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基于形态学滤波和CEEMDAN-WVD的车轮失圆诊断

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铁道机车车辆 2024年第2期44卷 8-14页

作者：李大柱梁树林池茂儒许文天西南交通大学牵引动力国家重点实验室成都610031

现有列车车轮失圆监测方法的准确性受车速及线路条件影响较大,为了更准确地监测车轮服役状态,文中提出基于形态学滤波和CEEMDAN-WVD的车轮失圆诊断方法:车辆轴箱垂向振动加速度经数学形态学滤波器滤波降噪后,运用完全噪声辅助聚合经验... 详细信息

现有列车车轮失圆监测方法的准确性受车速及线路条件影响较大,为了更准确地监测车轮服役状态,文中提出基于形态学滤波和CEEMDAN-WVD的车轮失圆诊断方法:车辆轴箱垂向振动加速度经数学形态学滤波器滤波降噪后,运用完全噪声辅助聚合经验模态分解(CEEMDAN)将其分解为一系列的固有模态函数(IMF),然后选取能量熵增量相对较大的几阶IMF分量进行Wigner-Ville分布(WVD)计算,从而叠加得到轴箱振动加速度的多尺度时频图,最后根据多尺度时频图的分布特征来诊断车轮状态。通过仿真分析和工程实例研究结果表明,运用该方法可有效地识别复杂工况下的车轮服役状态。

关键词：车轮失圆形态学滤波完全噪声辅助聚合经验模态分解 Wigner-Ville分布多尺度时频图

Cutting Force Fluctuation Suppression and Error Homogenization of Noncircular Gear Hobbing Based on the Tool Shifting Method

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Chinese Journal of Mechanical Engineering 2023年第4期36卷 167-179页

作者： dazhu li Jiang Han Xiaoqing Tian lian Xia Institute of Artificial Intelligence Anhui Polytechnic UniversityWuhu 241000China CIMS Institute Hefei University of TechnologyHefei 230009China

The current research on noncircular hobbing mainly focuses on the linkage model and motion ***,the intermittent cutting characteristics of hobbing would increase uncertainties in the manufacturing *** this paper,a hobbing machining model with tool-shifting characteristics was proposed to solve the problems of cutting force fluctuation and inconsistency of tooth profile envelope accuracy at different positions of the pitch curve in noncircular gear *** on the unit cutting force coefficient method,the undeformed chip volume generated by interrupted cutting was used to characterize the fluctuation trend of the hobbing *** fluctuation characteristics of the cutting force generated by different hobbing models were compared and *** the equivalent gear tooth and hob slotting numbers,an analysis model of the tooth profile envelope error of the noncircular gear was ***,the tooth profile envelope errors at different positions of the pitch curve were compared and analyzed based on the constructed *** transmission structure of the electronic gearbox was constructed based on the proposed hobbing model,and the hobbing experiment was conducted based on the selfdeveloped noncircular gear CNC hobbing *** paper proposes a hobbing method that can effectively suppress the fluctuation of the peak and whole circumference cutting force and reduce the maximum envelope error of the whole circumference gear teeth.

关键词： Noncircular gear Gear hobbing Cutting force Envelope error Machining model

基于ICEEMDAN和共振解调的轴承故障检测方法

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铁道机车车辆 2024年第4期44卷 84-91页

作者：唐斌池茂儒赵明花李大柱许文天西南交通大学轨道交通运载系统全国重点实验室成都610031 国家高速列车技术创新中心山东青岛266000

对于滚动轴承的故障检测,提出了一种基于带自适应噪声的改进完全集合经验模态分解(ICEEMDAN)和共振解调的轴承故障检测方法。通过ICEEMDAN算法,把原始振动信号分解为若干个IMF分量;选取有效IMF分量进行求和,得到重构信号;使用快速峭度... 详细信息

对于滚动轴承的故障检测,提出了一种基于带自适应噪声的改进完全集合经验模态分解(ICEEMDAN)和共振解调的轴承故障检测方法。通过ICEEMDAN算法,把原始振动信号分解为若干个IMF分量;选取有效IMF分量进行求和,得到重构信号;使用快速峭度图法确定共振频带,然后以此设计相应滤波器进行滤波;使用形态学滤波方法进行共振信号的解调,然后再利用FFT得到轴承的故障特征频谱图。内、外圈故障振动数据验证结果表明,该方法能够检测出滚动轴承的故障。

关键词：滚动轴承带自适应噪声的改进完全集合经验模态分解(ICEEMDAN) 共振解调快速峭度图形态学滤波

利培酮结合心理疗法对躯体疾病合并精神障碍患者心理弹性及BPRS评分的影响

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中国医学工程 2024年第6期32卷 94-97页

作者：姚刚杨晨晨姚海莹李大柱洛阳市第五人民医院精神科河南洛阳471002 郑州大学附属洛阳中心医院儿科二区河南洛阳471099 洛阳市第五人民医院康复科河南洛阳471002

目的探究利培酮结合心理疗法对躯体疾病合并精神障碍患者心理弹性及精神病评定量表(BPRS)评分的影响。方法选取洛阳市第五人民医院2021年6月至2023年4月收治的120例躯体疾病合并精神障碍患者作为研究对象,采用抽签法将其分为对照组(n=60... 详细信息

目的探究利培酮结合心理疗法对躯体疾病合并精神障碍患者心理弹性及精神病评定量表(BPRS)评分的影响。方法选取洛阳市第五人民医院2021年6月至2023年4月收治的120例躯体疾病合并精神障碍患者作为研究对象,采用抽签法将其分为对照组(n=60)和观察组(n=60)。对照组予以利培酮,观察组予以利培酮结合心理疗法。对比两组精神病性症状程度、心理弹性、生活质量、不良反应发生率。结果治疗后,观察组精神病性症状程度(焦虑忧郁、缺乏活力、思维障碍、激活性、敌对猜疑)评分均低于对照组(P0.05),观察组社会功能、心理健康、躯体健康均优于对照组(P0.05),但观察组(8.33%)低于对照组(16.67%)。结论利培酮结合心理疗法予以躯体疾病合并精神障碍患者治疗,有助于改善精神病性症状程度与生活质量水平,增强救治信心,促进患者恢复,值得临床推广。

关键词：利培酮心理疗法躯体疾病精神障碍心理弹性精神病评定量表

Tailored architecture of composite electrolyte for all-solid-state sodium batteries with superior rate performance and cycle life

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Nano Research 2024年第5期17卷 4171-4180页

作者： Xiang Guan Zhenhua Jian Xingan liao Wenchao liao Yanfei Huang dazhu Chen Robert K.Y.li Chen liu Shenzhen Key Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen 518055China Department of Materials Science and Engineering City University of Hong KongHong KongChina

Seeking for composite electrolytes reinforced all-solid-state sodium ion batteries with superior long lifespan and rate performance remains a great ***,a unique strategy to tailor the architecture of composite electrolyte via inserting polymer chains into a small quantity of sulfate sodium grafted C_(48)0H_(28)O_(32)Zr_(6)(UIOSNa)is *** intimate contact between polymer segments and UIOSNa with limited pore size facilitates the anion immobilization of sodium salts and reduction of polymer crystallinity,thereby providing rapid ion conduction and reducing the adverse effect caused by the immigration of *** tNa+grafting of-SO_(3)Na groups on fillers allows the free movement of more sodium ions to further improve and ionic ***,even with the low content of UIOSNa fillers,a high ionic conductivity of 6.62×10^(-4) S·cm^(-1) at 60℃ and a transference number of 0.67 for the special designed composite electrolyte are *** assembled all-solid-state sodium cell exhibits a remarkable rate performance for 500 cycles with 95.96%capacity retention at a high current rate of 4 *** corresponding pouch cell can stably work for 1000 cycles with 97.03%capacity retention at 1 C,which is superior to most of the reported composite electrolytes in the literature.

关键词： solid state sodium battery composite electrolyte rate performance cycle life

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基于半赫兹接触的车轮磨耗预测分析

中国机械工程 2023年第7期34卷 859-865,874页

作者：牛江池茂儒李大柱罗贇西南交通大学牵引动力国家重点实验室成都610036

为了对比赫兹与半赫兹接触算法在轮轨磨耗仿真过程中的差异,建立CR400BF动车组动力学模型,分别基于赫兹接触与半赫兹接触算法(STRIPES)进行长距离仿真,用Archard磨耗模型计算磨耗量,以实测250000km踏面磨耗量为参照分别比较两种算法的... 详细信息

为了对比赫兹与半赫兹接触算法在轮轨磨耗仿真过程中的差异,建立CR400BF动车组动力学模型,分别基于赫兹接触与半赫兹接触算法(STRIPES)进行长距离仿真,用Archard磨耗模型计算磨耗量,以实测250000km踏面磨耗量为参照分别比较两种算法的计算结果。结果表明:不同钢轨廓形对应磨耗量及磨耗分布差异明显;不同磨耗里程下半赫兹接触的接触斑形状差异明显,接触斑面积逐渐增大且最大接触应力逐渐减小;磨耗前期,两种接触算法得到的磨耗量及磨耗分布差异不大,且与实测结果较为接近,但磨耗中后期,两种算法得到的磨耗量较实测结果都偏大且半赫兹接触较赫兹接触更加符合实测结果,原因在于随着磨耗里程增大,轮轨接触不再满足赫兹接触假设。

关键词：轮轨接触车轮磨耗半赫兹接触 Archard模型

Exploring the Lagged Correlation Between Baidu Index and Influenza-like Illness-China,2014-2019

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China CDC weekly 2024年第26期6卷 629-634页

作者： Xuan Han Jiao Yang Yan Luo dazhu Huo Xuya Yu Xuancheng Hu ling Xin liuyang Yang Hualei Xin Ting Zhang Zhongjie li Weizhong Yang School of Population Medicine and Public Health Chinese Academy of Medical Sciences(CAMS)&Peking Union Medical CollegeBeijingChina School of Health Policy and Management Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijingChina Department of management science and information system Faculty of Management and EconomicsKunming University of Science and TechnologyKunming CityYunnan ProvinceChina

Introduction:This study investigated the lagged correlation between Baidu Index for influenza-related keywords and influenza-like illness percentage(Ili%)across regions in *** aim is to establish a scientific foundation for utilizing Baidu Index as an early warning tool for influenza-like illness ***:In this study,data on Ili%and Baidu Index were collected from 30 provincial-level administrative divisions(PLADs)spanning April 2014 to March *** Baidu Index was categorized into Overall Index,Ordinary Index,Prevention Index,Symptom Index,and Treatment Index based on search query *** lagged correlation between the Baidu Index and Ili%was examined through the cross-correlation function(CCF)***:Correlating the Baidu Overall Index of 30 PLADs with Ili%revealed CCF values ranging from 0.46 to 0.86,with a median lag of 0.5 *** analysis indicated that the Prevention Index and Symptom Index exhibited quicker responses to Ili%,with median lags of−9 and−0.5 days,respectively,compared to 0 and 3 days for the Ordinary and Treatment *** median lag days between the Baidu Index and the Ili%were earlier in the northern PLADs compared to the southern ***:The Prevention and Symptom Indexes show promising predictive capabilities for influenzalike illness epidemics.

关键词： utilizing illness Baidu

时频能量谱与VGG16结合的车轮扁疤损伤程度估计方法

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中国机械工程 2023年第16期34卷 1907-1914页

作者：李大柱牛江梁树林池茂儒西南交通大学牵引动力国家重点实验室成都610031

为了实现对运营中车辆车轮扁疤损伤程度的实时精准监测,提出了一种时频能量谱与VGG16卷积神经网络相结合的车轮扁疤损伤程度估计方法,该方法通过对车辆运营中轴箱振动加速度信号的分析处理来实时定量估计车轮扁疤的损伤程度。建立了车... 详细信息

为了实现对运营中车辆车轮扁疤损伤程度的实时精准监测,提出了一种时频能量谱与VGG16卷积神经网络相结合的车轮扁疤损伤程度估计方法,该方法通过对车辆运营中轴箱振动加速度信号的分析处理来实时定量估计车轮扁疤的损伤程度。建立了车辆轨道刚柔耦合系统动力学模型和车轮扁疤数学模型,仿真计算不同扁疤损伤工况下的车辆轴箱振动响应。运用形态学滤波器以及完全噪声辅助集合经验模态分解结合Wigner-Ville分布的时频分析方法,将轴箱振动加速度信号滤波降噪后表达在时频能量谱中。构造了VGG16卷积神经网络模型,通过大量车轮扁疤故障数据的时频能量谱构造的训练集来训练VGG16模型。随机仿真若干车轮扁疤工况,对训练完善的VGG16模型进行测试验证。仿真试验表明,运用时频能量谱与VGG16模型结合的方法能准确地估计运营中车辆的车轮扁疤损伤程度,估计误差在1.6 mm内。

关键词：车轮扁疤形态学滤波完全噪声辅助聚合经验模态分解 Wigner-Ville分布 VGG16 时频能量谱

Comparison Between Threshold Method and Artificial Intelligence Approaches for Early Warning of Respiratory Infectious Diseases-Weifang City,Shandong Province,China,2020-2023

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China CDC weekly 2024年第26期6卷 635-641,I0010,I0011页

作者： Ting Zhang liuyang Yang Ziliang Fan Xuancheng Hu Jiao Yang Yan Luo dazhu Huo Xuya Yu ling Xin Xuan Han Jie Shan Zhongjie li Weizhong Yang School of Population Medicine and Public Health Chinese Academy of Medical Sciences(CAMS)&Peking Union Medical College(PUMC)BeijingChina State Key Laboratory of Respiratory Health and Multimorbidity BeijingChina Key Laboratory of Pathogen Infection Prevention and Control(Peking Union Medical College) Ministry of EducationBeijingChina The Third Affiliated Hospital of Kunming Medical University Yunnan Cancer HospitalKunming CityYunnan ProvinceChina School of Data Science Fudan UniversityShanghaiChina Weifang Center for Disease Control and Prevention Weifang CityShandong ProvinceChina School of Health Policy and Management Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijingChina

Introduction:Respiratory infectious diseases,such as influenza and coronavirus disease 2019(COVID-19),present significant global public health *** emergence of artificial intelligence(AI)and big data offers opportunities to improve traditional disease surveillance and early warning ***:The study analyzed data from January 2020 to May 2023,comprising influenza-like illness(Ili)statistics,Baidu index,and clinical data from *** methodologies were evaluated:the adaptive dynamic threshold method(ADTM)for dynamic threshold adjustments,the machine learning supervised method(MLSM),and the machine learning unsupervised method(MLUM)utilizing anomaly *** comparison focused on sensitivity,specificity,timeliness,and warning ***:ADTM issued 37 warnings with a sensitivity of 71%and a specificity of 85%.MLSM generated 35 warnings,with a sensitivity of 82%and a specificity of 87%.MLUM produced 63 warnings with a sensitivity of 100%and specificity of 80%.The initial warnings from ADTM and MLUM preceded those from MLSM by five *** Kappa coefficient indicated moderate agreement between the methods,with values ranging from 0.52 to 0.62(Plidation of machine learning’s reliability and underscores the unique advantages of each ***,it stresses the significance of integrating machine learning models with various data sources to enhance public health preparedness and response,alongside acknowledging limitations and the need for broader validation.

关键词： specificity integrating utilizing