法选取极限学习机(ELM-IPSO)最优参数的大坝变形预测模型.针对传统粒子群算法搜索时间长、容易陷入局部最优的特点,采用自适应惯性权重和动态调整学习因子,对粒子群算法进行了改进.研究表明,IPSO算法提高了粒子群优化的全局搜索能力,提高了计算效率.应用IPSO优化ELM模型的初始权值和阈值.通过东江混凝土拱坝的实测资料,验证ELM-IPSO模型的预测性能.将计算结果与BPNN模型、ELM模型和传统ELM-PSO模型的结果进行比较.BPNN模型、ELM模型、ELM-PSO模型和ELM-IPSO模型的平方相关系数R2分别为89.15%、91.13%、93.87%和94.36%.ELM模型的R2大于BPNN模型,说明ELM模型比常规的BPNN模型预测精度更高,泛化性能更好.ELM-PSO模型的预测精度大于ELM模型,说明PSO对ELM的优化在提高预测精度方面具有良好的作用.4个模型中,ELM-IPSO模型的R^2最大,预测精度最高,这表明提出的ELM-IPSO模型能够有效提高混凝土坝变形的预测能力.

关键词：混凝土大坝变形极限学习机 BP神经网络改进的粒子群优化算法

Efficient Ship:A Hybrid Deep Learning Framework for Ship Detection in the River

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工程与科学中的计算机建模(英文) 2024年第1期138卷 301-320页

作者： Huafeng Chen junxing Xue Hanyun Wen Yurong Hu Yudong Zhang School of Computer Engineering Jingchu University of TechnologyJingmen448000China School of Computer Science Yangtze UniversityJingzhou434023China School of Computing and Mathematic Sciences University of LeicesterLeicesterLE17RHUK

Optical image-based ship detection can ensure the safety of ships and promote the orderly management of ships in offshore *** deep learning researches on optical image-based ship detection mainly focus on improving one-stage detectors for real-time ship detection but sacrifices the accuracy of *** solve this problem,we present a hybrid ship detection framework which is named EfficientShip in this *** core parts of the EfficientShip are DLA-backboned object location(DBOL)and CascadeRCNN-guided object classification(CROC).The DBOL is responsible for finding potential ship objects,and the CROC is used to categorize the potential ship *** also design a pixel-spatial-level data augmentation(PSDA)to reduce the risk of detection model *** compare the proposed EfficientShip with state-of-the-art(SOTA)literature on a ship detection dataset called *** show our ship detection framework achieves a result of 99.63%(mAP)at 45 fps,which is much better than 8 SOTA approaches on detection accuracy and can also meet the requirements of real-time application scenarios.

关键词： Ship detection deep learning data augmentation object location object classification