Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics最新文献

筛选
英文 中文
Proposing a novel nonlinear integrated control technique for an electric power steering system to improve automotive dynamic stability 为电动助力转向系统提出一种新型非线性集成控制技术,以提高汽车动态稳定性
T. Nguyen
{"title":"Proposing a novel nonlinear integrated control technique for an electric power steering system to improve automotive dynamic stability","authors":"T. Nguyen","doi":"10.1177/14644193241267200","DOIUrl":"https://doi.org/10.1177/14644193241267200","url":null,"abstract":"This article proposes a new control solution for an electric power steering (EPS) system to ensure the stability of car's dynamic behaviours. This work provides two new contributions which differ from previously existing publications. Firstly, a novel control method for the steering system is designed in this article based on a combination of proportional-integral-derivative (PID) and backstepping control techniques. The input to the backstepping algorithm is the output of the PID controller, whose parameters are tuned by a complex fuzzy algorithm with two inputs. Secondly, values of road reaction torque and other dynamic effects are calculated using a complex automotive dynamics model based on a nonlinear motion model and a spatial oscillation model. The stability of the control system is evaluated through the Lyapunov control function and the error between the output signals, while the dynamic stability is evaluated through the changes in car's dynamic behaviours. According to the simulation results, output values always closely follow ideal values with negligible errors if and only when the steering system is controlled by the proposed algorithm. In some conditions, the steering motor angle error achieved by the proposed controller does not exceed 0.022 rad, much lower than the fault scenario. In addition, the vehicle's roll angle and motion trajectory always follow the desired value with minimal errors. In conclusion, if the EPS system is controlled by the new control technique shown in this article, car dynamic stability will be guaranteed under all investigated conditions.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"11 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141921355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Negative effect and optimal control of in-wheel motor with inclined eccentricity on driving safety for electric vehicle 带倾斜偏心的轮内电机对电动汽车行驶安全的负面影响和优化控制
Zhaoxue Deng, Hansheng Qin, Tianji Ma, Shuen Zhao, Hanbing Wei
{"title":"Negative effect and optimal control of in-wheel motor with inclined eccentricity on driving safety for electric vehicle","authors":"Zhaoxue Deng, Hansheng Qin, Tianji Ma, Shuen Zhao, Hanbing Wei","doi":"10.1177/14644193241260975","DOIUrl":"https://doi.org/10.1177/14644193241260975","url":null,"abstract":"During the driving process of the in-wheel drive electric vehicle, the air gap eccentricity of the motor caused by external disturbance cannot be avoided, resulting in a negative effect on vehicle dynamics. In this paper, the negative effect of vehicle lateral dynamics caused by motor-inclined eccentricity and the corresponding control method are studied. According to the Maxwell stress tensor and the air gap permeance correction coefficient, the unbalanced radial force under the inclined eccentricity of the in-wheel motor is characterized, and the corresponding vehicle dynamics model is established. Based on the vehicle dynamics model, different steering conditions are set to explore the influence of inclined eccentricity on the negative effect of vehicle lateral dynamics. It is found that the inclined eccentricity affects the handling stability of the vehicle under normal conditions and affects the rollover stability under extreme conditions. In order to solve these problems, the integrated control strategy is formulated by using the steering and driving system of an electric vehicle, and the particle swarm optimization algorithm is introduced to optimize it. The simulation results show that the proposed integrated optimal control of active rear-wheel steering and direct yaw control can effectively alleviate the negative effect of vehicle lateral dynamics caused by the inclined eccentricity of the in-wheel motor under different working conditions.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"20 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141920498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Unified dynamics analysis of parallel manipulators: A joint-based approach and generalized inertia constraint matrix for parallel manipulators (GICM-P) framework 并联机械手的统一动力学分析:基于关节的方法和并联机械手的广义惯性约束矩阵(GICM-P)框架
Majid Koul, Vinay Gupta, S. K. Saha
{"title":"Unified dynamics analysis of parallel manipulators: A joint-based approach and generalized inertia constraint matrix for parallel manipulators (GICM-P) framework","authors":"Majid Koul, Vinay Gupta, S. K. Saha","doi":"10.1177/14644193241260117","DOIUrl":"https://doi.org/10.1177/14644193241260117","url":null,"abstract":"Parallel manipulators, a distinctive subset of closed-loop multi-body systems, are in high demand due to their precision-centric applications. This research introduces a unified approach to tackle both inverse and forward dynamic analyses of parallel manipulators, rooted in joint-based principles. The methodology dissects a given parallel manipulator into symmetric open-loop subsystems and a mobile body within either a planar or spatial context, depending on the manipulator’s nature. Conventional practices, involving the introduction of joint cuts at relevant locations, are employed to partition the system into multiple open-loop subsystems. Subsequently, the joint coordinate-based approach, typically applied to open-loop systems such as industrial manipulators, is utilized to derive solutions. In particular, this approach focuses on forward dynamics by introducing the generalized inertia constraint matrix for parallel manipulators (GICM-P), a concept built upon the authors’ prior work, originally addressing the GICM for general closed-loop systems. Notably, GICM-P aligns conceptually with the operational space inertia matrix (OSIM) designed for closed-loop systems elsewhere. However, unlike OSIM, which requires mapping joint-space inertia to operational-space inertia, GICM-P leverages acceleration-level constraints between subsystems and the moving platform through straightforward matrix operations. GICM-P offers a deeper understanding of the physics of the problem compared to OSIM, primarily due to its ability to explicitly express subsystem-level interactions via various block matrices – an aspect not previously documented. The paper provides explicit numerical values for GICM-P in the context of a spatial six degrees of freedom (6-DOF) Stewart platform and a planar 3-DOF parallel manipulator along with interpretations.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"55 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141349642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Dynamics analysis and chatter control of a polishing and milling nonideal flexible manipulator 抛光和铣削非理想柔性机械手的动力学分析和颤振控制
J. J. Lima, Jose M. Balthazar, Mauricio A. Ribeiro, Angelo M Tusseti, G. Kudra, Jan Awrejcewicz
{"title":"Dynamics analysis and chatter control of a polishing and milling nonideal flexible manipulator","authors":"J. J. Lima, Jose M. Balthazar, Mauricio A. Ribeiro, Angelo M Tusseti, G. Kudra, Jan Awrejcewicz","doi":"10.1177/14644193241247909","DOIUrl":"https://doi.org/10.1177/14644193241247909","url":null,"abstract":"Some robots are designed to be lightweight and flexible, enabling them to access small and challenging paths in various applications. These features enable robots to collaborate with humans in performing specific production tasks. However,the movement of the flexible manipulator can become self-excited when handling a cutting tool on a workpiece, which can lead to a control problem. This article presents a control solution for lightweight robotic manipulators with rotating tools, such as polishing and milling, using smart actuators. The control discretization method is also introduced to facilitate integration into digital controllers. The paper starts by describing the governing equations of the non-ideal flexible manipulator for polishing and milling and analysing its dynamic behavior. Subsequently, models for the controllers of the DC motor-only actuators and the hybrid (shape memory alloy and DC motors) actuators were formulated using shape memory alloy and a suboptimal control scheme known as the discrete state-dependent Riccati equation. The coupled system was analysed dynamically, and it was observed that it exhibits chaotic behavior. The results suggest that incorporating smart actuators into the motor group of the system could decrease the positioning error of the manipulator and significantly reduce the oscillation of the robot’s end-effector.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"46 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141355316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Dynamic modeling and vibration characteristics analysis of cylinder with local defects in axial piston pump 轴向柱塞泵中存在局部缺陷的气缸的动态建模和振动特性分析
Hesheng Tang, Jialun Wang, Pingting Ying, Anil Kumar
{"title":"Dynamic modeling and vibration characteristics analysis of cylinder with local defects in axial piston pump","authors":"Hesheng Tang, Jialun Wang, Pingting Ying, Anil Kumar","doi":"10.1177/14644193241260620","DOIUrl":"https://doi.org/10.1177/14644193241260620","url":null,"abstract":"The piston/cylinder pair suffers from excessive wear during the operation of axial piston pumps, and the local defects usually occur in the brass bush in the cylinder bore. Generally, the wear of cylinder is the main source of failure that affects the reliability of axial piston pumps. Thus, it is necessary to conduct an in-depth study on the vibration generated by the cylinder with local defects. Considering the effect of defect dimension, a novel time-varying displacement excitation model of the axial piston pump cylinder defect is proposed and establishes a 13 degrees of freedom lumped parameter dynamic model for cylinder fault. Then, investigating the effects of length and depth of the defect on the spectral amplitude and exploring the fault characteristic frequency of cylinder. Lastly, the model was validated on a test rig. The results demonstrate that the constructed model can predict the vibration caused by a locally defective cylinder with a frequency domain error of 0.69% and the fault characteristic frequency of cylinder is the same as its rotational frequency. Moreover, the defect length will influence the amplitude and duration of the cylinder-defect pulse waveform. The fault excitation amplitudes increase with the increase of defect depths.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"27 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141360252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Dynamic modeling of a synchronous reluctance machine for transient simulation of vibrations under variable rotor magnetization 同步磁阻机的动态建模,用于转子磁化可变情况下振动的瞬态模拟
Mario Hermle, Julius Kesten, M. Doppelbauer, Peter Eberhard
{"title":"Dynamic modeling of a synchronous reluctance machine for transient simulation of vibrations under variable rotor magnetization","authors":"Mario Hermle, Julius Kesten, M. Doppelbauer, Peter Eberhard","doi":"10.1177/14644193241259984","DOIUrl":"https://doi.org/10.1177/14644193241259984","url":null,"abstract":"This work introduces a new approach for the dynamic simulation of a permanent magnet-assisted synchronous reluctance machine with the ability to consider dynamic changes in the rotor magnetization. The aim is to comprehensively analyze the dynamics of a machine through transient simulations of the occurring magnetic and mechanical forces that influence the noise and vibration characteristics. A simplified magnetic model considering the effects of magnetic reluctances, leakage flux, and magnetic saturation is utilized to efficiently calculate the dynamically changing magnetic forces in the air gap. Unlike conventional designs employing rare earth magnets in the rotor, the design at hand utilizes non-rare earth magnets that enable adjustments of the magnets’ flux output. The novelty of the presented approach lies in its ability to consider these dynamic changes when calculating the air gap flux. The magnetic forces are then applied to an elastic multibody model of the motor, which includes the rotor, stator, bearings, and the housing, for the computation of the bearing forces and housing deformations. The presented multi-physical model allows for transient simulations of the forces acting on the bearings and the housing, capturing the dynamic response of the motor under varying rotor magnetization, air gaps, and loads. With the proposed approach, this study offers predictions regarding critical vibration characteristics that occur during dynamic operation, providing valuable insights for noise reduction efforts.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"35 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141356978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Anti-swing control of varying rope length tower crane based on adaptive neural network sliding mode 基于自适应神经网络滑动模式的不同绳长塔式起重机防摆控制
Jibin Zhang, Qing Zhang, Lulu Zhang, Shuai Sun, Yixin Jin
{"title":"Anti-swing control of varying rope length tower crane based on adaptive neural network sliding mode","authors":"Jibin Zhang, Qing Zhang, Lulu Zhang, Shuai Sun, Yixin Jin","doi":"10.1177/14644193241256857","DOIUrl":"https://doi.org/10.1177/14644193241256857","url":null,"abstract":"Due to its complex nonlinear, underdriven, and strongly coupled characteristics, the tower crane will cause the load to swing violently when working, which will cause the tower crane to tip over in serious cases, and there exists a huge safety hazard. In this article, a new artificial neural network sliding mode control method is designed for the control problems of tower crane lifting in position and load swing prevention, which has strong robustness to disturbances and unmodeled dynamics, and ensures that the tower crane lifting is accurately tracked in position and suppresses the load swing at the same time. First, a nonlinear dynamics model of a five-degree-of-freedom tower crane considering the actual working conditions is established. Aiming at the problem that it is difficult to effectively control the nonlinear model of the tower crane system, a new neural sliding mode controller and compensation controller are designed based on the sliding mode control theory and using radial basis function neural network. The neural sliding mode controller is used to approximate the sliding mode equivalent controller with uncertainty and strong nonlinearity, and the compensation controller realizes the compensation of the neural sliding mode controller for the difference between the system control inputs and the uncertainty of the system. The convergence and stability of the proposed control system is rigorously demonstrated using the Lyapunov stability theory. Simulation studies have been carried out to verify the correctness of the model established in this article, as well as the excellent control performance of the control system and the ability to deal with system uncertainty, proving its strong robustness.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"28 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141109422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Nonlinear dynamic characteristics of mechatronics integrated planetary gears considering wear and temperature effects 考虑磨损和温度效应的机电一体化行星齿轮的非线性动态特性
Jungang Wang, Xincheng Bi, Ruina Mo, Jiwen Ren, Yong Yi
{"title":"Nonlinear dynamic characteristics of mechatronics integrated planetary gears considering wear and temperature effects","authors":"Jungang Wang, Xincheng Bi, Ruina Mo, Jiwen Ren, Yong Yi","doi":"10.1177/14644193241253979","DOIUrl":"https://doi.org/10.1177/14644193241253979","url":null,"abstract":"The electromechanical planetary gear system has high work efficiency and long service life, but factors such as heat, wear, and electrical signals can affect the transmission performance of electromechanical planetary gears. This article comprehensively considers factors such as temperature, tooth surface wear, lubrication, current and voltage, damping ratio, etc. Based on the principle of thermal deformation, Archard wear model, and equivalent circuit principle, a dynamic model of electromechanical planetary gears is established. The existing literature has not comprehensively analyzed the effects of temperature, wear, and electrical signal changes on the nonlinear characteristics of electromechanical planetary gear systems. The results show that when the motor current is between 7 A and 18 A and the voltage is lower than the rated voltage, the system is in a stable state; as the temperature rises, the system tends to stabilize; the gear wear exceeds 30 μm, and the bifurcation characteristics of the system are more pronounced.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"41 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141122137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Mathematical modelling analysis of deep groove ball bearing with misalignment 带偏心深沟球轴承的数学建模分析
X. Yuan, Hui Liu, Huijie Zhang
{"title":"Mathematical modelling analysis of deep groove ball bearing with misalignment","authors":"X. Yuan, Hui Liu, Huijie Zhang","doi":"10.1177/14644193241228127","DOIUrl":"https://doi.org/10.1177/14644193241228127","url":null,"abstract":"Deep groove ball bearing is prone to misalignment due to installation and long-term use, which requires research on the frequency characteristics and evolution mechanism excited by misalignment. This article first outlines a mathematical model of a rotor supported at both ends, which is used to describe the multi-body vibration mechanism of bearing-rotor system. The previous investigation on the misalignment dynamics of rolling bearings mainly focuses on the frequency harmonic characteristics of displacement signals. This article explores the acceleration frequency characteristics of misalignment bearings, involving their low-frequency and high-frequency vibrations, and explains the formation mechanism from the perspective of the balls passing through the stiffness change region. This modelling method can clearly describe the periodic impact and frequency modulation characteristics excited by misalignment, with characteristic frequencies including cage frequency [Formula: see text] and its harmonics, inner race relative to cage frequency [Formula: see text] and its harmonics and fault frequency [Formula: see text] and its sideband, thus providing more reasonable reference for design and diagnosis. Furthermore, a mean geometry indicator is developed from square envelope domain to evaluate the vibration frequency characteristics. With the advantages of mean geometry in characterizing nonlinear systems, the stability reliability is investigated to reveal the vibration mechanism and dynamic evolution law of the misalignment. Numerical calculations and experiments have shown that the multi-body vibration model and misalignment mathematical expression proposed in this article can illustrate the multi-frequency characteristics excited by misalignment, and the stability reliability can objectively describe the evolution mechanism of such dynamic system.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"55 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139845482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Mathematical modelling analysis of deep groove ball bearing with misalignment 带偏心深沟球轴承的数学建模分析
X. Yuan, Hui Liu, Huijie Zhang
{"title":"Mathematical modelling analysis of deep groove ball bearing with misalignment","authors":"X. Yuan, Hui Liu, Huijie Zhang","doi":"10.1177/14644193241228127","DOIUrl":"https://doi.org/10.1177/14644193241228127","url":null,"abstract":"Deep groove ball bearing is prone to misalignment due to installation and long-term use, which requires research on the frequency characteristics and evolution mechanism excited by misalignment. This article first outlines a mathematical model of a rotor supported at both ends, which is used to describe the multi-body vibration mechanism of bearing-rotor system. The previous investigation on the misalignment dynamics of rolling bearings mainly focuses on the frequency harmonic characteristics of displacement signals. This article explores the acceleration frequency characteristics of misalignment bearings, involving their low-frequency and high-frequency vibrations, and explains the formation mechanism from the perspective of the balls passing through the stiffness change region. This modelling method can clearly describe the periodic impact and frequency modulation characteristics excited by misalignment, with characteristic frequencies including cage frequency [Formula: see text] and its harmonics, inner race relative to cage frequency [Formula: see text] and its harmonics and fault frequency [Formula: see text] and its sideband, thus providing more reasonable reference for design and diagnosis. Furthermore, a mean geometry indicator is developed from square envelope domain to evaluate the vibration frequency characteristics. With the advantages of mean geometry in characterizing nonlinear systems, the stability reliability is investigated to reveal the vibration mechanism and dynamic evolution law of the misalignment. Numerical calculations and experiments have shown that the multi-body vibration model and misalignment mathematical expression proposed in this article can illustrate the multi-frequency characteristics excited by misalignment, and the stability reliability can objectively describe the evolution mechanism of such dynamic system.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"120 32","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139785735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信