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Interaction analysis of sequentially installed support system and reinforced rock for deep tunnels 认领 引用
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作者 CHEN Xu ZHANG Ding-li +1 位作者 SUN Zhen-yu CHEN Xuan-hao 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第2期886-904,共19页
This study analyzed the interaction between sequentially installed combined support systems and the surrounding rock.Six distinct forms of elastic-brittle-plastic rock masses with reinforcement were analyzed,along wit... This study analyzed the interaction between sequentially installed combined support systems and the surrounding rock.Six distinct forms of elastic-brittle-plastic rock masses with reinforcement were analyzed,along with the critical displacements that governed their transition behaviors.Virtual support pressure was introduced to assess the spatial influence of the tunnel face.It was determined by integrating the longitudinal displacement profile with the proposed ground characteristic curve solutions under various ground conditions.Considering the timing of support installation,the support-rock interaction was divided into three phases.A method was presented to determine the evolution of this interaction based on critical displacements.An analytical approach was further proposed to describe the complete process of support system-rock interaction using displacement coordination.The analytical results are validated against numerical simulations and field measurements,and the method's advantages are demonstrated through comparisons with existing models and the convergence-confinement approach.Finally,the effects of surrounding rock and support parameters are examined.The results indicate that residual cohesion,the friction angle of reinforced ground,and reinforcement thickness strongly influence tunnel behavior.Additionally,increasing the stiffness or advancing the installation of secondary support substantially raises secondary support pressure. 展开更多
关键词 analytical model support-reinforced rock interaction ground reinforcement tunnel displacement combined support system virtual support pressure
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Characterization of rock damage evolution and support timing under true triaxial unloading paths 认领 引用
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作者 QI Min-jie ZHAO Guang-ming +6 位作者 MENG Xiang-rui LIU Chong-yan XU Wen-song XU Xin ZHAO Cong-hui SUN Kai ZHAO Bin 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第1期442-465,共24页
To study the influence of support timing and support strength on the mechanical properties and deformation damage characteristics of a single-sided unloaded rock mass,a true triaxial perturbation unloaded rock testing... To study the influence of support timing and support strength on the mechanical properties and deformation damage characteristics of a single-sided unloaded rock mass,a true triaxial perturbation unloaded rock testing system was used to conduct rock damage tests on sandstone with different support timing and strength paths.Based on the acoustic emission monitoring system,the spatial and temporal evolution characteristics of the whole process of rock body loaded instability under two stress paths were studied,and the mechanism of the reinforcing effect of stress support on the unloaded rock mass was analyzed.The results show that,within the scope of this study,both earlier applications of shoring and an increase in shoring strength can effectively improve the ultimate bearing capacity of the unloaded rock,which increases the ultimate bearing capacity of the unloaded rock mass by 60.31% and 54.96%,respectively;There is a phenomenon of rebound deformation of the rock mass during sudden changes in stress(single-sided unloading,stress support),which shows opposite expansion and compression platforms on the stress−strain curve;The crack evolution of unloaded rock under different stress support conditions shows the state law of"initial crack activation→middle steady state expansion→late main crack penetration",and the lagging support significantly accelerates the crack evolution from local activation to main penetration;The single-sided unloading and stress-supporting stages have less influence on the unloading deformationsσ1u,σ2u and support deformationsσ1 t,σ2t in theσ1 andσ2directions,while they show significant response characteristics toσ3u,σvu and σ3 t,σvt,and with the increase of the support strength,the stress-supporting stagesσ3 t,σvt gradually increase and exceed the deformations generated by the unloading stagesσ3u,σvu;The increase of support strength can effectively compensate for the rock stress loss caused by unloading,which makes the maximum,minimum,and volumetric strain support coefficients during the loading and unloading of the rock body increase gradually while the effect on the intermediate principal strain support coefficient is small;During loading,the support strength of rock masses seeks a new bearing area by regulating stress equilibrium states.This process primarily manifests as a shift in the locations of the crushing zone and the main bearing area,accompanied by a corresponding transformation in failure patterns.Consequently,the rock mass transitions from asymmetric three-zone damage under no or weak support to approximate symmetric three-zone damage under strong support.Simultaneously,the main load-bearing area of the rock mass shifts from deep bearing in the unsupported to middle bearing under strong support as the support strength increases. 展开更多
关键词 true triaxial single-sided unloading unloading effect support timing support strength
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Support engineering of single-atom electrocatalysis:Mechanism analysis and application expansion 认领 引用
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作者 Mingying Chen Junjie Ma +3 位作者 Xiyong Chen Qian Liu Yanhong Feng Xijun Liu 《Chinese Chemical Letters》 SCIE CAS CSCD 2026年第4期117-127,共11页
Electrocatalysis stands as a cornerstone in the pursuit of clean energy conversion and environmental sustainability,with single-atom catalysts(SACs)emerging as a transformative paradigm for enhancing electrocatalytic ... Electrocatalysis stands as a cornerstone in the pursuit of clean energy conversion and environmental sustainability,with single-atom catalysts(SACs)emerging as a transformative paradigm for enhancing electrocatalytic efficiency.In the architectural design of SACs,supports transcend conventional roles as mere supports,actively governing catalytic performance via robust metal-support interactions(SMSI).This review comprehensively analyses the key role of support engineering in modulating SACs performance.The study begins with a systematic assessment of currently popular SACs synthesis strategies,critically comparing their advantages and limitations.Through a hierarchical analysis,it reveals the impact of various support materials,such as carbon-based materials,metal oxides,MXenes,and metal-organic frameworks(MOFs),on the catalytic performance of SACs,with emphasis on their structural characteristics,electronic properties,and interaction mechanisms with active sites.The review further explores applications in energy conversion/storage and environmental remediation,while addressing current challenges and proposing future research directions for SACs development.By providing actionable insights,this work aims to guide the design of next-generation SACs and advance sustainable electrocatalysis. 展开更多
关键词 Electrocatalysis Single-atom catalysts Strong metal-support interactions Support engineering
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Support defect-mediated metal-support interactions in atomic layer deposition-prepared Pt/CeO2 catalysts for enhanced acetone oxidation 认领 引用
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作者 Ben Niu Ziyi Shui +5 位作者 Zhenwen Yang Xiaoxiao Duan Weiqi An Ganggang Li Jie Cheng Zhengping Hao 《Journal of Rare Earths》 SCIE EI CAS CSCD 2026年第7期2119-2128,I0004,共10页
Optimizing metal-support interactions(MSI)can significantly enhance catalytic activity,as the characteristics of the support play a decisive role in governing these interactions.Herein,this study systematically invest... Optimizing metal-support interactions(MSI)can significantly enhance catalytic activity,as the characteristics of the support play a decisive role in governing these interactions.Herein,this study systematically investigated the properties and catalytic performance of Pt/CeO2 catalysts prepared by atomic layer deposition(ALD)on three distinct supports:metal-organic framework(MOF)-derived CeO2(CeO2-M),ceria nanorods(CeO2-N),and ceria cubes(CeO2-C).Comprehensive characterization reveals that CeO2-M possesses the highest concentration of coordinatively unsaturated cerium(Ce)sites and surface oxygen vacancies,allowing for higher platinum(Pt)loading.Furthermore,the defect-rich structure of the support creates a unique coordination microenvironment for Pt species,which leads to optimized MSI as well as redox property.Therefore,Pt/CeO2-M catalyst achieves 99%acetone conversion at 200℃with the lowest activation energy of 57.9 kJ/mol.In situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)studies demonstrate that Pt/CeO2-M follows a distinct reaction pathway during acetone oxidation due to its unique coordination structure.These findings establish MOF-derived CeO2 as an ideal ALD support,where defect-mediated Pt anchoring can enhance both oxygen activation capacity and catalytic stability,providing new insights for the design of highperformance oxidation catalysts. 展开更多
关键词 Acetone oxidation Metal-organic framework Pt/CeO2 Metal-support interactions Support defect Rare earths
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Enhanced furfural hydrogenation via Ru nanoparticles supported on CeO2-Mg(OH)2composite nanosheet 认领 引用
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作者 Xiao-jun ZHAO Li-qiang WANG +3 位作者 Guang-ji ZHANG Yin FANG You-nian LIU Tie-chui YUAN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2026年第4期1258-1268,共11页
Ru nanoparticles(NPs)supported on CeO2-Mg(OH)2 composite nanosheets,donated as Ru/CeO2-Mg(OH)2,are developed as the highly active catalyst for selective hydrogenation of furfural to furfuryl alcohol.Charac... Ru nanoparticles(NPs)supported on CeO2-Mg(OH)2 composite nanosheets,donated as Ru/CeO2-Mg(OH)2,are developed as the highly active catalyst for selective hydrogenation of furfural to furfuryl alcohol.Characterization results demonstrate that Ru NPs are adsorbed on the surface of the polyhedra of CeO2,which are scattered on the surface of the thin Mg(OH)2 nanosheets.Ru/CeO2-Mg(OH)2-0.2 achieves 92.6%conversion of furfural and 96.3%selectivity to furfuryl alcohol.Ru/CeO2-Mg(OH)2-0.2 retains high activity after six cycles,due to the introduction of CeO2 to form composite support that effectively prevents the leaching of Ru NPs.The strong metal-support interaction(SMSI)between Ru NPs and the CeO2-Mg(OH)2 composite support can tune the electronic structure of Ru NPs,which facilitates the H2 activation.Moreover,the CeO2-Mg(OH)2 interface exhibits specific adsorption of C=O bonds compared to the CeO2 alone.The composite-supported nanoparticles provide a valuable strategy for constructing highly efficient hydrogenation catalysts. 展开更多
关键词 Ru nanoparticles CeO2-Mg(OH)2composite support hydrogenation of furfural strong metal-support interaction electronic structure regulation
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Using mixed kernel support vector machine to improve the predictive accuracy of genome selection 认领 引用 被引量：2
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作者 Jinbu Wang Wencheng Zong +6 位作者 Liangyu Shi Mianyan Li Jia Li Deming Ren Fuping Zhao Lixian Wang Ligang Wang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2026年第2期775-787,共13页
The advantages of genome selection(GS) in animal and plant breeding are self-evident.Traditional parametric models have disadvantage in better fit the increasingly large sequencing data and capture complex effects acc... The advantages of genome selection(GS) in animal and plant breeding are self-evident.Traditional parametric models have disadvantage in better fit the increasingly large sequencing data and capture complex effects accurately.Machine learning models have demonstrated remarkable potential in addressing these challenges.In this study,we introduced the concept of mixed kernel functions to explore the performance of support vector machine regression(SVR) in GS.Six single kernel functions(SVR_L,SVR_C,SVR_G,SVR_P,SVR_S,SVR_L) and four mixed kernel functions(SVR_GS,SVR_GP,SVR_LS,SVR_LP) were used to predict genome breeding values.The prediction accuracy,mean squared error(MSE) and mean absolute error(MAE) were used as evaluation indicators to compare with two traditional parametric models(GBLUP,BayesB) and two popular machine learning models(RF,KcRR).The results indicate that in most cases,the performance of the mixed kernel function model significantly outperforms that of GBLUP,BayesB and single kernel function.For instance,for T1 in the pig dataset,the predictive accuracy of SVR_GS is improved by 10% compared to GBLUP,and by approximately 4.4 and 18.6% compared to SVR_G and SVR_S respectively.For E1 in the wheat dataset,SVR_GS achieves 13.3% higher prediction accuracy than GBLUP.Among single kernel functions,the Laplacian and Gaussian kernel functions yield similar results,with the Gaussian kernel function performing better.The mixed kernel function notably reduces the MSE and MAE when compared to all single kernel functions.Furthermore,regarding runtime,SVR_GS and SVR_GP mixed kernel functions run approximately three times faster than GBLUP in the pig dataset,with only a slight increase in runtime compared to the single kernel function model.In summary,the mixed kernel function model of SVR demonstrates speed and accuracy competitiveness,and the model such as SVR_GS has important application potential for GS. 展开更多
关键词 genome selection machine learning support vector machine kernel function mixed kernel function
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Development of a smart device Android-based decision support system for controlling non-point source nitrogen and phosphorus pollution in an agricultural catchment 认领 引用 被引量：1
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作者 Meihui Wang Wenqian Jiang +5 位作者 Yuxi Fu Yi Wang Xinliang Liu Jianlin Shen Feng Liu Yong Li 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2026年第2期565-576,共12页
Intervention strategies to control non-point source nitrogen(N)and phosphorus(P)pollution in agriculture are expensive and there is a trade-off between engineering cost and treatment effectiveness.Implementing strateg... Intervention strategies to control non-point source nitrogen(N)and phosphorus(P)pollution in agriculture are expensive and there is a trade-off between engineering cost and treatment effectiveness.Implementing strategies often result in unsatisfactory outcomes and massive engineering costs when managing diffusive pollution in agricultural catchments.To address this issue,this paper proposes a robust,handy,catchment N&P decision support system(CNPDSS),an Android-based smartphone system integrated with a web-based geographic information system(GIS).The CNPDSS aims to provide artificial intelligence-driven decisions that minimize N&P loadings and engineering costs for mitigating pollution in agricultural catchments.It consists of four components:a general user interface(GUI),GIS,N&P pollution modeling(NPPM),and a DSS.The CNPDSS simplifies the GUI and integrates GIS modules to create a user-friendly interface,enabling non-professional users to operate the system easily through intuitive actions.The NPPM uses straightforward empirical models to predict N&P loadings,enhancing efficiency by avoiding excessive parameters.Taking into account the N&P movement pathway in the catchment,the DSS incorporates three control measures:source reduction in farmland(before migration stage),process retention by ecological ditch(midway transport stage),and down-end purification by constructed wetland(waterbody discharge stage),to formulate a comprehensive ternary controlling strategy.To optimize the cost-effectiveness of any proposed N&P control strategies for sub-catchments,a differential evolution algorithm(DEA)is employed in CNPDSS to carry out a dual-objective decision-making optimization computation.In this study,the CNPDSS is applied to a case study in an agricultural catchment in Central China to develop the most cost-effective ternary N&P control strategies that ensure the catchment water quality within Criterion Ⅲ of the Chinese Surface Water Quality Standard GB3838-2002 is met(total N concentration≤1.0 mg L-1and total P concentration≤0.2 mg L-1).Our results demonstrate that the CNPDSS is feasible and also possesses an adaptive design and flexible architecture to enable its generalization and extension to support strong hands-on applications in other catchments. 展开更多
关键词 decision support system non-point source N&P pollution a ternary controlling strategy dual-objective optimization agricultural catchment
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Support Vector Clustering Uncovered:Insights,Challenges,and Future Outlook 认领 引用
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作者 M.Tanveer Mohammad Tabish +2 位作者 Anuradha Kumari Ashwani Kumar Malik Weiping Ding 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2026年第4期749-775,共27页
Support vector clustering(SVC)has emerged as a powerful unsupervised learning technique,derived from support vector machines(SVMs),offering a robust solution to a wide range of complex clustering challenges.Its unique... Support vector clustering(SVC)has emerged as a powerful unsupervised learning technique,derived from support vector machines(SVMs),offering a robust solution to a wide range of complex clustering challenges.Its unique ability to handle noise,outliers,and clusters of diverse,irregular shapes sets it apart from traditional clustering methods.SVC's distinct advantage lies in its capacity to autonomously determine the optimal number of clusters without prior topological knowledge of the data.SVC maps data to a higher-dimensional space,encloses it in a minimal sphere,and identifies clusters when mapped back,supporting complex shapes and ensuring optimality through kernel functions.This review paper provides a comprehensive analysis of the SVC algorithms,exploring their variants such as robust,sparse,and fuzzy-based models and adaptations for large-scale data.Moreover,we analyze the potential of twin support vector clustering(TWSVC),with an emphasis on the use of various loss functions.Finally,the paper explores emerging trends and outlines promising future research directions for both SVC and twin SVC.These include advancements in feature engineering,extension to semi-supervised and weakly supervised learning,and the integration of multi-view and multi-modal data.Our work aims to deepen the understanding of SVC,fostering advancements that address the evolving needs of clustering in real-world scenarios. 展开更多
关键词 Clustering kernel methods support vector machine(SVM) twin support vector clustering (TWSVC) unsupervised learning
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A novel scaling method for the elastic ring supporting structure of an aero-engine rotor system: analytical and experimental investigations 认领 引用
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作者 Lei LI Tianyue MA +4 位作者 Zhong LUO Dongwu GAO Xiangdong GE Hui MA Shibin WANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2026年第1期1-18,共18页
The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometr... The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometric distortions, leading to a diminution in the predictive accuracy of the distorted similitude. To address this challenge, this study formulates a novel set of scaling laws, tailored to account for the intricate geometric distortions associated with elastic rings. The proposed scaling laws are formulated based on the intrinsic deformation characteristics of elastic rings, rather than the traditional systemic governing equations. Numerical and experimental cases are conducted to assess the efficacy and precision of the proposed scaling laws, and the obtained results are compared with those achieved by traditional methods. The outcomes demonstrate that the scaling laws put forth by this study significantly enhance the predictive capabilities for deformations of elastic rings. 展开更多
关键词 rotor system aero-engine elastic ring scaling method supporting structure
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Modal analysis on a fluid-conveying pipe subject to elastic supports with unknown-but-bounded parameters 认领 引用
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作者 Sha Wei Xulong Li +2 位作者 Xiong Yan Hu Ding Liqun Chen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第1期310-324,共15页
Uncertain parameters are widespread in engineering systems.This study investigates the modal analysis of a fluid-conveying pipe subjected to elastic supports with unknown-but-bound parameters.The governing equation fo... Uncertain parameters are widespread in engineering systems.This study investigates the modal analysis of a fluid-conveying pipe subjected to elastic supports with unknown-but-bound parameters.The governing equation for the elastically supported fluid-conveying pipe is transformed into ordinary differential equations using the Galerkin truncation method.The Chebyshev interval approach,integrated with the assumed mode method is then used to investigate the effects of uncertainties of support stiffness,fluid speed,and pipe length on the natural frequencies and mode shapes of the pipe.Additionally,both symmetrical and asymmetrical support stiffnesses are discussed.The accuracy and effectiveness of the Chebyshev interval approach are verified through comparison with the Monte Carlo method.The results reveal that,for the same deviation coefficient,uncertainties in symmetrical support stiffness have a greater impact on the first four natural frequencies than those of the asymmetrical one.There may be significant differences in the sensitivity of natural frequencies and mode shapes of the same order to uncertain parameters.Notably,mode shapes susceptible to uncertain parameters exhibit wider fluctuation intervals near the elastic supports,requiring more attention. 展开更多
关键词 Fluid-conveying pipe Elastic support Uncertainty Modal analysis Chebyshev interval method
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Performance Evolution of High-speed Railway Ballastless Track Supporting Layer Concrete:Influence of Wind Loads 认领 引用
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作者 YI Zhonglai JI Yuxuan +3 位作者 YANG Zhiqiang LIU Guanhong ZHANG Na LI Huajian 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2026年第3期757-767,共11页
Wind load caused by the high-speed running train is the typical environmental factor for ballastless track supporting layer concrete.Herein,the effect of wind load on the internal relative humidity(IRH),volume stabili... Wind load caused by the high-speed running train is the typical environmental factor for ballastless track supporting layer concrete.Herein,the effect of wind load on the internal relative humidity(IRH),volume stability and mechanical properties of supporting layer concrete were investigated by a designed device to produce stable wind loads.Mercury intrusion porosimeter(MIP)and scanning electron microscopy(SEM)were used to analyze the evolution of the microstructure and the morphology of hydration products.Results show that,under a wind velocity of 10 m/s,the IRH at a depth of 2 cm decreases to 35.9%within 10 days,leading to a 40.1%higher shrinkage compared to that under windless environment.Meanwhile,the volume of specific pores(200-10000 nm)is increased by 18.2%,which results in a 24.3%reduction in compressive strength and a weaker interfacial transfer zone(ITZ).Additionally,a model for IRH and internal restraint stress of supporting layer concrete under wind load was developed.This work can provide a reference for the design and maintenance of ballastless track supporting layer concrete. 展开更多
关键词 supporting layer concrete wind load internal relative humidity shrinkage pore structure
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Immobilization strategies,supporting materials,and performance advantages of photocatalysts in ammonia synthesis 认领 引用
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作者 Qian Su Pengfei Wang +1 位作者 Cheng Zuo Jinghe Jiang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2026年第1期157-186,共30页
Photocatalytic nitrogen fixation (PNF) is a promising alternative to the Haber-Bosch process.It achieves green ammonia production by utilizing solar energy for nitrogen fixation under mild conditions.While nanoscale p... Photocatalytic nitrogen fixation (PNF) is a promising alternative to the Haber-Bosch process.It achieves green ammonia production by utilizing solar energy for nitrogen fixation under mild conditions.While nanoscale photocatalysts offer enhanced performance due to their high surface area and abundant active sites,their small size makes them difficult to recover and prone to agglomeration.These bottlenecks severely limit industrial application.A promising solution is to immobilize the catalysts onto support surfaces.This paper provides a systematic review of recent advances in the design of immobilized photocatalysts for ammonia synthesis.It begins by outlining the key benefits of immobilization strategies,particularly in improving catalyst stability,recyclability,and overall photocatalytic performance.The working mechanisms and features of various immobilization techniques are then categorized and explained,covering physical adsorption/deposition,chemical bonding,in situ growth,and hybrid physico-chemical methods.Supported materials and common substrate types are also summarized.Furthermore,the widely used configurations of photoreactors suitable for immobilized systems are introduced.Finally,the review identifies current research limitations and challenges,and offers perspectives on future developments in the field of immobilized photocatalysis. 展开更多
关键词 Immobilization Photocatalysis Nitrogen fixation Support materials
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Deformation of servo steel supported zoned excavation pits in Hangzhou soft soil 认领 引用
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作者 Zhaorui Lin Yalong Jiang +5 位作者 Yun Duan Tao Fang Kaifang Yang Guohui Feng Gang Lin Changjie Xu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第4期3056-3069,共14页
Zonal excavation and servo-active regulation are two common methods for controlling deformation in soft soil deep foundation pits.However,in-depth research on the deformation behavior of foundation pits under the comb... Zonal excavation and servo-active regulation are two common methods for controlling deformation in soft soil deep foundation pits.However,in-depth research on the deformation behavior of foundation pits under the combined effect of these two methods remains limited.This study focuses on a large soft soil foundation-pit project adjacent to a subway station and tunnels in Hangzhou and proposes a method to evaluate surface settlement profilesoutside the zoned excavation pits.To this end,long-term on-site monitoring of soil displacements and diaphragm wall deformations during the excavation process is performed.The results show that surface settlement near the pit edge is primarily influenced by the construction of the outermost pit,whereas the settlement further away is predominantly affected by the construction of a second sub-pit from the edge.Pits located outside the metro protection line have a relatively smaller impact on surface settlement.The servo-active control system occasionally causes localized pushback of the diaphragm wall,leading to an“S-shaped”deformation pattern.The zonal excavation method proves beneficialin optimizing the excavation scheme and enhancing the rigidity of the support system.The combined use of the servo-active control system and zonal excavation method effectively regulates foundation pit deformation.The study findingsconfirmthe validity of the subway protection line and support the excavation scheme employed.Thus,this study serves as a guide for performing deformation control during the construction of large soft soil foundation pits in the Hangzhou area. 展开更多
关键词 Deep foundation pit Pit deformation Surface settlement Zonal excavation Servo-steel support Long-term monitoring
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Tunnel support in red bed soft rocks considering hydro-sensitivity and time-dependent behaviors:A review 认领 引用
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作者 Weizhong Chen Xiaoyun Shu +3 位作者 Hongming Tian Chenming Yang Xianjun Tan Zhende Zhu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第7期5862-5885,共24页
Red bed tunnel engineering presents significantchallenges due to the combined effects of hydrosensitivity and time-dependent nonlinear mechanical behavior of the surrounding rock masses.Despite critical stability conc... Red bed tunnel engineering presents significantchallenges due to the combined effects of hydrosensitivity and time-dependent nonlinear mechanical behavior of the surrounding rock masses.Despite critical stability concerns,globally recognized standardized design methodologies for support systems in such geological conditions are still under development.This comprehensive review systematically examines recent advancements in support technologies for red bed tunnels.The following conclusions can be drawn.First,based on the hydro-sensitive and time-dependent nature of red bed rocks,four dominant failure modes are identified:hydro-mechanical weakening failure,low-strength material failure,bedding plane-controlled structural failure,and time-dependent deformation failure.The applicability and performance of three representative stabilization strategies-prestressed anchorage,rock mass grouting,and yielding support systems-are then critically evaluated across different tunnel service stages.Second,prestressed anchorage and grouting are shown to effectively mitigate construction-phase instabilities caused by low rock strength and pronounced bedding structures,particularly using specialized anchorage systems and hydro-sensitive grouting materials that significantlyenhance the mechanical properties of red bed rock masses.Third,for long-term tunnel operation,the incorporation of compressible layers between the surrounding rock and secondary lining is highlighted as an effective solution to accommodate time-dependent deformation and prevent lining damage,with recommended ranges of mechanical parameters summarized from existing studies.Finally,key research frontiers are discussed,including the time-dependent anisotropic behavior of stratifiedred bed rock masses,scale effects in prestressed anchorage systems,and viscoelastic-plastic interactions in yielding support designs.The potential application of resilience-based design concepts is also emphasized,offering new perspectives for improving the long-term safety and adaptability of tunnels constructed in red bed soft rock formations. 展开更多
关键词 Red bed Tunnel support Time-dependent characteristics Water–rock interaction Tunnel construction
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Scheelite-type alkali metal perrhenates supported Co-based catalysts for highly efficient ammonia synthesis 认领 引用
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作者 Xuanbei Peng Mengqi An +8 位作者 Ruishao Mao Yanliang Zhou Ming Chen Dongya Huang Kailin Su Shiyong Zhang Jun Ni Xiuyun Wang Lilong Jiang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2026年第4期432-443,共12页
The development of highly efficient and stable non-precious metal catalysts under mild conditions is highly desirable for NH3 synthesis.However,the competitive adsorption of N2 and H2 on the single site and s... The development of highly efficient and stable non-precious metal catalysts under mild conditions is highly desirable for NH3 synthesis.However,the competitive adsorption of N2 and H2 on the single site and strong NH3 adsorption greatly hinder the catalytic efficiency of catalysts under mild conditions.Herein,we propose the use of responsive alkali metal perrhenates(AMReO4,AM=K,Na,or Cs)supports with scheelite-type structure that contains active Re metal and promoters to disperse cobalt(Co)species,constructing highly efficient catalysts by regulating the competitive reactant adsorption-activation pattern to a non-competitive mechanism.Our studies demonstrate that Co/KReO4 catalyst shows excellent catalytic performance for NH3 synthesis.Co and Re sites synergistically to promote the activation of N2 molecules,while the adsorption and activation of H2 primarily occur on Re sites of KReO4.The presence of Co species facilitates H-spillover that enables the migration of *H species from Re to Co sites,then cascade catalysis of hydrogen and dissociated nitrogen species to form NH3.Accordingly,the NH3 synthesis rate of Co/KReO4(11.48 mmolNH3 gcat-1h-1)is 3.2-fold higher than that of KReO4(3.58 mmolNH3 gcat-1h-1)at 400℃ and 1 MPa.This work emphasizes the significance of employing reactive supports containing promoters and active metals,in collaboration with non-precious Co sites,to enhance NH3 synthesis performance under mild conditions. 展开更多
关键词 Ammonia synthesis Responsive support Hydrogen spillover N2activation Alkali metal perrhenates
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Programmable mixed-kernel based on MoTe2/MoS2heterojunction for support vector machine learning 认领 引用
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作者 Xinyu Huang Jiapeng Du +3 位作者 Langlang Xu Lei Tong Xiangxiang Yu Lei Ye 《Journal of Semiconductors》 EI CAS CSCD 2026年第3期110-116,共7页
The von Neumann bottleneck in conventional computing architectures presents a significant challenge for data-inten-sive artificial intelligence applications.A promising approach involves designing specialized hardware... The von Neumann bottleneck in conventional computing architectures presents a significant challenge for data-inten-sive artificial intelligence applications.A promising approach involves designing specialized hardware with on-chip parameter tunability,which directly accelerates machine learning functions.This work demonstrates a continuously tunable mixed-kernel function physically realized within a van der Waals heterostructure.We designed and fabricated a MoTe2/MoS2type-Ⅱvertical heterojunction phototransistor,which exhibits a non-monotonic,Gaussian-like optoelectronic response owing to its unique inter-layer charge transfer mechanism.This intrinsic physical behavior directly maps to a mixed-kernel function combining Gaussian and Sigmoid characteristics.Furthermore,the hardware kernel can be continuously modulated by in-situ tuning of external opti-cal stimuli.The mixed-kernel exhibited exceptional performance,achieving precision,accuracy,and area under the curve(AUC)values of 95.8%,96%,and 0.9986,respectively,significantly outperforming conventional kernels.By successfully embedding a complex,adaptable mathematical function into the intrinsic physical properties of a single device,this work pioneers a novel pathway toward next-generation,energy-efficient intelligent systems with hardware-level adaptability. 展开更多
关键词 programmable mixed-kernel heterojunction support vector machine
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Conversion of tunnel excavation methods and optimization of support measures under transformation of rock stratum:A case study 认领 引用
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作者 JIANG Hua HU Hao +1 位作者 SHEN Qing-yun ZHANG Ao 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第4期1775-1793,共19页
Layered rock masses represent complex geological formations characterized by pronounced anisotropy in strength.This study monitors stress/deformation during construction to summarize layered rock mass deformation and ... Layered rock masses represent complex geological formations characterized by pronounced anisotropy in strength.This study monitors stress/deformation during construction to summarize layered rock mass deformation and support stress characteristics based on Yunwushan Tunnel.Shale shows greater vault settlement and asymmetric support deformation than sandstone.The excavation was optimized by establishing a numerical model,analyzing the advanced support effect,and redesigning the anchor rod to control the asymmetric large deformation.The results show that:1)It is effective to set a transition section before the sudden change of rock mass,and the optimal distance for setting the transition section is 6 m.2)The implementation of advance small pipe support has been shown to effectively mitigate settlement in the tunnel arch,whereas anchor bolt support is effective in controlling the horizontal convergence of the surrounding rock.3)Adjusting the angle of the anchor bolt is a cost-effective reinforcement method when facing asymmetric deformation.4)It is recommended to flexibly adjust the angle of the anchor bolts and increase the advance small pipe support in mountain tunnel projects under the transformation of rock strata.These outcomes may serve as a valuable reference for the design and construction of similar engineering projects. 展开更多
关键词 ubiquitous-joint model layered surrounding rock large deformation asymmetric support numerical simulation
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Experimental Study on Conductivity of Fractures Supported by Deep Shale in the Sichuan Basin of China 认领 引用
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作者 Chunting Liu Xiaozhi Shi +6 位作者 Juhui Zhu Bin Guan Subing Wang Le He Tianjun Qi Wenjun Xu Shun Qiu 《Energy Engineering》 EI 2026年第4期472-491,共20页
To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically anal... To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically analyzed the effects of closure stress,proppant concentration,formation temperature,and proppant size combination.Conductivity experiments were conducted using the HXDL-2C long-term proppant conductivity evaluation system under simulated reservoir conditions to determine the time-dependent evolution of fracture conductivity.The results showed that the 50-h conductivity retention of the rock-plate experiments ranged from 22%to 28%.With increasing closure stress,fracture conductivity exhibited a rapid decline.Under a formation temperature of 120℃ and a proppant concentration of 5 kg·m-2,the short-term conductivity of 70/140 mesh quartz-sand-propped fractures was 2.37μm2·cm,which decreased to 0.66μm2·cm after long-term testing.When the closure stress increased to 80 MPa,the short-term and long-term conductivities further declined to 1.36μm2·cm and 0.39μm2·cm,respectively.Increasing the proppant concentration from 5 to 7.5 kg·m-2at 120℃ and 80 MPa improved both short-term and long-term conductivities by enlarging the effective fracture width;however,the conductivity decay rate accelerated,and the 50-h retention dropped from 27.2%to 22.8%.Raising the temperature from 120℃ to 140℃ promoted proppant crushing and compaction,intensified shale creep,and accelerated fracture closure,reducing long-term conductivity from 0.37 to 0.30μm2·cm.Under identical conditions,40/70 mesh ceramic proppants maintained significantly higher conductivities than 70/140 mesh quartz sand,with short-term and long-term values of 8.71 and 2.19μm2·cm,respectively,at 120℃,80 MPa,and 5 kg·m-2.Pure quartz-sand systems failed to maintain effective conductivity under high-temperature and high-stress conditions,whereas adding 20%40/70 mesh ceramic proppant and thoroughly mixing it,the long-term conductivity has increased by 2.3 times,improving fracture stability while reducing overall cost.A predictive equation was derived from the experimental results to capture the dynamic decay characteristics of fracture conductivity.These outcomes provide a valuable experimental basis and technical support for optimizing fracturing fluid design,proppant selection,and operation parameters in deep shale formations. 展开更多
关键词 Deep continental shale conductivity supporting fractures high-temperature high-closure-pressure
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Deformation characteristics of arch shoulder and collaborative support technology of concrete-filled steel tubes in Hudi Coal Mine 认领 引用
19
作者 ZUO Jian-ping ZHU Fan +1 位作者 LIU De-jun WANG Jun 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第4期1838-1858,共21页
Aiming at the problem of large deformation of arch shoulder in deep high stress roadway of Hudi Coal Mine,through field sampling,experimental test and numerical simulation,the deformation mechanism of arch shoulder un... Aiming at the problem of large deformation of arch shoulder in deep high stress roadway of Hudi Coal Mine,through field sampling,experimental test and numerical simulation,the deformation mechanism of arch shoulder under the coupling action of high stress,soft and hard rock strata of roof,weakening of surrounding rock and disturbance of space staggered roadway was revealed.According to the research results,high-stress increases the range of the plastic zone,and the soft and hard rock strata change the expansion form of the plastic zone.With the decrease of the vertical distance of the space staggered roadway,the insufficient bearing capacity of the supporting material and other factors lead to the increase of the deformation of the shoulder angle and the side,forming the deformation characteristics of the arch shoulder.Based on this,the active and passive collaborative control technology is proposed,and the targeted support concept of"unloading control+strong support+collaborative"is adopted.The optimization scheme controls the deformation of roadway within 8%of the section size,significantly reduces the range of the plastic zone,and effectively solves the problem of difficult support of arch shoulder deformation. 展开更多
关键词 roadway arch shoulder deformation multi-factor coupling action plastic zone expansion active and passive collaborative differential support
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The Relationship between Parental Autonomy Support and Adolescent Academic Burnout:A Variable-Centered and Person-Centered Analysis 认领 引用
20
作者 Shuqing Wang Xiuqiu Liu +2 位作者 Siqi Yu Meili Zheng Shuhua Wei 《International Journal of Mental Health Promotion》 2026年第5期77-95,共19页
Background:While parenting is crucial for adolescents’academic adjustment,few studies have examined how parental autonomy support affects academic burnout or the underlying psychological processes.This study examined... Background:While parenting is crucial for adolescents’academic adjustment,few studies have examined how parental autonomy support affects academic burnout or the underlying psychological processes.This study examined the sequential mediating roles of growth mindset and self-esteem in the association between parental autonomy support and academic burnout,using both variable-centered and person-centered approaches.Methods:A total of 1032 Chinese junior and senior high school students were recruited through cluster sampling.Using self-report questionnaires,participants were assessed on parental autonomy support,growth mindset,self-esteem,and academic burnout.Data were analyzed using mediation modeling and latent profile analysis.Results:The findings revealed a significant inverse association between parental autonomy support and adolescent academic burnout;Both growth mindset and self-esteem showed significant partial mediating associations.Furthermore,they formed a sequential mediating pathway linking parental autonomy support and academic burnout.Four distinct academic burnout profiles were identified:Low-Burnout,Moderate-Exhaustion,High-Exhaustion and Reduced Accomplishment,and Severe Burnout.Higher levels of parental autonomy support,growth mindset,and self-esteem were all significantly associated with a lower likelihood of belonging to higher burnout profiles,particularly the Severe Burnout profile.Among these factors,self-esteem exhibited the most consistent and robust associations across different burnout profile comparisons.Overall,the relationship between parental autonomy support and adolescent academic burnout can be explained through the interconnected psychological processes of growth mindset and self-esteem,with self-esteem serving as a particularly central pathway.Conclusions:Parental autonomy support,growth mindset,and self-esteem serve as interrelated protective factors against adolescent academic burnout.This study paves the way for developing differentiated and targeted strategies for adolescent academic burnout. 展开更多
关键词 Parental autonomy support academic burnout growth mindset self-esteem latent profile analysis
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