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Research on fault diagnosis of a railway point machine based on a multi-entropy feature extraction method and support vector machine

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Transportation Safety and Environment 2023年第4期5卷 58-66页

作者： Yunting Zheng shaohua chen Zhiyong Tan Yongkui Sun Automation and Electrical Engineering College Dalian Jiaotong UniversityDalian 116028LiaoningChina CRRC Dalian Co.Ltd. Dalian 116021LiaoningChina National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong UniversityBeijing 100044China

A new fault diagnosis method is proposed to effectively extract the fault features of the sound signal of typical faults of ZDJ9 railway point machines.A multi-entropy feature extraction method is proposed by combing multi-scale permutation entropy and wavelet packet ***,empirical mode decomposition is performed on sound signals to obtain modal components with different time ***,multi-scale permutation entropy is extracted from these ***,the wavelet packet entropy of the sound signals of these sensitive nodes is obtained by analysing the reconstructed signals of the last layer *** the multi-scale permutation entropy and the wavelet packet entropy can distinguish the subtle features of the signal,the subtle features of the information among the high-dimensional features,ReliefF is ***,a support vector machine(SVM)is used to judge the original sismal can be obtained as the feature vector of the 2DJ9 iway point mnchine in ditterent states,To reduce the redundant fault type of a ZDJ9 rilway point machine.

关键词： railway point machine fault diagnosis sound signal support vector machine(SVM)

Occurrence and removal of organic micropollutants in the treatment of landfill leachate by combined anaerobic-membrane bioreactor technology

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Journal of Environmental Sciences 2008年第11期20卷 1281-1287页

作者： XU Yiping ZHOU Yiqi WANG Donghong chen shaohua LIU Junxin WANG Zijian State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Organic micropollutants,with high toxicity and environmental concern,are present in the landfill leachate at much lower levels than total organic constituents (chemical oxygen demand (COD),biochemical oxygen demand (BOD),or total organic carbon (TOC)),and few has been known for their behaviors in different treatment *** this study,occurrence and removal of 17 organochlorine pesticides (OCPs),16 polycyclic aromatic hydrocarbons (PAHs),and technical 4-nonylphenol (4-NP) in landfill leachate in a comb...

关键词： anaerobic landfill leachate membrane bioreactor organic micropollutant

腹腔镜经腹腹膜疝前修补术与开放无张力疝修补术治疗腹股沟疝的疗效及安全性

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当代医学 2024年第12期30卷 99-103页

作者：钟为青彭易鹏陈少华吉安市第一人民医院普外科江西吉安343000 吉安市第一人民医院儿科江西吉安343000

目的探究腹腔镜经腹腹膜疝前修补术(TAPP)与开放无张力疝修补术(OTFH)治疗腹股沟疝的疗效及安全性。方法选取2019年11月至2021年11月吉安市第一人民医院收治的91例腹股沟疝患者作为研究对象,按照随机数字表法分为对照组(n=45)与观察组(n... 详细信息

目的探究腹腔镜经腹腹膜疝前修补术(TAPP)与开放无张力疝修补术(OTFH)治疗腹股沟疝的疗效及安全性。方法选取2019年11月至2021年11月吉安市第一人民医院收治的91例腹股沟疝患者作为研究对象,按照随机数字表法分为对照组(n=45)与观察组(n=46)。对照组采用OTFH治疗,观察组采用TAPP治疗,比较两组手术时间、术中出血量、精索血管情况、疼痛情况及并发症发生率。结果两组手术时间比较差异无统计学意义;观察组术中出血量少于对照组,差异有统计学意义(P<0.05)。术后7d,两组精索动脉管径、精索静脉管径均宽于术前,精索动脉血流速度、精索静脉血流速度均慢于术前,但观察组精索动脉管径、精索静脉管径均窄于对照组,精索动脉血流速度、精索静脉血流速度均快于对照组,差异有统计学意义(P<0.05)。术后12h,观察组视觉模拟评分法(VAS)评分低于对照组,差异有统计学意义(P<0.05);术后24、48h,两组VAS评分均低于前一时间点,且观察组低于对照组,差异有统计学意义(P<0.05)。观察组并发症发生率为8.69%,低于对照组的24.44%,差异有统计学意义(P<0.05)。结论与OTFH治疗腹股沟疝患者相比,TAPP术中出血量更少,疼痛更轻,并发症发生率更低,对精索血管影响较小且不会延长手术时间,安全性更高。

关键词：腹腔镜经腹腹膜疝前修补术开放无张力疝修补术腹股沟疝精索血管情况疼痛

A new method based on the shear lag model for accurate determination of ice adhesion shear strength on solid surface

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Science China(Technological Sciences) 2023年第4期66卷 987-997页

作者： HUANG JiaNan LI DaWei PENG ZhiLong ZHANG Bo YAO Yin chen shaohua Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures Beijing Institute of TechnologyBeijing 100081China

Accurate measurement of the interfacial shear strength between ice and solid surface has important reference significance for the design of anti-icing and de-icing functional *** this paper,a new method is proposed based on the shear lag model of a single fiber pulled out from matrix,in order to accurately determine the interfacial shear strength(ISS)between ice and *** maximum pull-out force at the initiation of interface debonding is well measured in the pull-out test of a metal fiber embedded in an ice matrix.A shear lag model similar to the pull-out test is established and a closed-form relation between the non-uniform interfacial shear stress and the pull-out force is *** the pull-out force reaches its peak value,the ice/metal ISS can be consequently determined as the maximum interfacial shear *** a method takes into account the stress concentration at the interface,which overcomes underestimation of ice/solid ISS based on the apparent strength in previous *** achieved ISS is proven to not only have good convergence,but also be independent of the size and embedded depth of metal *** on the present method,the enhancing effects of freezing temperature and surface roughness on the ice adhesion are further *** present research provides a simple and reliable approach to accurately calibrate the ice/solid ISS,which should be of important reference significance for the design and assessment of anti-icing functional surfaces.

关键词： ice adhesion pull-out test shear lag model interfacial shear strength(isS) stress concentration

循经取穴贴敷疗法对腰椎内固定术后患者胃肠功能的影响

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实用医学杂志 2024年第2期40卷 267-271页

作者：赖培茜胡佩王洪伸郑延华蓝梅妍陈少华广州中医药大学第二附属医院广州510120

目的观察循经取穴贴敷疗法对腰椎内固定术后患者胃肠功能恢复的疗效。方法选取2020年1月至2022年3月在广州中医药大学第二附属医院收治的125例腰椎内固定术后患者,按随机数字表法分为对照组和观察组:对照组62例为常规腰椎内固定术后护理... 详细信息

目的观察循经取穴贴敷疗法对腰椎内固定术后患者胃肠功能恢复的疗效。方法选取2020年1月至2022年3月在广州中医药大学第二附属医院收治的125例腰椎内固定术后患者,按随机数字表法分为对照组和观察组:对照组62例为常规腰椎内固定术后护理,观察组63例在常规护理的基础上加用循经取穴贴敷疗法,观察两组患者术后恶心呕吐NVAS评分、腹胀腹痛、肠鸣音与首次排气、排便时间。结果两组患者术后均发生不同程度的胃肠功能障碍。其中观察组恶心人数、恶心NVAS评分、呕吐分级、腹胀发生率、肠鸣音恢复正常时间和首次排气、排便时间,均较对照组降低(均P0.05)。2组均未发生不良反应。结论循经取穴贴敷疗法可加快腰椎内固定术后患者胃肠功能恢复,促进术后快速康复,提高生活质量。

关键词：腰椎内固定术循经取穴贴敷疗法胃肠功能快速康复

Sorption behavior of tetracyclines on suspended organic matters originating from swine wastewater

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Journal of Environmental Sciences 2018年第3期30卷 144-152页

作者： Yaoyin Lou Zhi-Long Ye shaohua chen Xin Ye Yujun Deng Jianqiao Zhang Key Laboratory of Urban Pollutant Conversion Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China University of Chinese Academy of Sciences Beijing 100049 China

Tetracyclines（TCs） discharged from livestock wastewater have aroused public concerns due to their pharmacological threats to ecosystems and human health. As an important medium in the wastewater, suspended organic matters（SOMs） play vital roles in antibiotics transport and degradation. However, limited information has been reported in the relevant literature. This study investigated TCs sorption behavior on SOM, withdrawn from swine wastewater. High TCs sorption capacities were detected, with the maximum values ranging from 0.337 to 0.679 mg/g. Increasing p H and temperature led to the decline of sorption capacity. Results from three-dimensional excitation–emission matrix fluorescence spectroscopy and Fourier transform infrared spectrometry revealed that amide and carboxyl groups were the main functional groups for TCs adsorption. The interactions between SOM and TCs were clarified as predominated by hydrogen-bonding and cation-exchange in acid conditions, and electrostatic repulsion in neutral or alkaline conditions. Adsorption kinetics modeling was conducted, and a satisfactory fitting was achieved with the Freundlich equation. These results indicated that the adsorption process was a rather complex process, involving a combination of cation-exchange and hydrogen-bonding. The results will provide a better understanding of the capability of SOM for TCs transport and abatement in the wastewater treatment process.

关键词： Tetracycline Suspended organic matters Adsorption Swine wastewater

Numerical simulation of flow hydrodynamics of struvite pellets in a liquid–solid fluidized bed

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Journal of Environmental Sciences 2017年第7期29卷 391-401页

作者： Xin Ye Dongyuan Chu Yaoyin Lou Zhi-Long Ye Ming Kuang Wang shaohua chen Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China College of the Environment and Ecology Xiamen UniversityXiamen 361102China Fujian Academic of Agricultural Sciences Fuzhou 350003China

Phosphorus recovery in the form of struvite has been aroused in recent decades for its dual advantages in eutrophication control and resource *** usage of the struvite products is normally determined by the size which is largely depended on the *** this study,flow behavior of struvite pellets was simulated by means of Eulerian–Eulerian two-fluid model combining with kinetic theory of granular flow in a liquid–solid fluidized bed reactor（FBR）.A parametric study including the mesh size,time step,discretization strategy,turbulent model and drag model was first developed,followed by the evaluations of crucial operational conditions,particle characteristics and reactor *** results showed that a cold model with the mesh resolution of 16 × 240,default time step of 0.001 sec and first order discretization scheme was accurate enough to describe the *** struvite holdup profile using Syamlal–O＇Brien drag model was best fitted to the experimental data as compared with other drag models and the empirical Richardson–Zaki *** the model evaluation,it showed that liquid velocity and particle size played important roles on both solid holdups and *** reactor diameter only influenced the solid velocity while the static bed height almost took no *** results are direct and can be applied to guide the operation and process control of the struvite ***,the model parameters can also be used as the basic settings in further crystallization simulations.

关键词： Numerical simulation Flow hydrodynamics Struvite Liquid–solid fluidized bed

On the contact width in generalized plain strain JKR model for isotropic solids

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Acta Mechanica Sinica 2009年第4期25卷 491-497页

作者： Cong Yan shaohua chen LNM, Institute of Mechanics, Chinese Academy of Sciences,100190 Beijing. China LNM Institute of Mechanics Chinese Academy of Sciences Beijing China

Adhesive contact model between an elastic cylinder and an elastic half space is studied in the present paper, in which an external pulling force is acted on the above cylinder with an arbitrary direction and the contact width is assumed to be asymmetric with respect to the structure. Solutions to the asymmetric model are obtained and the effect of the asymmetric contact width on the whole pulling process is mainly discussed. It is found that the smaller the absolute value of Dundurs＇ parameter 13 or the larger the pulling angle O, the more reasonable the symmetric model would be to approximate the asymmetric one.

关键词： Contact mechanics Generalized JKRmodel Asymmetric contact width Oscillatory solution Non-oscillatory solution

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Science China(Life Sciences) 2015年第12期58卷 1282-1287页

作者： ZENG chengWu WANG WenTao YU XiBao YANG LiJian chen shaohua LI YangQiu First Affiliated Hospital Jinan University Institute of Hematology Medical College Jinan University Key Laboratory for Regenerative Medicine of Ministry of Education Jinan University Key Laboratory of Gene Engineering of the Ministry of Education State Key Laboratory for Biocontrol School of Life Science Sun Yat-sen University

Previous analyses have reported that the human monocytic cell line THP1 can be differentiated into cells with macrophage-like characteristics by phorbol 12-myristate 13-acetate(PMA). However, little is known about the mechanism responsible for regulating this differentiation process. Here, we performed high-throughput RNA-Seq analysis to investigate the genes differently expressed in THP1 cells treated with and without PMA and examined those that may be responsible for the PMA-induced differentiation of monocytes into macrophages. We found 3,000 genes to be differentially expressed after PMA treatment. Gene ontology analysis revealed that genes related to cellular processes and regulation of biological processes were significantly enriched. KEGG analysis also demonstrated that the differentially expressed genes(DEGs) were significantly enriched in the PI3K/AKT signaling pathway and phagosome pathway. Importantly, we reveal an important role of the PI3K/AKT pathway in PMA-induced THP1 cell differentiation. The identified DEGs and pathways may facilitate further study of the detailed molecular mechanisms of THP1 differentiation. Thus, our results provide numerous potential therapeutic targets for modulation of the differentiation of this disease.

关键词： acute myeloid leukemia differentiation macrophage PI3K/AKT pathway RNA sequencing