Computers and Geotechnics最新文献

{"title":"Peridynamic modeling and analysis of interfacial crack propagation by hydraulic fracturing in layered shale","authors":"Yingru Lu ,&nbsp;Zhuang Cai ,&nbsp;Dan Huang ,&nbsp;Xuehao Yao ,&nbsp;Qipeng Ma ,&nbsp;Ding Chen","doi":"10.1016/j.compgeo.2025.107280","DOIUrl":"10.1016/j.compgeo.2025.107280","url":null,"abstract":"<div><div>Hydraulic fractures at the bedding interface in layered shale will give rise to various phenomena including penetration, diversion and offset which significantly influence the production of shale gas exploitation. It is persistent challenge to simulate the uncertain fracture propagation paths induced by hydraulic fracturing when encountering interfaces. In this study, an alternative peridynamic model is proposed to investigate the interfacial crack propagation by hydraulic fracturing in layered shale. The water pressure loading process is described through equivalently transforming the water pressure applied on fracture surfaces into the water pressure density on broken bonds. The interface model and its cracking criterion are derived by employing bilinear cohesive zone model, which effectively characterize the interactions between rocks with different properties on different sides of the bedding plane. The proposed model is validated through comparison with experimental results, and then is further employed to investigate the complex hydraulic fracture propagation near bedding interfaces. It is found that smaller angle between hydraulic fracturing direction and bedding may lead to better fracturing effects and higher gas extraction in layered shale.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107280"},"PeriodicalIF":5.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838816","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 new integrated model of confinement-sensitive damage and bi-mechanism plasticity for rock-like materials","authors":"Xiaoli Wei ,&nbsp;Xiaodan Ren","doi":"10.1016/j.compgeo.2025.107255","DOIUrl":"10.1016/j.compgeo.2025.107255","url":null,"abstract":"<div><div>An integrated constitutive model has been developed for rock-like materials, incorporating confinement-sensitive damage and bi-mechanism plasticity. The model aims to improve the capability of the conventional damage model in depicting the strengthening and brittle-to-ductile transitions that occur under both active and passive confinement conditions. A thermodynamic analysis of energy transformation and dissipation, considering both damage and plasticity, underpins the model’s development. The model, rooted in damage-plastic theory, has been divided into two sub-models: (1) Confinement-Sensitive Model: This sub-model addresses the strengthening and ductility enhancements due to active confinement stress. It effectively captures the mechanical responses of rock-like materials under various levels of active confining stresses. (2) Endochronic Dilatancy Model: Based on endochronic theory, a separate dilatancy strain model is proposed, which effectively facilitates the interplay between lateral dilatancy and the growth of passive confining stress. Both sub-models, as well as the integrated model, have undergone validation using experimental data, including uniaxial tests, cyclic loading tests, actively confined tests, and passively confined tests of rock-like materials. These validations confirm the model’s accuracy and reliability in predicting the mechanical behavior of rock-like materials under complex loading conditions.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107255"},"PeriodicalIF":5.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838815","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":"Stabilized reduced-integration u-w coupled element for 3D dynamic modelling of saturated soils","authors":"Zexu Fan ,&nbsp;Yong Yuan ,&nbsp;Roberto Cudmani ,&nbsp;Stylianos Chrisopoulos","doi":"10.1016/j.compgeo.2025.107258","DOIUrl":"10.1016/j.compgeo.2025.107258","url":null,"abstract":"<div><div>Three-dimensional numerical analysis is crucial in revealing the complex dynamic behaviour of saturated soil under multidirectional loadings. In this study, the derivation and implementation of a stabilized reduced-integration coupled element based on the <strong><em>u</em></strong>-<strong><em>w</em></strong> formulated Biot theory are presented. The key improvement of this element is the modification of non-constant solid and fluid strains based on the enhanced strain method (ESM) and assumed strain method (ASM), which ensures its stability in the incompressible-impermeable limit while maintaining an efficient bilinear interpolation scheme. Additionally, a mixed integration scheme is also employed to reduce the computational cost. The performance of the proposed element is evaluated using two benchmark problems, and comparisons with analytical methods and other coupled elements demonstrate its superiority in terms of accuracy, stability, and efficiency. The applicability of the element in more complex geotechnical scenarios is further demonstrated by investigating soil liquefaction under uni- and bi- directional shakings. The results demonstrate that both the extent and severity of field liquefaction are significantly greater under bidirectional loadings compared to those under Airas-equivalent unidirectional loadings. This highlights the necessity of three-dimensional analyses for problems involving multidirectional loading conditions, as the negligence of out-of-plane loadings and strains in plane-strain analyses could result in unsafe engineering designs.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107258"},"PeriodicalIF":5.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839509","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":"Numerical modelling of displacements induced by rainfall infiltration in a clayey soil slope: The Miscano (Southern Italy) case study","authors":"Ali Tawalo ,&nbsp;Gaetano Falcone ,&nbsp;Marianna Pirone ,&nbsp;Anna d’Onofrio ,&nbsp;Gianfranco Urciuoli","doi":"10.1016/j.compgeo.2025.107267","DOIUrl":"10.1016/j.compgeo.2025.107267","url":null,"abstract":"<div><div>Predicting cumulative surface slope displacements induced by rainfall infiltration is crucial for accurately assessing the risks to potentially affected infrastructure. In this paper the numerical modelling of the case history of Miscano slope is presented. Plaxis 2D code has been used adopting two constitutive laws: the linear elasto-plastic model (Mohr-Coulomb, MC) and the Hardening Soil with small strain stiffness (HSsmall). The aim is to test the suitability of these constitutive laws in predicting the hydro-mechanical behaviour of clayey soil slope. Based on long-term field measurements, the parameters of MC and HSsmall have been determined by back analysing the first-year field measurements in terms of cumulative surficial horizontal displacements and pore water pressure. Subsequently, the numerical models have been validated against the analogous field measurements collected from the second year. The numerical models predict with a good agreement the field measurements for both years. In terms of cumulative surficial horizontal displacements, the HSsmall underestimates the field measurements by 21.2% at the end of the first year, while that based on MC exhibits a 32.8% overestimation. Moreover, the initialization procedure clearly affects the cumulative surficial horizontal displacements results obtained with both the HSsmall and MC models for the second year. In fact, the best results have been achieved when the second-year net rainfall have been applied starting from the initial phase used to generate the lithostatic stress state.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107267"},"PeriodicalIF":5.3,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834563","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":"Development of a p-multiplier for laterally loaded single batter piles in sand based on simple upper bound analysis","authors":"Xiaodong Shao ,&nbsp;Meijuan Xu ,&nbsp;Guoxiong Mei ,&nbsp;M. Hesham El Naggar ,&nbsp;Wenbing Wu","doi":"10.1016/j.compgeo.2025.107268","DOIUrl":"10.1016/j.compgeo.2025.107268","url":null,"abstract":"<div><div>Batter piles are prevalently found in foundation pits, bridges, transmission towers, and wharf structures, serving to withstand lateral loads. Nevertheless, the investigation and analysis methods related to batter piles remain scarce. Considering the limitations of existing <em>p</em>-multipliers for batter piles, this research develops an enhanced <em>p</em>-multiplier rooted in the soil failure mechanisms and upper bound analysis. The proposed <em>p</em>-multiplier is initially derived from simplified 2D soil failure modes, and then further enhanced based on extended 3D soil failure modes, which effectively reflect the 3D effects of soil-pile interaction. Comparative analyses demonstrate that the proposed <em>p</em>-multiplier well captures the influence of pile inclination and soil internal friction angle on soil resistance, showing superiority over previous studies. Moreover, incorporating the proposed <em>p</em>-multiplier with <span><math><mrow><mi>p</mi><mo>-</mo><mi>y</mi></mrow></math></span> curves allows rapid and fair assessment on the lateral behavior of single batter piles in sand, and the reliability is validated by two reported cases of batter piles. However, due to the ignorance of shaft friction and lateral component of axial displacement of batter pile, the proposed method is recommended for small batter angles. In the range of <span><math><mrow><mo>-</mo><msup><mn>15</mn><mo>°</mo></msup><mspace></mspace><msup><mn>15</mn><mo>°</mo></msup></mrow></math></span>, the proposed method is adequate as verified by the experimental results.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107268"},"PeriodicalIF":5.3,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834562","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":"Probabilistic investigation of the whole process of backward erosion piping for a two-layered levee in spatially variable soils","authors":"Wei Xiong ,&nbsp;Shui-Hua Jiang ,&nbsp;Jian-Hong Wan ,&nbsp;Chuang-Bing Zhou ,&nbsp;Liang Gao","doi":"10.1016/j.compgeo.2025.107244","DOIUrl":"10.1016/j.compgeo.2025.107244","url":null,"abstract":"<div><div>Backward erosion piping (BEP) at the base of levees is one of the main causes of levee failure. BEP typically occurs in two-layer levees systems and involves multiple stages throughout its development. While random field methods have been widely applied to model soil spatial variability, existing approaches predominantly focus on single-layer soil structures. Analyzing the impact of only single-layer spatial variability on piping development, especially during the initial uplift stage, may not adequately capture the complexities of actual conditions. To address this, this paper proposes a general framework that can be used to generate both single-layer or two-layer random field models. The Karhunen-Loève (K-L) series expansion method has been refined to generate two independent random fields, thereby facilitating the characterization of spatial variability in both the upper and lower soil layers. Monte Carlo Simulation (MCS) is employed to generate realizations of the random fields, which are then incorporated into numerical models to evaluate the effects of spatial variability on the whole process of BEP. The results show that single layer models tend to overestimate or underestimate the probability of piping initiation. The stage of backward erosion is influenced by the spatial variability of the upper and lower layered soil parameters. The single-layer random field model has a tendency to overestimate the probability of slope failure. In addition, the results of several stability analyses under the effects of extreme rainfall and upstream water level rise show that the probability of slope failure increases significantly during this process.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107244"},"PeriodicalIF":5.3,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834561","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 time-dependent microplane model for deformation and fracturing of brittle rock","authors":"Yang Yuan ,&nbsp;Tao Xu ,&nbsp;Philip G. Meredith ,&nbsp;Thomas M. Mitchell ,&nbsp;Michael J. Heap ,&nbsp;Zhen Heng","doi":"10.1016/j.compgeo.2025.107278","DOIUrl":"10.1016/j.compgeo.2025.107278","url":null,"abstract":"<div><div>A more comprehensive understanding of the progressive, time-dependent deformation and fracturing of brittle rock is crucial for assessing the long-term integrity of rock masses surrounding engineering structures. In this study, we propose a three-dimensional numerical model that integrates the microplane model and subcritical crack growth to investigate the progressive, time-dependent deformation and fracturing of brittle rock. The model incorporates subcritical crack growth and time-dependent damage evolution constitutive laws into the microplanes. By following the trend of subcritical crack growth observed in previous studies, the model accurately captures the time-dependent propagation of virtual cracks. The cooperative interaction between strain and damage evolution on the microplanes ultimately leads to localized material degeneration over extended time. Moreover, this model effectively characterizes the temporal and spatial distribution of damaged elements during time-dependent deformation and fracturing of brittle rock. The numerical simulations successfully replicate phenomena observed in laboratory experiments performed on brittle rock. Specifically, they demonstrate how different stress levels influence creep strain rate and time-to-failure. Additionally, the simulations reveal that the microscale interaction of potential cracks (microplanes) can effectively describe the complex macroscopic time-dependent behavior of brittle rock. As a result, it becomes possible to predict time-to-failure and rupture patterns using the calibrated model based on laboratory tests. The proposed numerical model holds the potential to be further extended for predicting the long-term stability of larger rock masses.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107278"},"PeriodicalIF":5.3,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143830141","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":"Microscopic insights into local scour around a vertical circular pile under steady current: Coupled LES-CGDEM simulations","authors":"Peiyun Zhang ,&nbsp;Linlong Mu ,&nbsp;Maosong Huang ,&nbsp;Xiaoqiang Gu","doi":"10.1016/j.compgeo.2025.107248","DOIUrl":"10.1016/j.compgeo.2025.107248","url":null,"abstract":"<div><div>Local scour around pile reduces its bearing capacity, jeopardizing the superstructure safety. Previous studies on this have primarily been based on continuum mechanics. Given that the scour process involves interactions between fluid-particle and particle–particle, the methods based on the continuum mechanics struggle to adequately account for collision effects between particles, while also failing to capture the migration process of soil particles. This study employs the coupled large eddy simulation (LES) and coarse-grained discrete element method (CGDEM) to conduct a detailed simulation of the local scour evolution around a vertical circular pile under unidirectional steady flow from a microscopic perspective, in which three flow intensities are considered in the simulation. It is found that as the flow intensity increases, the difference in scour depth upstream and downstream of the pile diminishes. Initially, the scour upstream of the pile is jointly controlled by scouring at the pile toe and soil erosion on the top slope surface, while it is dominated by pile toe scour in the later stage. The pile toe scour is associated with the multiple horseshoe vortices (HVs) upstream of the pile; the “NASA wall-mounted hump” downstream of the pile restricts further migration of the deposited sediment; an “unstable particles cluster” is formed on the sides of the pile, creating a preferential scour path. Particles upstream of the pile undergo a sequence of slow motion upstream, complex flow around the pile, accelerated movement downstream, and deposition, while particles on the sides of the pile experience slowly settling, accelerated motion, and deposition. The work further deepens the understanding of scour evolution mechanism.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107248"},"PeriodicalIF":5.3,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143825707","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":"Relationship between internal void ratio and morphological parameters of carbonate sand","authors":"Yan Qian ,&nbsp;Yuedong Wu ,&nbsp;Yuzhe Ren ,&nbsp;Yi Pik Cheng ,&nbsp;Abraham C.F. Chiu ,&nbsp;Jian Liu ,&nbsp;Tiange Ge","doi":"10.1016/j.compgeo.2025.107266","DOIUrl":"10.1016/j.compgeo.2025.107266","url":null,"abstract":"<div><div>With the advancement of marine geotechnical engineering, increasing attention has been focused on the influence of the particle morphology and internal voids of carbonate sand (CS) on its engineering properties. The purpose of this study was to explore the relationship between the internal void ratio and particle morphological parameters using X-ray computed tomography (CT) scanning and three-dimensional (3D) reconstruction of CS particles with a particle size of 0.5–1 mm. A unique particle-tray mould was designed using 3D printing to avoid over segmentation of images of the watershed segmentation algorithm during 3D reconstruction and to guarantee scanning accuracy. The mould was made of an acrylonitrile butadiene styrene (ABS) resin with a density that differed significantly from that of the CS, which also facilitated threshold segmentation in 3D reconstruction. In addition, an ambient occlusion algorithm was adopted to compute the surface-connected voids and surface recesses of the CS. Based on the internal void characteristics, CS particles were classified into three types: solid, distributed, and spiral. A random selection of 100 particles from each type was analysed to determine the internal void ratio and morphological parameters. The results indicated that spiral-type CS particles exhibited the highest internal void ratio, followed by distributed-type CS particles, whereas solid-type CS particles had the lowest internal void ratio. Distributed-type CS particles appeared in plate-like or flattened forms, spiral-type CS particles were elongated, and solid-type CS particles displayed significant variability in their shape distribution. Furthermore, no significant correlation was observed between the internal void ratio and particle morphological parameters such as elongation, flatness, or aspect ratio. However, a strong correlation was observed between the internal void ratio and sphericity, convexity, and <em>3D</em> shape angularity group indicator (<em>SAGI</em>). Both the sphericity and convexity decreased with increasing internal void ratio, whereas <em>3D-SAGI</em> increased as the internal void ratio increased. Notably, the internal void ratio, sphericity, convexity, and <em>3D-SAGI</em> of distributed-type CS particles were significantly influenced by the extent of particle surface smoothing, whereas solid- and spiral-type CS particles were not significantly affected. This study can provide the ranges of CS particle morphology parameters for discrete element method modelling and offer convenience for the calibration of void ratios in the future.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107266"},"PeriodicalIF":5.3,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823260","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":"Study on the influence of 3D pre-existing joint on rockfall fragmentation during impact based on discrete element method","authors":"Yongjie Zhao ,&nbsp;Yong Wu ,&nbsp;Yingpeng Wang ,&nbsp;Siming He ,&nbsp;Xinpo Li ,&nbsp;Lei Zhu ,&nbsp;Zhangqing Wang","doi":"10.1016/j.compgeo.2025.107270","DOIUrl":"10.1016/j.compgeo.2025.107270","url":null,"abstract":"<div><div>Rockfalls pose significant threats to human society as one of the three major geological hazards. Numerous joints developed internally during their geological formation, leading to their fragmentation in motion and affecting trajectory and accumulation range, thereby increasing the hazard uncertainty. There are few studies on the fragmentation of jointed rockfalls, and only some focus on the influence of terrain, impact angle, and material properties on rockfall failure with continuous mechanics and extended finite element methods. However, very few analyses of the fragmentation mechanism of 3D jointed rockfall are from the perspective of discontinuous medium mechanics. Based on the indoor experiments to acquire the calculation parameters and consider the fracture character, we use the Discrete Element Method (DEM) to establish an impact model of rockfall with pre-existing joints to address these. We conduct numerical impact tests on samples containing joints of varying lengths, inclinations, thicknesses, and positions. By proposing the volume fragmentation ratio and number of main fragments and calculating them, monitoring changes in crack propagation events, acoustic emission events, impact force, and energy, the study investigates the specific effects of joints on the impact fragmentation of samples. The results indicate that the Discrete Element Method with parameters corrected by fracture tests can realistically simulate the three-dimensional fragmentation of jointed rockfall under actual conditions, solving the problem of stress concentration at the crack tip in Finite Element analyses. The geometric parameters and spatial position of the pre-existing joint largely determine the fragmentation of rockfall and the shape of blocks after disintegration, significantly impacting the impact force and the kinetic energy of the bouncing stone. Among them, joint inclination and length greatly influence the overall fragmentation of rockfall. In contrast, the position of a side or centered joint notably influences the micro-cracks and local damage on the contact area of rockfall, and joint thickness close to the maximum radium of calculation particle affects fragmentation significantly.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"184 ","pages":"Article 107270"},"PeriodicalIF":5.3,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823257","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}