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A fault feature extraction method of gearbox based on compound dictionary noise reduction and optimized Fourier decomposition

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Journal of Southeast University(English Edition) 2021年第1期37卷 22-32页

作者： mao yifan Xu Feiyun School of Mechanical Engineering Southeast UniversityNanjing 211189China

Aimed at the problem that Fourier decomposition method(FDM)is sensitive to noise and existing mode mixing cannot accurately extract gearbox fault features,a gear fault feature extraction method combining compound dictionary noise reduction and optimized FDM(OFDM)is ***,the characteristics of the gear signals are used to construct a compound dictionary,and the orthogonal matching pursuit algorithm(OMP)is combined to reduce the noise of the vibration ***,in order to overcome the mode mixing phenomenon occuring during the decomposition of FDM,a method of frequency band division based on the extremum of the spectrum is proposed to optimize the decomposition ***,the OFDM is used to decompose the signal into several analytic Fourier intrinsic band functions(AFIBFs).Finally,the AFIBF with the largest correlation coefficient is selected for Hilbert envelope spectrum *** fault feature frequencies of the vibration signal can be accurately *** proposed method is validated through analyzing the gearbox fault simulation signal and the real vibration signals collected from an experimental gearbox.

关键词： Fourier decomposition compound dictionary mode mixing gearbox fault feature extraction

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单孔腹腔镜输卵管切除术40例

安徽医药 2024年第9期28卷 1847-1850页

作者：徐瑞毛轶凡张莉亚江飞云芜湖市第二人民医院妇产科安徽芜湖241000

目的探讨单孔腹腔镜在输卵管妊娠手术中行患侧输卵管切除术的临床应用可行性及效果优缺点。方法选取芜湖市第二人民医院妇产科2017年11月至2019年12月收治并因输卵管妊娠实施行输卵管切除手术的病人共204例。单孔组,40例病人行单孔腹腔... 详细信息

目的探讨单孔腹腔镜在输卵管妊娠手术中行患侧输卵管切除术的临床应用可行性及效果优缺点。方法选取芜湖市第二人民医院妇产科2017年11月至2019年12月收治并因输卵管妊娠实施行输卵管切除手术的病人共204例。单孔组,40例病人行单孔腹腔镜下患侧输卵管切除术;多孔组,164例病人行常规多孔腹腔镜下患侧输卵管切除术。比较两组病人手术时间、术中出血量、住院天数、术后住院天数、手术费用、术后排气时间、术后镇痛药使用率、术后并发症情况及切口满意度评分。结果所有病人均顺利完成手术,未出现病人中转开腹或中转行多孔腹腔镜手术。两组病人术中出血量、住院时间、术后住院时间、住院费用及术后并发症发生率比较,均差异无统计学意义(P>0.05)。单孔组病人术后排气时间为(17.35±6.15)h,多孔组病人术后排气时间(21.45±7.50)h,两组差异有统计学意义(P<0.05);单孔组病人术后镇痛药使用率为2.50%,多孔组病人术后镇痛药使用率为14.02%,单孔组病人术后镇痛药使用率低于多孔组(P<0.05);单孔组术后腹壁切口满意度评分(4.45±0.68)分,明显高于多孔组术后腹壁切口满意度评分(3.65±0.77)分(P<0.05)。结论单孔腹腔镜手术具有创伤小、恢复快、切口美观的特点,在输卵管切除术中具有可行性,值得临床推广。

关键词：输卵管切除术妊娠,输卵管最小侵入性外科手术单孔腹腔镜手术

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人工虎骨粉治疗绝经后骨质疏松的临床疗效

中国骨质疏松杂志 2024年第5期30卷 689-693页

作者：顾宏菲赵玲李旭云孔令成毛一凡李茜茜史晓林李威浙江中医药大学附属富阳中医骨伤医院浙江杭州311400 浙江中医药大学附属第二医院浙江杭州310005 浙江中医药大学浙江杭州310053

目的观察人工虎骨粉对绝经后骨质疏松症患者骨密度、躯体能力及骨折跌倒风险的影响。方法将浙江中医药大学附属富阳中医骨伤医院门诊收治的160例绝经后骨质疏松症患者分为对照组及试验组,每组80例。对照组予以阿法骨化醇软胶囊+钙尔奇D3... 详细信息

目的观察人工虎骨粉对绝经后骨质疏松症患者骨密度、躯体能力及骨折跌倒风险的影响。方法将浙江中医药大学附属富阳中医骨伤医院门诊收治的160例绝经后骨质疏松症患者分为对照组及试验组,每组80例。对照组予以阿法骨化醇软胶囊+钙尔奇D3片+阿仑膦酸钠片,试验组在此基础上增加人工虎骨粉胶囊进行治疗,比较两组患者骨密度、跌倒效能量表评分、简易躯体能力测试、脆性骨折及跌倒发生变化率等并进行统计分析。结果①研究过程中,试验组和对照组分别有2例和4例退出试验,最后共收集154例患者数据;②骨密度:治疗12个月后试验组与对照组骨密度均较治疗前提高,差异具有统计学意义(P<0.05),且试验组骨密度提升更优,两组比较差异具有统计学意义(P<0.05);③简易躯体能力测试:试验组在治疗6个月及12个月后躯体、下肢和移动能力比治疗前改善明显,差异具有统计学意义(P<0.05),治疗12个月后试验组躯体能力测试改善优于对照组,差异具有统计学意义(P<0.05);④跌倒效能量表:试验组在治疗6个月及12个月后跌倒效能评分均较治疗前提高,差异具有统计学意义(P<0.05),并且与对照组比较,跌倒效能量评分更优,差异具有统计学意义(P<0.05);⑤跌倒及骨折发生率:试验组跌倒24次,跌倒发生率30.77%;对照组跌倒35次,跌倒发生率46.05%。试验组骨折4次,骨折发生率5.13%;对照组骨折6次,骨折发生率7.89%。结论人工虎骨粉可有效改善患者骨密度、躯体活动能力,降低跌倒风险,降低骨折发生率,比单纯三联用药效果更佳。

关键词：骨质疏松症人工虎骨粉骨密度跌倒风险躯体能力

Effect of annealing treatment on the microstructure and mechanical properties of warm-rolled Mg-Zn-Gd-Ca-Mn alloys

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2208-2220页

作者： yifan Song Xihai Li Jinliang Xu Kai Zhang Yaozong mao Hong Yan Huiping Li Rongshi Chen School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Shandong Key Laboratory of Advanced Aluminium Materials and Technology Binzhou Institute of TechnologyBinzhou 256606China

The basal texture of traditional magnesium alloy AZ31 is easy to form and exhibits poor plasticity at room *** address these problems,a multi-micro-alloyed high-plasticity Mg-1.8Zn-0.8Gd-0.1Ca-0.2Mn(wt%)alloy was developed using the unique role of rare earth and Ca solute *** addition,the influence of the annealing process on the grain size,second phase,texture,and mechanical properties of the warm-rolled sheet at room temperature was analyzed with the goal of developing high-plasticity mag-nesium alloy sheets and obtaining optimal thermal-mechanical treatment *** results show that the annealing temperature has a significant effect on the microstructure and properties due to the low alloying content:there are small amounts of larger-sized block and long string phases along the rolling direction(RD),as well as several spherical and rodlike particle phases inside the *** increas-ing annealing temperature,the grain size decreases and then increases,and the morphology,number,and size of the second phase also change *** particle phase within the grains vanishes at 450℃,and the grain size increases *** the full recrystal-lization stage at 300-350℃,the optimum strength-plasticity comprehensive mechanical properties are presented,with yield strengths of 182.1 and 176.9 MPa,tensile strengths of 271.1 and 275.8 MPa in the RD and transverse direction(TD),and elongation values of 27.4%and 32.3%,***,there are still some larger-sized phases in the alloy that influence its mechanical properties,which offers room for improvement.

关键词： Mg-Zn-Gd-Ca-Mn alloy annealing treatment microstructure texture dynamic recrystallization mechanical properties

An End-To-End Hyperbolic Deep Graph Convolutional Neural Network Framework

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 537-563页

作者： Yuchen Zhou Hongtao Huo Zhiwen Hou Lingbin Bu yifan Wang Jingyi mao Xiaojun Lv Fanliang Bu School of Information Network Security People’s Public Security University of ChinaBeijing100038China Institute of Computing Technology China Academy of Railway Sciences Corporation LimitedBeijing100081China

Graph Convolutional Neural Networks(GCNs)have been widely used in various fields due to their powerful capabilities in processing graph-structured ***,GCNs encounter significant challenges when applied to scale-free graphs with power-law distributions,resulting in substantial ***,most of the existing GCN models are shallow structures,which restricts their ability to capture dependencies among distant nodes and more refined high-order node features in scale-free graphs with hierarchical *** more broadly and precisely apply GCNs to real-world graphs exhibiting scale-free or hierarchical structures and utilize multi-level aggregation of GCNs for capturing high-level information in local representations,we propose the Hyperbolic Deep Graph Convolutional Neural Network(HDGCNN),an end-to-end deep graph representation learning framework that can map scale-free graphs from Euclidean space to hyperbolic *** HDGCNN,we define the fundamental operations of deep graph convolutional neural networks in hyperbolic ***,we introduce a hyperbolic feature transformation method based on identity mapping and a dense connection scheme based on a novel non-local message passing *** addition,we present a neighborhood aggregation method that combines initial structural featureswith hyperbolic attention *** the above methods,HDGCNN effectively leverages both the structural features and node features of graph data,enabling enhanced exploration of non-local structural features and more refined node features in scale-free or hierarchical *** results demonstrate that HDGCNN achieves remarkable performance improvements over state-ofthe-art GCNs in node classification and link prediction tasks,even when utilizing low-dimensional embedding ***,when compared to shallow hyperbolic graph convolutional neural network models,HDGCNN exhibits notable advantages and performance enhanceme

关键词： Graph neural networks hyperbolic graph convolutional neural networks deep graph convolutional neural networks message passing framework

化肥与腐秆剂施用对秸秆还田下水稻土肥力和水稻产量的影响

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陕西农业科学 2024年第7期70卷 98-102页

作者：王时聪茆一钒张旋旋王珂李宇慧王擎运柳开楼马超杨凌职业技术学院陕西杨凌712100 安徽农业大学资源与环境学院农田生态保育与污染防控安徽省重点实验室安徽合肥230036 江西省红壤及种质资源研究所农业农村部酸化土改良与利用重点实验室江西进贤331717

为探明秸秆还田条件下,化肥和腐秆剂对土壤肥力和作物产量的影响,本研究选用在安徽省霍邱县麦稻轮作区的秸秆促腐还田定位试验,对比了秸秆完全破碎直接还田(S)、秸秆完全破碎直接还田+NPK优化施肥(SF),秸秆完全破碎直接还田+腐秆剂(SD)... 详细信息

为探明秸秆还田条件下,化肥和腐秆剂对土壤肥力和作物产量的影响,本研究选用在安徽省霍邱县麦稻轮作区的秸秆促腐还田定位试验,对比了秸秆完全破碎直接还田(S)、秸秆完全破碎直接还田+NPK优化施肥(SF),秸秆完全破碎直接还田+腐秆剂(SD)、秸秆完全破碎直接还田+NPK优化施肥+腐秆剂(SFD)处理后土壤活性有机碳库水平、土壤养分含量和作物产量的状况。研究结果显示:与对照S处理相比,仅SFD处理显著提高了土壤总有机碳、活性有机碳、碳库指数、土壤速效磷、速效钾和水稻产量,增幅分别为38.12%、38.47%、40.63%、55.38%、24.73%和439.44%(P<0.05);水稻产量与活性有机碳、碱解氮、速效磷之间呈显著正相关(P<0.05),与总有机碳、速效钾之间呈极显著正相关(P<0.01)。腐秆剂是培肥增产的关键因子,腐秆剂的促腐效果需在化肥施用后才能得以充分发挥,化肥与腐秆剂同时施用能最大化提升土壤肥力,并增加水稻产量。

关键词：腐秆剂化肥土壤有机碳水稻产量沿淮地区

Negative enthalpy alloys and local chemical ordering:a concept and route leading to synergy of strength and ductility

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National Science Review 2024年第4期11卷 172-184页

作者： Zibing An Tao Yang Caijuan Shi Shengcheng mao Lihua Wang Ang Li Wei Li Xianmeng Xue Ming Sun yifan Bai Yapeng He Fuzeng Ren Zhouguang Lu Ming Yan Yang Ren Chain-Tsuan Liu Ze Zhang Xiaodong Han Beijing Key Lab of Microstructure and Property of Advanced Materials College of Materials Science &Engineering Beijing University of Technology Department of Materials Science and Engineering City University of Hong Kong Key Laboratory of Partial Acceleration Physics& Technology Institute of High Energy PhysicsChinese Academy of Sciences Department of Materials Science &Engineering Southern University of Science and Technology Department of Physics City University of Hong Kong State Key Laboratory of Silicon Materials Department of Materials Science and Engineering Zhejiang University

Solid solutions are ubiquitous in metals and alloys. Local chemical ordering(LCO) is a fundamental sub-nano/nanoscale process that occurs in many solid solutions and can be used as a microstructure to optimize strength and ductility. However, the formation of LCO has not been fully elucidated, let alone how to provide efficient routes for designing LCO to achieve synergistic effects on both superb strength and ductility. Herein, we propose the formation and control of LCO in negative enthalpy alloys. With engineering negative enthalpy in solid solutions, genetic LCO components are formed in negative enthalpy refractory high-entropy alloys(RHEAs). In contrast to conventional ‘trial-and-error' approaches, the control of LCO by using engineering negative enthalpy in RHEAs is instructive and results in superior strength(1160 MPa) and uniform ductility(24.5%) under tension at ambient temperature, which are among the best reported so far. LCO can promote dislocation cross-slip, enhancing the interaction between dislocations and their accumulation at large tensile strains; sustainable strain hardening can thereby be attained to ensure high ductility of the alloy. This work paves the way for new research fields on negative enthalpy solid solutions and alloys for the synergy of strength and ductility as well as new functions.

关键词： negative enthalpy alloys local chemical ordering strength ductility dislocation

Coverage of the Combined DTaP-IPV/Hib Vaccine Among Children Aged 2-18 Months—9 PLADs,China,2019-2021

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China CDC weekly 2024年第19期6卷 418-423,I0001页

作者： Li Li Hui Liang yifan Song Zhaonan Zhang Jing An Ning Li Huifeng Sun Ying Bao Leijin mao Lin Ding Jie Yan Zhiguo Wang Lei Cao Jiakai Ye Wenzhou Yu National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases BeijingChina National Immunization Program Chinese Center for Disease Control and PreventionBeijingChina Zhejiang Center for Disease Control and Prevention Hangzhou CityZhejiang ProvinceChina Gansu Center for Disease Control and Prevention Lanzhou CityGansu ProvinceChina Hubei Center for Disease Control and Prevention Wuhan CityHubei ProvinceChina Shandong Center for Disease Control and Prevention Jinan CityShandong ProvinceChina Sichuan Center for Disease Control and Prevention Chengdu CitySichuan ProvinceChina Anhui Center for Disease Control and Prevention Hefei CityAnhui ProvinceChina Guizhou Center for Disease Control and Prevention Guiyang CityGuizhou ProvinceChina Hunan Center for Disease Control and Prevention Changsha CityHunan ProvinceChina Jiangsu Center for Disease Control and Prevention Nanjing CityJiangsu ProvinceChina

Summary What is already known on this topic?In China,there is limited data available on the use and coverage of the non-program,combined diphtheria,tetanus toxoid,acellular pertussis adsorbed,inactivated poliovirus and haemophilus influenzae type b(DTaPIPV/Hib)pentavalent vaccine,and its role as a substitute for the separately administered standalone program vaccines.

关键词： vaccine Hib DTaP

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基于轨道根数交接的弹道导弹落点快速预报

空军工程大学学报（自然科学版） 2017年第1期18卷 33-38页

作者：毛艺帆张多林王路空军工程大学防空反导学院西安710051

为实现弹道导弹精确落点的快速预报,提出基于轨道根数交接的落点预报方法。多功能地基相控阵雷达通过综合自身计算的目标轨道根数信息与远程预警相控阵雷达上报至预警中心的目标轨道根数信息,对弹道导弹实时定轨,待落点误差精度满足要求... 详细信息

为实现弹道导弹精确落点的快速预报,提出基于轨道根数交接的落点预报方法。多功能地基相控阵雷达通过综合自身计算的目标轨道根数信息与远程预警相控阵雷达上报至预警中心的目标轨道根数信息,对弹道导弹实时定轨,待落点误差精度满足要求后,进行落点精确预报。仿真结果表明,相对传统落点预报方法,能够将预报时间缩短近40%。

关键词：弹道导弹落点预报轨道根数雷达交接