Journal of Road Engineering最新文献

{"title":"Roller-compacted geopolymer concrete mixes with recycled asphalt pavement material","authors":"Avinash Talkeri ,&nbsp;Raghuram Chinnabhandar ,&nbsp;Harish Sagar","doi":"10.1016/j.jreng.2024.09.002","DOIUrl":"10.1016/j.jreng.2024.09.002","url":null,"abstract":"<div><div>The performance of roller compacted concrete (RCC) was greatly influenced by variations in material proportion, optimum moisture content, density of mixes and methodology adopted making it different from conventional concrete mixes. Even though RCC has gained popularity, the complex phenomenon involved in developing the RCC mixes limits it from large-scale applications. In this study, reclaimed asphalt pavement (RAP) incorporated roller-compacted geopolymer concrete (RGC) mixes were developed herein with different compaction techniques such as vibratory hammer (VH), modified proctor (MP), vibration table (VT) and compression machine (CM) are studied and compared with control mixes of natural aggregates. Initially, the effect of alkali solutions such as sodium hydroxide (SH) and sodium silicate (SS) on the physical properties. During, the second phase mechanical properties such as dry density, compressive, flexural and split-tensile strength, modulus of elasticity and microstructure properties will be investigated. The test results revealed that compaction efforts were greatly influenced by the alkali solution. Furthermore, the poor bond characteristics between RAP and the binder matrix had a significant effect on strength properties. Also, the various compaction techniques affected the mechanical properties of mixes developed herein. In Comparison with various compaction efforts, VH and MP produced comparable results, whereas the VT method underestimated and overestimated the various strength properties. Although, the CM method reports comparable results but difficult to maintain consistency in strength aspects. Therefore, optimization of various parameters influencing the concrete properties needs to be achieved for field density.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"5 1","pages":"Pages 106-115"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive state-of-art review on the use of rejuvenators in asphalt pavement","authors":"Basant Bhatt,&nbsp;Shenghua Wu","doi":"10.1016/j.jreng.2024.10.001","DOIUrl":"10.1016/j.jreng.2024.10.001","url":null,"abstract":"<div><div>The utilization of reclaimed asphalt pavement (RAP) in asphalt mixtures has gained momentum in recent years, yet concerns persist regarding the long-term performance and binder properties of high RAP content mixtures. To overcome these challenges, rejuvenators have emerged as a promising solution to enhance the properties of aged asphalt binders and improve the overall performance of asphalt mixtures. This paper provides a comprehensive state-of-the-art review of rejuvenator technology and its potential to enhance the performance and sustainability of asphalt pavements. Rejuvenators are additives used to restore the properties of aged asphalt binders, particularly when incorporating high percentages of RAP. The performance of these additives varies based on their origin, and different methods can be used to analyze the rejuvenation process. Since proper specifications for rejuvenators are not available, blending charts are used to determine the optimum dosage of rejuvenators. However, proper blending must be achieved to maximize results and reduce the effect of black rock. Laboratory tests and some field performance studies on rejuvenated aged asphalt binders and RAP mixtures have shown improved or similar performance compared to virgin materials. Additionally, the use of rejuvenators has been observed to reduce construction costs, suggesting that this is a cost-effective technology for asphalt pavements. While rejuvenators show promise in improving the performance of pavements with recycled materials, challenges remain regarding optimization, long-term durability, and environmental effects. This review paper also identifies key areas for future research, including life-cycle cost analyses, comprehensive environmental impact assessments, and long-term field performance monitoring.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"5 1","pages":"Pages 1-20"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of pavement friction decay on speed limits and autonomous vehicles: A theoretical and experimental study","authors":"Filippo Giammaria Praticò","doi":"10.1016/j.jreng.2024.09.001","DOIUrl":"10.1016/j.jreng.2024.09.001","url":null,"abstract":"<div><div>Commonly, the standards for the geometric design of roads refer to a given set of values for the friction coefficient (longitudinal and transverse friction). These \"reference\" values imply corresponding visibility sights, curvature radii, and speed limits. Unfortunately, not only do these reference values not correspond to a given standard to measure them, but nothing is said about the decrease of the posted speed limit (variable speed limits) when roads become slippery and lanes for autonomous vehicle (AV) are concerned.</div><div>Furthermore, the same assessment of the friction coefficient has plenty of uncertainties due to measurement device, temperature, location, time passed from the construction, alignment-related variables (e.g., curve, tangent, transition curve, convexity/crests or concavity/sags, longitudinal slope, superelevation, and ruling gradient), and supplementary singularities such as joints and bridge approaches. All the issues above may harm road safety and the complexity of forensic investigations of pavements.</div><div>Consequently, this study's objectives were confined to (1) carrying out friction measurements and analyzing the problem of friction decay over time; (2) setting up a method to lower the speed limits where friction decays are detected; (3) setting up a method to handle friction decays for autonomous vehicles. Results demonstrate that: (1) a power law describes how the speed limits are affected by friction; (2) for speeds up to 170 ​km/h, due to the lower reaction time, AV reaction distance is lower, which benefits AV traffic (lower stopping distance); (3) on the contrary, for higher values of friction and higher speeds, under the hypothesis of having the same reaction time law for non-AV (NAV) (i.e., decreasing with the initial speed), AV speed limits become lower than NAV speed limits; (4) not only do comfort-based speed profiles for AVs bring higher braking distances, but also, in the median part (of the deceleration process), this could pose safety issues and reduce the distance between the available and the needed friction.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"5 1","pages":"Pages 35-47"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinear rheological behavior of asphalt based on large amplitude oscillation shear test under different loading, aging, and modification conditions","authors":"Jiaqiu Xu ,&nbsp;Zijia Wang ,&nbsp;Zepeng Fan ,&nbsp;Junfu Liu ,&nbsp;Guoyang Lu ,&nbsp;Dawei Wang","doi":"10.1016/j.jreng.2024.12.001","DOIUrl":"10.1016/j.jreng.2024.12.001","url":null,"abstract":"<div><div>To reveal the effects of environmental and loading conditions, as well as asphalt properties on the nonlinear rheological behavior of asphalt, the large amplitude oscillation shear (LAOS) test was introduced, and the Fourier transform rheology, Lissajous curve method, and the LAOS fatigue test have been applied to investigate the nonlinear rheological behavior of asphalt binders. The research results indicate that a decrease in temperature, an increase in shear frequency and strain level, the introduction of polymer modifiers, and the aging effect of asphalt can significantly increase the nonlinearity of asphalt, manifested by the higher relative magnitude of the third harmonic and zero-strain nonlinear coefficient. For the two polymer modifiers selected in this study, the 4% polyurethane modifier exhibits a higher nonlinear lifting effect than the 4% styrene-butadiene-styrene (SBS). The impact of long-term aging on nonlinear viscoelasticity is observably greater than that of short-term aging. The zero-strain nonlinear coefficient estimated based on the average value method can accurately characterize the nonlinear viscoelasticity of asphalt, which can serve as an effective supplement to the relative magnitude of the third harmonic. All asphalts exhibit shear thinning behavior under the test temperature of 24 ​°C, and the decrease in test temperature, the increase in shear rate and strain level, the introduction of modifiers, and the aging effect of asphalt all exacerbate the shear thinning behavior of asphalt. In addition, the fatigue failure process of asphalt materials is accompanied by an increasing degree of nonlinearity.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"5 1","pages":"Pages 48-64"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical response analysis of asphalt pavement considering top-down crack based on FDM-DEM coupling simulation","authors":"Min Wang ,&nbsp;Xin Yu ,&nbsp;Chen Chen","doi":"10.1016/j.jreng.2024.07.004","DOIUrl":"10.1016/j.jreng.2024.07.004","url":null,"abstract":"<div><div>The occurrence of top-down (TD) cracking has gradually become a prevalent issue in semi-rigid base asphalt pavements after prolonged service. A coupled simulation model integrating the finite difference method (FDM) and discrete element method (DEM) was employed to investigate the mechanical behavior of asphalt pavement containing a pre-existing TD crack. The mesoscopic parameters of the model were calibrated based on the mixture modulus and the static mechanical response on the MLS66 test road. Finally, an analysis was performed to assess how variations in TD crack depth and longitudinal length affect the distribution patterns of transverse tensile stress, vertical shear stress, and vertical compressive stress. The results indicate that the vertical propagation of TD crack significantly increases both the tensile stress value and range on the middle surface, while the longitudinal development of TD crack has minimal impact. This phenomenon may result in more severe fatigue failure on the middle surface. With the vertical and longitudinal development of TD crack, the vertical shear stress and compressive stress show obvious \"two-stage\" characteristics. When the crack's vertical length reaches 40 ​mm, there is a sharp increase in stress on the upper surface. As the crack continues to propagate vertically, the growth of stress on the upper surface becomes negligible, while the stress in the middle and lower layers increased significantly. Conversely, for longitudinal development of TD crack, any changes in stress are insignificant when their length is less than 180 ​mm; however, as they continue to develop longitudinally beyond this threshold, there is a sharp increase in stress levels. These findings hold great significance for understanding pavement structure deterioration and maintenance behavior associated with TD crack.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"5 1","pages":"Pages 92-105"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the effect of particle composition on its distribution homogeneity in aggregate blend using discrete element method","authors":"Weixiao Yu ,&nbsp;Sudi Wang ,&nbsp;Zhenlong Gong ,&nbsp;Yinghao Miao","doi":"10.1016/j.jreng.2024.07.001","DOIUrl":"10.1016/j.jreng.2024.07.001","url":null,"abstract":"<div><div>The homogeneity of aggregate blend has a significant influence on the performance of asphalt mixture. The composition of aggregate blend, including the size combination and the mass ratio between each size particles (MRESP), is an important factor affecting the homogeneity. This study investigated the influence of the size combination and MRESP on the distribution homogeneity of particles in aggregate blend using discrete element method (DEM). An indicator quantifying the distribution homogeneity was established according to the coefficient of variation (CV) for particle number. Two-size, three-size, and four-size aggregate blends with various compositions were designed. Laboratory tests show the DEM simulation is feasible. The particle distribution homogeneity in various blends was analyzed. The results showed the distribution homogeneity of each size particles in a blend is closely related to their mass fraction. The higher the mass fraction of the particles, the more homogeneous the distribution of them. The MRESP has no significant influence on the homogeneity of the blend composed of only coarse aggregates. However, the homogeneity of the blend composed of coarse and fine aggregates improves gradually with the increase of the mass fraction of fine aggregates. The smaller the maximum particle size in a blend, the better the homogeneity. It is suggested that the mass fraction of fine aggregates should be between 33% and 50% for achieving good homogeneity of aggregate blends. The research results can provide a reference for gradation design of asphalt mixture.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"5 1","pages":"Pages 116-127"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review on composition properties, functionalization of bio-oil and its rejuvenation behavior and mechanism on aged asphalt","authors":"Peilong Li ,&nbsp;Lei Yue ,&nbsp;Zhan Ding ,&nbsp;Xiuming Jiang ,&nbsp;Huifeng Li ,&nbsp;Linyu An ,&nbsp;Chenxi Tian","doi":"10.1016/j.jreng.2024.07.002","DOIUrl":"10.1016/j.jreng.2024.07.002","url":null,"abstract":"<div><div>The objective of this paper is to comprehensively review the research progress of bio-oil properties and hot rejuvenation behavior and mechanism to aged asphalt. The preparation process, composition characteristics of bio-oils and their component correspondence with petroleum asphalt were compared. The diffusion and fusion effects of various bio-oils in aged asphalt were introduced. Bio-oil cannot be used as a direct alternative of petroleum asphalt, but it has the potential to effectively rejuvenate aged asphalt binders due to the component similarity with petroleum asphalt and good diffusion properties. For the asphalt rejuvenation, the functionalization treatment methods of bio-oil were discussed such as purification, composition modification and component conversion. The active groups and derivatives in bio-oil can be converted into the missing components of the aged binder through phenolate, grafting, polycondensation, resinifying, but the conversion process and mechanism are still unclear. From the perspectives of diffusion behavior, components regulation, dissolving asphaltene and micro-rejuvenation effect, the rejuvenation behavior and mechanism of bio-oil on aged asphalt were elaborated, and the effects of various types of bio-oil and aged asphalt on rejuvenation behavior were analyzed. The preparation process and dosage of bio-rejuvenator were summarized. The rejuvenation effects of bio-oil on aged asphalt were comprehensively investigated from the aspects of high and low temperature performances, rheological properties, microstructure and chemical composition of bio-rejuvenated asphalt binders. Finally, the limitations of bio-oil used as asphalt rejuvenators were discussed, and future research directions were prospected, which can provide reference and theoretical basis for the development of high-performance bio-oil rejuvenating agents and the engineering application of bio-oil to improve the properties of aged asphalt materials.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"5 1","pages":"Pages 21-34"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Models and methods for dynamic response of 3D flexible and rigid pavements to moving loads: A review by representative examples","authors":"Edmond V. Muho ,&nbsp;Niki D. Beskou ,&nbsp;Jiang Qian","doi":"10.1016/j.jreng.2024.07.003","DOIUrl":"10.1016/j.jreng.2024.07.003","url":null,"abstract":"<div><div>This work reviews models and methods for determining the dynamic response of pavements to moving vehicle loads in the framework of continuum-based three dimensional models and linear theories. This review emphasizes the most representative models and methods of analysis in the existing literature and illustrates all of them by numerical examples. Thus, 13 such examples are presented here in some detail. Both flexible and rigid (concrete) pavement models involving simple and elaborate cases with respect to geometry and material behavior are considered. Thus, homogeneous or layered half-spaces with isotropic or cross-anisotropic and elastic, viscoelastic or poroelastic properties are considered. The vehicles are modeled as simple point or distributed loads or discrete spring-mass-dashpot system moving with constant or variable velocity. The dynamic response of the above pavement-vehicle systems is obtained by analytical/numerical or purely numerical methods of solution. Analytical/numerical methods have mainly to do with Fourier transforms or complex Fourier series with respect to both space and time. Purely numerical methods involve the finite element method (FEM) and the boundary element method (BEM) working in time or frequency domain. Critical discussions on the advantages and disadvantages of the various pavement-vehicle models and their methods of analysis are provided and the effects of the main parameters on the pavement response are determined through parametric studies and presented in the examples. Finally, conclusions are provided and suggestions for future research are made.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"5 1","pages":"Pages 65-91"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review on the properties and mechanisms of asphalt modified with bio-oil and biochar","authors":"Xinxing Zhou ,&nbsp;Ziyang Zhang ,&nbsp;Haopeng Wang ,&nbsp;Meizhu Chen ,&nbsp;Shaopeng Wu ,&nbsp;Song Xu ,&nbsp;Xinglin Zhou ,&nbsp;Maoping Ran ,&nbsp;Linglin Li ,&nbsp;Guangjun Lu ,&nbsp;Zhibin Ma","doi":"10.1016/j.jreng.2024.06.001","DOIUrl":"10.1016/j.jreng.2024.06.001","url":null,"abstract":"<div><div>Bio-asphalt has a great application prospect in the replacement of petroleum-based asphalt to pave and maintain asphalt pavement. However, the problems of flow-induced crystallization and phase separation caused by flow-induced crystallization had severely restricted its application. This paper describes the progress of research on preparation, property evaluation and phase separation mechanism of bio-asphalt. The advantages and disadvantages of preparation methods of bio-asphalt are states. The fundamental physical and rheological properties of bio-asphalt are investigated, especially for flow-induced crystallization. There exists obvious flow-induced crystallization because bio-asphalt is rich in waxes that crystallize easily. Owing to the existence of excess biochar, bio-asphalt appears phase separation. A brief review of the effect of bio-oil and biochar on asphalt volatile organic compounds (VOCs) is presented. Research find that bio-oil/biochar are not only replenish the light components of asphalt, but also improve the flow-induced crystallization and phase separation of bio-asphalt. There exists synergistic effect of biochar and bio-oil in asphalt modification. Moreover, biochar can improve the durability of bio-oil modified asphalt, but excessive addition of biochar to bio-oil modified asphalt can cause phase separation. Adding an appropriate amount of bio-oil and biochar to asphalt can improve its high-temperature resistance, low-temperature crack resistance, and system compatibility.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"4 4","pages":"Pages 421-432"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143286087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effectiveness of heat-reflective asphalt pavements in mitigating urban heat islands: A systematic literature review","authors":"Tracy Leh Xin Wong ,&nbsp;Ewe Loon Lim ,&nbsp;Mohd Rosli Mohd Hasan ,&nbsp;Oumar Orozi Sougui ,&nbsp;Abdalrhman Milad ,&nbsp;Xin Qu","doi":"10.1016/j.jreng.2024.04.008","DOIUrl":"10.1016/j.jreng.2024.04.008","url":null,"abstract":"<div><div>Urban heat island (UHI) effect is a growing concern in numerous cities worldwide, which increases urban temperatures. Conventional asphalt pavements are a major contributor to the issue, causing environmental and health concerns. To tackle this issue, the implementation of cool pavements such as heat-reflective asphalt pavements has been introduced. This systematic literature review (SLR) thoroughly examines prior research to assess the effectiveness of heat-reflective asphalt pavements in reducing UHI effects. This SLR was conducted in accordance with the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines to enhance data reliability and minimize bias. This review process involved establishing review protocol, formulating review questions, systematically selecting articles through identification, screening, eligibility, quality appraisal, and data abstraction and analysis from various databases such as Scopus, Web of Science (WoS), Wiley, Taylor Francis, and ScienceDirect. Three primary themes and nine sub-themes were derived from the three review questions. From the results, heat-reflective asphalt pavements effectively minimized the UHI effect. However, their efficiency varies depending on factors such as pavement types, paving location, and use of cool materials. A comprehensive analysis examined heat-reflective pavement's mechanisms, benefits, and drawbacks. This investigation aimed to enhance comprehension and establish a robust basis for future studies in this field.</div></div>","PeriodicalId":100830,"journal":{"name":"Journal of Road Engineering","volume":"4 4","pages":"Pages 399-420"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143286092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}