1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are cha...1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are changing,a non-uniform load that varies with time and lateral location is applied to the underlying ground.The consolidation phenomenon under two-dimensional(2D)conditions will keep pace with the construction of the embankment.In addition,because of evaporation and rainfall,the soils are mostly unsaturated.Therefore,it is meaningful to research the consolidation properties of unsaturated ground under non-uniform loading.展开更多
The application of ecosystem services(ES)theories in land consolidation is a confusing issue that has long plagued scholars and government officials.As the upgraded version of traditional land consolidation,comprehens...The application of ecosystem services(ES)theories in land consolidation is a confusing issue that has long plagued scholars and government officials.As the upgraded version of traditional land consolidation,comprehensive land consolidation(CLC)emphasizes ecological benefits,but it does not achieve the expected effect during the pilot phase.This study first proposed a theoretical analysis framework based on ES knowledge to answer the three key questions of why,where,and how to implement CLC better.Taking mountainous counties as the study area,we found that ES trade-offs/synergies,bundles,and drivers were significantly affected by scale effects.ES knowledge can play a crucial role in designing multi-scale CLC strategies regarding the objective,zoning,intensity,and mode.Specifically,mitigating the significant trade-offs between recreational opportunities,food production,and other ES is the top priority of CLC.Land consolidation zoning based on the ES bundles analysis is more rational and can provide the scientific premise for designing locally adapted CLC measures.Land consolidation can be classified into high-intensity direct intervention and low-intensity indirect intervention modes,based on the major drivers of ES.These findings help narrow the gap between ES and CLC practices.展开更多
Precast driven piles are extensively used for infrastructure on soft soils,but the buildup of excess pore water pressure associated with pile driving is a challenging issue.The process of soil consolidation could take...Precast driven piles are extensively used for infrastructure on soft soils,but the buildup of excess pore water pressure associated with pile driving is a challenging issue.The process of soil consolidation could take several months.Measures are sought to shorten the drainage path in the ground,and permeable pipe pile is a concept that involves drainage channels at the peak pore pressure locations around the pile circumference.Centrifuge tests were conducted to understand the responses of permeable pipe pile treated ground,experiencing the whole pile driving,soil consolidating,and axially loading process.Results show that the dissipation rate of pore pressures can be improved,especially at a greater depth or at a shorter distance from the pile,since the local hydraulic gradient was higher.Less significant buildup of pore pressures can be anticipated with the use of permeable pipe pile.For this,the bearing capacity of composite foundation with permeable pipe pile can be increased by over 36.9%,compared to the case with normal pipe pile at a specific time period.All these demonstrate the ability of permeable pipe pile in accelerating the consolidation process,mobilizing the bearing capacity of treated ground at an early stage,and minimizing the set-up effect.展开更多
Existing empirical methods for interpreting the consolidation yield stress and the overconsolidation ratio （OCR） in clays from piezocone tests are briefly reviewed. It can be seen that no universal correlation exist...Existing empirical methods for interpreting the consolidation yield stress and the overconsolidation ratio （OCR） in clays from piezocone tests are briefly reviewed. It can be seen that no universal correlation exists for all worldwide sites. However, for a given clay deposit, there does exist a most appropriate method to reflect the consolidation yield stress and the OCR based on piezocone test data. Three empirical methods are compared based on the piezocone test data collected on Lixia River lagoonal deposit soil sites in the north of Jiangsu province. The objective of this study is to evaluate the validity of the existing relationships linking the consolidation yield stress to piezocone test data and identify the appropriate method for Lixia River lagoonal deposit soil. It is shown that the correlation based on the net tip resistance has much higher accuracy for estimating the consolidation yield stress of lagoonal deposit soil than other methods.展开更多
Memory is a cognitive process through which past experiences are encoded,stored,and retrieved,playing a crucial role in intelligent behavior.It is well established that the hippocampus continues to reactivate memories...Memory is a cognitive process through which past experiences are encoded,stored,and retrieved,playing a crucial role in intelligent behavior.It is well established that the hippocampus continues to reactivate memories for several days after learning,and this process primarily occurs during sleep[1,2].The prevailing view suggests that sharp-wave ripples(SWRs)during non-rapid eye movement(NREM)sleep serve as key electrophysiological signatures of memory replay[3,4].However,only a small portion of SWRs contain memory replay[5].The direct relationship among SWRs,memory replay,and memory consolidation remains an open question.Another unresolved issue is how the hippocampus simultaneously reactivates both new and old memories while preventing interference.展开更多
Memory enables organisms to encode,store,and retrieve information essential for interacting with and adapting to a dynamic environment.As an internal representation of the external world,memory serves as a crucial bri...Memory enables organisms to encode,store,and retrieve information essential for interacting with and adapting to a dynamic environment.As an internal representation of the external world,memory serves as a crucial bridge between past experiences and future behaviors.However,the brain continuously forms new memories,raising the question of how new memories are integrated without disrupting previously formed ones.展开更多
Understanding the sedimentation and simultaneous consolidation behavior of xanthan gum(XG)-biopolymer-treated soils remains a significant research gap in developing environmentally friendly ground-improvement techniqu...Understanding the sedimentation and simultaneous consolidation behavior of xanthan gum(XG)-biopolymer-treated soils remains a significant research gap in developing environmentally friendly ground-improvement techniques for geotechnical applications.This study addresses this gap by conducting laboratory experiments on kaolinite suspensions with varying XG-to-kaolinite mass ratios(mb/ms).The results showed that the XG treatment modified the sedimentation patterns by promoting larger floc formation and accelerated settling.Additionally,the XG treatment enhanced the shear stiffness and shear strength,particularly at shallow depths.At mb/ms ratios less than 1%,the volume compression was reduced by the XG;the coefficient of compressibility decreased by 49%at 1%mb/ms,and the consolidation was accelerated,as indicated by a 387%increase in the hydraulic conductivity at 0.5%mb/ms under the vertical effective stress of 40 kPa.Contrastingly,at mb/ms ratios greater than 1%,viscous XG hydrogels clogged pores,resulting in a 45%reduction in the coefficient of consolidation at 2%mb/ms under a vertical effective stress of 15 kPa and a 35%decrease in the hydraulic conductivity at 2%mb/ms under a vertical effective stress of 40 kPa.These findings underscore the potential of XG treatment in improving the sedimentation and consolidation processes,highlighting its applicability in geotechnical projects,such as dredging,landfilling,and artificial island construction.展开更多
Low-intensity ultrasound was applied to the pressureless consolidation of AlSi10Mg powders in a broad temperature range from 600 to 860℃.Under static conditions,the consolidation of AlSi10Mg powders can only be achie...Low-intensity ultrasound was applied to the pressureless consolidation of AlSi10Mg powders in a broad temperature range from 600 to 860℃.Under static conditions,the consolidation of AlSi10Mg powders can only be achieved at 860℃,but still with the presence of some residual unconsolidated regions.The introduction of low-intensity ultrasound at this temperature eliminates the unconsolidated regions and transforms the columnar grains observed in original directional solidification into equiaxed or globular grains.Remarkably,the application of low-intensity ultrasound significantly reduces the consolidation temperature to 620℃,without compromising the microhardness of the resulting samples when compared to static conditions.Furthermore,by lowering the temperature to 600℃,a well-sintered porous material is obtained through the assistance of the low-intensity ultrasound.展开更多
We study a novel replication mechanism to ensure service continuity against multiple simultaneous server failures.In this mechanism,each item represents a computing task and is replicated intoξ+1 servers for some int...We study a novel replication mechanism to ensure service continuity against multiple simultaneous server failures.In this mechanism,each item represents a computing task and is replicated intoξ+1 servers for some integerξ≥1,with workloads specified by the amount of required resources.If one or more servers fail,the affected workloads can be redirected to other servers that host replicas associated with the same item,such that the service is not interrupted by the failure of up toξservers.This requires that any feasible assignment algorithm must reserve some capacity in each server to accommodate the workload redirected from potential failed servers without overloading,and determining the optimal method for reserving capacity becomes a key issue.Unlike existing algorithms that assume that no two servers share replicas of more than one item,we first formulate capacity reservation for a general arbitrary scenario.Due to the combinatorial nature of this problem,finding the optimal solution is difficult.To this end,we propose a Generalized and Simple Calculating Reserved Capacity(GSCRC)algorithm,with a time complexity only related to the number of items packed in the server.In conjunction with GSCRC,we propose a robust replica packing algorithm with capacity optimization(RobustPack),which aims to minimize the number of servers hosting replicas and tolerate multiple server failures.Through theoretical analysis and experimental evaluations,we show that the RobustPack algorithm can achieve better performance.展开更多
Heat transfers at the interface of adjacent saturated soil primarily through the soil particles and the water in the voids.The presence of water induces the contraction of heat flow lines at the interface,leading to t...Heat transfers at the interface of adjacent saturated soil primarily through the soil particles and the water in the voids.The presence of water induces the contraction of heat flow lines at the interface,leading to the emergence of the thermal contact resistance effect.In this paper,four thermal contact models were developed to predict the thermal contact resistance at the interface of multilayered saturated soils.Based on the theory of thermal-hydro-mechanical coupling,semi-analytical solutions of thermal consolidation subjected to time-dependent heating and loading were obtained by employing Laplace transform and its inverse transformation.Thermal consolidation characteristics of multilayered saturated soils under four different thermal contact models were discussed,and the effects of thermal resistance coefficient,partition thermal contact coefficient,and temperature amplitude on the thermal consolidation process were investigated.The outcomes indicate that the general thermal contact model results in the most pronounced thermal gradient at the interface,which can be degenerated to the other three thermal contact models.The perfect thermal contact model overestimates the deformation of the saturated soil during the thermal consolidation.Moreover,the effect of temperature on consolidation properties decreases gradually with increasing interfacial contact thermal resistance.展开更多
Peat soil is a loose,moisture-rich organic matter accumulation formed by the deposition of plants in swamps and lakes after their death.It is characterized by high moisture content,large void ratio,high compressibilit...Peat soil is a loose,moisture-rich organic matter accumulation formed by the deposition of plants in swamps and lakes after their death.It is characterized by high moisture content,large void ratio,high compressibility,and strong rheological properties.These characteristics result in a complex consolidation process.A systematic understanding of the consolidation mechanism of peat soil is essential for elucidating its consolidation behavior.Previous studies have failed to provide consistent information on the microscopic morphology of peat soil.Moreover,quantitative studies on pore structure changes during peat soil consolidation remain lacking.To resolve these research gaps,the microscopic morphology and pore types of peat,highly organic peaty soil,and medium organic peaty soil from certain regions of Yunnan province,China,were observed and analyzed using scanning electron microscopy.Additionally,quantitative research on pore structure changes during peat soil consolidation was conducted.The results show that the humic acid in peat soil of Yunnan province has no pores,and there is no pore between humic acid and clay minerals.There are three typical pore structures,and the three typical pores were quantitatively analyzed.During consolidation,the consolidation deformation of peat soil is primarily caused by the internal pore compression of plant residues and pores between plant residues.At the same time,the revelation of the differentiated influence mechanism of load levels on the compression of inter/intra-plant residue pores.The decrease in the proportion of pores between plant residues first increased and then decreased with an increase in load,reaching a peak between 100-200 kPa.The decrease in pores inside the plant residues increased with an increasing load.Additionally,pore compression between the plant residues under different load levels primarily caused the compression deformation of Dali peat during the primary consolidation stage.By contrast,the pore compression inside the plant residues primarily caused the compression deformation during the secondary consolidation stage.展开更多
When the interface of a multilayered saturated soil is rough with noticeable gaps, heat flow lines converge towards the actual contact points, causing thermal flow contraction. Conversely, in the interface between two...When the interface of a multilayered saturated soil is rough with noticeable gaps, heat flow lines converge towards the actual contact points, causing thermal flow contraction. Conversely, in the interface between two layers of soil with different properties, pore water flows slowly along the pore channels, demonstrating laminar flow phenomenon. To predict the thermal contact resistance and flow contact resistance at the interface, this paper constructs general imperfect thermal contact model and general imperfect flow contact model, respectively. Utilizing a thermo-hydro- mechanical coupling model, the thermal consolidation behavior of multilayered saturated soil under two-dimensional conditions is investigated. Fourier and Laplace transformations are applied to decouple the governing equations, yielding expressions for the temperature increment, pore water pressure, and displacement in multilayered saturated soil. The inverse Fourier-Laplace transformation is then used to obtain numerical solutions, which are compared with degeneration solutions to validate the computational accuracy. The differences in the thermal consolidation process under various thermal contact and flow contact resistance models are discussed. Furthermore, the impact of parameters such as the thermal resistance coefficient, partition thermal contact coefficient, flow contact resistance coefficient, and partition flow contact coefficient on thermal consolidation are investigated. Results indicate that thermal contact resistance creates a relative thermal gradient at the interface, leading to increased pore water pressure and reduced displacement nearby. In contrast, flow contact resistance generates a relative pore pressure gradient at the interface, resulting in increased displacement within the saturated soil with minimal effect on temperature increment distribution.展开更多
Aeromagnetic compensation is one of the key issues in high-precision geomagnetic fl ight carrier navigation, directly determining the accuracy and reliability of real-time magnetic measurement data. The accurate model...Aeromagnetic compensation is one of the key issues in high-precision geomagnetic fl ight carrier navigation, directly determining the accuracy and reliability of real-time magnetic measurement data. The accurate modeling and compensation of interference magnetic measurements on carriers are of great signifi cance for the construction of reference and real-time maps for geomagnetic navigation. Current research on aeromagnetic compensation algorithms mainly focuses on accurately modeling interference magnetic fields from model- and data-driven perspectives based on measured aeromagnetic data. Challenges in obtaining aeromagnetic data and low information complexity adversely aff ect the generalization performance of a constructed model. To address these issues, a recursive least square algorithm based on elastic weight consolidation is proposed, which eff ectively suppresses the occurrence of catastrophic forgetting by controlling the direction of parameter updates. Experimental verifi cation with publicly available aeromagnetic datasets shows that the proposed algorithm can eff ectively circumvent historical information loss caused by interference magnetic field models during parameter updates and improve the stability, robustness, and accuracy of interference magnetic fi eld models.展开更多
Objective:Both allogeneic hematopoietic stem cell transplantation(allo-HSCT)and autologous HSCT(ASCT)are important therapies for extranodal natural killer/T-cell lymphoma(ENKTCL);however,no large-scale,multicenter stu...Objective:Both allogeneic hematopoietic stem cell transplantation(allo-HSCT)and autologous HSCT(ASCT)are important therapies for extranodal natural killer/T-cell lymphoma(ENKTCL);however,no large-scale,multicenter study has compared the efficacy and safety between allo-HSCT and ASCT in these patients.Our multicenter,real-world study aimed to evaluate the outcomes of allo-HSCT vs.ASCT as consolidation in ENKTCL patients who had achieved a complete response(CR)or partial response(PR).Methods:This was a multicenter,retrospective study with nine hospitals in China,and 114 patients with ENKTCL were enrolled.Sixty patients received ASCT and 54 received allo-HSCT.The primary outcome was progression-free survival(PFS).In the sensitivity analysis,propensity score matching(PSM)analyses were conducted to adjust for baseline prognostic factors.Landmark analysis were conducted to minimize immortal-time bias.Results:Patients in the allo-HSCT group presented with more adverse prognostic factors.Allo-HSCT group showed a significantly better PFS and a lower disease progression rate compared with ASCT group in patients with Ann Arbor stageⅢ/Ⅳdisease(PFS:100%vs.82.0%,P=0.023;disease progression rate:0 vs.25.4%,P=0.024),those with intermediate/high prognostic index of natural killer lymphoma(PINK)scores(PFS:100%vs.84.4%,P=0.034;disease progression rate:0 vs.22.1%,P=0.034),those with intermediate/high international prognostic index(IPI)scores(PFS:100%vs.82.0%,P=0.038;disease progression rate:0 vs.25.4%,P=0.038),or those receiving HSCT at PR(PFS:100%vs.50%,P=0.046;disease progression rate:0 vs.50%,P=0.046)at the 1.5-4.0 follow-up.In multivariate analysis,receiving ASCT was significantly associated with a poorer PFS[hazard ratio(HR)=2.23,P=0.038]and overall survival(OS)(HR=2.45,P=0.045).In the sensitivity analysis,patients receiving allo-HSCT showed a significantly better PFS(70.3%vs.39.1%,P=0.039),OS(73.9%vs.42.0%,P=0.044),and a lower disease progression rate(22.6%vs.57.0%,P=0.017)compared with those receiving ASCT after propensity score matching.Conclusions:ENKTCL patients with high-risk characteristics could benefit more from allo-HSCT as consolidation.展开更多
Focusing on comprehensive land consolidation in mountainous areas, this paper explores the connotation of comprehensive land consolidation and its internal logic for promoting rural revitalization. Furthermore, it elu...Focusing on comprehensive land consolidation in mountainous areas, this paper explores the connotation of comprehensive land consolidation and its internal logic for promoting rural revitalization. Furthermore, it elucidates the effectiveness and experience of mountainous area comprehensive land consolidation in the rural revitalization process by using practical cases. The aim is to provide theoretical reference and practical guidance for leveraging the role of comprehensive land consolidation in mountainous areas for rural revitalization, thereby promoting the sustainable utilization of land resources and the coordinated development of the economy and society in mountainous regions.展开更多
A novel steel–carbon fibre/polyetheretherketone(CF/PEEK)hybrid shaft is proposed,considering the thermal stability,negative coefficient of thermal expansion in fibre orientation,and high stiffness of CF/PEEK,which is...A novel steel–carbon fibre/polyetheretherketone(CF/PEEK)hybrid shaft is proposed,considering the thermal stability,negative coefficient of thermal expansion in fibre orientation,and high stiffness of CF/PEEK,which is expected to suppress the thermal deformation of shafts.A laser-assisted in-situ consolidation(LAC)process,together with its equipment,was developed to manufacture the hybrid shaft.Firstly,the optimal process parameters,including the laser-heated temperature and placement speed,were investigated.A maximum short-beam shear strength of 80.7 MPa was achieved when the laser-heated temperature was 500°C and the placement speed was 100 mm/s.In addition,the failure modes and the effect of environmental temperature on the CF/PEEK samples were analyzed.Both interlayer cracks and inelastic deformation failure modes were observed.The formation and propagation of cracks were further investigated through digital image correlation(DIC).Furthermore,internal defects of the CF/PEEK sample were detected using X-ray tomography scans,and a minimum porosity of 0.23%was achieved with the optimal process parameters.Finally,two steel–CF/PEEK hybrid shafts,with different fibre orientations,were manufactured based on the optimal process parameters.The surface temperature distributions and thermal deformations were investigated using a self-established deformation/temperature measurement platform.The hybrid shaft showed an 85.7%reduction in radial displacement with hoop fibre orientation and an 11.5%reduction in axial displacement with cross fibre orientation compared with the steel shaft.The results indicate that the proposed method has great potential to improve the thermal stability of hybrid shafts and the accuracy of machine tools.展开更多
Geotechnical engineering that relates to the energy and environmental problem is receiving more and more attention worldwide.It is of great theoretical and practical value to study the properties of soil under thermal...Geotechnical engineering that relates to the energy and environmental problem is receiving more and more attention worldwide.It is of great theoretical and practical value to study the properties of soil under thermal mechanical coupling and its mathematical description.Firstly,based on the general function,a unified primary and secondary consolidation model of saturated soil considering heating temperature is deduced.Combining the existing research achievements,a practical model is obtained which comprehensively reflects the effective stress change,creep and heating effects.After that,a series of thermo-consolidation tests are carried out using a temperature controlled consolidation instrument to study the effects of effective stress,temperature and consolidation duration on saturated soils.The corresponding functional formulas and parameters are obtained thusly.On this basis,the calculation and analysis are carried out to check the reliability and applicability of the newly proposed model.The new model is simple and practical and the parameters are easy to be obtained.And it describes the main law of consolidation compression of saturated soils under the thermal mechanical coupling effect.Therefore,it is suggested for theoretical analysis of thermal geotechnical engineering problems.展开更多
In order to study deposited sediment settlement and consolidation mechanisms, sediment settlement experiments were conducted using a settlement column. Based on the experimental results, sediment settlement stage defi...In order to study deposited sediment settlement and consolidation mechanisms, sediment settlement experiments were conducted using a settlement column. Based on the experimental results, sediment settlement stage definition, excessive pore pressure （EPP） dissipation, and consolidation constitutive equations are discussed. Three stages, including the free settlement, hindered settlement, and self-weight consolidation settlement stages, are defined. The results of this study show that sediment settlement is mainly affected by the initial sediment concentration and initial settlement height, and the interface settlement rate is linearly attenuated with time on bilogarithmic scales during the hindered settlement and self-weight consolidation settlement stages. Moreover, the deposited sediment layer in the self-weight consolidation settlement stage experiences large strains, and the settlement amount in this stage is about 32% to 59% of the initial height of deposited sediment. EPP is nonlinearly distributed in the settlement direction, and consolidation settlement is faster than EPP dissipation in the self-weight consolidation settlement stage. Consolidation constitutive equations for the hydraulic conductivity and effective stress, applicable to large-strain consolidation calculation, were also determined and fitted in the power function form.展开更多
Since 2009, Chinese nonferrous metals industry has been carried out industry consolidation with strong support by the central government. This work examined technical efficiency of Chinese nonferrous metals firms and ...Since 2009, Chinese nonferrous metals industry has been carried out industry consolidation with strong support by the central government. This work examined technical efficiency of Chinese nonferrous metals firms and its change during the period of 2007 and 2011. Based on financial data from nonferrous metals listed companies, technical efficiency of nonferrous metal minerals mining firms and nonferrous metal smelting, pressing and processing firms was estimated respectively using the data envelopment analysis （DEA） method. It was found that, in both sectors, number of pure technical and scale inefficient firms dominated over efficient ones. Overall, their technical and scale efficiency tended to be very low after 2009. In particular, efficiency scores of nonferrous metal smelting, pressing and processing firms fluctuated greatly during the research period. And a limited number of large leading firms were able to maintain 100% efficiency score in the industry, while efficiency of most of other leading firms has declined since 2009.展开更多
In comparison with the conventional equal channel angular pressing（ECAP） process,a comprehensive study of influence of twist extrusion（TE） process on consolidating pure aluminum powder in tubes（PITs） by equal ch...In comparison with the conventional equal channel angular pressing（ECAP） process,a comprehensive study of influence of twist extrusion（TE） process on consolidating pure aluminum powder in tubes（PITs） by equal channel angular pressing and torsion（ECAPT） was conducted via three-dimensional（3D） finite element simulation,experimental investigation and theoretical analysis.Simulation results revealed that during the consolidation of aluminum powder particles by ECAPT,TE process played a significant role of back pressure.Due to the torsional shear and high hydrostatic pressure exerted by twist channel,both the magnitude and homogeneity of the effective strain were increased markedly.After one pass of ECAPT process using a square channel with an inner angle of 90° and a twist slope angle of 36.5° at 200℃,commercial pure aluminum powder particles were successfully consolidated to nearly full density.Simulation and experimental results showed good agreement.In the microstructure observations,grains were greatly refined.At the same time,porosities were effectively eliminated by shrinking in size and breaking into small ones.Microhardness test indicated that strain distribution of ECAPT-processed billet was more homogeneous with respect to the ECAP-processed one.All these improvements may be attributed to the extreme intense shear strain induced during ECAPT and the increase in self-diffusion coefficient of aluminum due to the back pressure exerted by TE process.展开更多
基金supported by the National Nature Science Foundation of China(No.12172211)the National Key Research and Development Program of China(No.2019YFC1509800)。
文摘1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are changing,a non-uniform load that varies with time and lateral location is applied to the underlying ground.The consolidation phenomenon under two-dimensional(2D)conditions will keep pace with the construction of the embankment.In addition,because of evaporation and rainfall,the soils are mostly unsaturated.Therefore,it is meaningful to research the consolidation properties of unsaturated ground under non-uniform loading.
基金National Natural Science Foundation of China,No.42171255,No.41971216。
文摘The application of ecosystem services(ES)theories in land consolidation is a confusing issue that has long plagued scholars and government officials.As the upgraded version of traditional land consolidation,comprehensive land consolidation(CLC)emphasizes ecological benefits,but it does not achieve the expected effect during the pilot phase.This study first proposed a theoretical analysis framework based on ES knowledge to answer the three key questions of why,where,and how to implement CLC better.Taking mountainous counties as the study area,we found that ES trade-offs/synergies,bundles,and drivers were significantly affected by scale effects.ES knowledge can play a crucial role in designing multi-scale CLC strategies regarding the objective,zoning,intensity,and mode.Specifically,mitigating the significant trade-offs between recreational opportunities,food production,and other ES is the top priority of CLC.Land consolidation zoning based on the ES bundles analysis is more rational and can provide the scientific premise for designing locally adapted CLC measures.Land consolidation can be classified into high-intensity direct intervention and low-intensity indirect intervention modes,based on the major drivers of ES.These findings help narrow the gap between ES and CLC practices.
基金supported by the National Natural Science Foundation of China(Grant Nos.52168046 and 52178321)the Natural Science Foundation of Guangxi Province,China(Grant No.2021AC18019).
文摘Precast driven piles are extensively used for infrastructure on soft soils,but the buildup of excess pore water pressure associated with pile driving is a challenging issue.The process of soil consolidation could take several months.Measures are sought to shorten the drainage path in the ground,and permeable pipe pile is a concept that involves drainage channels at the peak pore pressure locations around the pile circumference.Centrifuge tests were conducted to understand the responses of permeable pipe pile treated ground,experiencing the whole pile driving,soil consolidating,and axially loading process.Results show that the dissipation rate of pore pressures can be improved,especially at a greater depth or at a shorter distance from the pile,since the local hydraulic gradient was higher.Less significant buildup of pore pressures can be anticipated with the use of permeable pipe pile.For this,the bearing capacity of composite foundation with permeable pipe pile can be increased by over 36.9%,compared to the case with normal pipe pile at a specific time period.All these demonstrate the ability of permeable pipe pile in accelerating the consolidation process,mobilizing the bearing capacity of treated ground at an early stage,and minimizing the set-up effect.
基金Jiangsu Transportation Research Program Fund (No03Y007)
文摘Existing empirical methods for interpreting the consolidation yield stress and the overconsolidation ratio （OCR） in clays from piezocone tests are briefly reviewed. It can be seen that no universal correlation exists for all worldwide sites. However, for a given clay deposit, there does exist a most appropriate method to reflect the consolidation yield stress and the OCR based on piezocone test data. Three empirical methods are compared based on the piezocone test data collected on Lixia River lagoonal deposit soil sites in the north of Jiangsu province. The objective of this study is to evaluate the validity of the existing relationships linking the consolidation yield stress to piezocone test data and identify the appropriate method for Lixia River lagoonal deposit soil. It is shown that the correlation based on the net tip resistance has much higher accuracy for estimating the consolidation yield stress of lagoonal deposit soil than other methods.
基金supported by the National Natural Science Foundation of China(32371028,32300822,U24A20373,and 82071177)the Shanghai Rising-Star Program(24QA2704800)+2 种基金the Shanghai Jiao Tong University 2030 InitiativeShanghai Municipal Health Commission(202340046)the Fund for Excellent Young Scholars of Shanghai Ninth People's Hospital,Shanghai Jiao Tong University School of Medicine.
文摘Memory is a cognitive process through which past experiences are encoded,stored,and retrieved,playing a crucial role in intelligent behavior.It is well established that the hippocampus continues to reactivate memories for several days after learning,and this process primarily occurs during sleep[1,2].The prevailing view suggests that sharp-wave ripples(SWRs)during non-rapid eye movement(NREM)sleep serve as key electrophysiological signatures of memory replay[3,4].However,only a small portion of SWRs contain memory replay[5].The direct relationship among SWRs,memory replay,and memory consolidation remains an open question.Another unresolved issue is how the hippocampus simultaneously reactivates both new and old memories while preventing interference.
文摘Memory enables organisms to encode,store,and retrieve information essential for interacting with and adapting to a dynamic environment.As an internal representation of the external world,memory serves as a crucial bridge between past experiences and future behaviors.However,the brain continuously forms new memories,raising the question of how new memories are integrated without disrupting previously formed ones.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(Grant No.2022R1A2C2091517).
文摘Understanding the sedimentation and simultaneous consolidation behavior of xanthan gum(XG)-biopolymer-treated soils remains a significant research gap in developing environmentally friendly ground-improvement techniques for geotechnical applications.This study addresses this gap by conducting laboratory experiments on kaolinite suspensions with varying XG-to-kaolinite mass ratios(mb/ms).The results showed that the XG treatment modified the sedimentation patterns by promoting larger floc formation and accelerated settling.Additionally,the XG treatment enhanced the shear stiffness and shear strength,particularly at shallow depths.At mb/ms ratios less than 1%,the volume compression was reduced by the XG;the coefficient of compressibility decreased by 49%at 1%mb/ms,and the consolidation was accelerated,as indicated by a 387%increase in the hydraulic conductivity at 0.5%mb/ms under the vertical effective stress of 40 kPa.Contrastingly,at mb/ms ratios greater than 1%,viscous XG hydrogels clogged pores,resulting in a 45%reduction in the coefficient of consolidation at 2%mb/ms under a vertical effective stress of 15 kPa and a 35%decrease in the hydraulic conductivity at 2%mb/ms under a vertical effective stress of 40 kPa.These findings underscore the potential of XG treatment in improving the sedimentation and consolidation processes,highlighting its applicability in geotechnical projects,such as dredging,landfilling,and artificial island construction.
基金National Natural Science Foundation of China(Nos.52101051,52130405,51872241,52101142)Key Research Plan of Shaanxi Province,China(No.2020ZDLGY13-03)+1 种基金Key Research and Development Program of Shaanxi Province,China(No.2023-YBGY-439)Fundamental Research Funds for the Central Universities,China(No.5000210653)。
文摘Low-intensity ultrasound was applied to the pressureless consolidation of AlSi10Mg powders in a broad temperature range from 600 to 860℃.Under static conditions,the consolidation of AlSi10Mg powders can only be achieved at 860℃,but still with the presence of some residual unconsolidated regions.The introduction of low-intensity ultrasound at this temperature eliminates the unconsolidated regions and transforms the columnar grains observed in original directional solidification into equiaxed or globular grains.Remarkably,the application of low-intensity ultrasound significantly reduces the consolidation temperature to 620℃,without compromising the microhardness of the resulting samples when compared to static conditions.Furthermore,by lowering the temperature to 600℃,a well-sintered porous material is obtained through the assistance of the low-intensity ultrasound.
基金supported in part by the National Key R&D Program of China under No.2023YFB2703800the National Science Foundation of China under Grants U22B2027,62172297,62102262,61902276 and 62272311+3 种基金Tianjin Intelligent Manufacturing Special Fund Project under Grants 20211097the China Guangxi Science and Technology Plan Project(Guangxi Science and Technology Base and Talent Special Project)under Grant AD23026096(Application Number 2022AC20001)Henan Provincial Natural Science Foundation of China under Grant 622RC616CCF-Nsfocus Kunpeng Fund Project under Grants CCF-NSFOCUS202207。
文摘We study a novel replication mechanism to ensure service continuity against multiple simultaneous server failures.In this mechanism,each item represents a computing task and is replicated intoξ+1 servers for some integerξ≥1,with workloads specified by the amount of required resources.If one or more servers fail,the affected workloads can be redirected to other servers that host replicas associated with the same item,such that the service is not interrupted by the failure of up toξservers.This requires that any feasible assignment algorithm must reserve some capacity in each server to accommodate the workload redirected from potential failed servers without overloading,and determining the optimal method for reserving capacity becomes a key issue.Unlike existing algorithms that assume that no two servers share replicas of more than one item,we first formulate capacity reservation for a general arbitrary scenario.Due to the combinatorial nature of this problem,finding the optimal solution is difficult.To this end,we propose a Generalized and Simple Calculating Reserved Capacity(GSCRC)algorithm,with a time complexity only related to the number of items packed in the server.In conjunction with GSCRC,we propose a robust replica packing algorithm with capacity optimization(RobustPack),which aims to minimize the number of servers hosting replicas and tolerate multiple server failures.Through theoretical analysis and experimental evaluations,we show that the RobustPack algorithm can achieve better performance.
基金Projects(U24B20113,42477162) supported by the National Natural Science Foundation of ChinaProject(2025C02228) supported by the Primary Research and Development Plan of Zhejiang Province,China。
文摘Heat transfers at the interface of adjacent saturated soil primarily through the soil particles and the water in the voids.The presence of water induces the contraction of heat flow lines at the interface,leading to the emergence of the thermal contact resistance effect.In this paper,four thermal contact models were developed to predict the thermal contact resistance at the interface of multilayered saturated soils.Based on the theory of thermal-hydro-mechanical coupling,semi-analytical solutions of thermal consolidation subjected to time-dependent heating and loading were obtained by employing Laplace transform and its inverse transformation.Thermal consolidation characteristics of multilayered saturated soils under four different thermal contact models were discussed,and the effects of thermal resistance coefficient,partition thermal contact coefficient,and temperature amplitude on the thermal consolidation process were investigated.The outcomes indicate that the general thermal contact model results in the most pronounced thermal gradient at the interface,which can be degenerated to the other three thermal contact models.The perfect thermal contact model overestimates the deformation of the saturated soil during the thermal consolidation.Moreover,the effect of temperature on consolidation properties decreases gradually with increasing interfacial contact thermal resistance.
基金supported by the Fundamental Research Funds for the Central Universities(2025JBZY019)the Funding of Key Research and Development Project of CCCC(2021-ZJKJ-18).
文摘Peat soil is a loose,moisture-rich organic matter accumulation formed by the deposition of plants in swamps and lakes after their death.It is characterized by high moisture content,large void ratio,high compressibility,and strong rheological properties.These characteristics result in a complex consolidation process.A systematic understanding of the consolidation mechanism of peat soil is essential for elucidating its consolidation behavior.Previous studies have failed to provide consistent information on the microscopic morphology of peat soil.Moreover,quantitative studies on pore structure changes during peat soil consolidation remain lacking.To resolve these research gaps,the microscopic morphology and pore types of peat,highly organic peaty soil,and medium organic peaty soil from certain regions of Yunnan province,China,were observed and analyzed using scanning electron microscopy.Additionally,quantitative research on pore structure changes during peat soil consolidation was conducted.The results show that the humic acid in peat soil of Yunnan province has no pores,and there is no pore between humic acid and clay minerals.There are three typical pore structures,and the three typical pores were quantitatively analyzed.During consolidation,the consolidation deformation of peat soil is primarily caused by the internal pore compression of plant residues and pores between plant residues.At the same time,the revelation of the differentiated influence mechanism of load levels on the compression of inter/intra-plant residue pores.The decrease in the proportion of pores between plant residues first increased and then decreased with an increase in load,reaching a peak between 100-200 kPa.The decrease in pores inside the plant residues increased with an increasing load.Additionally,pore compression between the plant residues under different load levels primarily caused the compression deformation of Dali peat during the primary consolidation stage.By contrast,the pore compression inside the plant residues primarily caused the compression deformation during the secondary consolidation stage.
基金Projects(52108347, 52179112, 52178371) supported by the National Natural Science Foundation of ChinaProjects(2020C01147, 2023C01165) supported by the Primary Research and Development Plan of Zhejiang Province,ChinaProject(LQ22E080010) supported by the Outstanding Youth Project of Natural Science Foundation of Zhejiang Province,China。
文摘When the interface of a multilayered saturated soil is rough with noticeable gaps, heat flow lines converge towards the actual contact points, causing thermal flow contraction. Conversely, in the interface between two layers of soil with different properties, pore water flows slowly along the pore channels, demonstrating laminar flow phenomenon. To predict the thermal contact resistance and flow contact resistance at the interface, this paper constructs general imperfect thermal contact model and general imperfect flow contact model, respectively. Utilizing a thermo-hydro- mechanical coupling model, the thermal consolidation behavior of multilayered saturated soil under two-dimensional conditions is investigated. Fourier and Laplace transformations are applied to decouple the governing equations, yielding expressions for the temperature increment, pore water pressure, and displacement in multilayered saturated soil. The inverse Fourier-Laplace transformation is then used to obtain numerical solutions, which are compared with degeneration solutions to validate the computational accuracy. The differences in the thermal consolidation process under various thermal contact and flow contact resistance models are discussed. Furthermore, the impact of parameters such as the thermal resistance coefficient, partition thermal contact coefficient, flow contact resistance coefficient, and partition flow contact coefficient on thermal consolidation are investigated. Results indicate that thermal contact resistance creates a relative thermal gradient at the interface, leading to increased pore water pressure and reduced displacement nearby. In contrast, flow contact resistance generates a relative pore pressure gradient at the interface, resulting in increased displacement within the saturated soil with minimal effect on temperature increment distribution.
基金supported by the National Natural Science Foundation of China under Grant 61673017in part by the Science and Technology Department of Shaanxi Province under Grant 2024JC-YBQN-0657。
文摘Aeromagnetic compensation is one of the key issues in high-precision geomagnetic fl ight carrier navigation, directly determining the accuracy and reliability of real-time magnetic measurement data. The accurate modeling and compensation of interference magnetic measurements on carriers are of great signifi cance for the construction of reference and real-time maps for geomagnetic navigation. Current research on aeromagnetic compensation algorithms mainly focuses on accurately modeling interference magnetic fields from model- and data-driven perspectives based on measured aeromagnetic data. Challenges in obtaining aeromagnetic data and low information complexity adversely aff ect the generalization performance of a constructed model. To address these issues, a recursive least square algorithm based on elastic weight consolidation is proposed, which eff ectively suppresses the occurrence of catastrophic forgetting by controlling the direction of parameter updates. Experimental verifi cation with publicly available aeromagnetic datasets shows that the proposed algorithm can eff ectively circumvent historical information loss caused by interference magnetic field models during parameter updates and improve the stability, robustness, and accuracy of interference magnetic fi eld models.
基金supported by Talent development plan for the future in Medical-Engineering Integration by BRACDCHE and ZTA,National Key Research and Development Program of China(No.2022YFC2502600,No.2022YFC2502606)the Beijing Natural Science Foundation(No.Z230016)+2 种基金the National Natural Science Foundation of China(No.82570262,No.82170206,and No.82170208)Science and Technology Plan of Tongzhou District(No.KJ2024CX045)Shanghai Municipal Health Commission Project of Disciplines of Excellence(No.20224Z0022).
文摘Objective:Both allogeneic hematopoietic stem cell transplantation(allo-HSCT)and autologous HSCT(ASCT)are important therapies for extranodal natural killer/T-cell lymphoma(ENKTCL);however,no large-scale,multicenter study has compared the efficacy and safety between allo-HSCT and ASCT in these patients.Our multicenter,real-world study aimed to evaluate the outcomes of allo-HSCT vs.ASCT as consolidation in ENKTCL patients who had achieved a complete response(CR)or partial response(PR).Methods:This was a multicenter,retrospective study with nine hospitals in China,and 114 patients with ENKTCL were enrolled.Sixty patients received ASCT and 54 received allo-HSCT.The primary outcome was progression-free survival(PFS).In the sensitivity analysis,propensity score matching(PSM)analyses were conducted to adjust for baseline prognostic factors.Landmark analysis were conducted to minimize immortal-time bias.Results:Patients in the allo-HSCT group presented with more adverse prognostic factors.Allo-HSCT group showed a significantly better PFS and a lower disease progression rate compared with ASCT group in patients with Ann Arbor stageⅢ/Ⅳdisease(PFS:100%vs.82.0%,P=0.023;disease progression rate:0 vs.25.4%,P=0.024),those with intermediate/high prognostic index of natural killer lymphoma(PINK)scores(PFS:100%vs.84.4%,P=0.034;disease progression rate:0 vs.22.1%,P=0.034),those with intermediate/high international prognostic index(IPI)scores(PFS:100%vs.82.0%,P=0.038;disease progression rate:0 vs.25.4%,P=0.038),or those receiving HSCT at PR(PFS:100%vs.50%,P=0.046;disease progression rate:0 vs.50%,P=0.046)at the 1.5-4.0 follow-up.In multivariate analysis,receiving ASCT was significantly associated with a poorer PFS[hazard ratio(HR)=2.23,P=0.038]and overall survival(OS)(HR=2.45,P=0.045).In the sensitivity analysis,patients receiving allo-HSCT showed a significantly better PFS(70.3%vs.39.1%,P=0.039),OS(73.9%vs.42.0%,P=0.044),and a lower disease progression rate(22.6%vs.57.0%,P=0.017)compared with those receiving ASCT after propensity score matching.Conclusions:ENKTCL patients with high-risk characteristics could benefit more from allo-HSCT as consolidation.
文摘Focusing on comprehensive land consolidation in mountainous areas, this paper explores the connotation of comprehensive land consolidation and its internal logic for promoting rural revitalization. Furthermore, it elucidates the effectiveness and experience of mountainous area comprehensive land consolidation in the rural revitalization process by using practical cases. The aim is to provide theoretical reference and practical guidance for leveraging the role of comprehensive land consolidation in mountainous areas for rural revitalization, thereby promoting the sustainable utilization of land resources and the coordinated development of the economy and society in mountainous regions.
基金supported by the National Nature Science Foundation of China(No.52175440)the Aeronautics Science Foundation of China(No.2023Z049076001)+3 种基金the Science and Technology Innovation Fund of Shanghai Aerospace(No.SAST2022-058)the Open Fund of State Key Laboratory of Mechanical Transmissions(No.SKLMT-MSKFKT-202202)the Key R&D Program of Zhejiang Province(No.2023C01058)the Experimental Technique Project of Zhejiang University(No.SYBJS202302),China.
文摘A novel steel–carbon fibre/polyetheretherketone(CF/PEEK)hybrid shaft is proposed,considering the thermal stability,negative coefficient of thermal expansion in fibre orientation,and high stiffness of CF/PEEK,which is expected to suppress the thermal deformation of shafts.A laser-assisted in-situ consolidation(LAC)process,together with its equipment,was developed to manufacture the hybrid shaft.Firstly,the optimal process parameters,including the laser-heated temperature and placement speed,were investigated.A maximum short-beam shear strength of 80.7 MPa was achieved when the laser-heated temperature was 500°C and the placement speed was 100 mm/s.In addition,the failure modes and the effect of environmental temperature on the CF/PEEK samples were analyzed.Both interlayer cracks and inelastic deformation failure modes were observed.The formation and propagation of cracks were further investigated through digital image correlation(DIC).Furthermore,internal defects of the CF/PEEK sample were detected using X-ray tomography scans,and a minimum porosity of 0.23%was achieved with the optimal process parameters.Finally,two steel–CF/PEEK hybrid shafts,with different fibre orientations,were manufactured based on the optimal process parameters.The surface temperature distributions and thermal deformations were investigated using a self-established deformation/temperature measurement platform.The hybrid shaft showed an 85.7%reduction in radial displacement with hoop fibre orientation and an 11.5%reduction in axial displacement with cross fibre orientation compared with the steel shaft.The results indicate that the proposed method has great potential to improve the thermal stability of hybrid shafts and the accuracy of machine tools.
基金Project(51608281)supported by the National Natural Science Foundation of ChinaProject(LGG21E080005)supported by the Provincial Natural Science Foundation of Zhejiang Province,China。
文摘Geotechnical engineering that relates to the energy and environmental problem is receiving more and more attention worldwide.It is of great theoretical and practical value to study the properties of soil under thermal mechanical coupling and its mathematical description.Firstly,based on the general function,a unified primary and secondary consolidation model of saturated soil considering heating temperature is deduced.Combining the existing research achievements,a practical model is obtained which comprehensively reflects the effective stress change,creep and heating effects.After that,a series of thermo-consolidation tests are carried out using a temperature controlled consolidation instrument to study the effects of effective stress,temperature and consolidation duration on saturated soils.The corresponding functional formulas and parameters are obtained thusly.On this basis,the calculation and analysis are carried out to check the reliability and applicability of the newly proposed model.The new model is simple and practical and the parameters are easy to be obtained.And it describes the main law of consolidation compression of saturated soils under the thermal mechanical coupling effect.Therefore,it is suggested for theoretical analysis of thermal geotechnical engineering problems.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2009B13514)the Doctoral Fund of the Ministry of Education of China(Grant No.20100094110002)
文摘In order to study deposited sediment settlement and consolidation mechanisms, sediment settlement experiments were conducted using a settlement column. Based on the experimental results, sediment settlement stage definition, excessive pore pressure （EPP） dissipation, and consolidation constitutive equations are discussed. Three stages, including the free settlement, hindered settlement, and self-weight consolidation settlement stages, are defined. The results of this study show that sediment settlement is mainly affected by the initial sediment concentration and initial settlement height, and the interface settlement rate is linearly attenuated with time on bilogarithmic scales during the hindered settlement and self-weight consolidation settlement stages. Moreover, the deposited sediment layer in the self-weight consolidation settlement stage experiences large strains, and the settlement amount in this stage is about 32% to 59% of the initial height of deposited sediment. EPP is nonlinearly distributed in the settlement direction, and consolidation settlement is faster than EPP dissipation in the self-weight consolidation settlement stage. Consolidation constitutive equations for the hydraulic conductivity and effective stress, applicable to large-strain consolidation calculation, were also determined and fitted in the power function form.
基金Project(70921001)supported by the National Natural Science Foundation of ChinaProject(NCET-10-0799)supported by Program for New Century Excellent Talents in University,ChinaProjects(11YJA790158)supported by Humanities and Social Sciences Planning Fund by Chinese Ministry of Education
文摘Since 2009, Chinese nonferrous metals industry has been carried out industry consolidation with strong support by the central government. This work examined technical efficiency of Chinese nonferrous metals firms and its change during the period of 2007 and 2011. Based on financial data from nonferrous metals listed companies, technical efficiency of nonferrous metal minerals mining firms and nonferrous metal smelting, pressing and processing firms was estimated respectively using the data envelopment analysis （DEA） method. It was found that, in both sectors, number of pure technical and scale inefficient firms dominated over efficient ones. Overall, their technical and scale efficiency tended to be very low after 2009. In particular, efficiency scores of nonferrous metal smelting, pressing and processing firms fluctuated greatly during the research period. And a limited number of large leading firms were able to maintain 100% efficiency score in the industry, while efficiency of most of other leading firms has declined since 2009.
基金Project(51401177)supported by the National Natural Science Foundation of ChinaProject(13KJD430005)supported by the Natural Science Foundation of Jiangsu Higher Education Institutions of ChinaProject(JSKLEDC201309)supported by Jiangsu Key Laboratory of Large Engineering Equipment Detection and Control,China
文摘In comparison with the conventional equal channel angular pressing（ECAP） process,a comprehensive study of influence of twist extrusion（TE） process on consolidating pure aluminum powder in tubes（PITs） by equal channel angular pressing and torsion（ECAPT） was conducted via three-dimensional（3D） finite element simulation,experimental investigation and theoretical analysis.Simulation results revealed that during the consolidation of aluminum powder particles by ECAPT,TE process played a significant role of back pressure.Due to the torsional shear and high hydrostatic pressure exerted by twist channel,both the magnitude and homogeneity of the effective strain were increased markedly.After one pass of ECAPT process using a square channel with an inner angle of 90° and a twist slope angle of 36.5° at 200℃,commercial pure aluminum powder particles were successfully consolidated to nearly full density.Simulation and experimental results showed good agreement.In the microstructure observations,grains were greatly refined.At the same time,porosities were effectively eliminated by shrinking in size and breaking into small ones.Microhardness test indicated that strain distribution of ECAPT-processed billet was more homogeneous with respect to the ECAP-processed one.All these improvements may be attributed to the extreme intense shear strain induced during ECAPT and the increase in self-diffusion coefficient of aluminum due to the back pressure exerted by TE process.
