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Unsupervised construction of health indicator for rotating machinery via multi-criterion feature selection and attentive variational autoencoder

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Science China(Technological Sciences) 2024年第5期67卷 1524-1537页

作者： LI XinYu cheng changming PENG ZhiKe State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai200240China School of Mechanical Engineering Ningxia UniversityYinchuan750021China

Health indicator(HI)construction is a crucial task in degradation evaluation and facilitates the prognostic and health management(PHM)of rotating *** interference from artificial labeling,the HI construction approaches in an unsupervised manner have attracted substantial ***,current unsupervised methods generally struggle with two problems:(1)ignorance of both redundancy between features and global variability of features during the feature selection process;(2)inadequate utilization of information from different sampling *** tackle these problems,this work develops a novel unsupervised approach for HI construction that integrates multi-criterion feature selection and the Attentive Variational Autoencoder(Attentive VAE).Explicitly,a multi-criterion feature selection(Mc FS)algorithm together with an elaborately designed metric is proposed to determine a superior feature subset,considering the relevance,the redundancy,and the global variability of features ***,for the adequate utilization of the information from distinct sampling moments,a deep learning model named Attentive VAE is *** Attentive VAE is solely fed with the selected features in the health state for model training and the HI is derived through the reconstruction error to reveal the degradation degree of *** case studies based on genuine experimental datasets are involved to quantitatively evaluate the superiority of the developed approach,demonstrating its superiority over other unsupervised methods for characterizing degradation *** effectiveness of both the Mc FS algorithm and the Attentive VAE is verified by ablation experiments,respectively.

关键词： health indicator(HI) unsupervised learning multi-criterion feature selection global variability attention mechanism

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Sufficient variable selection of high dimensional nonparametric nonlinear systems based on Fourier spectrum of density-weighted derivative

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Applied Mathematics and Mechanics(English Edition) 2024年第11期45卷 2011-2022页

作者： Bing SUN changming cheng Qiaoyan CAI Zhike PENG State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai200240China China Academy of Launch Vehicle Technology Beijing100076China School of Mechanical Engineering Ningxia UniversityYinchuan750021China

The variable selection of high dimensional nonparametric nonlinear systems aims to select the contributing variables or to eliminate the redundant *** a high dimensional nonparametric nonlinear system,however,identifying whether a variable contributes or not is not ***,based on the Fourier spectrum of densityweighted derivative,one novel variable selection approach is developed,which does not suffer from the dimensionality curse and improves the identification ***,a necessary and sufficient condition for testing a variable whether it contributes or not is *** proposed approach does not require strong assumptions on the distribution,such as elliptical *** simulation study verifies the effectiveness of the novel variable selection algorithm.

关键词： nonlinear system identification variable selection Fourier spectrum non-parametric nonlinear system

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An Interpretable Denoising Layer for Neural Networks Based on Reproducing Kernel Hilbert Space and its Application in Machine Fault Diagnosis

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Chinese Journal of Mechanical Engineering 2021年第3期34卷 104-114页

作者： Baoxuan Zhao changming cheng Guowei Tu Zhike Peng Qingbo He Guang Meng State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

Deep learning algorithms based on neural networks make remarkable achievements in machine fault diagnosis,while the noise mixed in measured signals harms the prediction accuracy of *** denoising methods in neural networks,such as using complex network architectures and introducing sparse techniques,always suffer from the difficulty of estimating hyperparameters and the lack of physical *** address this issue,this paper proposes a novel interpretable denoising layer based on reproducing kernel Hilbert space(RKHS)as the first layer for standard neural networks,with the aim to combine the advantages of both traditional signal processing technology with physical interpretation and network modeling strategy with parameter *** investigating the influencing mechanism of parameters on the regularization procedure in RKHS,the key parameter that dynamically controls the signal smoothness with low computational cost is selected as the only trainable parameter of the proposed ***,the forward and backward propagation algorithms of the designed layer are formulated to ensure that the selected parameter can be automatically updated together with other parameters in the neural ***,exponential and piecewise functions are introduced in the weight updating process to keep the trainable weight within a reasonable range and avoid the ill-conditioned *** studies verify the effectiveness and compatibility of the proposed layer design method in intelligent fault diagnosis of machinery in noisy environments.

关键词： Machine fault diagnosis Reproducing kernel Hilbert space(RKHS) Regularization problem Denoising layer Neural network

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Ultrathin covalent organic framework nanosheet-based photoregulated metal-free oxidase-like nanozyme

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Nano Research 2022年第10期15卷 8783-8790页

作者： Yongwu Peng Minchu Huang Liangjun Chen chengtao Gong Nanjun Li Ying Huang changming cheng College of Materials Science and Engineering and College of Chemical Engineering Zhejiang University of TechnologyHangzhou 310014China State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and TechnologyMianyang 621010China Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics(CAEP)Mianyang 612900China Jiangsu Province Engineering Research Center of Agricultural Breeding Pollution Control and Resource Yancheng Teachers UniversityYancheng 224007China

The exploration of low-cost and metal-free nanozymes with oxidase-mimicking activity is highly desired due to their attractive properties and potential ***,it is still challenging and remains unexploited to fully realize oxidase-like nanozyme in the emerging covalent organic frameworks(COFs)due to their polymeric nature and weak photoelectric *** herein report the first example of the preparation and oxidase-mimicking activity of novel ultrathin two-dimensional(2D)COF(termed as TTPA-COF)*** ultrathin TTPA-COF nanosheets with hexagonal layered structure are constructed from two flexible photoactive(diarylamino)benzene-based linkers,and exhibit remarkable catalytic activity toward the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)in the presence of O_(2) due to their large specific surface areas and abundant active ***,it is worth noting that the nanozyme activity could be regulated by external light *** on the oxidasemimicking activity of TTPA-COF nanosheets,a green colorimetric sensor is proposed for the sensitive and selective determination of glutathione(GSH)in a wide linear range of 0.5–40μM with a detection limit of 0.5μ*** work reported here would open new avenues for the exploration of low-cost and high-efficiency nanozymes,as well as extend the application of 2D COF nanosheets in the fields of catalysis and sensing.

关键词： covalent organic framework nanosheets ultrathin photoregulated metal-free oxidase mimics

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The States of Thermal Plasma Torch and Its Application

Southwestern Institute of Physics Annual Report

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Southwestern Institute of Physics Annual Report 2005年第1期 156-158页

作者： cheng changming TANG Deli

In recent years, plasma technology has emerged as a novel technique for the manufacture of newer and better materials. The thermodynamic state of thermal plasma approaches local thermodynamic equilibrium, temperature of heavy particle is higher （ 10^3 -10^4 K ） and the temperature range of electron is 10^4- 10^6 K. The state of thermal plasma can be described by an unitive thermodynamic temperature. The characteristics of thermal plasmas are high temperature, high enthalpy, high energy density, controllable atmosphere, steep temperature gradient etc. It has been widely applied in field of processing, metallurgy, material, chemical engineering, environmental protection.

关键词： Thermal plasma Local thermodynamic equilibrium Plasma torch

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阳极结构对直流非转移型等离子体射流特性的影响

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核技术 2008年第1期31卷 27-30页

作者：程昌明唐德礼赵杰核工业西南物理研究院成都610041

本文介绍了自行研制的直流非转移弧等离子体炬的结构和工作原理,研究了不同阳极结构等离子体射流的特性与气体流量、弧功率的关系,以及侧向垂直送气对射流形貌的影响。结果表明,阳极结构对等离子体射流特性的影响较大,弧压随着阳极压缩... 详细信息

本文介绍了自行研制的直流非转移弧等离子体炬的结构和工作原理,研究了不同阳极结构等离子体射流的特性与气体流量、弧功率的关系,以及侧向垂直送气对射流形貌的影响。结果表明,阳极结构对等离子体射流特性的影响较大,弧压随着阳极压缩角的增大而下降,较小压缩角的射流稳定性更好;通道直径较小的等离子体射流刚性更强;不同阳极结构的等离子体炬可以有不同的应用领域。

关键词：等离子体炬,等离子体射流,阳极压缩角,伏安特性

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Characteristics of End Hall Ion Source with Magnetron Hollow Cathode Discharge

Southwestern Institute of Physics Annual Report

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Southwestern Institute of Physics Annual Report 2006年第1期 192-193页

作者： TANG Deli WANG Lisheng PU Shihao cheng changming Chu Paul K. 不详 Department of Physics and Materials Science City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong China

1 Introduction Hall effects plasma accelerators have been developed as plasma thrusters in satellite propulsion since the early 1960＇ s The hall plasma accelerator is based on closed drift of electrons in the crossed E ×B fields and it is possible to obtain high current ion beam acceleration in quasi-neutral plasma. Recently, there have been growing interests in the generation of intense ion beam fluxes by hall accelerators for applications such as ion thrusters, plasma accelerators, and ion beam sources for surface modification.

关键词：离子源磁控管阴极流量

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人工挖孔桩结合高压旋喷桩在高层建筑基础施工中的应用

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铁道建筑 2009年第8期49卷 98-100页

作者：程长明湖南省建筑工程集团总公司长沙410004

人工挖孔桩和高压旋喷桩是各具特点的基础施工方法,各有施工针对性和适用性。当高层建筑工程基础施工遇到复杂工程地质,如岩溶地质、地下水丰富状况,单一桩基形式无法满足施工要求。通过将人工挖孔桩和高压旋喷桩相结合,发挥各自优势,... 详细信息

人工挖孔桩和高压旋喷桩是各具特点的基础施工方法,各有施工针对性和适用性。当高层建筑工程基础施工遇到复杂工程地质,如岩溶地质、地下水丰富状况,单一桩基形式无法满足施工要求。通过将人工挖孔桩和高压旋喷桩相结合,发挥各自优势,成功完成了复杂工程地质下的基础工程施工。

关键词：人工挖孔桩高压旋喷桩岩溶地质地下水丰富高层建筑基础

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农业新质生产力与新型生产关系:逻辑思路与改革路径

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中国农业大学学报（社会科学版） 2024年第4期41卷 41-54页

作者：高强程长明南京林业大学经济管理学院滁州学院经济与管理学院

推动农业强国建设需要培育和发展农业新质生产力。根据生产关系要适合生产力发展的基本规律,发展农业新质生产力必然要求加快推进生产关系变革,形成与农业新质生产力相适应的新型生产关系。文章在厘清农业新质生产力基本内涵的基础上,... 详细信息

推动农业强国建设需要培育和发展农业新质生产力。根据生产关系要适合生产力发展的基本规律,发展农业新质生产力必然要求加快推进生产关系变革,形成与农业新质生产力相适应的新型生产关系。文章在厘清农业新质生产力基本内涵的基础上,深入探讨农业新质生产力与新型生产关系的理论逻辑、历史逻辑和现实逻辑,并提出通过全面深化农村改革破除阻碍农业新质生产力发展的体制机制性障碍。研究认为,以新型生产关系塑造推动农业新质生产力发展,要正确处理好人与地、人与技、人与业和人与村的关系,并通过深化农村土地制度改革、农业科技体制改革、农业产业体系改革、要素市场配置改革和农村人才体制改革,塑造适应农业新质生产力发展的制度安排。

关键词：农业新质生产力新型生产关系农业强国农业科技创新农村改革

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长江经济带物流业环境效率与环境全要素生产率分析

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统计与决策 2018年第18期34卷 125-130页

作者：程长明陈学云滁州学院经济与管理学院

资源环境约束下的物流效率是评价产业发展质量的重要因素,是实现经济、社会和生态效益协调发展的核心。文章在供给侧改革的背景下,结合长江经济带物流业的投入产出特点和资源环境约束,运用超效率SBM和ML模型,对物流业环境效率和环境全... 详细信息

资源环境约束下的物流效率是评价产业发展质量的重要因素,是实现经济、社会和生态效益协调发展的核心。文章在供给侧改革的背景下,结合长江经济带物流业的投入产出特点和资源环境约束,运用超效率SBM和ML模型,对物流业环境效率和环境全要素生产率进行实证分析。结果显示,长江经济带物流业环境效率总体呈现类“U”型趋势,环境全要素生产率年均提高1.7%,技术进步是效率的突破点。

关键词：长江经济带供给侧改革环境效率环境全要素生产率 SBM模型

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