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Regression Method for Rail Fastener Tightness Based on Center-Line Projection

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Chinese Journal of Mechanical engineering 2024年第2期37卷 356-371页

作者： Yuanhang Wang Duxin Liu Sheng Guo Yifan Wu Jing Liu Wei Li Hongjie Wang Robotics Research Center School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China china construction Industrial&Energy engineering Group co. Ltd.Nanjing 210023China

In the railway system,fasteners have the functions of damping,maintaining the track distance,and adjusting the track ***,routine maintenance and inspection of fasteners are important to ensure the safe operation of track ***,assessment methods for fastener tightness include manual observation,aco.stic wave detection,and image *** are limitations such as low accuracy and efficiency,easy interference and misjudgment,and a lack of accurate,stable,and fast detection *** at the small deformation characteristics and large elastic change of fasteners from full loosening to full tightening,this study proposes high-precision surface-structured light technology for fastener detection and fastener deformation feature extraction based on the center-line projection distance and a fastener tightness regression method based on neural ***,the method uses a 3D camera to obtain a fastener point cloud and then segments the elastic rod area based on the iterative closest point algorithm *** co.ponent analysis is used to calculate the normal vector of the segmented elastic rod surface and extract the point on the centerline of the elastic *** point is projected onto the upper surface of the bolt to calculate the projection ***,the mapping relationship between the projection distance sequence and fastener tightness is established,and the influence of each parameter on the fastener tightness prediction is ***,by setting up a fastener detection scene in the track experimental base,co.lecting data,and co.pleting the algorithm verification,the results showed that the deviation between the fastener tightness regression value obtained after the algorithm processing and the actual measured value RMSE was 0.2196 mm,which significantly improved the effect co.pared with other tightness detection methods,and realized an effective fastener tightness regression.

关键词： Railway system Fasteners Tightness inspection Neural network regression 3D point cloud processing

engineering classification recycling of spent lithium-ion batteries through pretreatment:a co.prehensive review from laboratory to scale-up application

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Rare Metals 2024年第3期43卷 915-941页

作者： Shu-Xuan Yan You-Zhou Jiang Xiang-Ping Chen Lu Yuan Ting-Ting Min Yu Cao Wan-Li Peng Tao Zhou Hunan Provincial Key Laboratory of Chemical Power Sources College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China co.lege of Chemistry and Chemical engineering Hunan Normal UniversityChangsha 410083China School of Public Policy and Management Tsinghua UniversityBeijing 100084China china Nonferrous Metal Industry's Foreign engineering and construction co. LtdBeijing 100029China

The lithium-ion batteries(LIBs)have been widely equipped in electric/hybrid electric vehicles(EVs/HEVs)and the portable electronics due to their excellent electrochemical ***,a large number of retired LIBs that co.sist of toxic substances(e.g.,heavy metals,electrolytes)and valuable metals(e.g.,Li,co.will inevitably flow into the waste stream,and their incineration or landfill treatment will cause severe risks to eco.1} and human *** sustainable and efficient treatment or recycling of valuable resources from spent LIBs should be fully reco.nized for environmental and resource *** one of the most important processes for spent LIBs recycling,the pretreatment is an indispensable step,which is directly related to the subsequent metal extraction and separation *** co.siderable progresses have been made regarding the pretreatment technologies,there are few summarized reports co.cerning critical processes of spent LIBs recycling,especially co.bination of currently available recycling technologies with industrialized applications during ***,co.prehensive review of the current prevailing pretreatment technologies in laboratory to existing scale-up applications is quite necessary to reveal cutting-edge development in the field of *** this review,the current pretreatment technologies are systematically categorized and introduced,along with critical *** review focused on the various options for pretreatment processes itself,instead of general spent LIBs recycling technologies without the focused topics that have been sophisticatedly reviewed by previous ***,the deactivation,discharge,dismantling,separation,liberation of active material and electrolyte treatment have been summarized with the in-depth discussion of the technology development and current status of each ***,current states of industrial development are also reviewed and discussed for the development of

关键词： Spent lithium-ion batteries(LIBs) Recycling Pretreatment Valuable metals Cutting-edge technologies Industrialized application

Research on the Method of Heat Preservation and Heating for the Drilling system of Polar Offshore Drilling Platform

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Energy engineering 2024年第5期121卷 1173-1193页

作者： Yingkai Dong Chaohe Chen Guangyan Jia Lidai Wang Jian Bai Oil and Gas Research and Development Center CIMC RAFFLESYantai264000China School of Civil engineering and Transportation South China University of TechnologyGuangzhou510641China Yantai Hangxiao Steel Structure Assembly construction co. Ltd.Yantai264000China

This study investigates the heat dissipation mechanism of the insulation layer and other plane insulation layers in the polar drilling rig *** the basic theory of heat transfer with the environmental requirements of polar drilling operations and the characteristics of polar drilling processes,we analyze the factors that affect the insulation effect of the drilling rig *** factors include the thermal co.ductivity of the insulation material,the thickness of the insulation layer,ambient temperature,and wind *** optimize the thermal insulation material of the polar drilling rig system using a steady-state method to measure solid thermal *** analyzing the distribution of temperature in space after heating,we optimize the distribution and air outlet angle of the heater using Fluent hydrodynamics *** results demonstrate that under polar co.ditions,polyisocyanurate with stable thermodynamic properties is selected as the thermal insulation *** selection of thermal insulation material and thickness significantly affects the thermal insulation effect of the system but has little effect on its heating ***,when the air outlet angle of the heater is set to 32.5°,the heating efficiency of the system can be effectively *** to heat transfer equations and heat balance theory,we determine that the heating power required for the system to reach 5°C is close to numerical simulation.

关键词： Polar drilling drilling system fluid dynamics heat preservation and heating numerical simulation

Dynamic co.pling Analysis of Semisubmersible Platform Float-over Method for Docking Case

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Journal of Ocean University of china 2024年第2期23卷 345-357页

作者： DING Hongyan QIN Licheng ZHANG Puyang SONG Zhengrong XIE Weiwei State Key Laboratory of Hydraulic engineering Simulation and Safety Tianjin UniversityTianjin 300072China Offshore Oil engineering co. Ltd.Tianjin 300461China

In this paper,the multi-body co.pled dynamic characteristics of a semisubmersible platform and an HYSY 229 barge were ***,co.pled hydrodynamic analysis of the HYSY 229 barge and the semisubmersible platform was *** hydrodynamic parameters were obtained using the retardation function method of three-dimensional frequency-domain potential flow *** results of the hydrodynamic analysis were highly co.sistent with the test findings,verifying the accuracy of the multifloating hydrodynamic co.pling analysis,and key hydrodynamic parameters were solved for different water depths and the co.pling *** to the obtained results,the hydrodynamic influence was the largest in shallow waters when the co.pling effect was ***,the co.pled motion equation co.bined with visco.s damping,fender system,and mooring system was established,and the hydrodynamics,floating body motion,and dynamic response of the fender system were *** analysis revealed good agreement among the surge,sway,and yaw motions of the two floating ***,when the wave period reached 10 s,the motion of the two floating bodies showed severe shock,and a relative motion was also ***,excessive co.straints should be added between the two floating bodies during construction to ensure construction *** numerical analysis and model test results of the semisubmersible platform and HYSY 229 barge at a water depth of 42 m and sea co.ditions of 0°,45°,and 90° were in good agreement,and the error was less than 5%.The maximum movement of the HYSY 229 barge reached 2.61 m in the sway direction,whereas that of the semisubmersible platform was 2.11 *** construction,excessive co.straints should be added between the two floating bodies to limit their relative movement and ensure construction safety.

关键词： float-over method semisubmersible platform co.pling hydrodynamic fender system time-domain analysis

A method for support stiffness failure identification in a steel spring floating slab track of urban railway: a case study in china

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第3期25卷 206-222页

作者： Junyuan ZHENG Caiyou ZHAO Duojia SHI Ping WANG Jian WANG Bolong JIANG Xi SHENG Key Laboratoryof High-speed Railway engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 60031China School of Civil engineering Southwest Jiaotong UniversityChengdu 610031China 01 DYNA(Qingdao)Test&Data co. Ltd.Qingdao 266000China Rail Transit Digital construction and Measurement Technology National engineering Research Center China Railway Design CorporationTianjin300308China Institute of Urban Smart Transportation&Safety Maintenance Shenzhen UniversityShenzhen 518060China

The extensive use of steel spring floating slab tracks has effectively addressed the challenge of alleviating the environmental vibrations induced by urban rail transit ***,under the co.bined action of train dynamic loads and co.plex environmental factors,problems,such as the fracture of steel spring vibration isolators and suspension vibrations induced by the uneven settlement of the base,often *** failure of isolator support stiffness is often hidden in its early stages and is challenging to identify by co.ventional detection *** the same time,it will aggravate the wheel-rail interaction,accelerate the deterioration of track structure,and even affect the driving *** study first establishes a detailed co.pled train-floating slab track-foundation analytical *** the influence of the vibration isolator support stiffness failure on the dynamic indices of the floating slab track system response is analyzed.A set of defect identification methods that can detect the number of failed steel springs,severity of damage,and their location is ***,an intelligent monitoring system for support stiffness of floating slab track is built by co.bining the density-based spatial clustering of applications with noise algorithm and statistical data analysis and is applied to a rail line in southern *** a three-year monitoring campaign,a suspension failure and a fracture of a steel spring were each successfully detected and detailed failure information was *** investigation results were co.sistent with the damage identification *** repair,the track structure dynamic response returned to the average pre-damage level and further deterioration had been *** proposed damage identification methods and monitoring system provide an approach for intelligent identification of track structure support stiffness failures.

关键词： Floating slab track Support stiffness Detailed analytical model Failure identification Monitoring system

Self-powered wireless environmental monitoring system for in-service bridges by galloping piezoelectric-triboelectric hybridized energy harvester

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Science china(Technological Sciences) 2024年第5期67卷 1498-1509页

作者： HUANG KangXu WANG XiaoFei WANG Li ZHOU YuHui LIU FuHai CHANG ShiYuan ZHU JunTao ZHOU YuXuan ZHANG He LUO JiKui co.lege of Civil engineering and Architecture Zhejiang UniversityHangzhou310058China Anhui Transport co.sulting&Design Institute co. Ltd.Hefei230088China co.lege of electronics&Information Hangzhou Dianzi UniversityHangzhou310018China Center for Balance Architecture Zhejiang UniversityHangzhou310058China co.lege of Information Science&Electronic engineering Zhejiang UniversityHangzhou310027China

The energy harvesting technology for the ubiquitous natural wind enables a desirable solution to the issue of distributed sensors in the bridge environmental sensing Internet of Things(Io T)system being restricted to co.ventional energy *** this work,a self-powered system based on a co.pact galloping piezoelectric-triboelectric energy harvester(GPTEH)is developed to achieve efficient wind energy *** GPTEH is co.structed on the prototype of a cantilever structure with piezoelectric macro-fiber co.posite(MFC)sheets and a rectangular bluff body with triboelectric nanogenerators(TENGs).Through a special swing-type structural design with iron blocks inside the bluff body,the GPTEH exhibits preferable aerodynamic behavior and excellent energy co.version efficiency,co.pared to co.ventional cantilever kind of piezoelectric wind energy harvester(PWEH).The GPTEH also demonstrates the capability of high output power density(PEH of 23.65 W m^(-2)and TENG of 1.59 W m^(-2)),superior response wind speed(about 0.5 m s^(-1)),and excellent long-term stability(over 14000 cyclic tests).Furthermore,a power management system is developed to efficiently utilize the output energy from GPTEH to power the sensors and wirelessly transmit environmental data to the *** proposed GPTEH-powered system exhibits a great potential for the bridge environmental monitoring and Io T technologies.

关键词： self-powered hybrid nanogenerator triboelectric nanogenerator macro-fiber co.posite wireless environmental monitoring system

Towards experimental studying the airborne sound insulation of light frame walls with staggered studs

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Science china(Technological Sciences) 2024年第7期67卷 2230-2243页

作者： ZHANG YuCai YUE Kong XIE YiFan CHENG XiangYu SHI XinLei WU Peng ZHAO Hui co.lege of Civil engineering Nanjing Tech UniversityNanjing 211800China Key Laboratory of Architectural Aco.stic Environment of Anhui Higher Education Institutes Hefei 230601China Nanjing Gongda construction Technology co.Ltd. Nanjing 211800China

Light frame walls(LFWs) serve as co.mon partition walls in prefabricated buildings due to their lightweight nature, co.teffectiveness, energy efficiency, and adaptability for rapid on-site assembly. However, their aco.stic insulation capability is hindered by issues such as sound bridges, resonance, and co.ncidence dips, resulting in inadequate sound insulation. This study aims to propose LFW designs with superior aco.stic insulation suitable for practical engineering while meeting prevailing national standards. Nine full-scale LFW co.figurations were subjected to laboratory testing to evaluate the impact of staggered stud arrangements, stud types, and inco.poration of co.pounded materials. The tests were performed between 100 and 5000 Hz,and the sound pressure level and reverberation time at 1/3 octave band were measured and used to calculate the weighted sound insulation index(Rw). Results demonstrated that the outlined design modifications significantly enhanced the sound insulation of the LFW. These modifications effectively mitigate the influence of sound bridges while addressing resonance and co.ncidence dips inherent in the wall system. Particularly noteworthy was the superior sound insulation achieved by staggered-stud LFWs with co.pounded materials, surpassing that of autoclaved lightweight co.crete walls co.monly used in prefabricated constructions despite having lesser thickness and surface density. Rwvalues increased from 43 to 54 dB co.pared to co.ventional LFWs, translating to a notable elevation in airborne sound insulation level from 4 to 7 as an internal separation co.ponent,meeting the requisite standards for most applications.

关键词： light frame wall staggered stud airborne sound insulation weighted sound insulation index

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Application of GNSS-PPP on Dynamic Deformation Monitoring of Offshore Platforms

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china Ocean engineering 2024年第2期38卷 352-361页

作者： YU Li-na XIONG Kuan GAO Xi-feng LI Zhi FAN Li-long ZHANG Kai Institute of Ocean Energy and Intelligent construction Tianjin University of TechnologyTianjin 300384China china Railway construction Bridge engineering Bureau Group co.LTD Tianjin 300300China School of Civil engineering Tianjin UniversityTianjin 300072China Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong KongChina State Key Laboratory of Precision Blasting Jianghan UniversityWuhan 430056China

The real-time dynamic deformation monitoring of offshore platforms under environmental excitation is crucial to their safe *** Global Navigation Satellite system-Precise Point Positioning(GNSS-PPP)has been co.sidered for this purpose,its monitoring accuracy is relatively ***,the influence of background noise on the dynamic monitoring accuracy of GNSS-PPP remains ***,it is imperative to further validate the feasibility of GNSS-PPP for deformation monitoring of offshore *** address these co.cerns,vibration table tests with different amplitudes and frequencies are *** results demonstrate that GNSS-PPP can effectively monitor horizontal vibration displacement as low as±30 mm,which is co.sistent with ***,the spectral characteristic of background noise in GNSS-PPP is similar to that of GNSS-RTK(Real Time Kinematic).Building on this observation,an improved co.plete Ensemble Empirical Mode Deco.position with Adaptive Noise(CEEMDAN)has been proposed to de-noise the data and enhance the dynamic monitoring accuracy of *** monitoring application research is also undertaken,successfully extracting and analyzing the dynamic deformation of an offshore platform structure under environmental excitation using GNSS-PPP monitoring in co.junction with improved CEEMDAN *** co.paring the de-noised dynamic deformation trajectories of the offshore platform during different periods,it is observed that the platform exhibits reversible alternating vibration responses under environmental excitation,with more pronounced displacement deformation in the direction of load *** research results co.firm the feasibility and potential of GNSS-PPP for dynamic deformation monitoring of offshore platforms.

关键词： GNSS-PPP offshore platform dynamic deformation monitoring improved CEEMDAN de-noising

An Image Fingerprint and Attention Mechanism Based Load Estimation Algorithm for Electric Power system

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co.puter Modeling in engineering & Sciences 2024年第7期140卷 577-591页

作者： Qing Zhu Linlin Gu Huijie Lin Electricity Technology Branch Nari Technology Co.Ltd.Nanjing211106China NARI-TECH Nanjing co.trol systems co. Ltd.Nanjing211106China

With the rapid development of electric power systems,load estimation plays an important role in system operation and ***,load estimation techniques co.tain traditional,time series,regression analysis-based,and machine learning-based *** the machine learning-based method can lead to better performance,in this paper,a deep learning-based load estimation algorithm using image fingerprint and attention mechanism is ***,an image fingerprint construction is proposed for training *** the data preprocessing,the training data matrix is co.structed by the cyclic shift and cubic spline ***,the linear mapping and the gray-co.or transformation method are proposed to form the co.or image ***,a co.volutional neural network(CNN)co.bined with an attentionmechanism is proposed for training performance *** last,an experiment is carried out to evaluate the estimation *** with the support vector machine method,CNN method and long short-term memory method,the proposed algorithm has the best load estimation performance.

关键词： Load estimation deep learning attention mechanism image fingerprint construction