International Journal for Numerical and Analytical Methods in Geomechanics最新文献

{"title":"Revisiting Slope Stability Analysis Using Tension-Truncated Power-Law Yield Criterion","authors":"R. Ganesh","doi":"10.1002/nag.70050","DOIUrl":"10.1002/nag.70050","url":null,"abstract":"<div>\u0000 \u0000 <p>Existing studies on slope stability have mostly been performed using the linear yield criterion without accounting for the true tensile strength of soils. However, soils generally exhibit marked nonlinearity in shear strength and practically negligible tensile strengths compared to theoretical estimates from the yield function. This research revisits the finite slope stability problem under plane strain conditions by employing a power-law (PL) yield criterion with a tensile strength cut-off. Here, a PL yield criterion is truncated with a circular stress envelope that tangentially encompasses the nonlinear PL yield function for a given uniaxial tensile strength. Unlike earlier studies, this research proposes a new horizontal slice-based rotational failure mechanism, and the solutions are rigorously determined within the upper bound plasticity theory by fully accounting for the variable nature of friction angles along the slip surface in a nonlinear bonded medium. The effect of pore-water pressure on the results is also investigated. The study shows that additional nonlinearity in the yield function, due to the tensile strength cut-off, can significantly influence the outcome of the stability assessment. The results of this study compared reasonably well with findings in the existing literature. The novelty of this study lies in presenting a new slice-based numerical solution procedure for investigating slope stability with variable friction angles and demonstrating the significant impact of tensile strength cut-off on stability assessment outcomes in nonlinear bonded soils.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3931-3943"},"PeriodicalIF":3.6,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144906035","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":"Stress and Displacement Fields of Elliptical Tunnels in Fractional Order Viscoelastic Transversely Isotropic Medium","authors":"Zhi Yong Ai,&nbsp;Yi Xuan Pan,&nbsp;Zi Kun Ye,&nbsp;Da Shan Wang","doi":"10.1002/nag.70049","DOIUrl":"10.1002/nag.70049","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents the fractional viscoelastic solutions of transversely isotropic surrounding rock for deeply buried elliptical tunnels by using the Fourier series fitting, complex function method, and conformal transformation technique. The elastic–viscoelastic correspondence principle and the Laplace transformation technique are introduced to derive the solutions, and the accuracy of the theory in this paper is verified by comparing with that in existing literature. Numerical examples are designed to analyze the accuracy of the series fitting terms, the influence of the transversely isotropic parameters, the shape of the tunnel, and the lateral pressure coefficient on the mechanical response of the surrounding rock of the deeply-buried tunnel, providing useful suggestions for the practice of tunnel engineering.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3917-3930"},"PeriodicalIF":3.6,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144906036","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 Unified Treatment to 1D Consolidation of Unsaturated Soils","authors":"Lianghua Jiang,&nbsp;Aifang Qin,&nbsp;Qingqing Zheng","doi":"10.1002/nag.70056","DOIUrl":"10.1002/nag.70056","url":null,"abstract":"<div>\u0000 \u0000 <p>The initial conditions, boundary conditions, and external loading are the key factors influencing consolidation characteristics in the one-dimensional (1D) consolidation of unsaturated soils. In previous studies, it was necessary to establish different consolidation models for different conditions, which complicates the solution. To effectively unify these models, this paper establishes a generalized analytical model for 1D consolidation of unsaturated soils under a unified boundary condition. The model also considers the depth-dependent initial stress and time-dependent load. By employing the Laplace integral transform and Crump's numerical inverse transform, semi-analytical solutions for excess pore pressures (EPPs) and average degree of consolidation in the time domain are derived. The accuracy of the obtained solution is verified by comparison with existing solutions under fully permeable boundaries and numerical results under semi-permeable boundaries. Finally, the results under exponential loading show that, by appropriately setting boundary parameters, the unified boundary can be used to simulate arbitrary boundaries with different permeability characteristics, ranging from impermeable to permeable boundaries, thereby demonstrating the generality of the semi-analytical solution. Under different initial conditions, the time required for EPPs dissipation and for settlement stabilization remains the same, determined by the maximum initial EPP. Additionally, the boundary parameters exhibit distinct effects on the degree of consolidation, indicating that the geometric characteristics and permeability of the soil layer and horizontal drainage layer influence soil consolidation differently. Investigating these effects will provide important guidance for improving the consolidation period of unsaturated soils.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3970-3982"},"PeriodicalIF":3.6,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144906033","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 DEM Parameter Calibration Method Based on BP Neural Network and Genetic Algorithm","authors":"Yaodong Ni,&nbsp;Xianlun Leng,&nbsp;Ruirui Wang,&nbsp;Fengmin Xia,&nbsp;Feng Wang,&nbsp;Chengtang Wang","doi":"10.1002/nag.70043","DOIUrl":"10.1002/nag.70043","url":null,"abstract":"<div>\u0000 \u0000 <p>The discrete element method (DEM) represents a crucial numerical simulation approach for investigating the internal damage mechanisms of rocks. However, in order to construct an accurate simulation model, it is essential to set the correct microscopic parameters. Consequently, parameter calibration has emerged as a key area of focus within this field. The existing parameter calibration methods have yielded satisfactory results; however, there is still scope for further improvement and advancement. In this study, a novel intelligent parameter calibration method has been proposed, combining the benefits of the BP neural network and genetic algorithm (GA). The method constructs a parameter relationship model with micro-parameters as inputs and macro-parameters as outputs. Then GA is employed to invert the relationship model to calculate the parameter calibration. The results demonstrate that the method is capable of calculating a set of high-precision micro-parameter solutions in a mere 2 min, with the majority of its errors being within 5%.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3897-3916"},"PeriodicalIF":3.6,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144906038","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":"Kinematic Limit Analysis of Roof Stability for Elliptical Tunnels in Rock Masses","authors":"Tae-Won Seo,&nbsp;Dowon Park","doi":"10.1002/nag.70053","DOIUrl":"10.1002/nag.70053","url":null,"abstract":"<p>Noncircular cross-sections are commonly encountered in engineering practice; however, primary attempts to analyze roof stability have focused on circular and rectangular configurations. This study investigates the roof stability of elliptical tunnels with varying aspect ratios, employing two semi-analytical approaches: piecewise linear and continuous analytical failure mechanisms. The former directly incorporates the generalized Hoek–Brown criterion, whereas the latter requires approximating its shear strength envelope through regression analysis. Notably, when the regression analysis achieved sufficient accuracy, the two approaches produced computationally consistent results (&lt;1% difference), including closely aligned failure surface geometries. The findings demonstrate that the roof stability of elliptical tunnels—evaluated in terms of stability number, factor of safety, and support pressure—varies significantly from that of standard cross-sections. Considering the self-weight of a detached rock block as the primary cause of roof collapse, elliptical tunnels with a small horizontal-to-vertical axis ratio (i.e., a vertically elongated major axis) exhibit enhanced stability compared to circular tunnels. This improved stability is attributed to increased confining stress in the roof region and a reduced collapse block size. Furthermore, a comparative analysis encompassing various practical tunnel cross-sections, including horseshoe and mining configurations, provides a comprehensive understanding of roof stability across diverse geometric profiles.</p>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3880-3896"},"PeriodicalIF":3.6,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/nag.70053","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144900115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Settlement Analysis of a Large Pile Group Supporting an LNG Storage Tank","authors":"Wuyu Zhang,&nbsp;Jikai Shi,&nbsp;Guoming Lin,&nbsp;Cheng Lin","doi":"10.1002/nag.70052","DOIUrl":"10.1002/nag.70052","url":null,"abstract":"<div>\u0000 \u0000 <p>Liquefied natural gas (LNG) storage tanks are often supported by large pile groups (&gt;100 piles). The design of such foundations is generally governed by settlement rather than bearing capacity. However, minimal information is available regarding the settlement performance of the LNG tank foundations. This article first presents a comprehensive program of the settlement analysis for an LNG tank foundation comprising 1600 driven concrete piles. The field test program, including site characterization, pile load tests, and hydrotest, was performed. The test data were used to calibrate and assess four different methods for group settlement calculation, including the equivalent raft method, equivalent pier and equivalent raft method, nonlinear interaction factor method, and 3D continuum finite element method. The parametric analyses were further conducted using these methods to evaluate the effects of different factors on the group settlement. This study highlights (1) the importance of considering the deep soil condition (below pile toe to a depth of 1.5 times group diameter), which contributes to 78%–89% of the total settlement, (2) the drastic difference in load transfer mechanisms between central piles and perimeter piles, and (3) the need for considering the self-weight of tanks in the settlement analysis.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3858-3879"},"PeriodicalIF":3.6,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144900117","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 Multi-Resolution Material Point Method Based on Penalty Formulation","authors":"Kai-Yuan He,&nbsp;Yin-Fu Jin,&nbsp;Xi-Wen Zhou,&nbsp;Zhen-Yu Yin,&nbsp;Xiangsheng Chen","doi":"10.1002/nag.70048","DOIUrl":"10.1002/nag.70048","url":null,"abstract":"<div>\u0000 \u0000 <p>The computational cost of the material point method (MPM) primarily arises from the information transfer between material points and the grid. In some high-precision simulations, using a globally high-resolution background grid and sufficient material particles per cell (PPC) can severely reduce computational efficiency. Many problems in geomechanics focus on local large deformations or failures, making global refinement an unsuitable choice. To address these issues, this study introduces a novel multi-resolution material point method (MR-MPM). This approach constructs MPM models at different resolution levels using bounded material points that connect these levels. By enforcing positional deviations of bounded material points through the penalty function, the high-resolution and low-resolution models are linked together, achieving local refinement. During implementation, it is only necessary to map the penalty forces of bounded material points to the corresponding level background grids. No other modifications are required, and no local equations need to be solved. Furthermore, this study derives a penalty factor value that eliminates the influence of material elastic modulus and background grid spacing, effectively simplifying parameter adjustment. Finally, a series of classical numerical examples, including elastic and elasto-plastic cases, are used to verify the algorithm's accuracy, convergence, and efficiency. The results predicted by MR-MPM closely match finite element reference solutions and demonstrate good convergence. Compared to globally refined MPM, MR-MPM significantly improves computational efficiency. These features give MR-MPM great potential in large-scale simulation analyses involving large local deformation, such as tunnel excavation, submarine landslides, and similar events.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3839-3857"},"PeriodicalIF":3.6,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144900119","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":"Displacement-Dependent Active Earth Pressure on Retaining Wall in Cohesive Soil: DEM Simulation and Theoretical Analysis","authors":"Wei Ci,&nbsp;Kai Cui,&nbsp;Shangchuan Yang","doi":"10.1002/nag.70047","DOIUrl":"10.1002/nag.70047","url":null,"abstract":"<div>\u0000 \u0000 <p>Accurately assessing active earth pressure is crucial for the design and stability analysis of retaining structures in geotechnical engineering. This study investigates the displacement-dependent active earth pressure on retaining walls in cohesive soil under three modes of motion, including translation, rotation around the wall bottom, and rotation around the wall top, using the discrete element method (DEM) and theoretical analysis. The resultant force on the retaining wall, the mobilized wall-soil friction angle, and the principal stress direction are analyzed using DEM. Based on the DEM numerical results of this study, the displacement-dependent active earth pressure of cohesive soil in three movement modes is calculated using the horizontal flat-element method and the arched differential element method. The proposed solutions accurately capture the distribution of displacement-dependent active earth pressure of the three movement modes. Furthermore, the analytical solutions show good agreement with the DEM simulation results under different movement modes. The validity of the proposed solution has been confirmed through comparisons with experimental data and alternative solutions, providing a valuable reference for retaining wall design.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3822-3838"},"PeriodicalIF":3.6,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144900118","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":"Analytical Solution for the Transient Response of a One-Dimensional Viscoelastic Unsaturated Porous Medium","authors":"Yun Zhao,&nbsp;Ya-bo Shi,&nbsp;Zhang-long Chen,&nbsp;Jing Hu,&nbsp;Ping Xu,&nbsp;Zhen-dong Shan","doi":"10.1002/nag.70046","DOIUrl":"10.1002/nag.70046","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 &lt;p&gt;The Laplace transform method is widely used for solving viscoelastic dynamic problems. However, the numerical inversion process of this method suffers from instability, especially for long-duration response issues. Moreover, the solutions obtained via the Laplace transform method are often semi-analytical. In this study, addressing the one-dimensional transient response problem of unsaturated viscoelastic porous media, an analytical solution is proposed based on the finite Fourier transform method. First, leveraging the symmetry of the problem, the solution of a typical stress-displacement boundary problem is transformed into the solution of a stress-stress boundary problem. Second, by applying finite Fourier sine and cosine transforms, the original second-order viscoelastic partial differential governing equations are transformed into a system of first-order ordinary differential equations in the frequency domain for solution, and the analytical solution in the frequency domain is provided using the state-space method. Finally, the finite Fourier inverse transform method is used to present the analytical solution in series form for the original problem in the time domain. The accuracy of the proposed method is validated through comparison with the Laplace solution method and existing elastic solution results. The analysis of numerical examples shows that the damping coefficient &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;η&lt;/mi&gt;\u0000 &lt;annotation&gt;$eta $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; has a significant influence on the &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${P}_3$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; wave velocity. As the damping coefficient &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;η&lt;/mi&gt;\u0000 &lt;annotation&gt;$eta $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; increases, the wave phase generally tends to decrease. With the increase in saturation &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;S&lt;/mi&gt;\u0000 &lt;mi&gt;w&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${S}_w$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, the velocities of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${P}_1$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${P}_2$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; waves increase, while the velocity of the &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 ","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3809-3821"},"PeriodicalIF":3.6,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144900121","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":"Predicting Responses of a Single Pile Considering Lateral Load to Tunnelling Induced Ground Movement: Analytical and Numerical Insights","authors":"Mukhtiar Ali Soomro,&nbsp;Mengle Dai,&nbsp;Kai Liu,&nbsp;Sharafat Ali Darban,&nbsp;Zhen-Dong Cui,&nbsp;Naeem Mangi","doi":"10.1002/nag.70039","DOIUrl":"10.1002/nag.70039","url":null,"abstract":"<div>\u0000 \u0000 <p>Pile foundations are essential for supporting structures built on clay, such as high-rise buildings. These piles must withstand both vertical loads and lateral loads, such as those caused by wind forces. In urban areas, subway tunnelling often takes place in densely populated regions, impacting nearby buildings. This study examines the influence of different tunnelling depths on the mechanical response of a single pile subjected to lateral loading through numerical modelling in clay. A hypoplastic soil model is used for the clay, while a concrete damage plasticity model assesses pile damage. The results show that lateral loads significantly increase lateral deflection, bending moments and tensile damage in piles during adjacent tunnelling. The combined effects of tunnelling and lateral loading result in the most pronounced pile failure, while tunnelling alone causes no damage in the absence of lateral loads. By examining the lateral load effects on pile responses during tunnel excavation at various depths, the study proposes an analytical solution based on the Pasternak foundation—Timoshenko beam model to estimate tunnelling-induced lateral displacement and bending moments in piles. The validity of this method is confirmed through comparisons with centrifuge test data and numerical modelling.</p>\u0000 </div>","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"49 16","pages":"3753-3776"},"PeriodicalIF":3.6,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144900122","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}