Transportation Geotechnics最新文献

{"title":"Assessment of landslide susceptibility along the Lanzhou-xinjiang high-speed railway: A case study of Menyuan-Shandanmachang","authors":"Jiao Li , Zhiwei Zhou , Wei Ma","doi":"10.1016/j.trgeo.2024.101473","DOIUrl":"10.1016/j.trgeo.2024.101473","url":null,"abstract":"<div><div>The Menyuan-Shandanmachang section of the Lanzhou-Xinjiang High-Speed Railway is located in the cold and high-elevation area at the northeastern edge of the Qinghai-Tibet Plateau, where geological activities are frequent and earthquakes occur often. Meanwhile, this section has become a more sensitive region for the transition from alpine permafrost to deep-seasonal frozen soil due to the warming of the climate. A large number of landslides introduced by earthquakes and freeze–thaw processes cause a serious threat to railway safety. This investigation first explored the spatial distribution characteristics of landslides in the study area by overlapping raster data of 255 landslide samples triggered by the 2016 Menyuan Ms6.4 Earthquake and 12 influencing factors. Subsequently, 255 non-landslide samples were randomly generated in the non-landslide areas to form a database by combining them with the above-mentioned landslide samples. The logistic regression (LR), support vector machine (SVM), and random forest (RF) machine learning models were trained (70 %) and validated (30 %) in a 7:3 split method. The model accuracy was evaluated by using the Receiver Operating Characteristic curve (ROC) and Area Under Curve (AUC). Then, the trained models were used to predict the landslide susceptibility for the 2016 Menyuan Ms6.4 Earthquake and the 2022 Menyuan Ms6.9 Earthquake, respectively. The prediction results were contrasted by landslide samples and the inversion results of InSAR surface deformation to evaluate the performance of the ML models. The results show that the main controlling factors of landslide disasters are elevation, seismic intensity, distance to fault, plane curvature, and rainfall. The prediction accuracy of the three models is RF (0.773) > SVM (0.747) > LR (0.682). The landslide warning degree of RF is higher than that of the other two models, but it performs poorly in the detailed depiction of low-seismicity areas. Although the prediction accuracy of the SVM model is slightly lower than that of RF, it has higher stability and generalization ability. Both models can be used as reference models for predicting the susceptibility of earthquake-induced landslides in the study area. This investigation provided the threshold values of influencing factors with relatively high landslide frequencies in this study area and explored the corresponding mechanism. Multiple evaluation methods combining quantitative analysis, landslide sample analysis, and InSAR surface deformation analysis were adopted to improve the reliability of the evaluation results. The complexity of the geographical environment, the particularity of the geographical location, and the diversity of verification methods for research results contribute to the uniqueness of this study. The research results can offer analysis methods and technical means for the temporal and spatial distribution and evolution characteristics of landslide disasters along the Lanzhou-Xin","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101473"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103059","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":"Dynamic analysis of high-speed vehicle-track coupled system due to lateral differential deformation induced by subgrade frost heave","authors":"Binqiang Li ,&nbsp;Jun Luo ,&nbsp;Yanbo Bai ,&nbsp;Zhenxing He ,&nbsp;Yapeng Wang ,&nbsp;Jianfeng Yun ,&nbsp;Penghao Li ,&nbsp;Wanming Zhai","doi":"10.1016/j.trgeo.2024.101479","DOIUrl":"10.1016/j.trgeo.2024.101479","url":null,"abstract":"<div><div>Subgrade frost heave poses a serious challenge to service safety of high-speed railways in cold regions. Traditional studies often regard subgrade frost heave as uneven deformation along the longitudinal direction. However, this approach is limited as it fails to account for the spatial variability of subgrade frost heave. Specifically, it overlooks lateral differential deformation induced by subgrade frost heave, and neglects its effect on the lateral deformation of the track and dynamic responses of the vehicle. This paper conducts a comprehensive analysis of the mapping relationship between lateral differential deformation of the subgrade and rail deformation, as well as its effects on the dynamic performance of vehicle-track system. Firstly, a refined finite element model of the ballastless track-subgrade system is developed to investigate the correlation between lateral differential deformation of the subgrade and rail deformation. Subsequently, a vehicle-track coupled dynamics model is established to assess the effects of sunny-shady slope ratio, amplitude, and wavelength of lateral frost heave on system dynamic responses. Finally, a control threshold for frost heave is proposed based on the system dynamic responses. The research results indicate that lateral differential deformation induced by subgrade frost heave significantly affects both vertical and lateral dynamic performance, reducing the riding comfort and even threatening driving safety. These findings provide theoretical support for operation and maintenance of ballastless tracks in seasonal frozen soil regions.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101479"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103062","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":"Big data-driven global modeling of cohesive soil compaction across conceptual and arbitrary energies through machine learning","authors":"Zia ur Rehman ,&nbsp;Usama Khalid ,&nbsp;Nauman Ijaz ,&nbsp;Zain Ijaz","doi":"10.1016/j.trgeo.2024.101470","DOIUrl":"10.1016/j.trgeo.2024.101470","url":null,"abstract":"<div><div>This study aims to propose an intelligent modeling framework for accurately predicting compaction characteristics of cohesive soils across compaction energy (CE) levels. A comprehensive database of 1001 observations falling within the theoretical bounds was created through experimental investigation encompassing sieve analysis, hydrometer analysis, liquid limit (<em>w_L</em>), plastic limit (<em>w_P</em>), specific gravity (<em>G_s</em>), and compaction tests on natural soil samples and literature review, encompassing diverse cohesive soils, CE levels, and compaction characteristics. Multiple machine learning techniques, including Extreme Gradient Boosting (XGBoost), Random Forest (RF), Gene Expression Programming (GEP), Multi Expression Programming (MEP), Artificial Neural Networks (ANN), and Multiple Linear Regression (MLR), were applied to develop predictive models. XGBoost demonstrated superior performance in predicting maximum dry density (<em>γ_dmax</em>) and optimum moisture content (<em>w_opt</em>) as evaluated by statistical indicators and external validation and compared with existing models in the literature. The proposed models effectively captured the influence of key parameters, highlighting the primary role of CE and <em>w_L</em>, the secondary role of plastic limit (<em>w_P</em>), the tertiary role of plasticity index (<em>I_P</em>) and fines activity (<em>A_F</em>), and the quaternary role of soil gradation in predicting and influencing the compaction characteristics of cohesive soils. This approach enables accurate global modeling of cohesive soil compaction across varying CE levels, providing a valuable tool for geotechnical engineers and researchers to determine compaction characteristics for a known CE level using basic soil properties used for soil classification.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101470"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102346","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":"Semi-analytical solution for the transient response of saturated viscoelastic porous media based on fractional Poynting-Thomson model","authors":"Yun Zhao ,&nbsp;Dandan Liu ,&nbsp;Daosheng Ling ,&nbsp;Xuemei Chen ,&nbsp;Zhanglong Chen ,&nbsp;Zhendong Shan","doi":"10.1016/j.trgeo.2024.101460","DOIUrl":"10.1016/j.trgeo.2024.101460","url":null,"abstract":"<div><div>The vibration and deformation of subgrade soil under the dynamic load is the main research topic in transportation geotechnics, yet existing studies rarely provide analytical solutions for viscoelastic transient response problems. Building on the Biot wave equations and considering the material’s compressibility, this work introduces the fractional Poynting-Thomson viscoelastic model to establish a transient response model for a saturated viscoelastic single-layer porous medium under typical boundary conditions. By integrating the state-space method, Laplace transform, and the elasticity-viscoelasticity correspondence principle, an analytical solution in the Laplace domain is derived. Employing the inverse Laplace transform, the time-domain solution to the original problem is obtained. The correctness of the solution is verified through comparison with existing solutions. Analysis of numerical examples indicates that the fractional time parameter <span><math><mrow><mi>α</mi><mi>f</mi></mrow></math></span> significantly influences the medium’s long-term response. The dash-pot viscosity coefficients have a pronounced effect on the hysteresis of <span><math><msub><mi>P</mi><mn>2</mn></msub></math></span> wave.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101460"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102477","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":"Soil-aggregate-cement mixtures for base pavement layers: A strength and stiffness characterization","authors":"André Lapa de Moraes Tavares ,&nbsp;Ana Paula Furlan ,&nbsp;Glauco Tulio Pessa Fabbri ,&nbsp;Jorge Ubirajara Pedreira Junior","doi":"10.1016/j.trgeo.2024.101456","DOIUrl":"10.1016/j.trgeo.2024.101456","url":null,"abstract":"<div><div>Pavements subjected to high volume load require a robust structure. In Brazil, cemented base layer is usually used instead of asphalt concrete thick layer due to cost issues. Soil-aggregate-cement (SAC) mixture is an alternative in pavement application, but the lack of design and dosage protocols hinders the understanding of the parameters influencing its mechanical behavior. This study presents a mechanical characterization of SAC mixtures in terms of strength (UCS and ITS) and stiffness (Mr), focusing on integrating the needs of pavement design to dosage purposes. For this, different SAC mixtures are produced, varying the soil-aggregate proportion (30:70 and 20:80) and cement content (3, 5 and 7 %). Mechanical properties were measured on cured mixtures at 0, 7 and 28 days and compared to structural responses of hypothetical pavements computed by mechanistic analysis. The results indicate a potential for using SAC mixtures in base layers due to their higher strength and stiffness. Predictive models relating ITS x UCS, Mr x UCS, and Mr x ITS with good statistical fit were proposed to assist researchers and engineers in selecting mixtures more adequate and durable for pavement applications, based on the concept of limiting the tensile stress acting on the cemented base course.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101456"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102479","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":"Development and verification of subgrade service performance test system considering the principal stress rotation","authors":"Zhenhao Bao ,&nbsp;Xinzhuang Cui ,&nbsp;Yefeng Du ,&nbsp;Qing Jin ,&nbsp;Jianwen Hao ,&nbsp;Tiancai Cao ,&nbsp;Xiangyang Li ,&nbsp;Xiaoning Zhang","doi":"10.1016/j.trgeo.2024.101474","DOIUrl":"10.1016/j.trgeo.2024.101474","url":null,"abstract":"<div><div>To accurately simulate the three-dimensional stress state and service performance of subgrade under long-term traffic loads, a subgrade service performance test system was developed. The test system consists of the loading system, a fully digital servo control system, and a data acquisition system. Based on the time-history characteristics of total stress components (three normal stresses and three shear stresses) of subgrade soil elements under traffic loads, the loading system was designed with four dynamic actuators and three static actuators. The loading system can simulate the rotation of principal stress axis in any subgrade soil elements through coordinated dynamic and static loading. The calculation method of load system was established to achieve the three-dimensional stress state of subgrade soil element under traffic loads. Furthermore, the model tests were conducted on the developed test system to verify the three-dimensional stress state of subgrade under the typical traffic loads, such as highways, railways and airports. Results shows that the actual output load deviation of each dynamic and static servo actuator is under 1%. The time-history curves of dynamic stress components and the attenuation of vertical dynamic stress are in good fit with the theoretical calculations. Besides, the vertical dynamic stress in the subgrade decreases progressively with depth, and the stress path of the soil element is approximately “heart-shaped”. The above validated results indicate that the test system accurately simulates the three-dimensional stress state of subgrade under different traffic loads. Therefore, the subgrade service performance test system developed in this study offers a new concept, method, and technology for investigating the evolution of subgrade service performance under long-term traffic loads.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101474"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102923","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":"Evolution of axial cumulative strain and micro-pore structure characteristics of solidified mud under cyclic loading","authors":"Liangjie Xu ,&nbsp;Rongjun Zhang ,&nbsp;Junjie Zheng ,&nbsp;Honglei Sun ,&nbsp;Yingchao Gao","doi":"10.1016/j.trgeo.2024.101454","DOIUrl":"10.1016/j.trgeo.2024.101454","url":null,"abstract":"<div><div>Embankments and foundation geotechnical structures are frequently subjected to long-term cyclic loading due to traffic during their service life. Excessive cumulative deformation can lead to pavement cracking and uneven settlement of the subgrade. This study conducts a series of dynamic triaxial tests to analyze the effects of the number of cycles (<em>N</em>), effective confining pressure (<em>σ</em>_c), and dynamic stress amplitude (<em>σ</em>_d) on the axial cumulative strain (<em>ε</em>_d) characteristics of solidified mud samples. Additionally, it investigates the evolution model of <em>ε</em>_d of solidified mud and establishes a predictive model for this strain. In conjunction with the NMR tests, this research further investigates the effects of <em>σ</em>_c and <em>σ</em>_d on the pore distribution of solidified mud after loading. Ultimately, the correlation between microscopic pore structure indicators and <em>ε</em>_d is elucidated. The results indicate that the <em>ε</em>_d behavior of solidified mud under cyclic loading exhibits characteristics of plastic shakedown. Furthermore, the exponential hyperbolic function model more accurately characterizes the relationship between <em>ε</em>_d of the samples and <em>N</em>. Before and after cyclic loading, the micropores of the samples accounted for over 95 % of the total pore volume, predominantly concentrated in the radius range of <em>r</em> &lt; 0.3 μm. A correlation exists between the average pore size of the sample and <em>ε</em>_d, which is primarily influenced by <em>σ</em>_d and <em>σ</em>_c.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101454"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102926","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":"Influence of Collapsible Shape of Loess Foundation on High-Speed Railway Subgrade under Train Vibration Loading","authors":"Zejie Li ,&nbsp;Xiaolin Weng ,&nbsp;Shuaijie Guo ,&nbsp;Muhan Yan ,&nbsp;Chunli Wang","doi":"10.1016/j.trgeo.2024.101414","DOIUrl":"10.1016/j.trgeo.2024.101414","url":null,"abstract":"<div><div>Collapsible loess has special sensitivity to water, and its engineering mechanical properties deteriorate significantly after immersion in water, causing the foundation to sink, which seriously threatens the safety and stability of the high-speed railway subgrade under train vibration loading. Studying this effect is essential to prevent and control the disasters of high-speed railway subgrades. In this study, a model with the function of simulating foundation settlement is established to conduct disaster testing of high railway subgrade under train vibration loading. The results indicate that when different foundation shapes are settled, the surface of the subgrade under static load is gradually settled in a short time, and the settlement value of the track surface is lower than that of the corresponding subgrade surface. Under train vibration load, the maximum dynamic settlement occurs at the middle of the subgrade slope, which is smaller than the corresponding settlement under static load. The number of stabilization times required from different monitoring positions on the subgrade surface is different under different excitation forces, and the number of stabilization times required is more in the middle of the subgrade slope and the slope shoulder. The influence of train speed on subgrade has a critical respond speed that increases with increasing vibration times. There are horizontal, vertical and 45° angle cracks in the middle of subgrade slope. It is qualitatively assessed that the slope of the high-speed railway subgrade in the collapsible loess area is unstable under the effect of train load. The data and rules provided in this document provide some reference values for the construction of a high-speed railway in the collapsible loess area.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101414"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102930","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":"Settlement prediction of a high embankment based on non-linear regression and neural network algorithm","authors":"Enhui Yang ,&nbsp;Kai Wang ,&nbsp;Jinhong He ,&nbsp;Kaiwen Liu ,&nbsp;Junxin Wang ,&nbsp;Haopeng Zhang ,&nbsp;Yanjun Qiu","doi":"10.1016/j.trgeo.2024.101443","DOIUrl":"10.1016/j.trgeo.2024.101443","url":null,"abstract":"<div><div>This study reports in-situ measured data from single-point settlement meters buried in layers at the road shoulders and the center of a high embankment respectively. Based on the measured data, the nonlinear fitting models and neural network algorithm were proposed to establish the method of settlement prediction, and the mean absolute percentage error (MAPE) and mean square errors (MSE) were used to evaluate the accuracy of the settlement prediction model. The results show that the MAPE value of the exponential curve prediction model is less than 10%, and the MAPE value of the hyperbolic model is between 10% and 20%, and the MAPE value of the logarithmic model is greater than 20%, which shows that the exponential curve model of the three nonlinear fitting models has the highest accuracy. After establishing the back propagation (BP) neural network model, the settlement data of the four monitoring points were learned and trained, and the prediction accuracy of the two BP neural network prediction models and the exponential curve prediction model were compared. The model fitting coefficient of <em>R</em>² of BP neural network were both greater than 0.99, and the MSE and MAPE were less than 1%. In addition, the multi-step rolling BP neural network prediction model has the highest prediction accuracy, followed by the BP neural network prediction model based on influencing factors while the exponential curve prediction model has the worst performance and weak practicability. This research can provide new inspiration for embankment settlement prediction and give technical support to monitor the disaster of high embankment.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101443"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102460","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":"A novel thermodynamic constitutive model of coarse-grained soils considering the particle breakage","authors":"Bing Bai ,&nbsp;Bixia Zhang ,&nbsp;Hongju Chen ,&nbsp;Peipei Chen","doi":"10.1016/j.trgeo.2024.101462","DOIUrl":"10.1016/j.trgeo.2024.101462","url":null,"abstract":"<div><div>The granular thermodynamics was extended to the solid–liquid system, developing a constitutive model for coarse-grained soils (CGS). The model combined the physical conservation equation, thermodynamic differential equation and entropy increase equation to construct a new elastic potential energy density function (EDF). The dissipation energy caused by particle breakage and deformation was associated with macroscopic mechanical behavior using dissipation system, migration coefficients, and particle breakage function. The particle breakage function was applied to convey the change in particle gradation, as well as the critical-state stress ratio. The model integrated the concept of critical-state line drift, revealing the attenuation of shear stiffness/strength due to dilatancy/shrinkage. Test results of Toyoura sand (TS), crushed cambric slate (CCS), and calcareous sand (CS) were selected to validate the proposed model, manifesting a great advantage and high prediction accuracy.</div></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":"50 ","pages":"Article 101462"},"PeriodicalIF":4.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102480","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}