Mechanical Systems and Signal Processing最新文献

{"title":"Surface roughness online prediction using parallel ensemble learning in robotic side milling for aluminum alloy","authors":"Ci Song,&nbsp;Zhibing Liu,&nbsp;Xibin Wang,&nbsp;Tianyang Qiu,&nbsp;Zhiqiang Liang,&nbsp;Wenhua Shen,&nbsp;Yuhang Gao,&nbsp;Senjie Ma","doi":"10.1016/j.ymssp.2025.112932","DOIUrl":"10.1016/j.ymssp.2025.112932","url":null,"abstract":"<div><div>Robotic machining has the advantages of large workspace and high flexibility, and the acquisition of high surface quality parts has become the research focus. To realize surface roughness online prediction in robotic side milling for aluminum alloy, an intelligent model driven by cutting vibration was adopted. Combined with variational modal decomposition (VMD) and fast fourier transformation (FFT), a rough and fine two-layer decomposition strategy of stable cutting vibration signals was proposed, which can effectively avoid the adverse effects of modal aliasing and endpoint action on the extraction of high-sensitivity features. Based on support vector machine (SVM), random forest (RF) and extreme learning machine (ELM), weighted reconstruction and voting selection were introduced to form a parallel ensemble learning model. Considering the posture influence in the sample construction, the machining system vibration state within common range was fully reflected by orthogonal cutting experiments at the corresponding postures of envelope zone vertices. For the setting process parameters, the obtained surface roughness was within 1.62–2.90 μm. Experiments under the testing postures showed the root mean square error (RMSE) and mean absolute error (MAE) of the model were 0.087 μm and 0.076 μm. The average relative error of 3.57 % and maximum relative error of 8.65 % had shown that the model obtained better surface roughness prediction ability. Finally, the influence significance and the factor action trend between cutting parameters and surface roughness were explored by range analysis, which has been proved by experiments that they can provide guidance for the dynamic regulation of cutting parameters.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112932"},"PeriodicalIF":7.9,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144195662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equivalent circuit modeling for triboelectric energy harvesters","authors":"Zicheng Liu ,&nbsp;Guobiao Hu ,&nbsp;Xin Li ,&nbsp;Chaoyang Zhao ,&nbsp;Yaowen Yang","doi":"10.1016/j.ymssp.2025.112916","DOIUrl":"10.1016/j.ymssp.2025.112916","url":null,"abstract":"<div><div>The utilization of triboelectric transduction for vibration energy harvesting has garnered considerable attention owing to its manifold advantages. Researchers across diverse disciplines have endeavored to develop various theoretical models to investigate the properties of triboelectric energy harvesters (TEHs). Initially, material scientists formulated analytical models to explain triboelectric transduction’s electric energy generation process. Subsequently, experts in mechanical engineering devised dynamical models to describe the mechanical response of TEHs, often simplifying the energy extraction circuit (EEC) to a mere resistor. Conversely, researchers in electrical engineering derived models for intricate EECs but tended to oversimplify the harvesters’ mechanical response as sinusoidal motions. Consequently, the integration of models addressing both the electromechanical response of the harvesters and the practical EECs remains largely unaddressed due to the analytical challenges posed by such intricate systems. This article presents a novel technique to reconcile the disparity between the electromechanical and EEC models of TEHs by implementing an equivalent circuit model (ECM). Initially, the equivalent circuit parameters of the harvester are identified based on an electromechanical model of a cantilever-based harvester. Subsequently, an ECM encompassing both the mechanical and electrical responses is established. Finally, the ECM is experimentally validated, demonstrating its capability to simulate the harvester’s performance on a holistic system level. This proposed methodology serves as a crucial step towards comprehensive modeling and optimization of TEH systems for enhanced energy harvesting efficiency and applicability in various domains.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112916"},"PeriodicalIF":7.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144189330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Moving load identification in the presence of uncertainties in the computational model","authors":"Zakaria Bitro ,&nbsp;Anas Batou ,&nbsp;Huajiang Ouyang","doi":"10.1016/j.ymssp.2025.112866","DOIUrl":"10.1016/j.ymssp.2025.112866","url":null,"abstract":"<div><div>Most standard methods for moving load identification make use of a deterministic computational or analytical models under strong modelling assumptions concerning the geometry of the supporting structure on which the moving loads are applied and the speed of these moving loads. Nevertheless, these quantities are in general not perfectly known (thus uncertain) and the identified moving loads, as well as the dynamic response of the structure, can be very sensitive to their values. It is therefore crucial to examine the effects of these uncertainties on the predictability of computational models and support decision-makers. This paper introduces a stochastic framework for modelling a vehicle-bridge interaction (VBI) system, accounting for uncertainties in the road profile and the speed of the moving loads yielding uncertainties in the geometry of the supporting structure and the position of the moving loads. The explicit form of the Newmark-<span><math><mi>β</mi></math></span> method is utilised to establish an inverse model and identify the moving loads, and the Monte Carlo simulation method is used to build the statistics of the identified moving loads.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112866"},"PeriodicalIF":7.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144189332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic detection mechanism model of acoustic emission for high-speed train axle box bearings with local defects","authors":"Defu Han ,&nbsp;Hongyuan Qi ,&nbsp;Dongming Hou ,&nbsp;Shuangxin Wang ,&nbsp;Jinzhen Kong ,&nbsp;Xining Xu ,&nbsp;Cuiping Wang","doi":"10.1016/j.ymssp.2025.112943","DOIUrl":"10.1016/j.ymssp.2025.112943","url":null,"abstract":"<div><div>Acoustic emission (AE), as a promising technology, is suitable for the fault diagnosis and state monitoring of high-speed train axle box bearings (HSTABs). However, the mechanism of the correlation between bearing states and dynamic AE signals remains unclear. Existing studies have failed to explain the relationship between contact deformation energy and dynamic root-mean-square (RMS) of the AE signals generated by HSTABs, while also neglecting the asperity-induced dynamic displacement and local defect-induced transient elastic waves. Moreover, there is no study on the attenuation behavior of AE waves in complete HSTAB. This paper presents an AE dynamic detection mechanism model of the HSTAB state, revealing the generation mechanism of AE waves by rough contact and local defect impact and their propagation characteristics. First, based on the load pattern of the HSTAB, a dynamic model was established considering asperity contact, local defect impact, and lubrication oil, and the dynamic contact force of the rollers was determined. Second, a mathematical model of the rough contact with RMS was established jointly with the contact force. Further, the attenuation features of the AE waves in the HSTAB and its housing were investigated, and an AE dynamic mechanism model was established. The model not only resolves the dynamic RMS characterization of the AE signals from moving bearings but also describes the relationship between the dynamic RMS and running speed, bearing state, and time scale. Finally, with different defective HSTABs as examples, the correctness of the model was verified by performing experiments on a full-size high-speed train test rig, providing a theoretical basis for the application of the AE technology in the diagnosis and quantitative analysis of bearing faults.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112943"},"PeriodicalIF":7.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144189331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A digital twin-based framework for reliability estimation in ultrasonic guided wave structural health monitoring systems with temperature variations","authors":"Panpan Xu ,&nbsp;Georgios Sarris ,&nbsp;Robin Jones ,&nbsp;Peter Huthwaite","doi":"10.1016/j.ymssp.2025.112848","DOIUrl":"10.1016/j.ymssp.2025.112848","url":null,"abstract":"<div><div>The reliability estimation of ultrasonic guided wave structural health monitoring (SHM) systems is crucial yet challenging due to the need to represent practical conditions that evolve over a system’s lifespan. These conditions include various variables and uncertainties in measurements, which must be captured through experimental data collection or numerical data generation. This paper proposes and validates a novel digital twin-based framework that provides tailored reliability estimations throughout an SHM system’s lifecycle, accounting for specific measurement conditions, particularly temperature variations. The framework develops a digital twin model reflecting real-time measurement conditions using installed SHM measurements, from which key simulation parameters affected by environmental temperatures are updated. Laboratory experiments demonstrate the model’s ability to generate high-fidelity guided wave signals, effectively capturing temperature effects and noise levels. The framework’s reliability estimation performance is verified by comparing probability of detection (POD) analyses with the established superposition method. The paper further illustrates the framework’s capability to provide more accurate reliability assessments compared to traditional model-assisted POD methods by offering progressive, time-evolving performance evaluations that effectively account for dynamic temperature variations and changes in transducer performance over time. This approach represents a significant advancement in SHM reliability estimation, providing a feasible solution with improved accuracy and adaptability to real-world conditions through the dynamic development of the digital twin model.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112848"},"PeriodicalIF":7.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144195659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stereo-point tracking of inherent structural features for 3D computer vision measurements","authors":"Fabio Bottalico ,&nbsp;Alessandro Sabato","doi":"10.1016/j.ymssp.2025.112937","DOIUrl":"10.1016/j.ymssp.2025.112937","url":null,"abstract":"<div><div>Computer vision techniques have gained popularity for structural health monitoring and structural dynamics thanks to advancements in camera technology and computational capability. Among these techniques, three-dimensional-digital image correlation (3D-DIC) and 3D-point tracking (3D-PT) have been used as substitutes for traditional contact-based methods. To produce accurate measurements, 3D-DIC and 3D-PT require high-contrast patterns such as stochastic speckles or fabricated optical targets on the surface of the targeted structure. However, when large-scale engineering structures such as bridges and wind turbines must be analyzed, applying the high-contrast speckles/targets may not always be feasible, thus limiting the applicability of 3D-DIC and 3D-PT. This research develops an approach to identify and track inherent features such as bolts, letters, stains, rusted patches, and holes that are already present on the structure. To achieve this goal, the Augmented Convex Polygon of Gradients (ACPG), an algorithm based on a novel custom interpolation method, is developed to track the motion of inherent structural features. In this research, the performance of the proposed ACPG algorithm is compared with traditional 3D-PT measurements and contact-based sensors in laboratory and field tests. Results show that measurements obtained with the ACPG algorithm are in excellent agreement with those obtained with traditional approaches, yielding accuracy between 93<!--> <!-->% and 99<!--> <!-->%. The outcomes of this research prove that the proposed ACPG algorithm can extend the applicability of computer vision techniques for 3D measurements of real-world structures.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112937"},"PeriodicalIF":7.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144195660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A long-stroke lifetime piezo inertial actuation and its application in micro-nano observation","authors":"Guangda Qiao ,&nbsp;Yuning Jiang ,&nbsp;Qing Cao ,&nbsp;Guofang Gong ,&nbsp;Dan Zhang ,&nbsp;Huayong Yang ,&nbsp;Dong Han","doi":"10.1016/j.ymssp.2025.112921","DOIUrl":"10.1016/j.ymssp.2025.112921","url":null,"abstract":"<div><div>Instruments used for micro-nano observation, often have optical components with lifespans spanning several decades. While piezo inertial actuators offer the benefit of a compact structure, their limited travel life due to frictional wear poses a challenge for adapting to such applications. Currently, direct-drive piezo and electromagnetic hybrid drives are the preferred commercial solutions; however, hybrid systems tend to increase overall system complexity and size. In this work, we present a compact, wear-adaptive piezo inertial actuator that combines long travel life with cross-scale driving capabilities. Its unique structure ensures stable normal force between friction pairs under surface-to-surface contact conditions, with systematic analysis demonstrating its feasibility for wear adaptation. The <em>XY</em> degrees of freedom (DOFs) exhibited bidirectional motion velocities exceeding 11 mm/s at 2100 Hz and 100 V_p-p. For the <em>Z</em> DOF, at 900 Hz and 100 V_p-p, the forward and reverse velocities were 3.53 mm/s and −4.79 mm/s, respectively. A dual-mode control system integrating fuzzy adaptive PID control and traditional PID control for stepping and scanning modes was developed, effectively addressing the limitations of traditional PID control such as excessive tracking error and slow convergence caused by frequent mode switching. The proposed actuator was applied for various tasks, including graphene surface mechanical characterization, integrated circuit inspection, micro-nano structure detection, and biological cell observation using atomic force and optical microscopes.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112921"},"PeriodicalIF":7.9,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144184513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An ultrasensitive self-powered smart bearing pedestal with fault locating capability","authors":"Zhaoye Qin,&nbsp;Lichang Qin,&nbsp;Qingyu Zhu,&nbsp;Peng Wang,&nbsp;Feibin Zhang,&nbsp;Fulei Chu","doi":"10.1016/j.ymssp.2025.112924","DOIUrl":"10.1016/j.ymssp.2025.112924","url":null,"abstract":"<div><div>For bearing condition monitoring, commonly used measuring points on the casing suffer from low signal-to-noise ratios and strong interference. These issues are expected to be addressed through embedded wireless sensors. To tackle the challenges faced by wireless sensor nodes in terms of energy supply and to enhance their intelligence level, this paper proposes a self-powered smart bearing pedestal with ultrasensitive sensing capabilities. The proposed bearing pedestal features a segmented arrangement of piezoelectric stacks integrated into the structure, utilizing the varying contact load generated by rolling elements. To evaluate the operating characteristics of the smart bearing pedestal, an electromechanical coupling dynamic model is developed, upon which dynamic analysis is carried out for both healthy and faulty bearings. Subsequently, a smart bearing pedestal prototype is manufactured and rotor tests are conducted to further investigate the performance of the proposed smart bearing pedestal. It is observed that the test data aligns well with the simulation results. The smart bearing pedestal has condition monitoring and fault detecting capabilities of high sensitivity, allowing it to sense bearing rotational speed and identify faults of different bearing components, as well as localize the defects on the outer ring. Additionally, it exhibits excellent power supply performance, with a quite low internal resistance of approximately 100 Ω, and is capable of generating an electrical output of 525.9 μW at the rotating speed of 1800 rpm. This research provides a new solution for smart bearing support systems, contributing to intelligent sensing in rotating machinery.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112924"},"PeriodicalIF":7.9,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Actuations in direct-ink-writing based on continuum deformations of a flexible curved pipe conveying fluid","authors":"Runqing Cao ,&nbsp;Yixiang He ,&nbsp;Wei Chen ,&nbsp;Huliang Dai ,&nbsp;Lin Wang","doi":"10.1016/j.ymssp.2025.112899","DOIUrl":"10.1016/j.ymssp.2025.112899","url":null,"abstract":"<div><div>The objective of this study is to investigate actuations based on the continuum deformation of flexible curved magnetically impregnated pipes conveying fluid. This flexible actuation due to flow-induced and magnetic forces offers a novel perspective in direct-ink-writing (DIW). The motion of the pipe’s tip-ends can be seen as a pen freely writing on paper. A kind of soft material, namely hard-magnetic soft (HMS) material, is selected to comprise the magnetic segment of flexible curved pipes. The HMS locally and totally distributed on the curved pipe are considered. The theoretical model is constructed based on the geometrically exact model to predict large deformations of HMS pipes conveying subcritical fluid flows under a magnetic field. The theoretical models for the flexible pipe with locally and totally distributed HMS are validated by experiments. Subsequently, the stability and critical fluid velocity are obtained to determine the DIW workspace of the flexible pipes. Accordingly, the deformations of flexible curved pipe guided DIW can be performed within the designated safe workspace. Horizontal and vertical DIWs are theoretically realized, with consideration of initial curved configurations. The results show that the writing route of the target in each DIW is strongly dependent on the magnetic field and fluid velocity. Furthermore, a curved pipe with a greater curvature can provide a larger writing workspace. For the same writing target, the DIW driven by the totally-distributed HMS pipe requires lower values of magnetic field and fluid velocity, compared to the locally-distributed HMS pipe.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112899"},"PeriodicalIF":7.9,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accelerated lifetime test considering with optimal surface roughness for gas foil bearings","authors":"Jungwan Kim ,&nbsp;Yeongdo Lee ,&nbsp;Yunseok Ha ,&nbsp;Yongbok Lee","doi":"10.1016/j.ymssp.2025.112892","DOIUrl":"10.1016/j.ymssp.2025.112892","url":null,"abstract":"<div><div>This study experimentally evaluates the lifetime of PTFE coating on Inconel-X750 specimens, a material commonly used in gas foil bearings (GFBs), based on surface roughness using a reciprocating test apparatus from a tribological perspective. The primary objective is to verify the enhancement of coating lifetime for GFBs, specifically focusing on the top foil coatings employing solid lubricants. The surface roughness of Inconel specimens was manipulated in five cases within the range of 0.1–1.0 µm using an electrochemical etching method. A coating of consistent thickness was applied using a Polytetrafluoroethylene (PTFE) solvent-based coating material. Lifetime evaluation was conducted by ASTM G133-05, with normal direction load as a variable to simulate accelerated stress conditions. To simulate the line contact environment of the rotor of the turbo machinery, test specimens were fabricated using a Roll-on-Flat method. A test roller was implemented to maintain the perpendicular angle between the roller and the coated specimens, allowing for automated alignment. The experimental verification demonstrated that the lifetime of the coating reached its maximum in the specific surface roughness range of the test specimen, with a R_a of 0.3 to 0.4 μm (Case: 3). In the SEM (Scanning Electron Microscope) image analysis of the cross-section of Inconel specimens coated with PTFE, it was verified that the region where PTFE particles adhere varies according to the surface roughness of the sample. This results in a tangible increase in the bonding force (mechanical interlocking) between the coating and the Inconel sample. The test results could be utilized to predict the lifetime of Inconel X-750 specimens with PTFE coating through accelerated life test (ALT) evaluation using the Weibull-linear function model. The ALT test results in this study were determined by correlating the actual rotor and bearing interactions under Hertzian-contact pressure conditions. Friction coefficient characteristics and sliding distances observed in a reciprocating test rig were converted into estimations representative of the actual bearing-rotor environment. In conclusion, it was predicted that the cyclic lifetime of GFB at the optimal surface roughness (Case 3) of the Inconel specimens would be approximately 1.4 × 10⁵, confirming an extension of the bearing lifetime by over 18 times compared to Case 1 without surface treatment.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"235 ","pages":"Article 112892"},"PeriodicalIF":7.9,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144184512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}