Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology最新文献

{"title":"Research on surface magnetorheological polishing technology for optical grade components","authors":"Zhuangzhuang Cheng ,&nbsp;Cong Sun ,&nbsp;Mengjiao Duan ,&nbsp;Zhenbiao Zhang ,&nbsp;Kun Liang ,&nbsp;Wenxin Wang ,&nbsp;Xueliang Zhang","doi":"10.1016/j.precisioneng.2025.09.018","DOIUrl":"10.1016/j.precisioneng.2025.09.018","url":null,"abstract":"<div><div>Optical grade components face significant challenges in manufacturing due to hard and brittle material properties and stringent requirements for damage-free surfaces. Most existing manufacturing methods have limitations in manufacturing cost and efficiency. Therefore, a multi-parameter synergistic control of the magnetorheological polishing (MRP) method is proposed, to optimize the excitation performance of the excitation device through magnetic field simulation, to regulate the anti-settling characteristics of the MRP fluid by combining with additive ratios, and to systematically investigate the influence of multi-dimensional parameters such as kinematic parameters of the polishing device, process parameters and so on, on the polishing effect. The regulation mechanism of magnetic flux density and particle size on the structure of magnetic chains is revealed by Monte Carlo simulation. The further established mesh density model of abrasive particle motion trajectory provides the theoretical basis for the synergistic optimization of the multi-parameters. This study provides a systematic experimental and theoretical method for the ultra-precision machining of optical components. It provides new ideas for the application of MRP technology in the machining of other hard and brittle materials.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 249-267"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and analysis of forces in laser-assisted micro-milling Inconel 718 under softening effects and size effects","authors":"Chen Cong ,&nbsp;Xiaohong Lu ,&nbsp;Ying Chen ,&nbsp;Xiuqing Hao ,&nbsp;Wentian Shi ,&nbsp;Steven Y. Liang","doi":"10.1016/j.precisioneng.2025.10.024","DOIUrl":"10.1016/j.precisioneng.2025.10.024","url":null,"abstract":"<div><div>Inconel 718 is a critical material in aerospace, energy, and power sectors for manufacturing micro-components because of its exceptional properties such as high-temperature strength, thermal stability, and resistance to thermal fatigue. It is also a typically difficult-to-machine material. Laser-assisted micro-milling (LAMM) is a potentially effective processing method for such materials. However, the elevated temperatures induced by the laser can alter the material properties within the cutting zone. Coupled with the size effects inherent to micro-milling, this gives rise to highly complex fluctuations in cutting forces that are difficult to characterize accurately. To this end, the traditional Johnson-Cook (JC) constitutive model is modified by comprehensively considering the thermal softening effects and size effects. A cutting force prediction model for LAMM is established based on the mechanical analysis of different deformation zones. Cutting experiments are conducted to verify the accuracy of the cutting force model. The model simulation shows that the maximum errors of the three-directional forces are 9.84 %, 7.12 %, and 11.2 % respectively. The proposed force prediction model provides robust theoretical support for subsequent tool wear monitoring and machining accuracy control in LAMM processes.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 742-756"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of subsurface crack depth during abrasive machining of brittle materials based on nanoindentation tests","authors":"Huapan Xiao ,&nbsp;Shenxin Yin ,&nbsp;Yilin Wu ,&nbsp;Qingqing Huang ,&nbsp;Sen Yin","doi":"10.1016/j.precisioneng.2025.11.012","DOIUrl":"10.1016/j.precisioneng.2025.11.012","url":null,"abstract":"<div><div>Subsurface damages (SSDs) are inevitably produced during traditional abrasive machining processes of brittle materials. Such damages significantly impact the service performance and lifespan of these materials, which should be evaluated. This paper develops a method for predicting the subsurface crack depth based on nanoindentation tests. The method attempts to establish new relationships between the deformation zone depth and the median crack depth, with particular attention to the indenter shape, subsurface crack inclination, and material elastic recovery. To validate the method, diamond wire sawing experiments are conducted on a single-crystal silicon ingot, and then the subsurface morphologies and indentation behavior of the silicon wafers are analyzed. The result shows that the subsurface median cracks exhibit a certain inclination angle, ranging from 10.3° to 19.3°. There is a turning point or position for the elastic recovery, nominal contact modulus, and hardness versus the maximum indentation load curve. The experimental values of SSD depth fall within the range of theoretical ones. The relative error between the theoretical and experimental values of SSD depth is minimized when utilizing some newly established relationships in contrast to prior relationships. The theoretical values of SSD depth for the conical indenter, considering crack inclination and elastic recovery, align more closely with the experimental values. Using prior relationships, the minimum relative errors are 18.5 % (conical indenter) and 20.7 % (pyramidal indenter). With the newly established relationships, these errors reduce to 16.6 % and 18.8 %, respectively. This research presents a novel method for evaluating SSDs in abrasive-machined brittle materials.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 936-952"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Translation-rotation positioning stage-assisted tool servo diamond turning of high-homogeneity curved microlens arrays","authors":"Hao Wu,&nbsp;ZeLong Jia,&nbsp;ZhiYue Wang,&nbsp;MingJun Ren,&nbsp;XinQuan Zhang,&nbsp;LiMin Zhu","doi":"10.1016/j.precisioneng.2025.11.007","DOIUrl":"10.1016/j.precisioneng.2025.11.007","url":null,"abstract":"<div><div>Tool servo diamond turning is a promising technique for machining complex-shaped optics, but its application to curved microlens arrays (MLAs) encounters significant challenges, particularly in achieving homogeneous surface quality. These challenges stem from the conflict between the single spiral tool path, based on a polar coordinate system, and the periodic structural features of the curved MLAs. To address these challenges, this paper proposes a novel ultra-precision cutting process: the translation-rotation positioning stage (TRPS)-assisted tool servo diamond turning process. This process integrates an auxiliary TRPS onto the rotary axis of the ultra-precision machine tool, creating a machining system controlled by a master-slave coordinated strategy. The TRPS assists in repositioning the center of each microlens unit to the rotational center of the machine tool's rotary axis before each cut, ensuring that each lens is machined with an individual true spiral tool path. A calibration strategy is proposed to define the positional relationship between the TRPS and the machine tool, and a tool path generation algorithm is developed to precisely guide the diamond turning tool during material removal. Experimental validation on a commercial ultra-precision lathe equipped with a self-developed TRPS confirms the effectiveness of the proposed process in achieving high-precision and high-homogeneity MLAs on curved substrates. These results highlight the significant potential of the TRPS-assisted approach for industrial applications.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 890-903"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and experimental research on the front edge chipping characteristics of dicing monocrystalline silicon with ultra-thin diamond dicing blades","authors":"Jiao Lin,&nbsp;Jingyu Li,&nbsp;Dingxin Li,&nbsp;Chuang Zhang,&nbsp;Jun Cheng","doi":"10.1016/j.precisioneng.2025.09.014","DOIUrl":"10.1016/j.precisioneng.2025.09.014","url":null,"abstract":"<div><div>Monocrystalline silicon is crucial for manufacturing integrated circuits in modern electronics. Dicing is a key semiconductor fabrication step that improves production efficiency, reduces material waste, and ensures chip conformity. Ultra-thin diamond dicing blades are preferred for dicing monocrystalline silicon wafers due to their exceptional precision and efficiency in producing high-quality chips with minimal material waste and damage. However, the material removal mechanism during the dicing of hard and brittle semiconductor materials remains unclear. This study presents a comprehensive front edge chipping (FEC) model to predict the motion trajectory of diamond abrasive grains, grinding force, crack length, and chipping width during monocrystalline silicon dicing. The models reveal that dicing parameters affect chipping quality by altering the grinding force of diamond grains and lateral crack propagation, thus changing the chipping width. To verify these models, ultra-micro-scale dicing experiments were conducted using self-developed ultra-thin diamond blades. The experimental results are analyzed to derive empirical formulas and variation laws of chipping width with respect to process parameters. This study shows the key role of dicing parameters in surface quality and offers a foundation for optimizing dicing quality. It addresses chipping width control challenges, meeting modern semiconductor manufacturing requirements for precision, efficiency, and quality. The findings deepen the understanding of material behavior during dicing hard and brittle materials, benefiting the advancement of ultra-micro-scale monocrystalline silicon dicing. They provide a foundation for future work in this field.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 195-212"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assembly deviation modelling for a swing roller movable teeth reducer considering machining precision based on Jacobi-Torsor model","authors":"Yali Yi ,&nbsp;Meiyu Chen ,&nbsp;Ran Cao ,&nbsp;Rui Wei ,&nbsp;Herong Jin","doi":"10.1016/j.precisioneng.2025.10.002","DOIUrl":"10.1016/j.precisioneng.2025.10.002","url":null,"abstract":"<div><div>Due to the integration of deceleration and output mechanism, the swing roller movable teeth reducer has a more compact structure. However, the assembly joint surface of the reducer is more complex, and the assembly chains are coupled in series and parallel, which lead to difficulties in modelling assembly deviations. To address this issue, this paper focuses on modelling of assembly deviation for the reducer transmission system. Firstly, the composition of reducer is clarified by meta-action analysis. The small displacement torsor is introduced to analyze the constraint attributes of the degree of freedom of components and assembly joint surface. Secondly, the propagation path and error components of assembly deviation are investigated to establish an assembly deviation propagation model for the reducer. Thirdly, the key influence tolerance terms of assembly deviations are identified by combining the theoretical calculations and simulation analysis. Finally, based on the contribution rate of assembly deviation analysis, a hierarchical adjustment strategy for machining accuracy targeting key tolerance terms is proposed. The results show that the proposed adjustment strategy can reduce assembly deviation and processing cost simultaneously for the reducer.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 504-526"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pseudo-random and dynamic selective trajectories generation for mid-spatial frequency error rapid convergence","authors":"Linqiang Gong ,&nbsp;Longxiang Li ,&nbsp;Lei Zhang ,&nbsp;Bowen Zhang ,&nbsp;Dongyue Zheng ,&nbsp;Nianju Li","doi":"10.1016/j.precisioneng.2025.10.015","DOIUrl":"10.1016/j.precisioneng.2025.10.015","url":null,"abstract":"<div><div>Due to the limitations of traditional polishing methods in suppressing mid-spatial frequency (MSF) errors, this study proposes an integrated solution combining pseudo-random trajectory with selective dynamic coverage complex trajectory optimization based on MSF error spatial distribution characteristics. A high-degree-of-freedom pseudo-random trajectory generation strategy is developed, utilizing uniformly distributed initial MSF stripe spacing value as input data to generate path retrieval points with optimized spatial distribution. This process ultimately produces high-degree-of-freedom pseudo-random trajectories featuring non-periodic path characteristics, thereby eliminating the inherent repetitiveness of conventional polishing trajectories. The proposed pseudo-random trajectory achieves MSF error rapid convergence while suppressing additional MSF components induced by path periodicity. For addressing inconsistent residual MSF error distribution after pseudo-random trajectory polishing, a dynamic complex trajectory generation method based on error pixel data analysis is established. Based on the spatial distribution characteristics of MSF errors, this method leverages the adaptive capability of trajectories to perform targeted corrections on different error regions. Thereby, it effectively enhances the convergence efficiency and distribution uniformity of residual MSF errors, and ultimately improves the convergence limit of MSF errors. Experimental results demonstrate that the synergistic integration of pseudo-random trajectory and selective dynamic complex trajectory optimization significantly enhances MSF error convergence efficiency without compromising existing surface form accuracy.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 572-594"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modular system of additive manufacturing benchmarking artefacts for XCT inspection using a design-for-metrology approach","authors":"Darragh A. Broadbent ,&nbsp;David M. Gorman ,&nbsp;Wenhan Zeng ,&nbsp;Shan Lou","doi":"10.1016/j.precisioneng.2025.10.012","DOIUrl":"10.1016/j.precisioneng.2025.10.012","url":null,"abstract":"<div><div>Additive Manufacturing (AM) offers freedom in both design and materials selection. Safety critical industries, such as aerospace and healthcare, stand to benefit from the unique capabilities offered by AM. However, adoption of AM is hindered by the unique and complex inspection and quality assurance requirements that conventional line-of-sight techniques struggle to fulfil. X-ray computed tomography (XCT) is a non-destructive, non-line-of-sight, volumetric imaging technique, which has gained traction as a viable inspection method over the last two decades and shows promise as a next generation dimensional metrology tool for AM. This paper details the development of a system of modular artefacts which provide a reconfigurable toolkit to address a variety of AM metrology challenges. The toolkit consists of AM test, and XCT data validation modules. The test modules are engineered to assess the ability of an AM system to produce challenging geometries. Additionally, several XCT data validation modules are introduced, which are intended to reduce measurement uncertainty by providing a consistent repeatably measured ground truth in the form of features of known size and shape in each dataset. The AM test modules are parameterised based on AM process and XCT scanning parameters, enabling the modules to be adapted for specific requirements.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 706-721"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental research on the performance of micro-textured CVD diamond-coated abrasive tools in longitudinal-torsional ultrasonic grinding of die steel","authors":"Zhiqiang Zhang,&nbsp;Daohui Xiang,&nbsp;Chaosheng Song,&nbsp;Jun Zhang,&nbsp;Shuaikun Yang,&nbsp;Junjin Ma,&nbsp;Guofu Gao","doi":"10.1016/j.precisioneng.2025.09.001","DOIUrl":"10.1016/j.precisioneng.2025.09.001","url":null,"abstract":"<div><div>Precision grinding employs the micro-cutting action of abrasive micro-edges to achieve high accuracy and low roughness in machined surfaces. However, the extremely high hardness and wear resistance of diamond abrasive grains present a significant challenge in generating micro-cutting edges on the surface through grinding wheel dressing. Therefore, diamond abrasive tools with micro-edges were prepared by the hot filament chemical vapor deposition (HFCVD) method in this paper. Firstly, the cemented carbide was pretreated, that is, Square and concentric circles micro-textures were prepared on the surface of the cemented carbide by laser technology. Secondly, the concentric circle groove micro-texture boron-doped micro-nano (CCGMT-BDMN) and square groove micro-textured boron-doped micro-nano (SGMT-BDMN) diamond abrasive tools were prepared by HFCVD. The surface morphology, quality and adhesion strength of the textured diamond films were characterized by scanning electron microscopy (SEM), Raman spectroscopy and Rockwell hardness tester. Results indicate incomplete filling of the groove textures with diamond particles, leading to sloping sidewalls at the texture edges. The coating exhibited significant residual stress, which diminished away from the texture edge. Micro-texturing with square grooves enhanced outer edge diamond quality and bond strength, resulting in superior adhesion of SGMT-BDMN abrasive tools. Longitudinal-torsional ultrasonic vibration-assisted grinding (LTUVAG) was evaluated to mitigate diffusion wear between diamond and die steel. Compared to conventional grinding (CG), LTUVAG achieves circumferential intermittent cutting, which reduces grinding forces, suppresses carbon atom diffusion wear on the abrasive tool surface, significantly minimizes adhesive wear, and extends the service life of diamond abrasive tools. Furthermore, the impact of various processing parameters on surface quality was examined. Within specific ranges, enhancing ultrasonic amplitude and grinding speed, while reducing feed speed, positively influences surface quality improvement.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 52-67"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data-driven optimization of the quality and efficiency of silica glass microchannels in femtosecond laser processing via Gaussian process regression","authors":"Kai Liao ,&nbsp;Wenjun Wang ,&nbsp;Wenwen Tian ,&nbsp;Chunjin Wang ,&nbsp;Chi Fai Cheung","doi":"10.1016/j.precisioneng.2025.11.002","DOIUrl":"10.1016/j.precisioneng.2025.11.002","url":null,"abstract":"<div><div>Silica glass, renowned for its exceptional physical, chemical, and biocompatible properties, serves as a critical substrate for microfluidic devices. However, its inherent hardness and brittleness present significant challenges for achieving precise and efficient fabrication. Although femtosecond lasers offer remarkable advantages in precision machining, achieving simultaneous enhancements in machining quality and processing efficiency remains a complex challenge. This study introduces a data-driven framework that integrates a Gaussian Process Regression (GPR) model with an improved Non-dominated Sorting Genetic Algorithm II (NSGA-II) for the multi-objective optimization of femtosecond laser-based microchannel fabrication. The GPR model systematically captures the relationships between processing parameters, surface roughness (<em>S</em>_<em>a</em>), and material removal rate (<em>MRR</em>), effectively addressing nonlinear interactions during multi-pass scanning. The enhanced NSGA-II algorithm incorporates adaptive parameter adjustments and improved population diversity to robustly explore the solution space, enabling the identification of optimal trade-offs between surface quality and processing efficiency. Experimental validation of the optimization results reveals strong agreement between predicted and actual outcomes, demonstrating the framework's effectiveness in simultaneously minimizing surface roughness and maximizing material removal rate. This work underscores the potential of combining GPR and NSGA-II to optimize femtosecond laser micromachining, offering a robust methodology to significantly improve both the quality and efficiency of microfabrication processes.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"97 ","pages":"Pages 828-838"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145473700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}