With the rapid development of science and technology,the application of intelligent technology in the field of civil engineering is more extensive,especially in the safety evaluation and management of engineering stru...With the rapid development of science and technology,the application of intelligent technology in the field of civil engineering is more extensive,especially in the safety evaluation and management of engineering structures.This paper discusses the role of intelligent technologies(such as artificial intelligence,Internet of Things,BIM,big data analysis,etc.)in the monitoring,evaluation,and maintenance of engineering structure safety.By studying the principle,application scenarios,and advantages of intelligent technology in structural safety evaluation,this paper summarizes how intelligent technology can improve engineering management efficiency and reduce safety risks,and puts forward the trend and challenge of future development.展开更多
Near-surface geological defects pose a serious threat to human life and infrastructure.Hence,the exploration of geological hazards is essential.Currently,there are various geological hazard exploration methods;however...Near-surface geological defects pose a serious threat to human life and infrastructure.Hence,the exploration of geological hazards is essential.Currently,there are various geological hazard exploration methods;however,those require improvements in terms of economic feasibility,convenience,and lateral resolution.To address this,this study examined an extraction method to determine spatial autocorrelation velocity dispersion curves for application in near-surface exploration.展开更多
Due to the continuous increase in global energy demand,photovoltaic solar energy generation and associated maintenance requirements have significantly expanded.One critical maintenance challenge in photovoltaic instal...Due to the continuous increase in global energy demand,photovoltaic solar energy generation and associated maintenance requirements have significantly expanded.One critical maintenance challenge in photovoltaic installations is detecting hot spots,localized overheating defects in solar cells that drastically reduce efficiency and can lead to permanent damage.Traditional methods for detecting these defects rely on manual inspections using thermal imaging,which are costly,labor-intensive,and impractical for large-scale installations.This research introduces an automated hybrid system based on two specialized convolutional neural networks deployed in a cascaded architecture.The first convolutional neural network efficiently detects and isolates individual solar panels from high-resolution aerial thermal images captured by drones.Subsequently,a second,more advanced convolutional neural network accurately classifies each isolated panel as either defective or healthy,effectively distinguishing genuine thermal anomalies from false positives caused by reflections or glare.Experimental validation on a real-world dataset comprising thousands of thermal images yielded exceptional accuracy,significantly reducing inspection time,costs,and the likelihood of false defect detections.This proposed system enhances the reliability and efficiency of photovoltaic plant inspections,thus contributing to improved operational performance and economic viability.展开更多
Climate change is significantly impacting cotton production in the Tarim River Basin.The study investigated the climate change characteristics from 2021 to 2100 using climate change datasets simulated per the coupled ...Climate change is significantly impacting cotton production in the Tarim River Basin.The study investigated the climate change characteristics from 2021 to 2100 using climate change datasets simulated per the coupled model inter-comparison project phase six(CMIP6)climatic patterns under the shared socioeconomic pathways SSP2-4.5 and SSP5-8.5.The DSSAT-CROPGROCotton model,along with stepwise multiple regression analyses,was used to simulate changes in the potential yield of seed cotton due to climate change.The results show that while future temperatures in the Tarim River Basin will rise significantly,changes in precipitation and radiation during the cotton-growing season are minimal.Seed cotton yields are more sensitive to low temperatures than to precipitation and radiation.The potential yield of seed cotton under the SSP2-4.5 scenario would increase by 14.8%,23.7%,29.0%,and 29.4%in the 2030S,2050S,2070S,and 2090S,respectively.In contrast,under the SSP5-8.5 scenario,the potential yield of seed cotton would see increases of 17.5%,27.1%,30.1%,and 22.6%,respectively.Except for the 2090s under the SSP5-8.5 scenario,future seed cotton production can withstand a 10%to 20%deficit in irrigation.These findings will help develop climate change adaptation strategies for cotton cultivation.展开更多
Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycli...Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycling,and reuse in different industries.Currently,a large portion of tailings are managed through the tailing storage facilities(TSF)where these tailings undergo hydro-thermal-mechanical stresses with seasonal cycles which are not comprehensively understood.This study presents an investigative study to evaluate the performance of control and cement-stabilized copper MT under the influence of seasonal cycles,freeze-thaw(F-T)and wet-dry(W-D)conditions,representing the seasonal variability in the cold and arid regions.The control and cement-stabilized MT samples were subjected to a maximum of 12 F-T and 12 W-D cycles and corresponding micro-and-macro behavior was investigated through scanning electron microscope(SEM),volumetric strain(εvT,wet density(r),moisture content loss,and unconfined compressive strength(UCS)tests.The results indicated the vulnerability of Copper MT to 67%and 75%strength loss reaching residual states with 12 F-T and 8 W-D cycles,respectively.Whereas the stabilized MT retained 39%-55%and 16%-34%strength with F-T and W-D cycles,demonstrating increased durability.This research highlights the impact of seasonal cycles and corresponding strength-deformation characteristics of control and stabilized Copper MT in cold and arid regions.展开更多
Evaluation of hydromechanical shear behavior of unsaturated soils is still a challenging issue. The time and cost needed for conducting precise experimental investigation on shear behavior of unsaturated soils have en...Evaluation of hydromechanical shear behavior of unsaturated soils is still a challenging issue. The time and cost needed for conducting precise experimental investigation on shear behavior of unsaturated soils have encouraged several investigators to develop analytical, empirical, or semi-empirical models for predicting the shear behavior of unsaturated soils. However, most of the previously proposed models are for specimens subjected to the isotropic state of stress, without considering the effect of initial shear stress. In this study, a hydromechanical constitutive model is proposed for unsaturated collapsible soils during shearing, with consideration of the effect of the initial shear stress. The model implements an effective stress-based disturbed state concept (DSC) to predict the stress-strain behavior of the soil. Accordingly, material/state variables were defined for both the start of the shearing stage and the critical state of the soil. A series of laboratory tests was performed using a fully automated unsaturated triaxial device to verify the proposed model. The experimental program included 23 suction-controlled unsaturated triaxial shear tests on reconstituted specimens of Gorgan clayey loess wetted to different levels of suctions under both isotropic and anisotropic stress states. The results show excellent agreement between the prediction by the proposed model and the experimental results.展开更多
A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety problems.Our study addresses the...A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety problems.Our study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves conductivity.mPR-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain dispersion.Integrating this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 cycles.In situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen reactions.Ex situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability tests.The present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.展开更多
In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive streng...In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive strength.In this study,505 groups of data were collected,and a new database of compressive strength of PFGC was constructed.In order to establish an accurate prediction model of compressive strength,five different types of machine learning networks were used for comparative analysis.The five machine learning models all showed good compressive strength prediction performance on PFGC.Among them,R2,MSE,RMSE and MAE of decision tree model(DT)are 0.99,1.58,1.25,and 0.25,respectively.While R2,MSE,RMSE and MAE of random forest model(RF)are 0.97,5.17,2.27 and 1.38,respectively.The two models have high prediction accuracy and outstanding generalization ability.In order to enhance the interpretability of model decision-making,we used importance ranking to obtain the perception of machine learning model to 13 variables.These 13 variables include chemical composition of fly ash(SiO_(2)/Al_(2)O_(3),Si/Al),the ratio of alkaline liquid to the binder,curing temperature,curing durations inside oven,fly ash dosage,fine aggregate dosage,coarse aggregate dosage,extra water dosage and sodium hydroxide dosage.Curing temperature,specimen ages and curing durations inside oven have the greatest influence on the prediction results,indicating that curing conditions have more prominent influence on the compressive strength of PFGC than ordinary Portland cement concrete.The importance of curing conditions of PFGC even exceeds that of the concrete mix proportion,due to the low reactivity of pure fly ash.展开更多
A clean environment with low carbon emissions is the goal of research on the development of green and sustainable buildings that use bio-sourced materials in conjunction with solar energy to create more sustainable ci...A clean environment with low carbon emissions is the goal of research on the development of green and sustainable buildings that use bio-sourced materials in conjunction with solar energy to create more sustainable cities.This is particularly true in Africa,where there aren’t many studies on the topic.The current study suggests a 90 m^(2) model of a sustainable building in a dry climate that is movable to address the issue of housing in remote areas,ensures comfort in harsh weather conditions,uses solar renewable resources—which are plentiful in Africa—uses biosourced materials,and examines how these materials relate to temperature and humidity control while emitting minimal carbon emissions.In order to solve the topic under consideration,the work is split into two sections:numerical and experimental approaches.Using TRNSYS and Revit,the suggested prototype building is examined numerically to examine the impact of orientation,envelope composition made of bio-sourced materials,and carbon emissions.Through a hygrothermal investigation,experiments are conducted to evaluate this prototype’s effectiveness.Furthermore,an examination of the photovoltaic system’s production,consumption,and several scenarios used tomaximize battery life is included in the paper.Because the biosourcedmaterial achieves a thermal transmittance of 0.15(W.m^(-2).K^(-1)),the results demonstrate an intriguing finding in terms of comfort.This value satisfies the requirements of passive building,energy autonomy of the dwelling,and injection in-network with an annual value of 15,757 kWh.Additionally,compared to the literature,the heating needs ratio is 6.38(kWh/m^(2).an)and the cooling needs ratio is 49(kWh/m^(2).an),both of which are good values.According to international norms,the inside temperature doesn’t go above 26℃,and the humidity level is within a comfortable range.展开更多
Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and hea...Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and health challenges posed by pollution,there is a growing interest in treating waters contaminated with EIPs.This paper explores biochar characteristics and modification methods,encompassing physical,chemical,and biological approaches for adsorbing EIPs.It offers a comprehensive review of research advancements in employing biochar for EIPs remediation in water,outlines the adsorption mechanisms of EIPs by biochar,and presents an environmental and economic analysis.It can be concluded that using biochar for the adsorption of EIPs in wastewater exhibits promising potential.Nonetheless,it is noteworthy that certain EIPs like Au(III),Rh(III),Ir(III),Ru(III),Os(III),Sc(III),and Y(III),have not been extensively investigated regarding their adsorption onto biochar.This comprehensive review will catalyze further inquiry into the biochar-based adsorption of EIPs,addressing current research deficiencies and advancing the practical implementation of biochar as a potent substrate for EIP removal from wastewater streams.展开更多
Landslides are significant natural geological hazards.Landslide susceptibility evaluation involves the quantitative assessment and prediction of potential landslide locations and their probabilities.Research has explo...Landslides are significant natural geological hazards.Landslide susceptibility evaluation involves the quantitative assessment and prediction of potential landslide locations and their probabilities.Research has explored susceptibility assessment methods based on spatial-scale analysis.This evaluation integrates two models—global and local scale—using a CNN model and a PSO-CNN coupled model.Key aspects include selecting evaluation factors and optimizing model parameters for landslide susceptibility at different scales.A major focus of current landslide research is utilizing prediction results to enhance prevention and control measures.展开更多
Li-argyrodites are promising solid electrolytes(SEs)for solid-state Li-ion batteries(SSLBs),but their large-scale industrial application remains a challenge.Conventional synthesis methods for SEs suffer from long reac...Li-argyrodites are promising solid electrolytes(SEs)for solid-state Li-ion batteries(SSLBs),but their large-scale industrial application remains a challenge.Conventional synthesis methods for SEs suffer from long reaction times and high energy consumption.In this study,we present a wet process for the synthesis of halogen-rich argyrodite Li_(6-a)PS_(5-a)Cl_(1+a)precursors(LPSCl_(1+a)-P,a=0–0.7)via an energysaving microwave-assisted process.Utilizing vibrational heating,we accelerate the formation of Liargyrodite precursor,even at excessive Cl-ion concentration,which significantly shortens the reaction time compared to traditional methods.After crystallization,we successfully synthesize the Liargyrodite,Li_(5.5)PS_(4.5)Cl_(1.5),which exhibits the superior ionic conductivity(7.8 mS cm^(-1))and low activation energy(0.23 eV)along with extremely low electric conductivity.The Li_(5.5)PS_(4.5)Cl_(1.5)exhibits superior Li compatibility owing to its high reversible striping/plating ability(over 5000 h)and high current density acceptability(1.3 mA cm^(-2)).It also exhibits excellent cycle reversibility and rate capability with NCM622 cathode(148.3 mA h g^(-1)at 1 C for 100 cycles with capacity retention of 85.6%).This finding suggests a potentially simpler and more scalable synthetic route to produce high-performance SEs.展开更多
Achieving the synergy of strength and ductility of Ti2AlNb alloy is challenging since its invention.Previous works showed that nano-size O phases in single B2 phase Ti2AlNb alloys can achieve synergetic enhancement in...Achieving the synergy of strength and ductility of Ti2AlNb alloy is challenging since its invention.Previous works showed that nano-size O phases in single B2 phase Ti2AlNb alloys can achieve synergetic enhancement in both strength and ductility.However,the precipitation mechanism of the nano-size O phase remains unclear.The precipitation of nano-size O phases in the single B2 phase Ti2AlNb alloy was achieved through hot compression test and the precipitation mechanism of the O phase was studied.Results show that dislocations form in the Ti2AlNb alloy when it undergoes compression.Dislocation wall formed by partial dislocation ordering acts as high-quality heterogeneous nucleation sites for nano-size O phase,which could form within very short time.Prolonged high-temperature process causes growth of the O phase.The orientation relation[111]_(B2)//[110]_(O) is confirmed and the densely arranged surface(110)of B2 is found to be parallel to the densely arranged surface(001)of O.The transformation from B2 to O can be attributed to displacement transformation and chemical ordering under the combined effect of high stress and high dislocation diffusion velocity.展开更多
The presence of heavy metals in soil negatively impacts its mechanical properties.Reactive MgO carbonation presents a promising approach to enhance the solidification of Pb-contaminated sandy soils.However,the mechani...The presence of heavy metals in soil negatively impacts its mechanical properties.Reactive MgO carbonation presents a promising approach to enhance the solidification of Pb-contaminated sandy soils.However,the mechanical properties and structural behavior of contaminated soils during carbonation can vary significantly due to differences in soil composition.This study examines the potential application and underlying mechanisms of reactive MgO carbonation in improving the mechanical properties of Pb-contaminated red clay.The findings demonstrate that Pb-contaminated red clay transitions from a plastic to a brittle state following reactive MgO carbonation.After 1 h of treatment,the strength of the red clay exceeded 3 MPa,even at high Pb^(2+)concentrations.The deformation modulus to unconfined compressive strength(UCS)ratio was calculated to be 37.761,with the failure strain primarily ranging from 1.5%to 4.0%.A strength prediction model for the reactive MgO-stabilized Pb-contaminated red clay was proposed,which showed good predictive accuracy.Furthermore,reactive MgO carbonation significantly reduced the Pb leaching concentration in the high-level Pb-contaminated soil to below 0.1 mg/L.Microscopic analysis revealed that an optimal amount of hydrated magnesium carbonates(HMCs)formed a stable and compact structure with the soil particles.However,long-term carbonation causes red clay particles to become sandy,and excessive HMCs can harm the soil structure.Therefore,to maximize the strength improvement while avoiding structural damage,the carbonation time should be controlled to 1 h.展开更多
To study the dynamic response rules of pile foundations of mega-bridges over faults in strong seismic areas,a finite element model of the pile foundation-soil-fault interaction of the Haiwen Bridge is established.The ...To study the dynamic response rules of pile foundations of mega-bridges over faults in strong seismic areas,a finite element model of the pile foundation-soil-fault interaction of the Haiwen Bridge is established.The 0.2-0.6 g peak acceleration of the 5010 seismic waves is input to study the effect of the seismic wave of different intensities and the distance changes between the fault and the pile foundation on the dynamic response of the pile body.The results show that the soil layer covering the bedrock amplifies the peak pile acceleration,and the amplifying effect decreases with increasing seismic wave intensity.However,bedrock has less of an effect on peak acceleration.The relative pile displacement shows the mechanical properties of elastic long piles.The pile foundation generates a large bending moment at the bedrock face and the upper soil layer interface,and a large shear force at the pile top and the soft-hard soil body interface.The relative displacement,bending,and shear bearing characteristics of the pile foundations on the upper and lower plates of the fault are significantly different.The deformation characteristics are affected by faults in a region ten times the pile diameter.Analysis of the dynamic p-y curves shows that the soil resistance on the pile side of the lower plate at the same depth is greater than that of the upper plate.Sensitivity of the dynamic response of pile foundations on either side of the fault to the effects of seismic intensity and distance between the pile foundation and the fault:distance l seismic intensity q.展开更多
The directional explosion behavior of finite volume water confined within nanochannels holds considerable potential for applications in precision nanofabrication and bioengineering.However,precise control of nanoscale...The directional explosion behavior of finite volume water confined within nanochannels holds considerable potential for applications in precision nanofabrication and bioengineering.However,precise control of nanoscale mass transfer remains challenging in nanofluidics.This study examined the dynamic evolution of water clusters confined within a single-end-opened carbon nanotube(CNT)under pulsed electric field(EF)excitation,with a particular focus on the structural reorganization of hydrogen bond(H-bond)networks and dipole orientation realignment.Molecular dynamics simulations reveal that under the influence of pulsed EF,the confinedwatermolecules undergo cooperative restructuring to maximize hydrogen bond formation through four independent motions during deformation,such as waving,spinning,axial slipping,and radial migration.In this process,the dynamic fracture and recombination of the hydrogen bond network generate an instantaneous high pressure,and drive a unidirectional explosion along the CNT axis.A smaller CNT diameter or a reduced water volume under the same EF conditions leads to a stronger explosion.In contrast,in a wider CNT,the water cluster expands axially and forms a cylindrical shell whose thickness gradually decreases as the axial expansion slows.These insights offer precise control strategies for nanofluidic systems in nanofabrication or bioengineering applications,where finite volume water serves as a programmable nanoscale energy transfer medium.展开更多
With the rapid development of heavy haul railway transportation technology,tunnel foundation defects and their effects on structural performance have attracted wide attention.This paper systematically investigates the...With the rapid development of heavy haul railway transportation technology,tunnel foundation defects and their effects on structural performance have attracted wide attention.This paper systematically investigates the evolution mechanism of tun-nel foundation defects in heavy haul railway tunnels and their impact on structural stiffness degradation through experiments and numerical simulations.A heavy haul train-ballasted track-tunnel basement-surround rock dynamic interaction model(TTTR model)is constructed.Firstly,the study reveals the four-stage evolution process of initial defects in the tunnel base-ment under complex environmental conditions.Experiments were conducted to measure the load-bearing capacity and stiff-ness degradation of the tunnel basement structure under different defect states.It is found that foundation defects,especially under the coupling of loose fill in the basement with the water-rich environment of the surrounding rock,significantly reduce the stiffness of the tunnel bottom structure and increase the risk of structural damage.Then,based on refined simulation of wheel-rail interaction and multi-scale coupled modeling technology,the TTTR dynamic interaction model was successfully constructed,and its validity was proven through numerical validation.A time-varying coupling technique of constrained boundary substructures(CBS technique)was adopted,significantly improving computational efficiency while ensuring calculation accuracy.The study also analyzes the effects of different degrees of void defects on the dynamic behavior of the train and the dynamic characteristics of the tunnel structure.It finds that foundation defects have a significant impact on the train’s operational state,track vibration displacement,and vibration stress of the tunnel lining structure,especially under the coupling effect of basement voids and the water-rich environment,which has the greatest impact.The research results of this paper provide a theoretical basis and technical support for the maintenance and reinforcement of tunnel foundation structures.展开更多
Two cross⁃sectional configurations of thin⁃walled square tubes partially filled with lightweight metallic foams are proposed,and termed as double⁃cell configuration partially filled with foam(DC⁃PF)and double⁃tube con...Two cross⁃sectional configurations of thin⁃walled square tubes partially filled with lightweight metallic foams are proposed,and termed as double⁃cell configuration partially filled with foam(DC⁃PF)and double⁃tube configuration partially filled with foam(DT⁃PF),respectively.The bending crashworthiness is investigated based on three⁃point bending tests using finite element ABAQUS/Explicit code.The two key mechanical indicators including Crash Load Efficiency(CLE)and Specific Energy Absorption(SEA)are introduced to evaluate the effect of foams in comparison with empty square tubes and fully filled square tubes.The numerical results show that the two partially filled configurations,especially DT⁃PF,display dramatically excellent bending crashworthiness compared with empty and fully filled square tubes.There exists a foam density threshold,beyond which the CLE of DT⁃PF achieves a maximum constant.In addition,there seems to be another foam density threshold,beyond which the SEA of DT⁃PF gets to the maximum value.It is also shown that the foam density threshold corresponding to the maximum SEA varies with the thickness of thin⁃walled square tubes.展开更多
文摘With the rapid development of science and technology,the application of intelligent technology in the field of civil engineering is more extensive,especially in the safety evaluation and management of engineering structures.This paper discusses the role of intelligent technologies(such as artificial intelligence,Internet of Things,BIM,big data analysis,etc.)in the monitoring,evaluation,and maintenance of engineering structure safety.By studying the principle,application scenarios,and advantages of intelligent technology in structural safety evaluation,this paper summarizes how intelligent technology can improve engineering management efficiency and reduce safety risks,and puts forward the trend and challenge of future development.
基金supported by the Henan Province science and technology research project(Grant No.242102321031)National Natural Science Foundation of China(grant numbers 42207200).
文摘Near-surface geological defects pose a serious threat to human life and infrastructure.Hence,the exploration of geological hazards is essential.Currently,there are various geological hazard exploration methods;however,those require improvements in terms of economic feasibility,convenience,and lateral resolution.To address this,this study examined an extraction method to determine spatial autocorrelation velocity dispersion curves for application in near-surface exploration.
基金funded by the Spanish Ministerio de Ciencia,Innovación y Universidades,grant number RTC2019-007364-3(FPGM)by the Comunidad de Madrid through the direct grant with ref.SI4/PJI/2024-00233 for the promotion of research and technology transfer at the Universidad Autónoma de Madrid。
文摘Due to the continuous increase in global energy demand,photovoltaic solar energy generation and associated maintenance requirements have significantly expanded.One critical maintenance challenge in photovoltaic installations is detecting hot spots,localized overheating defects in solar cells that drastically reduce efficiency and can lead to permanent damage.Traditional methods for detecting these defects rely on manual inspections using thermal imaging,which are costly,labor-intensive,and impractical for large-scale installations.This research introduces an automated hybrid system based on two specialized convolutional neural networks deployed in a cascaded architecture.The first convolutional neural network efficiently detects and isolates individual solar panels from high-resolution aerial thermal images captured by drones.Subsequently,a second,more advanced convolutional neural network accurately classifies each isolated panel as either defective or healthy,effectively distinguishing genuine thermal anomalies from false positives caused by reflections or glare.Experimental validation on a real-world dataset comprising thousands of thermal images yielded exceptional accuracy,significantly reducing inspection time,costs,and the likelihood of false defect detections.This proposed system enhances the reliability and efficiency of photovoltaic plant inspections,thus contributing to improved operational performance and economic viability.
基金supported by the Science and Technology Program of Xinjiang Construction Corps(No.2024AB064)the National Natural Science Foundation of China(Nos.41975044,42001314)。
文摘Climate change is significantly impacting cotton production in the Tarim River Basin.The study investigated the climate change characteristics from 2021 to 2100 using climate change datasets simulated per the coupled model inter-comparison project phase six(CMIP6)climatic patterns under the shared socioeconomic pathways SSP2-4.5 and SSP5-8.5.The DSSAT-CROPGROCotton model,along with stepwise multiple regression analyses,was used to simulate changes in the potential yield of seed cotton due to climate change.The results show that while future temperatures in the Tarim River Basin will rise significantly,changes in precipitation and radiation during the cotton-growing season are minimal.Seed cotton yields are more sensitive to low temperatures than to precipitation and radiation.The potential yield of seed cotton under the SSP2-4.5 scenario would increase by 14.8%,23.7%,29.0%,and 29.4%in the 2030S,2050S,2070S,and 2090S,respectively.In contrast,under the SSP5-8.5 scenario,the potential yield of seed cotton would see increases of 17.5%,27.1%,30.1%,and 22.6%,respectively.Except for the 2090s under the SSP5-8.5 scenario,future seed cotton production can withstand a 10%to 20%deficit in irrigation.These findings will help develop climate change adaptation strategies for cotton cultivation.
基金the W.M.Keck Center for Nano-Scale Imaging in the Department of Chemistry and Biochemistry at the University of Arizona(Grant No.RRID:SCR_022884),with funding from the W.M.Keck Foundation Grant.
文摘Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycling,and reuse in different industries.Currently,a large portion of tailings are managed through the tailing storage facilities(TSF)where these tailings undergo hydro-thermal-mechanical stresses with seasonal cycles which are not comprehensively understood.This study presents an investigative study to evaluate the performance of control and cement-stabilized copper MT under the influence of seasonal cycles,freeze-thaw(F-T)and wet-dry(W-D)conditions,representing the seasonal variability in the cold and arid regions.The control and cement-stabilized MT samples were subjected to a maximum of 12 F-T and 12 W-D cycles and corresponding micro-and-macro behavior was investigated through scanning electron microscope(SEM),volumetric strain(εvT,wet density(r),moisture content loss,and unconfined compressive strength(UCS)tests.The results indicated the vulnerability of Copper MT to 67%and 75%strength loss reaching residual states with 12 F-T and 8 W-D cycles,respectively.Whereas the stabilized MT retained 39%-55%and 16%-34%strength with F-T and W-D cycles,demonstrating increased durability.This research highlights the impact of seasonal cycles and corresponding strength-deformation characteristics of control and stabilized Copper MT in cold and arid regions.
文摘Evaluation of hydromechanical shear behavior of unsaturated soils is still a challenging issue. The time and cost needed for conducting precise experimental investigation on shear behavior of unsaturated soils have encouraged several investigators to develop analytical, empirical, or semi-empirical models for predicting the shear behavior of unsaturated soils. However, most of the previously proposed models are for specimens subjected to the isotropic state of stress, without considering the effect of initial shear stress. In this study, a hydromechanical constitutive model is proposed for unsaturated collapsible soils during shearing, with consideration of the effect of the initial shear stress. The model implements an effective stress-based disturbed state concept (DSC) to predict the stress-strain behavior of the soil. Accordingly, material/state variables were defined for both the start of the shearing stage and the critical state of the soil. A series of laboratory tests was performed using a fully automated unsaturated triaxial device to verify the proposed model. The experimental program included 23 suction-controlled unsaturated triaxial shear tests on reconstituted specimens of Gorgan clayey loess wetted to different levels of suctions under both isotropic and anisotropic stress states. The results show excellent agreement between the prediction by the proposed model and the experimental results.
基金supported by a National Research Foundation of Korea(NRF)Grant funded by the Ministry of Science and ICT(2021R1A2C1014294,2022R1A2C3003319)the BK21 FOUR(Fostering Outstanding Universities for Research)through the National Research Foundation(NRF)of Korea.
文摘A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety problems.Our study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves conductivity.mPR-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain dispersion.Integrating this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 cycles.In situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen reactions.Ex situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability tests.The present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.
基金Funded by the Natural Science Foundation of China(No.52109168)。
文摘In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive strength.In this study,505 groups of data were collected,and a new database of compressive strength of PFGC was constructed.In order to establish an accurate prediction model of compressive strength,five different types of machine learning networks were used for comparative analysis.The five machine learning models all showed good compressive strength prediction performance on PFGC.Among them,R2,MSE,RMSE and MAE of decision tree model(DT)are 0.99,1.58,1.25,and 0.25,respectively.While R2,MSE,RMSE and MAE of random forest model(RF)are 0.97,5.17,2.27 and 1.38,respectively.The two models have high prediction accuracy and outstanding generalization ability.In order to enhance the interpretability of model decision-making,we used importance ranking to obtain the perception of machine learning model to 13 variables.These 13 variables include chemical composition of fly ash(SiO_(2)/Al_(2)O_(3),Si/Al),the ratio of alkaline liquid to the binder,curing temperature,curing durations inside oven,fly ash dosage,fine aggregate dosage,coarse aggregate dosage,extra water dosage and sodium hydroxide dosage.Curing temperature,specimen ages and curing durations inside oven have the greatest influence on the prediction results,indicating that curing conditions have more prominent influence on the compressive strength of PFGC than ordinary Portland cement concrete.The importance of curing conditions of PFGC even exceeds that of the concrete mix proportion,due to the low reactivity of pure fly ash.
文摘A clean environment with low carbon emissions is the goal of research on the development of green and sustainable buildings that use bio-sourced materials in conjunction with solar energy to create more sustainable cities.This is particularly true in Africa,where there aren’t many studies on the topic.The current study suggests a 90 m^(2) model of a sustainable building in a dry climate that is movable to address the issue of housing in remote areas,ensures comfort in harsh weather conditions,uses solar renewable resources—which are plentiful in Africa—uses biosourced materials,and examines how these materials relate to temperature and humidity control while emitting minimal carbon emissions.In order to solve the topic under consideration,the work is split into two sections:numerical and experimental approaches.Using TRNSYS and Revit,the suggested prototype building is examined numerically to examine the impact of orientation,envelope composition made of bio-sourced materials,and carbon emissions.Through a hygrothermal investigation,experiments are conducted to evaluate this prototype’s effectiveness.Furthermore,an examination of the photovoltaic system’s production,consumption,and several scenarios used tomaximize battery life is included in the paper.Because the biosourcedmaterial achieves a thermal transmittance of 0.15(W.m^(-2).K^(-1)),the results demonstrate an intriguing finding in terms of comfort.This value satisfies the requirements of passive building,energy autonomy of the dwelling,and injection in-network with an annual value of 15,757 kWh.Additionally,compared to the literature,the heating needs ratio is 6.38(kWh/m^(2).an)and the cooling needs ratio is 49(kWh/m^(2).an),both of which are good values.According to international norms,the inside temperature doesn’t go above 26℃,and the humidity level is within a comfortable range.
基金support from the earmarked fund for XJARS(No.XJARS-06)the Bingtuan Science and Technology Program(Nos.2021DB019,2022CB001-01)+1 种基金the National Natural Science Foundation of China(No.42275014)the Guangdong Foundation for Program of Science and Technology Research,China(No.2023B1212060044)。
文摘Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and health challenges posed by pollution,there is a growing interest in treating waters contaminated with EIPs.This paper explores biochar characteristics and modification methods,encompassing physical,chemical,and biological approaches for adsorbing EIPs.It offers a comprehensive review of research advancements in employing biochar for EIPs remediation in water,outlines the adsorption mechanisms of EIPs by biochar,and presents an environmental and economic analysis.It can be concluded that using biochar for the adsorption of EIPs in wastewater exhibits promising potential.Nonetheless,it is noteworthy that certain EIPs like Au(III),Rh(III),Ir(III),Ru(III),Os(III),Sc(III),and Y(III),have not been extensively investigated regarding their adsorption onto biochar.This comprehensive review will catalyze further inquiry into the biochar-based adsorption of EIPs,addressing current research deficiencies and advancing the practical implementation of biochar as a potent substrate for EIP removal from wastewater streams.
基金Jiangxi Provincial Innovative Training Project“Post-earthquake Landslide Risk Evaluation Study under Spatial Scale Modelling”(Project No.:S202311318050)。
文摘Landslides are significant natural geological hazards.Landslide susceptibility evaluation involves the quantitative assessment and prediction of potential landslide locations and their probabilities.Research has explored susceptibility assessment methods based on spatial-scale analysis.This evaluation integrates two models—global and local scale—using a CNN model and a PSO-CNN coupled model.Key aspects include selecting evaluation factors and optimizing model parameters for landslide susceptibility at different scales.A major focus of current landslide research is utilizing prediction results to enhance prevention and control measures.
基金supported by the Basic Science Research Program through National Research Foundation of Korea(NRF)grant funded by the Ministry of Science and ICT(RS-2022-NR070534)supported by the National Research Council of Science&Technology(NST)grant by the Korea government(MSIT)(2710024139)。
文摘Li-argyrodites are promising solid electrolytes(SEs)for solid-state Li-ion batteries(SSLBs),but their large-scale industrial application remains a challenge.Conventional synthesis methods for SEs suffer from long reaction times and high energy consumption.In this study,we present a wet process for the synthesis of halogen-rich argyrodite Li_(6-a)PS_(5-a)Cl_(1+a)precursors(LPSCl_(1+a)-P,a=0–0.7)via an energysaving microwave-assisted process.Utilizing vibrational heating,we accelerate the formation of Liargyrodite precursor,even at excessive Cl-ion concentration,which significantly shortens the reaction time compared to traditional methods.After crystallization,we successfully synthesize the Liargyrodite,Li_(5.5)PS_(4.5)Cl_(1.5),which exhibits the superior ionic conductivity(7.8 mS cm^(-1))and low activation energy(0.23 eV)along with extremely low electric conductivity.The Li_(5.5)PS_(4.5)Cl_(1.5)exhibits superior Li compatibility owing to its high reversible striping/plating ability(over 5000 h)and high current density acceptability(1.3 mA cm^(-2)).It also exhibits excellent cycle reversibility and rate capability with NCM622 cathode(148.3 mA h g^(-1)at 1 C for 100 cycles with capacity retention of 85.6%).This finding suggests a potentially simpler and more scalable synthetic route to produce high-performance SEs.
基金supported by the Basic Research Expenses for Provincial Universities in Heilongjiang Province,China(No.2022-KYYWF-0134)。
文摘Achieving the synergy of strength and ductility of Ti2AlNb alloy is challenging since its invention.Previous works showed that nano-size O phases in single B2 phase Ti2AlNb alloys can achieve synergetic enhancement in both strength and ductility.However,the precipitation mechanism of the nano-size O phase remains unclear.The precipitation of nano-size O phases in the single B2 phase Ti2AlNb alloy was achieved through hot compression test and the precipitation mechanism of the O phase was studied.Results show that dislocations form in the Ti2AlNb alloy when it undergoes compression.Dislocation wall formed by partial dislocation ordering acts as high-quality heterogeneous nucleation sites for nano-size O phase,which could form within very short time.Prolonged high-temperature process causes growth of the O phase.The orientation relation[111]_(B2)//[110]_(O) is confirmed and the densely arranged surface(110)of B2 is found to be parallel to the densely arranged surface(001)of O.The transformation from B2 to O can be attributed to displacement transformation and chemical ordering under the combined effect of high stress and high dislocation diffusion velocity.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3707900)the National Natural Science Foundation of China(Grant Nos.42030710 and 42472337).
文摘The presence of heavy metals in soil negatively impacts its mechanical properties.Reactive MgO carbonation presents a promising approach to enhance the solidification of Pb-contaminated sandy soils.However,the mechanical properties and structural behavior of contaminated soils during carbonation can vary significantly due to differences in soil composition.This study examines the potential application and underlying mechanisms of reactive MgO carbonation in improving the mechanical properties of Pb-contaminated red clay.The findings demonstrate that Pb-contaminated red clay transitions from a plastic to a brittle state following reactive MgO carbonation.After 1 h of treatment,the strength of the red clay exceeded 3 MPa,even at high Pb^(2+)concentrations.The deformation modulus to unconfined compressive strength(UCS)ratio was calculated to be 37.761,with the failure strain primarily ranging from 1.5%to 4.0%.A strength prediction model for the reactive MgO-stabilized Pb-contaminated red clay was proposed,which showed good predictive accuracy.Furthermore,reactive MgO carbonation significantly reduced the Pb leaching concentration in the high-level Pb-contaminated soil to below 0.1 mg/L.Microscopic analysis revealed that an optimal amount of hydrated magnesium carbonates(HMCs)formed a stable and compact structure with the soil particles.However,long-term carbonation causes red clay particles to become sandy,and excessive HMCs can harm the soil structure.Therefore,to maximize the strength improvement while avoiding structural damage,the carbonation time should be controlled to 1 h.
基金funded by National Natural Science Foundation of China Projects(51708040)Hainan Provincial Transportation Science and Technology Project(HNZXY2015-045R)Changan University Central University Basic Research Business Fund Special Funds(No.300102218115).
文摘To study the dynamic response rules of pile foundations of mega-bridges over faults in strong seismic areas,a finite element model of the pile foundation-soil-fault interaction of the Haiwen Bridge is established.The 0.2-0.6 g peak acceleration of the 5010 seismic waves is input to study the effect of the seismic wave of different intensities and the distance changes between the fault and the pile foundation on the dynamic response of the pile body.The results show that the soil layer covering the bedrock amplifies the peak pile acceleration,and the amplifying effect decreases with increasing seismic wave intensity.However,bedrock has less of an effect on peak acceleration.The relative pile displacement shows the mechanical properties of elastic long piles.The pile foundation generates a large bending moment at the bedrock face and the upper soil layer interface,and a large shear force at the pile top and the soft-hard soil body interface.The relative displacement,bending,and shear bearing characteristics of the pile foundations on the upper and lower plates of the fault are significantly different.The deformation characteristics are affected by faults in a region ten times the pile diameter.Analysis of the dynamic p-y curves shows that the soil resistance on the pile side of the lower plate at the same depth is greater than that of the upper plate.Sensitivity of the dynamic response of pile foundations on either side of the fault to the effects of seismic intensity and distance between the pile foundation and the fault:distance l seismic intensity q.
基金The Start-up Research Fund from Shenzhen,the Natural Science Foundation of Guangdong(Grant Nos.2024A1515010821,2025A1515011727)the Shenzhen Development and ReformCommission(Grant No.XMHT20220103004).
文摘The directional explosion behavior of finite volume water confined within nanochannels holds considerable potential for applications in precision nanofabrication and bioengineering.However,precise control of nanoscale mass transfer remains challenging in nanofluidics.This study examined the dynamic evolution of water clusters confined within a single-end-opened carbon nanotube(CNT)under pulsed electric field(EF)excitation,with a particular focus on the structural reorganization of hydrogen bond(H-bond)networks and dipole orientation realignment.Molecular dynamics simulations reveal that under the influence of pulsed EF,the confinedwatermolecules undergo cooperative restructuring to maximize hydrogen bond formation through four independent motions during deformation,such as waving,spinning,axial slipping,and radial migration.In this process,the dynamic fracture and recombination of the hydrogen bond network generate an instantaneous high pressure,and drive a unidirectional explosion along the CNT axis.A smaller CNT diameter or a reduced water volume under the same EF conditions leads to a stronger explosion.In contrast,in a wider CNT,the water cluster expands axially and forms a cylindrical shell whose thickness gradually decreases as the axial expansion slows.These insights offer precise control strategies for nanofluidic systems in nanofabrication or bioengineering applications,where finite volume water serves as a programmable nanoscale energy transfer medium.
基金funded by the National Natural Science Foundation of China (Grant No. 52178402 & 52378468)the Open Foundation of MOE Key Laboratory of Engineering Structures of Heavy Haul Railway (Central South University) (Grant No. 2022JZZ01)+1 种基金the National Engineering Research Center for High-Speed Railway Construction Technology for their project supportthe support from the MOE Key Laboratory of Engineering Structure of Heavy Haul Railway (Central South University)
文摘With the rapid development of heavy haul railway transportation technology,tunnel foundation defects and their effects on structural performance have attracted wide attention.This paper systematically investigates the evolution mechanism of tun-nel foundation defects in heavy haul railway tunnels and their impact on structural stiffness degradation through experiments and numerical simulations.A heavy haul train-ballasted track-tunnel basement-surround rock dynamic interaction model(TTTR model)is constructed.Firstly,the study reveals the four-stage evolution process of initial defects in the tunnel base-ment under complex environmental conditions.Experiments were conducted to measure the load-bearing capacity and stiff-ness degradation of the tunnel basement structure under different defect states.It is found that foundation defects,especially under the coupling of loose fill in the basement with the water-rich environment of the surrounding rock,significantly reduce the stiffness of the tunnel bottom structure and increase the risk of structural damage.Then,based on refined simulation of wheel-rail interaction and multi-scale coupled modeling technology,the TTTR dynamic interaction model was successfully constructed,and its validity was proven through numerical validation.A time-varying coupling technique of constrained boundary substructures(CBS technique)was adopted,significantly improving computational efficiency while ensuring calculation accuracy.The study also analyzes the effects of different degrees of void defects on the dynamic behavior of the train and the dynamic characteristics of the tunnel structure.It finds that foundation defects have a significant impact on the train’s operational state,track vibration displacement,and vibration stress of the tunnel lining structure,especially under the coupling effect of basement voids and the water-rich environment,which has the greatest impact.The research results of this paper provide a theoretical basis and technical support for the maintenance and reinforcement of tunnel foundation structures.
基金Sponsored by National Natural Science Foundation of China (Grant Nos.12272064 and 12101086)University Natural Science Research Project of Anhui Province (Grant No.KJ2018A0481)+2 种基金Major Project of Basic Science (Natural Science) Research in Jiangsu Universities (Grant Nos.22KJA460001,23KJA580001)Changzhou Science and Technology Plan Project (Grant No.CE20235049)Changzhou Leading Innovative Talents C ultivation Project (Grant No.CQ20220092).
文摘Two cross⁃sectional configurations of thin⁃walled square tubes partially filled with lightweight metallic foams are proposed,and termed as double⁃cell configuration partially filled with foam(DC⁃PF)and double⁃tube configuration partially filled with foam(DT⁃PF),respectively.The bending crashworthiness is investigated based on three⁃point bending tests using finite element ABAQUS/Explicit code.The two key mechanical indicators including Crash Load Efficiency(CLE)and Specific Energy Absorption(SEA)are introduced to evaluate the effect of foams in comparison with empty square tubes and fully filled square tubes.The numerical results show that the two partially filled configurations,especially DT⁃PF,display dramatically excellent bending crashworthiness compared with empty and fully filled square tubes.There exists a foam density threshold,beyond which the CLE of DT⁃PF achieves a maximum constant.In addition,there seems to be another foam density threshold,beyond which the SEA of DT⁃PF gets to the maximum value.It is also shown that the foam density threshold corresponding to the maximum SEA varies with the thickness of thin⁃walled square tubes.
