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An effective crack position diagnosis method for the hollow shaft rotor system based on the convolutional neural network and deep metric learning

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Chinese Journal of Aeronautics 2022年第9期35卷 242-254页

作者： yuhong jin Lei HOU Yushu CHEN Zhenyong LU School of Astronautics Harbin Institute of TechnologyHarbin 150001China Institute of Dynamics and Control Science Shandong Normal UniversityJi'nan 250014China

In recent years, the crack fault is one of the most common faults in the rotor system and it is still a challenge for crack position diagnosis in the hollow shaft rotor system. In this paper, a method based on the Convolutional Neural Network and deep metric learning(CNN-C) is proposed to effectively identify the crack position for a hollow shaft rotor system. Center-loss function is used to enhance the performance of neural network. Main contributions include: Firstly, the dynamic response of the dual-disks hollow shaft rotor system is obtained. The analysis results show that the crack will cause super-harmonic resonance, and the peak value of it is closely related to the position and depth of the crack. In addition, the amplitude near the non-resonant region also has relationship with the crack parameters. Secondly, we proposed an effective crack position diagnosis method which has the highest 99.04% recognition accuracy compared with other algorithms. Then,the influence of penalty factor on CNN-C performance is analyzed, which shows that too high penalty factor will lead to the decline of the neural network performance. Finally, the feature vectors are visualized via t-distributed Stochastic Neighbor Embedding(t-SNE). Naive Bayes classifier(NB) and K-Nearest Neighbor algorithm(KNN) are used to verify the validity of the feature vectors extracted by CNN-C. The results show that NB and KNN have more regular decision boundaries and higher recognition accuracy on the feature vectors data set extracted by CNN-C,indicating that the feature vectors extracted by CNN-C have great intra-class compactness and inter-class separability.

关键词： Convolutional neural networks Cracked rotor Deep metric learning Fault diagnosis Hollow shaft rotor

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Crack Fault Diagnosis and Location Method for a Dual-Disk Hollow Shaft Rotor System Based on the Radial Basis Function Network and Pattern Recognition Neural Network

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Chinese Journal of Mechanical Engineering 2023年第2期36卷 180-197页

作者： yuhong jin Lei Hou Zhenyong Lu Yushu Chen School of Astronautics Harbin Institute of TechnologyHarbin 150001China Institute of Dynamics and Control Science Shandong Normal UniversityJi’nan 250014China

The crack fault is one of the most common faults in the rotor system,and researchers have paid close attention to its fault ***,most studies focus on discussing the dynamic response characteristics caused by the crack rather than estimating the crack depth and position based on the obtained vibration *** this paper,a novel crack fault diagnosis and location method for a dual-disk hollow shaft rotor system based on the Radial basis function(RBF)network and Pattern recognition neural network(PRNN)is ***,a rotor system model with a breathing crack suitable for a short-thick hollow shaft rotor is established based on the finite element method,where the crack's periodic opening and closing pattern and different degrees of crack depth are ***,the dynamic response is obtained by the harmonic balance *** adjusting the crack parameters,the dynamic characteristics related to the crack depth and position are analyzed through the amplitude-frequency responses and waterfall *** analysis results show that the first critical speed,first subcritical speed,first critical speed amplitude,and super-harmonic resonance peak at the first subcritical speed can be utilized for the crack fault *** on this,the RBF network and PRNN are adopted to determine the depth and approximate location of the crack respectively by taking the above dynamic characteristics as *** results show that the proposed method has high fault diagnosis *** research proposes a crack detection method adequate for the hollow shaft rotor system,where the crack depth and position are both unknown.

关键词： Hollow shaft rotor Breathing crack Radial basis function network Pattern recognition neural network Machine learning

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A novel adaptive harmonic balance method with an asymptotic harmonic selection

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Applied Mathematics and Mechanics(English Edition) 2023年第11期44卷 1887-1910页

作者： Rongzhou LIN Lei HOU Yi CHEN yuhong jin N.A.SAEED Yushu CHEN School of Astronautics Harbin Institute of TechnologyHarbin 150001China Department of Physics and Engineering Mathematics Faculty of Electronic EngineeringMenoufia UniversityMenouf 32952Egypt Department of Automation Biomechanicsand MechatronicsFaculty of Mechanical EngineeringLodz University of TechnologyLodz 90924Poland Mathematics Department Faculty of ScienceGalala UniversityGalala 43511Egypt

The harmonic balance method(HBM)is one of the most widely used methods in solving nonlinear vibration problems,and its accuracy and computational efficiency largely depend on the number of the harmonics *** adaptive harmonic balance(AHB)method is an improved HBM *** paper presents a modified AHB method with the asymptotic harmonic selection(AHS)*** new harmonic selection procedure selects harmonics from the frequency spectra of nonlinear terms instead of estimating the contribution of each harmonic to the whole nonlinear response,by which the additional calculation is avoided.A modified continuation method is proposed to deal with the variable size of nonlinear algebraic equations at different values of path parameters,and then all solution branches of the amplitude-frequency response are *** experiments are carried out to verify the performance of the AHB-AHS *** typical nonlinear dynamic equations with different types of nonlinearities and excitations are chosen as the illustrative *** with the classical HBM and Runge-Kutta methods,the proposed AHB-AHS method is of higher accuracy and better *** AHB-AHS method proposed in this paper has the potential to investigate the nonlinear vibrations of complex high-dimensional nonlinear systems.

关键词： harmonic balance method(HBM) adaptive harmonic balance(AHB)method harmonic selection nonlinear vibration multi-frequency excitation

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MXene supported PtCo bimetallic catalyst for hydrogen evolution in acidic conditions

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Frontiers in Energy 2024年第3期18卷 369-377页

作者： Guangxun CHEN Jian-hua ZHANG Kai-Ling ZHOU Yang YANG Haoxiang MA yuhong jin jingbin LIU Hao WANG Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China Institute of Deep-Sea Science and Engineering Chinese Academy of SciencesSanya 572000China

Using the electrochemical technology to split water molecules to produce hydrogen is the key to obtain green hydrogen for solving the energy crisis. The large-scale application of hydrogen evolution reaction (HER) in water dissociation requires a highly active catalyst. In this paper, the highly dispersed PtCo bimetallic nanoparticles loading on MXene (PtCo/MXene) were prepared by using a step-to-step reduction strategy. The mentioned PtCo/MXene catalyst exhibits a high current density of −100 mA/cm2 in an acidic medium with just a 152 mV overpotential. In addition, the PtCo/MXene catalyst also displays a superior stability. Computational analysis and experimental testing demonstrate that the electronic interaction between Pt and Co can effectively modify the electronic structure of the active site, thereby enhancing the inherent catalytic performance of the material. More importantly, MXene two-dimensional nanosheets can expose more active sites because of their large specific surface area. Furthermore, MXene substrate with excellent electrical conductivity and harmonious interfaces between PtCo and MXene enhance charge transfer efficiency and lower the reaction activation energy.

关键词： MXene PtCo bimetallic hydrogen evolution reaction(HER)

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SWOT analysis of the developing situation of sports Tourism industry in Anhui province

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International Journal of Technology Management 2014年第12期 63-65页

作者： Ruijin jin yuhong XIAO School of Physical Education Huaibei Normal University Huaibei City 235000 China

By using the method of SWOT analysis, the author carries on a brief analysis of the advantages and disadvantages and opportunities and threats of the development of sports tourism industry in Anhui Province. Its aim is to put forward countermeasures to develop sports tourism industry in Anhui province, increase propagandist, arouse the consumption demand, make best use of features, create the brand project, reserve talent cultivation and improve service levels.

关键词： Anhui province sports tourism SWOT analysis

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An Inter-Shaft Bearing Fault Diagnosis Dataset from an Aero-Engine System

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Journal of Dynamics, Monitoring and Diagnostics 2023年第4期2卷 228-242页

作者： Lei Hou Haiming Yi yuhong jin Min Gui Lianzheng Sui Jianwei Zhang Yushu Chen School of Astronautics Harbin Institute of TechnologyHarbin 150001China Factory of Xiangyang Hangtai Power Machinery Xiangyang 441000China

In this paper,the aero-engine test with inter-shaft bearing fault is carried out,and a dataset is proposed for the first time based on the vibration signal of rotors and ***,a test rig based on a real aero-engine is established,driven by motors and equipped with a lubricating ***,the aero-engine is disassembled and assembled following the specification process,and the inter-shaft bearing with artificial fault is ***,the aero-engine test is conducted at 28 groups of high-and low-pressure *** measuring points are arranged,including two displacement sensors to test the displacement vibration signals of the low-pressure rotor and four acceleration sensors to test the acceleration vibration signals of the *** test results are integrated into an inter-shaft bearing fault ***,based on the dataset in this paper,frequency spectrum,envelope spectrum,CNN,LSTM,and TST are used for fault diagnosis,and the results are compared with those of CWRU and XJTU *** results show that the characteristic fault frequency cannot be found directly in the spectrum and envelope spectrum corresponding to this paper’s dataset but in CWRU and XJTU *** CNN,LSTM,and TST for fault diagnosis of the dataset in this paper,the accuracy is 83.13%,85.41%,and 71.07%,respectively,much lower than the diagnosis results of CWRU and XJTU *** can be seen that the dataset in this paper is closer to the actual fault diagnosis situation and is a more challenging *** dataset provides a new benchmark for the validation of fault diagnosis *** data:https://***/HouLeiHIT/HIT-dataset.

关键词： aero-engine test dataset fault diagnosis inter-shaft bearing

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A trial of using the cluster analysis to classify the ship noises and EEG (electroencephalogram)

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Chinese Journal of Acoustics 1991年第1期10卷 37-46页

作者： CHEN Geng and WEI Xuehuan(Institute of Acoustics Academia Sinica) WANG yuhong and jin Zhang lei(Institute of Aeroforce Medicine)

Cluster analysis is a method often used in pattern recognition. With the aid of the signal processing and the learning of the computer, disfferent samples can be classifeid and recognized in a dimension reduction space of the characteristics because of the differences of their character -istics. To realize dimension reduction transformation, a nonlinear mapping method was discussed in this paper. To prove that the cluster analysis is suitable for quite different fields of samples, in this paper some ship noises and some EEG as the samples belong to two different fields are classified and shown. And it is worthy to point out that an adaptive step size expression of adaptive iteration deduced here will also be effective if it is applied to speed adaptive algorithm convergence of general signal processing.

关键词： A trial of using the cluster analysis to classify the ship noises and EEG electroencephalogram

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促进理解的图示:结构模型和设计原则

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电化教育研究 2020年第12期41卷 12-19页

作者：金玉宏肖龙海浙江大学教育学院浙江杭州310058

图示是科学教育中交流的重要形式,也是数字媒体呈现的基础。但由于缺乏系统的理论框架,关于什么样的图示更能促进理解仍存在争论。针对这一问题,研究以扎根理论为方法论指导,以中德高中生物教材图示为基础,对30位教师进行深度访谈,建构... 详细信息

图示是科学教育中交流的重要形式,也是数字媒体呈现的基础。但由于缺乏系统的理论框架,关于什么样的图示更能促进理解仍存在争论。针对这一问题,研究以扎根理论为方法论指导,以中德高中生物教材图示为基础,对30位教师进行深度访谈,建构促进理解的图示结构模型。该模型认为:(1)知识映射为图形和文本,从而帮助理解;(2)知识应包括学习者的已有知识,映射为图形时应遵循简洁、相似、相近等原则,映射为文本时应遵循锚定、延拓和升华原则;(3)实现事实、联系和大概念各层次的理解离不开知识、图形和文本三者之间有效的交互。以此阐明图示适度简化能促进理解,过度简化会导致理解困难,不同简化水平的图示共同呈现有助于高阶理解的实现。研究提出了较全面的理论模型,弥合了现有研究间的冲突,也为图示的设计、研究和应用提供了依据。

关键词：图示促进理解扎根理论模型建构

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德国高中科学新标准探析

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比较教育研究 2021年第10期43卷 78-85页

作者：肖龙海金玉宏浙江大学教育学院浙江杭州310058

2020年6月,德国出台了《高等学校入学资格生物、化学、物理化育标准》作为高中阶段科学标准,并同时在线发布了大量示范性教学任务。德国高中科学标准是德国近20年课程改革的最新成果,首次在科学标准中要求真正实现德国传统的"化育"目标... 详细信息

2020年6月,德国出台了《高等学校入学资格生物、化学、物理化育标准》作为高中阶段科学标准,并同时在线发布了大量示范性教学任务。德国高中科学标准是德国近20年课程改革的最新成果,首次在科学标准中要求真正实现德国传统的"化育"目标,并形成了能力的结构化体系。该体系涵盖四大能力领域,以基本概念为基础,以主要内容为落脚点,通过三级划分实现具体化、操作化。分析发现,德国高中科学标准和配套任务具备以下特点:回归学科的基本概念、全面融入的数字化战略、多元的评估方式和面向真实世界的教学任务。

关键词：德国高中教育科学教育课程标准

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LPA protects hepatic injury after trauma hemorrhagic shock

LPA protects hepatic injury after trauma hemorrhagic shock

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第四届重症心脏全国学术大会暨第五届西湖重症医学大会、2019年浙江省重症医学学术大会（重症心脏-心与心外器官)

作者： LINHUI SHI PANPAN LIU LONGQIANG YE YAN WANG GONGJIE YE KEQIN CHAI yuhong jin ZHOUZHOU DONG

Background:Lysophosphatidic acid(LPA) is a phospholipid derivative that can act as a signaling ***,it has been shown involved in many pathophysiological processes such as heart *** we explore the role of LPA in traumatic hemorrhagic shock(T/HS).Methods:We used rat Trauma-Hemorrhagic Shock Model to study T/*** from each group of rats was collected and ALT,AST and TBL levels were analyzed using a multichannel automated analyzer while TNF-α and IL-10 levels were measured with *** also performed western blot to determine expressions of caspase3,GAPDH,Akt and p-Akt.H&E staining and electron microscopy were used to examine histology of *** effect of LPA on hepatic cell apoptosis was analyzed with TUNEL ***:We found that LPA alleviated liver injury and inflammation induced by T/*** cell apoptosis was inhibited by *** the molecular level,we observed that LPA suppressed apoptosis-related protein caspase3 expression but upregulated Akt ***:LPA possesses protective abilities to the liver during T/HS by inhibiting cell apoptosis and promoting cell *** may serve as a potential target for T/HS therapy in the future.

关键词： Lysophosphatidic acid(LPA) traumatic hemorrhagic shock(T/HS) caspase3 Akt apoptosis

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