Engineering Geology最新文献

{"title":"Localised fluidisation in a giant loess landslide","authors":"Ye Chen ,&nbsp;Fawu Wang ,&nbsp;Youqian Feng ,&nbsp;Xingliang Peng ,&nbsp;Guolong Zhu","doi":"10.1016/j.enggeo.2024.107854","DOIUrl":"10.1016/j.enggeo.2024.107854","url":null,"abstract":"<div><div>On 1 September 2022, a giant loess landslide occurred in Huzhu Tu Autonomous County, Qinghai Province, China. This catastrophic event brought to light a unique loess fluidisation phenomenon. In specific parts of the landslide, the loess completely transformed into a viscous, fluid-like state, whereas other parts showed a deep-seated slide that retained their structural integrity. In this case, loess with different sliding patterns exhibited varying levels of mobility and destructive potential. Based on the field investigation, electrical resistivity tomography was employed to investigate the groundwater condition of the slope. Subsequently, ring-shear tests were carried out to examine the mechanical properties of the sliding zone loess under different saturation degrees and its response to rainfall as a triggering factor. The results indicate that the natural water content in the original slope was unevenly distributed, influenced by local terrain and groundwater runoff. Following the initial slide caused by cumulative rainfall, the overlying sliding material with high degree of saturation was likely to fluidise due to the increase in excess porewater pressure caused by continued shearing, ultimately resulting in flow-like movement features. In contrast, in areas with a deeper groundwater table, the initial shear could only be sustained over a short distance. This study reveals a mechanism of multiple movement patterns that may coexist in giant loess landslides.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107854"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142823127","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":"Seepage and stability analysis of hydraulically anisotropic unsaturated infinite slopes under steady infiltration","authors":"Chuanjie Dai,&nbsp;Guo Hui Lei","doi":"10.1016/j.enggeo.2024.107838","DOIUrl":"10.1016/j.enggeo.2024.107838","url":null,"abstract":"<div><div>An analytical model is derived for predicting the flow field and stability of an unsaturated infinite slope subjected to steady infiltration. The proposed model is novel because it accounts for the hydraulic anisotropy of unsaturated soil. The governing equation for steady-state seepage in an infinite slope is established in terms of matric suction under a constant surface flux boundary condition. On the basis of the available experimental findings on the hydraulic anisotropy behavior of unsaturated soils, the relative hydraulic conductivity for a soil under unsaturated conditions with respect to the soil at saturation is postulated to be a direction-independent scalar. This postulation simplifies the governing equation to a form that is directly solvable via the relative hydraulic conductivity and the saturated hydraulic conductivity tensor. To enable sophisticated applications, an exponential law and a power law that are well established in the unsaturated soil literature are used to relate the relative hydraulic conductivity to the matric suction and the effective degree of saturation, respectively. Closed-form solutions are derived for the matric suction, the flow net (potential function and stream function), and the effective degree of saturation. Analytical solutions are also derived for the soil unit weight and overburden stress. These solutions are incorporated into the unsaturated infinite slope stability formula constructed on a suction stress-based effective stress failure criterion. Hydraulic anisotropy has been shown to directly affect the flow field and the change in matric suction, which, in turn, drastically affects the slope safety factor against shallow landslides. This finding demonstrates that neglecting hydraulic anisotropy can cause a considerable overestimation of the safety factor, resulting in an unsafe slope stability prediction. The proposed model is useful for preliminary evaluation of the long-term stability of unsaturated slopes during wet periods and the antecedent slope conditions for shallow landslide initiation under transient infiltration.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107838"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789954","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":"Flume investigation of debris flow entrained boulders with cylindrical baffles and a rigid barrier","authors":"Beom-Jun Kim ,&nbsp;Chan-Young Yune","doi":"10.1016/j.enggeo.2024.107836","DOIUrl":"10.1016/j.enggeo.2024.107836","url":null,"abstract":"<div><div>Large boulders entrained by debris flow can generate destructive impact force and cause significant damage to a rigid barrier located downstream. Baffle arrays can be installed in front of the rigid barrier to reduce the potential damage from large boulders by dissipating flow energy with filtering boulders from the debris flows. In this study, to investigate the effect of baffle arrays on the flow behavior and the dynamic impact force of debris flows acting on the terminal barrier, small-scale flume experiments were performed with various baffle configurations. After the experiments, the dynamic flow behavior with boulders, impact forces, and travel distances of boulders, were analyzed with transverse blockage ratios and numbers of baffle rows. As a result, entrained boulders in debris flows significantly increased impact force about six times. With the installations of baffle arrays, however, peak impact force decreased by an average of 70 % and by up to 94 %. In addition, increasing the number of rows of baffles from one to two led to an average reduction of 50 % in impact force for each transverse blockage ratio. However, in the case of one row of baffles, the impact force reduction for high <em>s/δ</em> values proved to be less effective compared to the other baffle configurations. Finally, the results of this study can provide appropriate ranges for the baffle spacing and the number of baffle rows in the baffle design to estimate the load attenuation due to boulder filtration.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107836"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789956","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":"Model test study on the rainfall erosion mechanisms and reclamation potential of open-pit coal mine dump soil improved by fly ash and polyacrylamide","authors":"Shiyu Li ,&nbsp;Shuhong Wang ,&nbsp;Zhonghua Zhao ,&nbsp;Natalia Telyatnikova ,&nbsp;Marinichev Maxim","doi":"10.1016/j.enggeo.2024.107837","DOIUrl":"10.1016/j.enggeo.2024.107837","url":null,"abstract":"<div><div>Increasing the soil erosion resistance is one of the core issues in slope erosion control and ecological environmental restoration of open-pit coal mine (OPCM) dumps. In this study, fly ash (FA) and polyacrylamide (PAM) were used to improve the soil quality of an OPCM dump, and an indoor physical model was constructed to investigate the water and soil loss characteristics of the improved soil via simulated rainfall experiments. Scanning electron microscopy and Pore and Crack Analysis System software were employed to systematically investigate the erosion resistance mechanisms of the improved soil qualitatively and quantitatively. Finally, the improved technique for order preference by similarity to an ideal solution (TOPSIS) method was adopted to evaluate the reclamation potential of the improved soil. The results revealed that under the action of PAM (PAM and PAM–FA), the average erosion rate of the slope decreased by more than 90 %. Compared with that in the control group, when FA was applied alone, the slope erosion rate first decreased and then increased with increasing FA content. Upon PAM addition, the erosion pattern changed from the splash erosion stage, cave erosion stage, gully erosion stage, and tensile slip stage to the splash erosion stage and cave erosion stage. However, no obvious change in the runoff pattern. Erosion and runoff patterns are generally affected by the amendment type, addition concentration, porosity, pore shape, pore direction and hydrological environment. The erosion resistance mechanism of the improved soil entailed the formation of more stable soil aggregates via filling, cementation, skeleton support generation, and flocculation of FA and PAM. In addition, the optimal soil improvement was achieved when FA and PAM were added at levels of 16 % and 0.01 %, respectively. The obtained research results could be used for erosion control and ecological environmental protection of coarse-grained soil slopes in mining areas, highways and other fields and could be widely applied.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107837"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142793508","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":"Towards physics-informed neural networks for landslide prediction","authors":"Ashok Dahal,&nbsp;Luigi Lombardo","doi":"10.1016/j.enggeo.2024.107852","DOIUrl":"10.1016/j.enggeo.2024.107852","url":null,"abstract":"<div><div>For decades, solutions to regional-scale landslide prediction have primarily relied on data-driven models, which, by definition, are disconnected from the physics of the failure mechanism. The success and spread of such tools came from the ability to exploit proxy variables rather than explicit geotechnical ones, as the latter are prohibitive to acquire over broad landscapes. Our work implements a Physics Informed Neural Network (PINN) approach, thereby adding an intermediate constraint to a standard data-driven architecture to solve for the permanent deformation typical of Newmark slope stability methods. This translates into a neural network tasked with explicitly retrieving geotechnical parameters from common proxy variables and then minimizing a loss function with respect to the available coseismic landslide inventory. The results are promising because our model not only produces excellent predictive performance in the form of standard susceptibility output but, in the process, also generates maps of the expected geotechnical properties at a regional scale. Therefore, Such architecture is framed to tackle coseismic landslide prediction, which, if confirmed in other studies, could open up PINN-based near-real-time predictions.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107852"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142823147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Seismic and environmental controls on slow-moving landslides: Insights from the 2008 Wenchuan Earthquake","authors":"Huiyan Lu ,&nbsp;Hakan Tanyaş ,&nbsp;Weile Li ,&nbsp;Qiang Xu ,&nbsp;Cees J. van Westen ,&nbsp;Luigi Lombardo","doi":"10.1016/j.enggeo.2024.107865","DOIUrl":"10.1016/j.enggeo.2024.107865","url":null,"abstract":"<div><div>Earthquakes can initiate slow-moving landslides and cause them to transition into rapid failures. Although observations are limited, the literature suggests that strong earthquakes are more likely to trigger nearby failures, while smaller earthquakes may increase susceptibility. However, understanding the role of seismic disturbances requires considering other environmental conditions. This study focuses on the 2008 M_w 7.9 Wenchuan earthquake, using a data-driven multivariate approach to analyze slow-moving landslides. Our findings highlight topographic relief, road proximity, river distance, average monthly precipitation, lithology, and distance to the earthquake surface rupture as key factors. While the distance to the surface rupture is inversely related to landslide occurrence, it is the least influential variable, suggesting that most slow-moving landslides near the rupture may not have failed during the earthquake. Our finding also suggests that persistent disturbances from road networks may be as significant as the impact of a strong earthquake in influencing the existence of slow-moving landslides.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107865"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142823090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Improving subsurface structural interpretation in complex geological settings through geophysical imaging and machine learning","authors":"Yonatan Garkebo Doyoro ,&nbsp;Samuel Kebede Gelena ,&nbsp;Chih-Ping Lin","doi":"10.1016/j.enggeo.2024.107839","DOIUrl":"10.1016/j.enggeo.2024.107839","url":null,"abstract":"<div><div>This study employs seismic refraction tomography (SRT) and electrical resistivity tomography (ERT) to assess subsurface geological conditions along the proposed Porsgrunn Highway in Norway. The primary objective is to analyze SRT and ERT tomograms to identify subsurface geological structures. However, interpreting tomograms is often limited by smoothed boundaries and reduced resolution. To address these challenges, we apply <em>k</em>-means clustering, a machine learning technique that groups data based on similarities in physical properties, to post-process the geophysical tomograms. This study pioneers the use of <em>k</em>-means clustering to interpret tomograms from SRT and ERT data in complex geological settings. We first evaluate the effectiveness of clustering techniques using numerical modeling for two geological scenarios: a horizontally layered case and a layered case with undulation and a fault structure. Utilizing automated methods (Elbow and Silhouette), we objectively determine the optimal number of clusters for each geophysical tomogram. Subsequently, we compare the performance of the <em>k</em>-means clustering algorithm with subjective expert interpretations and the Laplacian edge detection method. Borehole data validate the clustering results and confirm the effectiveness of optimal cluster selection techniques. The findings of this study demonstrate that <em>k</em>-means clustering significantly enhances the detection of geological structures by establishing clearer boundaries and minimizing noise interference, enabling more accurate fault zone delineation. Compared to traditional edge detection and subjective interpretation methods, <em>k</em>-means clustering offers a systematic and objective approach that improves consistency and reliability across diverse geological settings. Moreover, its automated classification of geophysical data into meaningful clusters enables efficient analysis of large datasets. This study underscores the value of integrating machine learning techniques with geophysical methods such as SRT and ERT to improve interpretability and accurately identify subsurface geological structures, particularly in fault zone identification.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107839"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789953","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":"Moving beyond single slope quantitative analysis: A 3D slope stability assessment at urban scale","authors":"Angelo Ugenti ,&nbsp;Federica Angela Mevoli ,&nbsp;Daniela de Lucia ,&nbsp;Piernicola Lollino ,&nbsp;Nunzio Luciano Fazio","doi":"10.1016/j.enggeo.2024.107841","DOIUrl":"10.1016/j.enggeo.2024.107841","url":null,"abstract":"<div><div>A very large percentage of the Italian municipalities is exposed to landslides, floods, and/or coastal erosion, according to the 2021 edition of the Report on hydrogeological instability in Italy. Even the south-eastern area of the country, the Apulia Region, is affected by different geo-hydrological hazards, with a concentration of landslides in the north-western portion, named the Daunia Apennine sector. Such a significant exposure to landslide hazard imposes the need of defining reliable quantitative methodologies to assess landslide susceptibility at both the slope scale and urban scale, so that appropriate land planning policies, as well as effective prevention and mitigation measures, can be implemented according to a more rational approach. The main purpose of this study is to propose a physically-based methodology, at the urban area scale, aimed at assessing landslide susceptibility, for both shallow and deep instability processes affecting almost all the urban areas in the Daunia Apennines. The proposed methodology has been applied to the municipality of Carlantino (FG) as a test case study, using the available geological and geomorphological maps as well as the soil physical and mechanical data. A three-dimensional geotechnical model, 2.5 km² wide, including the Carlantino urban area and the slopes surrounding the town, was created. Later on, a three-dimensional limit equilibrium analysis, taking into account the equilibrium conditions both in the slip and the transverse directions, was performed to obtain a mechanically-based map of safety factors at the urban area scale. The results of this study, obtained for three different scenarios related to the assumed depth of the groundwater table, allowed the identification of the areas more susceptible to landsliding, i.e. characterised by lower safety factor values. The proposed 3D approach represents a significant advancement with respect to the traditional 2D stability calculation methods in terms of accuracy of the representative geometrical and geological model, which is assumed to fit more effectively the complexity of the actual slope conditions. Moreover, the methodology can have significant practical applications, since the corresponding results provide a prompt overview of the slope stability conditions of an overall urban area and can be directly used for urban planning as well as risk management activities. Based on a comparison against geomorphological evidence and remote sensing data, this approach has proven to be a valuable tool to support landslide susceptibility assessments, to be promptly used for land planning policies, and is supposed to be exportable to other geological environments.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107841"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Research on floor failure characteristics of dip direction in non-pillar mining with automatically formed roadway above confined water","authors":"Qiukai Gai ,&nbsp;Manchao He ,&nbsp;Yubing Gao ,&nbsp;Yu Fei","doi":"10.1016/j.enggeo.2024.107844","DOIUrl":"10.1016/j.enggeo.2024.107844","url":null,"abstract":"<div><div>The floor water inrush is one of main threats that restrict safe and efficient mining of coal mine. The non-pillar mining with automatically formed roadway (AFR) is a new mining method above confined water. To explore its distribution characteristics of “floor four zones” in dip direction is of great significance for optimizing water prevention and control engineering. First, technical principle of the AFR was analyzed and its process flow was summarized. Second, based on the theory of mine pressure and elastic mechanics, the AFR floor additional stress theoretical model above confined water was established. Then, the theoretical shape and depth of floor failure zone of the 11,005-working face in Rongkang Coal Mine was drawn by Mathcad, and compared with four empirical formulas of retained coal pillar mining. After that, a two two-dimensional AFR model test system above confined water was developed, which indirectly characterized development characteristics of deep fractures by monitoring lifting phenomenon of confined water, and thus divided the confined water conducting zone. On this basis, a FLAC-PFC^3D coupled numerical model above confined water was established to study floor displacement, fracture and water pressure evolution along dip direction. The results of the theoretical model and the model test were verified, and the range of floor damage zone and the complete water-resisting zone was obtained. Finally, the maximum failure depth was verified by using borehole direct current electric method, and the absolute value cloud map of change in apparent resistivity at different magnifications was displayed visually. The research results have filled the gap in AFR theoretical system regarding floor research and provided a reference for prevention and control technology of water inrush in confined water mining areas.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107844"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874045","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":"Energy-based method for the failure criterion and resistance evaluation of marine clay under cyclic loading","authors":"Xing Xiao ,&nbsp;Xin Guan ,&nbsp;Qi Wu ,&nbsp;Dingfeng Zhao ,&nbsp;Ruirong Zhou ,&nbsp;Guoxing Chen","doi":"10.1016/j.enggeo.2024.107833","DOIUrl":"10.1016/j.enggeo.2024.107833","url":null,"abstract":"<div><div>Energy dissipation can macroscopically synthesize the evolutions in the microstructure of the marine clay during cyclic loading. Hence an energy-based method was employed to investigate the failure criterion and cyclic resistance of marine clay. A series of constant-volume cyclic direct simple shear tests was conducted on undisturbed saturated marine clay from the Yangtze Estuary considering the effects of the plasticity index (<em>I</em>_P) and cyclic stress ratio (<em>CSR</em>). The results indicated that a threshold <em>CSR</em> (<em>CSR</em>_th) exhibiting a power function relationship with <em>I</em>_P exists in marine clay, which divides the cyclic response into non-failure and failure states. For failed specimens, the development of energy dissipation per cycle (<em>W</em>_<em>i</em>) with the number of cycles (<em>N</em>) exhibited an inflection point owing to the onset of serious damage to the soil structure. In this regard, the energy-based failure criterion was proposed by considering the inflection point as the failure point. Consequently, a model was proposed to quantify the relationships between failure energy dissipation per cycle (<em>W</em>_f) [or failure accumulative energy dissipation (<em>W</em>_af)], initial vertical effective stress, <em>I</em>_P, and the number of cycles to failure (<em>N</em>_f,E). An evaluation model capturing the correlation among <em>CSR</em>, <em>I</em>_P, and <em>N</em>_f,E was then established to predict the cyclic resistance, and its applicability was verified. Compared with the strain-based cyclic failure criterion, the energy-based failure criterion provides a more robust and rational approach. Finally, a failure double-amplitude shear strain (<em>γ</em>_DA,f) evaluation method applicable to marine clay in different seas was presented for use in practical geotechnical engineering.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"344 ","pages":"Article 107833"},"PeriodicalIF":6.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789957","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}