2019 IEEE International Conference on Prognostics and Health Management (ICPHM)最新文献

筛选
英文 中文
Calculating the Contact Forces at Imperfect Surfaces Considering Elastohydrodynamic Lubrication Effects in Rolling Element Bearings 考虑弹流润滑作用的滚动轴承非完美表面接触力计算
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819428
Linkai Niu, Fengtao Wang, Guoyan Li, Chenguang Niu, Yuan Lan, Xiaoyan Xiong
{"title":"Calculating the Contact Forces at Imperfect Surfaces Considering Elastohydrodynamic Lubrication Effects in Rolling Element Bearings","authors":"Linkai Niu, Fengtao Wang, Guoyan Li, Chenguang Niu, Yuan Lan, Xiaoyan Xiong","doi":"10.1109/ICPHM.2019.8819428","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819428","url":null,"abstract":"The contact forces largely affect the vibrations of rolling element bearings with geometrical imperfections, such as pits, spalls, etc. In the current paper, a novel method to calculate the contact force of rolling element at imperfect race surfaces in rolling element bearings is proposed considering the elastohydrodynamic lubrication effect. In the proposed method, the oil film thickness, the oil film pressure and the elastic deformation are determined by solving the Reynolds equation, the oil film thickness equation, the viscosity-pressure equation, the density-pressure equation and the force balance equation simultaneously. The geometrical imperfection is considered by modifying the oil film thickness equation. The above equations are solved iteratively until satisfy the balance relationship of oil film thickness, elastic deformation and geometrical interaction. Finally, the contact force is calculated by integrating the oil film pressure in the entire contact region. Results show that the geometrical imperfection would largely affect the oil film thickness and the oil film pressure, and thus affect the contact force. The current investigation could provide a theoretical tool to calculate the contact force in dynamic models of rolling element bearings with imperfect surfaces. Meanwhile, the current method can also be used in the calculation of the contact force at textured surfaces in rolling element bearings.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124558003","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: 2
Prognostics of polygonalization of high-speed railway train wheels using a generalized additive model smoothed by spline-backfitted kernel 用样条背拟合核平滑的广义加性模型预测高速铁路列车车轮多面化
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819407
Zhexiang Chi, Lijian Yang, Jing Lin, Simin Huang
{"title":"Prognostics of polygonalization of high-speed railway train wheels using a generalized additive model smoothed by spline-backfitted kernel","authors":"Zhexiang Chi, Lijian Yang, Jing Lin, Simin Huang","doi":"10.1109/ICPHM.2019.8819407","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819407","url":null,"abstract":"A method for the prognosis of polygonalization in high-speed railway train wheels is developed based on a generalized additive model. Unlike most previous studies, this study uses field data, so findings can help improve practical maintenance efficiency. A spline-backfitted kernel is used to improve computation efficiency when figuring out model parameters. This prognostics method can be applied to practical railway management decisions.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130316986","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: 1
Visual explanation of neural network based rotation machinery anomaly detection system 基于神经网络的旋转机械异常检测系统可视化说明
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819396
Mao Saeki, Jun Ogata, M. Murakawa, Tetsuji Ogawa
{"title":"Visual explanation of neural network based rotation machinery anomaly detection system","authors":"Mao Saeki, Jun Ogata, M. Murakawa, Tetsuji Ogawa","doi":"10.1109/ICPHM.2019.8819396","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819396","url":null,"abstract":"To make a practical anomaly detection system for rotating machinery in large infrastructures, such as wind turbines, providing an explanation along with the detection results is important so that faults can be easily verified by human experts. Therefore, a method for providing a visual explanation of the predictions of a convolutional neural network (CNN)-based anomaly detection system is considered in this paper. More specifically, the CNN used takes the monitoring target machine’s vibrational data as input and predicts whether the target’s state is healthy or anomalous. A CNN visualization technique is applied this network to obtain an explanation of its predictions. In order to evaluate the obtained explanation, it is compared with an expert diagnosis made on the same data set. The results indicate that the frequency used by the experts to detect faults was also included in the network’s explanation, indicating that the proposed visualization method can be used to provide useful information to help experts verify faults.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120959344","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: 11
Fault Detection and Isolation in Industrial Networks using Graph Convolutional Neural Networks 基于图卷积神经网络的工业网络故障检测与隔离
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819403
H. Khorasgani, Arman Hasanzadeh, Ahmed K. Farahat, Chetan Gupta
{"title":"Fault Detection and Isolation in Industrial Networks using Graph Convolutional Neural Networks","authors":"H. Khorasgani, Arman Hasanzadeh, Ahmed K. Farahat, Chetan Gupta","doi":"10.1109/ICPHM.2019.8819403","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819403","url":null,"abstract":"Industrial networks represent large-scale systems that consist of several interacting components. In this paper, we present a solution for Fault Detection and Isolation (FDI) in industrial networks with same type of components (electrical, mechanical, etc.) such as power grids, and water supply networks. Traditional FDI algorithms are trained to detect and isolate faults on the level of a single component by considering features from this component and sometimes from nearby components. These algorithms are sub-optimal as they are independently applied to individual components without explicitly taking into consideration the dependency between the several components that co-exist in industrial network. The interaction between the components makes fault isolation challenging. An operation change or a fault in a component can affect the neighboring components. This negatively impact the diagnosis accuracy when we design an independent diagnoser for each component. On the other hand, designing a global diagnoser without considering the network structure can lead to overfitting which can degrade the diagnosis performance significantly specially when the training data is limited. Moreover, because of the large number of components in these systems, the single fault assumption may not stand. This increases the complexity of the problem. In order to solve this problem, we first model the industrial network as a weighted undirected graph structure. The graph structure represents the connected components. The weights quantify these connections. We then apply Graph Convolutional Neural Networks (GCNN) to detect and isolate faulty components in these systems. In the case study, we apply our solution to a simulated industrial network with 100 components. The case study shows that GCNN outperforms several baseline algorithms.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127132010","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: 15
A Measurement Frequency Estimation Method for Failure Prognosis of an Automated Tire Condition Monitoring System 轮胎状态自动监测系统故障预测的测量频率估计方法
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819422
R. Meissner, H. Meyer, F. Raddatz
{"title":"A Measurement Frequency Estimation Method for Failure Prognosis of an Automated Tire Condition Monitoring System","authors":"R. Meissner, H. Meyer, F. Raddatz","doi":"10.1109/ICPHM.2019.8819422","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819422","url":null,"abstract":"The ongoing digitalization allows operators and manufacturers to constantly gain new insights about their asset’s performance and degradation status. This information could potentially help to reduce operating and maintenance costs. Although significant amount of research has been spent in determining Remaining Useful Lifetimes (RUL) of various systems, these efforts often implicitly assume an unrestricted availability of measurement data. However, the amount of acquired data significantly drives the necessary investment cost or is sometimes even impossible to obtain in required frequencies in reality. In this paper, we will investigate the changes of the precision for the RUL prognosis on the example of a Tire Pressure Indication System (TPIS). After a possible layout with sensor requirements for a fully automated condition monitoring system has been developed in theory, we describe necessary data cleansing steps to account for environmental impacts on the system’s performance and to derive the system’s health status. With the help of a Monte Carlo (MC) simulation, we evaluate the system’s sensitivity towards changes in precision of the RUL for different measurement frequencies, prognostic models, and parameter settings. The results allow an estimation of the minimum pressure measurement frequency for a fully automated TPIS in order to obtain the required prognostic performance and to maximize cost efficiency.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127433010","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: 2
A New Anomaly Detection Method Based on Multi-dimensional Condition Monitoring Data for Aircraft Engine 基于航空发动机多维状态监测数据的异常检测新方法
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819410
Shaowei Chen, Meng Wu, Shuai Zhao, Pengfei Wen, Dengshan Huang, Yan Wang
{"title":"A New Anomaly Detection Method Based on Multi-dimensional Condition Monitoring Data for Aircraft Engine","authors":"Shaowei Chen, Meng Wu, Shuai Zhao, Pengfei Wen, Dengshan Huang, Yan Wang","doi":"10.1109/ICPHM.2019.8819410","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819410","url":null,"abstract":"Identifying the degradation state of aircraft engine accurately and carrying out suitable maintenance is significant for the safe and reliable operation of the aircraft system. In this paper, an anomaly detection system is proposed for multi-dimensional time series for aircraft engine. To represent the degradation degree of the device, the degradation index is proposed utilizing the Dynamic Time Warping algorithm (DTW) which possesses good similarity measure quality and can capture the changing characteristics of the indicator well. On the basis of the degradation index, three decision-making strategies including the Cumulative Sum algorithm (CUSUM), the Youden Index, and the Impact Factor are applied to determine the threshold values. For the threshold, two detection time points are obtained to discriminate different degradation stages in the device, in which the former refers to the initiation of degradation and the latter time point indicates that the device suffers from the anomaly. The experimental results demonstrate that all three decision strategies are able to detect system performance effectively before the device fails, which facilitates the incipient fault warning of aircraft engine in order to keep the equipment safe and reliable.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134540706","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
An FBG based smart clamp fabricated by 3D printing technology and its application to incipient clamp looseness detection 基于FBG的3D打印智能夹具及其在夹具早期松动检测中的应用
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819399
Zechao Wang, Mingyao Liu, Yongzhi Qu, Qin Wei, Zude Zhou, Yuegang Tan, Liu Hong, Jun Zhang
{"title":"An FBG based smart clamp fabricated by 3D printing technology and its application to incipient clamp looseness detection","authors":"Zechao Wang, Mingyao Liu, Yongzhi Qu, Qin Wei, Zude Zhou, Yuegang Tan, Liu Hong, Jun Zhang","doi":"10.1109/ICPHM.2019.8819399","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819399","url":null,"abstract":"Distributed block clamps are widely used in hydraulic piping systems to fix the pipeline and to adjust the natural frequencies of pipes. However, the clamps may get loosen due to wear over time, and if not detected, it will lead to catastrophic failures. Piezoelectric lead Zirconate Titanate (PZT) based active sensing methods have been widely used to monitor the looseness of the bolted structures. However, this method bears some drawbacks, e.g., saturation, electromagnetic interference and high cost. Therefore, Fiber Bragg Grating (FBG) based sensing technology, which is robust to electromagnetic interference and easy for multiplexing, has been employed to design smart bolts and washers to monitor the preload of the bolted structures in existing literatures. However, the applications of those structures are limited due to specific customization, e.g. the distributed feature of the smart bolt is limited by the blind hole structure and the smart washer can only be used to the bolted connections with big-diameter bolts. To address these issues, a smart clamp is presented in present study. Moreover, the 3D printing technology is also investigated to fabricate FBG based smart clamps in a flexible and cost-effective way. A novel FBG based smart clamp is proposed in this work. The influence of different print layer heights, 0.15mm and 0.2mm on the sensitivity of clamp is also evaluated. It is shown that the 0.2mm height leads to a higher sensitivity than the 0.15mm height. Its application to incipient clamp looseness detection is further performed in an industrial piping system.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124097910","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: 1
Formulation and Solution for the Predictive Maintenance Integrated Job Shop Scheduling Problem 预测性维修综合作业车间调度问题的提出与解决
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819397
S. Zhai, Alexander Rieß, G. Reinhart
{"title":"Formulation and Solution for the Predictive Maintenance Integrated Job Shop Scheduling Problem","authors":"S. Zhai, Alexander Rieß, G. Reinhart","doi":"10.1109/ICPHM.2019.8819397","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819397","url":null,"abstract":"Predictive Maintenance has gained a lot of attention in recent years due to the development of improved sensors and intelligent algorithms. These allow for monitoring the health condition of production machinery and predict its future deterioration. In order to generate added value for industrial use cases, two more steps are required: considering the machine’s time-varying operational conditions and integrating its dependent deterioration prediction in a holistic scheduling approach. This publication identifies a shortage of deterioration estimation frameworks under time-varying operational conditions as well as a lack of Predictive Maintenance integrated scheduling problems in the literature. Subsequently, a new conceptual framework to model future machine deterioration under time-varying operational conditions and its application in production scheduling is introduced. The Operation Specific Stress Equivalent (OSSE) represents the load of a future production job on the machine and supports a general formulation of the maintenance integrated job shop scheduling problem (MIJSSP). This formulation is presented together with benchmark instances and corresponding sample data. Finally, the formulation is tested with the help of a genetic algorithm that illustrates the potential of using new objective functions for decision support, such as the Reliability Weighted Makespan CmaxR.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124306415","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: 10
Load sharing analysis of compound planetary gear set with cracked sun gear 含裂纹太阳齿轮的复合行星齿轮组载荷分担分析
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819401
Guoyan Li, Linkai Niu, Liang Ma, Dehao Dong
{"title":"Load sharing analysis of compound planetary gear set with cracked sun gear","authors":"Guoyan Li, Linkai Niu, Liang Ma, Dehao Dong","doi":"10.1109/ICPHM.2019.8819401","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819401","url":null,"abstract":"The load sharing analysis of planetary transmissions has significant influence on the operation and reliability of the gear system. In order to reveal the impact of crack propagation on the load sharing behaviors, a nonlinear lumped-parameter model of the compound planetary gear set with cracked sun gear is established. The mesh deformation of each mesh pair without and with crack are numerically analyzed. The time histories, FFT spectra, phase portraits and Poincaré maps are adopted to investigate the influence of crack propagation on the nonlinear dynamic behaviors of the system. Further, the load sharing ratio (LSR) with respect to different crack levels are calculated and the influence of crack propagation on the load sharing characteristics of the system is discussed. The results will be useful for fault diagnosis and reliability analysis of the planetary gear transmissions.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122253045","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: 2
A Multivalued Test and Diagnostic Strategy Optimization Method for Aircraft System Fault Diagnosis 飞机系统故障诊断的多值测试与诊断策略优化方法
2019 IEEE International Conference on Prognostics and Health Management (ICPHM) Pub Date : 2019-06-17 DOI: 10.1109/ICPHM.2019.8819388
Yan Su, Xuerui Liang, Chenxuan Gu, Varun Khemani, M. Pecht
{"title":"A Multivalued Test and Diagnostic Strategy Optimization Method for Aircraft System Fault Diagnosis","authors":"Yan Su, Xuerui Liang, Chenxuan Gu, Varun Khemani, M. Pecht","doi":"10.1109/ICPHM.2019.8819388","DOIUrl":"https://doi.org/10.1109/ICPHM.2019.8819388","url":null,"abstract":"Diagnostic strategy optimization is a critical part of testability design. The complex functional structure of aircraft systems leads to a large number of failure modes and corresponding tests. Many tests of aircraft systems have multivalued attributes that correspond to different states of the system. These attributes lead to the computational complexity of existing test and diagnostic methods. Considering the multivalued test diagnosis problems of aircraft systems, this paper develops a multivalued test and diagnostic strategy optimization generation method based on rollout and information entropy. A rollout algorithm was combined with an information entropy algorithm to iteratively update information entropy and achieve balance between computational complexity and accuracy. The method is applied to the diagnostic strategy optimization generation of an engine air-bleed system for a certain type of aircraft.","PeriodicalId":113460,"journal":{"name":"2019 IEEE International Conference on Prognostics and Health Management (ICPHM)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133576325","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: 1
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