BACKGROUND Pediatric liver transplantation(LT)is the definitive treatment for end-stage liver disease and acute liver failure in children.However,graft size mismatch poses significant challenges,particularly in infant...BACKGROUND Pediatric liver transplantation(LT)is the definitive treatment for end-stage liver disease and acute liver failure in children.However,graft size mismatch poses significant challenges,particularly in infants weighing less than 10 kg.Large-forsize grafts can lead to severe complications,including vascular thrombosis and impaired graft perfusion.Surgical innovations,such as hyper-reduced left lateral segment(HRLLS)grafts and monosegmental grafts(MSG),offer viable solutions by tailoring graft size without compromising vascular or biliary integrity.AIM To analyze the techniques and outcomes of HRLLS and MSG grafts in pediatric liver trabsplantation.METHODS Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across PubMed,Scopus,and Google Scholar,including studies up to February 2025.Eligible studies included case-control,observational,and randomized controlled trials reporting clinical outcomes of HRLLS,MSG,or reduced left lateral segment grafts(RLLS)in pediatric LT.The Joanna Briggs Institute Critical Appraisal Checklist was used for quality assessment.Meta-analysis was performed using MetaXL software to pool survival outcomes and assess complication profiles.RESULTS Eighteen studies involving various graft reduction techniques were included.Both HRLLS and MSG demonstrated comparable one-year survival rates exceeding 80%,with some studies reporting rates above 95%.Complications such as hepatic artery thrombosis,portal vein thrombosis,and sepsis were slightly more frequent in HRLLS/RLLS recipients but remained within acceptable limits.Meta-analysis revealed no significant differences in survivability between graft types.CONCLUSION HRLLS and MSG techniques enable successful liver transplantation in small pediatric recipients,achieving longterm outcomes comparable to standard approaches.These graft modification strategies expand donor pool utilization and optimize patient survival while mitigating large-for-size complications.展开更多
Silicon-air batteries(SABs),a new type of semiconductor air battery,have a high energy density.However,some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge,a...Silicon-air batteries(SABs),a new type of semiconductor air battery,have a high energy density.However,some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge,and the anode utilization rate is low.In this work,reduced graphene oxide(RGO)fabricated via high-temperature annealing or L-ascorbic acid(L.AA)reduction was first used to obtain Si nanowires/RGO-1000(Si NWs/RGO-1000)and Si nanowires/RGO-L.AA(Si NWs/RGO-L.AA)composite anodes for SABs.It was found that RGO suppressed the passivation and self-corrosion reactions and that SABs using Si NWs/RGO-L.AA as the anode can discharge for more than 700 h,breaking the previous performance of SABs,and that the specific capacity was increased by 90.8%compared to bare Si.This work provides a new solution for the design of high specific capacity SABs with nanostructures and anode protective layers.展开更多
Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption materials.In t...Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption materials.In this study,a flake-like nickel cobaltate/re-duced graphene oxide/melamine-derived carbon foam(FNC/RGO/MDCF)was successfully fabricated through a combination of solvo-thermal treatment and high-temperature pyrolysis.Results indicated that RGO was evenly distributed in the MDCF skeleton,providing ef-fective support for the load growth of FNC on its surface.Sample S3,the FNC/RGO/MDCF composite prepared by solvothermal method for 16 h,exhibited a minimum reflection loss(RL_(min))of-66.44 dB at a thickness of 2.29 mm.When the thickness was reduced to 1.50 mm,the optimal effective absorption bandwidth was 3.84 GHz.Analysis of the absorption mechanism of FNC/RGO/MDCF revealed that its excellent absorption performance was primarily attributed to the combined effects of conduction loss,multiple reflection,scattering,in-terface polarization,and dipole polarization.展开更多
In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational homogenization.The method is based on the reduced-order hom...In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational homogenization.The method is based on the reduced-order homogenization(ROH)approach.The ROH method typically involves solving multiple finite element problems under periodic conditions to evaluate elastic strain and eigenstrain influence functions in an‘off-line’stage,which offers substantial cost savings compared to direct computational homogenization methods.Due to the unique structure of the fibrous unit cell,“off-line”stage calculation can be eliminated by influence functions obtained analytically.Introducing the standard solid model to the ROH method enables the creation of a comprehensive analytical homogeneous viscoelastic constitutive model.This method treats fibrous composite materials as homogeneous,anisotropic viscoelastic materials,significantly reducing computational time due to its analytical nature.This approach also enables precise determination of a homogenized anisotropic relaxation modulus and accurate capture of various viscoelastic responses under different loading conditions.Three sets of numerical examples,including unit cell tests,three-point beam bending tests,and torsion tests,are given to demonstrate the predictive performance of the homogenized viscoelastic model.Furthermore,the model is validated against experimental measurements,confirming its accuracy and reliability.展开更多
Biodiesel is a clean and renewable energy,and it is an effective measure to optimize engine combustion fueled with biodiesel to meet the increasingly strict toxic and CO_(2) emission regulations of internal combustion...Biodiesel is a clean and renewable energy,and it is an effective measure to optimize engine combustion fueled with biodiesel to meet the increasingly strict toxic and CO_(2) emission regulations of internal combustion engines.A suitable-scale chemical kinetic mechanism is very crucial for the accurate and rapid prediction of engine combustion and emissions.However,most previous researchers developed the mechanism of blend fuels through the separate simplification and merging of the reduced mechanisms of diesel and biodiesel rather than considering their cross-reaction.In this study,a new reduced chemical reaction kinetics mechanism of diesel and biodiesel was constructed through the adoption of directed relationship graph (DRG),directed relationship graph with error propagation,and full-species sensitivity analysis (FSSA).N-heptane and methyl decanoate (MD) were selected as surrogates of traditional diesel and biodiesel,respectively.In this mechanism,the interactions between the intermediate products of both fuels were considered based on the cross-reaction theory.Reaction pathways were revealed,and the key species involved in the oxidation of n-heptane and MD were identified through sensitivity analyses.The reduced mechanism of n-heptane/MD consisting of 288 species and 800 reactions was developed and sufficiently verified by published experimental data.Prediction maps of ignition delay time were established at a wide range of parameter matrices (temperature from 600 to 1 700 K,pressure from 10 bar to 80 bar,equivalence ratio from 0.5 to 1.5) and different substitution ratios to identify the occurrence regions of the crossreaction.Concentration and sensitivity analyses were then conducted to further investigate the effects of cross-reactions.The results indicate temperature as the primary factor causing cross-reactivity.In addition,the reduced mechanism with cross-reactions was more accurate than that without cross-reactions.At 700–1 000 K,the cross-reactions inhibited the consumption of n-heptane/MD,which resulted in a prolonged ignition delay time.At this point,the elementary reaction,NC_(7)H_(16)+OH<=>C_(7)H_(15)-2+H_(2)O,played a dominant role in fuel consumption.Specifically,the contribution of the MD consumption reaction to ignition decreased,and the increased generation time of OH,HO_(2),and H_(2)O_(2) was directly responsible for the increased ignition delay.展开更多
Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological infor...Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological information associated with environmental changes as it reflects their growth potential.To evaluate the effects of the changes in salinity and nutrients,the photosynthetic efficiency of a green macroalga Ulva fasciata from the Daya Bay was tested at a range of salinity(i.e.,31 to 10 psu)and nitrogen content(i.e.,5 to 60μmol L^(-1)).The results showed that cellular chlorophyll a(Chl a),carbohydrate and protein contents of U.fasciata were increased due to reduced salinity,and were decreased by interactive nitrogen enrichment.Within a short culture period(i.e.,18 h),the reduced salinity decreased the maximum photosynthetic efficiency(rETRmax and Pmax)derived from the rapid light response curve and photosynthetic oxygen evolution rate versus irradiance curve,respectively,as well as the saturation irradiance(E_(K)).This reducing effect diminished with enlonged cultivation time and reversed to a stimulating effect after 24 h of cultivation.The nitrogen enrichment stimulated the rETRmax and Pmax,as well as the E_(K),regardless of salinity,especially within short-term cultivation period(i.e.,<24 h).In addition,our results indicate that seawater freshening lowers the photosynthetic efficiency of U.fasciata in the short term,which is mitigated by nitrogen enrichment,but stimulates it in the long term,providing insight into how macroalgae thrive in coastal or estuarine waters where salinity and nutrients normally covary strongly.展开更多
The indiscriminate use and disposal of ciprofloxacin(CIP)have led to its detection in water globally,which pose a huge risk to public health and water environment.Herein,(Zn-Al)LDHs modified 3D reduced graphene oxide ...The indiscriminate use and disposal of ciprofloxacin(CIP)have led to its detection in water globally,which pose a huge risk to public health and water environment.Herein,(Zn-Al)LDHs modified 3D reduced graphene oxide nanocomposite((Zn-Al)LDHs/3D-rGO)was synthesized through a feasible onepot hydrothermal method for CIP removal.The highly distributed(Zn-Al)LDHs flakes on the surface of 3D-rGO endow the resulted(Zn-Al)LDHs/3D-rGO with an excellent adsorption performance for CIP.The adsorption results showed that the adsorption process could be well interpreted by Temkin isothermal model and the pseudo second-order kinetics model.The maximal adsorption capacity of 20.01 mg·g^(-1)for CIP could be achieved under the optimal conditions optimized by response surface methodology(RSM).The inhibitory effect of co-existing ions on CIP adsorption were also discussed.The probable adsorption mechanism might be ascribed toπ-πinteractions,hydrogen bonding,electrostatic,and surface complexation.Regeneration tests showed that the obtained 3D porous material also possessed pronounced recyclability.The obtained(Zn-Al)LDHs/3D-rGO holds a great potential for removal of CIP from actual wastewater.展开更多
A critical challenge for global food security and sustainable agriculture is enhancing crop yields while reducing chemical N inputs.Improving N use efficiency in crops is essential for increasing agricultural producti...A critical challenge for global food security and sustainable agriculture is enhancing crop yields while reducing chemical N inputs.Improving N use efficiency in crops is essential for increasing agricultural productivity.The aim of this study was to evaluate the impacts of intercropping maize with leguminous green manure on grain yield and N utilization under reduced N-fertilization conditions.A field experiment with a split-plot design was conducted in northwestern China from 2018 to 2021.The main plots consisted of two cropping systems:maize-common vetch intercropping(IM)and sole maize(SM).The subplots had three N levels:zero N application(N0,0 kg ha^(-1)),a 25%reduction from the traditional chemical N supply(N1,270 kg ha^(-1)),and the traditional chemical N supply(N2,360 kg ha^(-1)).The results showed that the negative effects of N reduction on maize grain yield and N uptake were compensated by intercropping leguminous green manure,and the improvements increased with cultivation years.The integrated system involving maize-leguminous green manure intercropping and a reduced N supply enhanced N translocation from maize vegetative organs to grains and increased the nitrate reductase and glutamine synthetase activities in maize leaves.The supercompensatory effect in maize leaves increased year by year,reaching values of 16.1,21.3,and 25.5%in 2019,2020,and 2021,respectively.These findings suggest that intercropping maize with leguminous green manure under reduced chemical N input can enhance N assimilation and uptake in maize.By using this strategy,chemical fertilizer is effectively replaced by leguminous green manure,thereby improving N use efficiency and maintaining stable yields in the maize-based intercropping system.展开更多
The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene...The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene oxide(HPAN/rGO)composite aerogel was prepared by combining electrospinning and unidirectional freeze-drying.The anisotropic HPAN/rGO composite aerogel exhibited a honeycomb morphology in the direction perpendicular to the growth of ice crystals,and a through-well structure of directed microchannels in the direction parallel to the temperature gradient.By varying the mass ratio of HPAN/rGO,a composite aerogel with an ultra-low density of 5.34-7.81 mg·cm^(-3) and an ultra-high porosity of 98%-99%was obtained.Benefiting from the anisotropic structure,the radial and axial thermal conductivities of HPAN/rGO-3 composite aerogel were 29.37 and 44.35 mW·m^(-1)·K^(-1),respectively.A combination of software simulation and experiments was used to analyze the effect of anisotropic structures on the thermal insulation properties of aerogels.Moreover,due to the intrinsic self-extinguishing properties of heterocyclic para-aramid and the protection of the graphene carbon layer,the composite aerogel also exhibits excellent flame retardancy properties,and its total heat release rate(THR)was only 5.8 kJ·g^(-1),which is far superior to many reported aerogels.Therefore,ultralight anisotropic HPAN/rGO composite aerogels with excellent high-temperature thermal insulation and flame retardancy properties have broad application prospects in complex environments such as aerospace.展开更多
Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect repair.In this study,TiO_(2)@reduced graphene oxide(rGO...Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect repair.In this study,TiO_(2)@reduced graphene oxide(rGO)composites were synthesized using a hydrothermal method in which rGO,which possesses very high electrical conductivity,promotes the separation of photoelectron-hole pairs of TiO_(2),thus improving the efficiency of photocatalytic production of reactive oxygen species(ROS).Subsequently,TiO_(2)@rGO composites were introduced into poly-L-lactic acid(PLLA)to prepare bone scaffolds with photocatalytic antibacterial function via selective laser sintering.The results showed that TiO_(2)grew on the surface of rGO and formed a covalent bond connection(Ti-O-C)with rGO.A decreased electrochemical impedance of TiO_(2)@rGO composites was observed,and the transient photocurrent intensity increased from 0.05 to 0.5μA/cm^(2).Analysis of electron spin resonance found that the photocatalytic products of TiO_(2)were·OH and·O^(2-),two kinds of ROS capable of killing bacteria via disrupting the structure of the bacterial membrane in vitro.Antibacterial experiments showed that the PLLA/TiO_(2)@rGO scaffolds had good antibacterial properties against Escherichia coli and Staphylococcus aureus.Finally,we report that these scaffolds exhibited both enhanced mechanical properties due to the addition of TiO_(2)@rGO as a reinforcement material and good biocompatibility during cell proliferation.展开更多
The present work investigates the microstructural evolution and mechanical properties in a novel medium-Si 12%Cr reduced activation ferritic/martensitic steel cladding tube(Fe-11.8Cr-0.2C-1.4W-0.17Ta-0.2V-0.55Si-0.5Mn...The present work investigates the microstructural evolution and mechanical properties in a novel medium-Si 12%Cr reduced activation ferritic/martensitic steel cladding tube(Fe-11.8Cr-0.2C-1.4W-0.17Ta-0.2V-0.55Si-0.5Mn,wt%)during multipass cold rolling and annealing.The initial hot-extruded tube exhibited a full martensitic matrix with the prior austenite grain size of~32μm.After annealing,Cr_(23)C_(6) and TaC particles were precipitated,which are basically unchanged(152-183 nm and 84-113 nm,respectively)during the manufacturing process.Meanwhile,with the cold-rolling strain(ε)increasing and subsequent annealing,the martensitic lath gradually diminishes,and the recrystallization volume fraction(f_(r))is increased.Based on the static recrystallization kinetics model,a clear relationship between f_(r) andεis established,in which the newly proposed kinetic equation demonstrates a strong correlation with the experimental results.Furthermore,the yield strength(σ_(YS)=362 MPa)of the final annealed state was much lower than that(σ_(YS)=482 MPa)of the initial annealed state,which can be attributed to the recrystallization from the martensitic matrix to ferritic matrix.Various strengthening mechanisms are further discussed,and the calculated strengths are in good agreement with the experimental results.This work provides a guidance for the optimization of cold-rolling and annealing treatments in the manufacture of cladding tube.展开更多
Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the wo rld.In general,it is thought that the electrochemical performance of recha rgeable batt...Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the wo rld.In general,it is thought that the electrochemical performance of recha rgeable batteries is mostly determined by the electrodes within them and that the electrolyte plays a relatively passive role.However,ion transport and storage can be greatly influenced by the electrolyte solution structure,specifically,ion solvation within the bulk and ion desolvation across the electrode/electrolyte interfaces.Herein,we studied the role of the electrolyte as an active component of electrochemical energy storage devices.We found that with an appropriate electrolyte formulation,ion storage in disordered carbonaceous anode materials can occur spontaneously without externally supplied electrical energy.Reduced graphene oxide(RGO)in an ether-based electrolyte demonstrates'spontaneous'ion storage behaviors of adsorbing and inserting the solvated ions utilizing facilitated permeability and wettability of RGO,which results in Coulombic efficiency of~145%due to additional charging capacity of~180 mAh g^(-1)during electrochemical processes.The unexpected spontaneous ion storage behavior was extensively investigated using a combination of electrochemical analyses and diagnostics,advanced characterizations,and computational simulation.We believe the spontaneous ion storage behavior offers a new way to further improve the energy efficiency of practical rechargeable batteries.展开更多
The iron and steel industry,standing as a quintessential manufacture example with high consumption,pollution and emissions,faces significant environmental and sustainable development challenges.Electric arc furnace(EA...The iron and steel industry,standing as a quintessential manufacture example with high consumption,pollution and emissions,faces significant environmental and sustainable development challenges.Electric arc furnace(EAF)steelmaking process mainly uses scrap as raw material and is characterized by environmentally friendly and recyclable process.However,the further development of EAF route in China is limited by the reserve,supply,availability and quality of scrap resource.Direct reduced iron(DRI)is one of typical low-carbon and clean charges,which can effectively make up for the adverse effects caused by the lack of scrap.The physical and chemical properties,classifications,and production technologies of DRI are firstly reviewed.In particular,the reducing gas types,reduction temperature,and reduction mechanism of the DRI production with gas-based shaft furnace(SF)technology are detailed.Considering the crucial role played by DRI application in EAF,the influences of DRI addition on EAF smelting rules and operations including the blending and charging process,heat transfer and melting in molten bath,slag formation operation,refractory corrosion,and slag system evolution are then further discussed.Finally,the comparative analysis and assessment of the consumption level of material and energy as well as the cleaner production both covering the clean chemical composition of molten steel and the clean environment impact in EAF steelmaking with DRI charged are conducted.From perspectives of metallurgical process engineering,a suitable route of hydrogen generation and application(from coke oven gas,methanol,and clean energy power),CO_(2) capture and utilization integrated with SF–EAF process is proposed.In view of the difficulties in large-scale DRI application in EAF,the follow-up work should focus on the investigation of DRI charging and melting,slag system evolution and molten pool reaction rules,as well as the developments of the DRI standardized use technology and intelligent batching and control models.展开更多
Accurate traffic flow prediction(TFP)is vital for efficient and sustainable transportation management and the development of intelligent traffic systems.However,missing data in real-world traffic datasets poses a sign...Accurate traffic flow prediction(TFP)is vital for efficient and sustainable transportation management and the development of intelligent traffic systems.However,missing data in real-world traffic datasets poses a significant challenge to maintaining prediction precision.This study introduces REPTF-TMDI,a novel method that combines a Reduced Error Pruning Tree Forest(REPTree Forest)with a newly proposed Time-based Missing Data Imputation(TMDI)approach.The REP Tree Forest,an ensemble learning approach,is tailored for time-related traffic data to enhance predictive accuracy and support the evolution of sustainable urbanmobility solutions.Meanwhile,the TMDI approach exploits temporal patterns to estimate missing values reliably whenever empty fields are encountered.The proposed method was evaluated using hourly traffic flow data from a major U.S.roadway spanning 2012-2018,incorporating temporal features(e.g.,hour,day,month,year,weekday),holiday indicator,and weather conditions(temperature,rain,snow,and cloud coverage).Experimental results demonstrated that the REPTF-TMDI method outperformed conventional imputation techniques across various missing data ratios by achieving an average 11.76%improvement in terms of correlation coefficient(R).Furthermore,REPTree Forest achieved improvements of 68.62%in RMSE and 70.52%in MAE compared to existing state-of-the-art models.These findings highlight the method’s ability to significantly boost traffic flow prediction accuracy,even in the presence of missing data,thereby contributing to the broader objectives of sustainable urban transportation systems.展开更多
Interfacial evolution and bonding mechanism of reduced activation ferritic/martensitic(RAFM)steel were systematically investigated through a series of hot compression tests conducted at various strains(0.15-0.8),strai...Interfacial evolution and bonding mechanism of reduced activation ferritic/martensitic(RAFM)steel were systematically investigated through a series of hot compression tests conducted at various strains(0.15-0.8),strain rates(0.001-1 s^(-1)),and temperatures(950-1050℃).Interfacial microstructural analysis revealed that plastic deformation of surface asperities effectively removes interfacial voids,and the evolution of dynamic recrystallization(DRX)aids in achieving a joint characterized by homogeneously refined microstructure and adequate interfacial grain boundary(IGB)migration.Electron backscattered diffraction analysis demonstrated that the continuous dynamic recrystallization,characterized by progressive subgrain rotation,is the prevailing DRX nucleation mechanism in RAFM steel during hot compression bonding.During DRX evolution,emerging DRX grains in the interfacial region expand into adjacent areas,transforming T-type triple junction grain boundaries into equal form,and resulting in a serrated and intricate interface.Elevated temperatures and strains,coupled with reduced strain rates,augment DRX grain nucleation and IGB migration,thus enhancing RAFM joint quality with regard to the interface bonding ratio and the interface migration ratio.展开更多
Sodium-ion batteries have garnered significant attention as a cost-effective alternative to lithium-ion batteries due to the abundance and affordability of sodium precursors.However,the lack of suitable electrode mate...Sodium-ion batteries have garnered significant attention as a cost-effective alternative to lithium-ion batteries due to the abundance and affordability of sodium precursors.However,the lack of suitable electrode materials with both high capacity and excellent stability continues to hinder their practical viability.Herein,we couple lattice strain and sulfur deficiency effects in a tin monosulfide/reduced graphene oxide composite to enhance sodium storage performance.Experimental results and theoretical calculations reveal that the synergistic effects of lattice strain and sulfur vacancies in tin monosulfide promote rapid(de)intercalation near the surface/edge of the material,thereby enhancing its pseudocapacitive sodium storage properties.Consequently,the strained and defective tin monosulfide/reduced graphene oxide composite demonstrates a high reversible capacity of 511.82 mAh g^(-1) at 1 A g^(-1) and an outstanding rate capability of 450.60 mAh g^(-1) at 3 A g^(-1).This study offers an effective strategy for improving sodium storage performance through lattice strain and defect engineering.展开更多
The tensile properties and deformation mechanisms of the reduced activation ferritic/martensitic steel—China low activation martensitic(CLAM)steel are determined from tests carried out over a wider range of strain ra...The tensile properties and deformation mechanisms of the reduced activation ferritic/martensitic steel—China low activation martensitic(CLAM)steel are determined from tests carried out over a wider range of strain rate and temperature.During high-temperature deformation,the plastic deformation modes involve dynamic recrystallization(DRX)and dynamic recovery(DRV)processes,which govern the mechanical behaviors of CLAM steel under different loading conditions.This work systematically explored the effects of increasing strain rates and temperatures,finding that the microstructure evolution process is facilitated by nano-sized M_(23)C_(6)precipitates and the grain boundaries of the initial microstructure.Under quasi-static loading conditions,DRX grains preferentially nucleate around M_(23)C_(6) precipitates,and the dominant deformation mechanism is DRX.However,under dynamic loading conditions,the number of DRX grains decreases significantly,and the dominant deformation mechanism converts to DRV.It was concluded that the coupling effects of strain rates and temperatures strongly influence DRX and DRV processes,which ultimately determine the mechanical properties and microstructure evolution.Moreover,dynamic deformation at elevated temperatures achieves much finer grain sizes,offering a novel method for grain refinement through dynamic straining processes.展开更多
The production of hydrogen peroxide(H_(2)O_(2))via artificial photosynthesis using single-atom semiconductor photocatalysts represents a promising green and sustainable technology.However,its efficiency is still limit...The production of hydrogen peroxide(H_(2)O_(2))via artificial photosynthesis using single-atom semiconductor photocatalysts represents a promising green and sustainable technology.However,its efficiency is still limited by sluggish water oxidation kinetics,poor photogenerated charge separation,and insufficient O_(2)adsorption and activation capabilities.Herein,uniformly dispersed single-atom catalysts(SACs)with a Co-N_(4)coordination structure have been synthesized by thermally transforming cobalt phthalocyanine(CoPc)assemblies pre-anchored on phosphate functionalized reduced graphene oxide(Co@rGO-P),and then used to construct heterojunctions with perylenetetracarboxylic acid(PTA)nanosheets for photocatalytic H_(2)O_(2)production by an in-situ growth method.The optimized Co@rGO-P/PTA achieved an H_(2)O_(2)production rate of 1.4 mmol g^(-1)h^(-1)in pure water,with a 12.9-fold enhancement compared to pristine PTA nanosheets exhibiting competitive photoactivity among reported perylene-based materials.Femtosecond transient absorption spectra,in-situ diffuse reflectance infrared Fourier transform spectra and theoretical calculations reveal that the exceptional performance is attributed to the enhanced electron transfer from PTA to rGO via the phosphate bridge and then to the Co-N_(4),and to the promoted O_(2)adsorption and activation at Co-N_(4)active sites.This work provides a feasible and effective strategy for designing highly efficient single-atom semiconductor heterojunction photocatalysts for H_(2)O_(2)production.展开更多
In this paper,the nonlinearization of the Lax pair and the Darboux transformation method are used to construct the rogue wave on the elliptic function background in the reduced Maxwell–Bloch system,which is described...In this paper,the nonlinearization of the Lax pair and the Darboux transformation method are used to construct the rogue wave on the elliptic function background in the reduced Maxwell–Bloch system,which is described by four component nonlinear evolution equations(NLEEs).On the background of the Jacobian elliptic function,we obtain the admissible eigenvalues and the corresponding non-periodic eigenfunctions of the model spectrum problem.Then,with the help of the one-fold Darboux transformation and two-fold Darboux transformation,rogue waves on a dn-periodic background and cn-periodic background are derived,respectively.Finally,the corresponding complex dynamical properties and evolutions of the four components are illustrated graphically by choosing suitable parameters.展开更多
Considering the serious electromagnetic wave(EMW)pollution problems and complex application condition,there is a pressing need to amalgamate multiple functionalities within a single substance.However,the effective int...Considering the serious electromagnetic wave(EMW)pollution problems and complex application condition,there is a pressing need to amalgamate multiple functionalities within a single substance.However,the effective integration of diverse functions into designed EMW absorption materials still faces the huge challenges.Herein,reduced graphene oxide/carbon foams(RGO/CFs)with two-dimensional/three-dimensional(2D/3D)van der Waals(vdWs)heterostructures were meticulously engineered and synthesized utilizing an efficient methodology involving freeze-drying,immersing absorption,secondary freeze-drying,followed by carbonization treatment.Thanks to their excellent linkage effect of amplified dielectric loss and optimized impedance matching,the designed 2D/3D RGO/CFs vdWs heterostructures demonstrated commendable EMW absorption performances,achieving a broad absorption bandwidth of 6.2 GHz and a reflection loss of-50.58 dB with the low matching thicknesses.Furthermore,the obtained 2D/3D RGO/CFs vdWs heterostructures also displayed the significant radar stealth properties,good corrosion resistance performances as well as outstanding thermal insulation capabilities,displaying the great potential in complex and variable environments.Accordingly,this work not only demonstrated a straightforward method for fabricating 2D/3D vdWs heterostructures,but also outlined a powerful mixeddimensional assembly strategy for engineering multifunctional foams for electromagnetic protection,aerospace and other complex conditions.展开更多
文摘BACKGROUND Pediatric liver transplantation(LT)is the definitive treatment for end-stage liver disease and acute liver failure in children.However,graft size mismatch poses significant challenges,particularly in infants weighing less than 10 kg.Large-forsize grafts can lead to severe complications,including vascular thrombosis and impaired graft perfusion.Surgical innovations,such as hyper-reduced left lateral segment(HRLLS)grafts and monosegmental grafts(MSG),offer viable solutions by tailoring graft size without compromising vascular or biliary integrity.AIM To analyze the techniques and outcomes of HRLLS and MSG grafts in pediatric liver trabsplantation.METHODS Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across PubMed,Scopus,and Google Scholar,including studies up to February 2025.Eligible studies included case-control,observational,and randomized controlled trials reporting clinical outcomes of HRLLS,MSG,or reduced left lateral segment grafts(RLLS)in pediatric LT.The Joanna Briggs Institute Critical Appraisal Checklist was used for quality assessment.Meta-analysis was performed using MetaXL software to pool survival outcomes and assess complication profiles.RESULTS Eighteen studies involving various graft reduction techniques were included.Both HRLLS and MSG demonstrated comparable one-year survival rates exceeding 80%,with some studies reporting rates above 95%.Complications such as hepatic artery thrombosis,portal vein thrombosis,and sepsis were slightly more frequent in HRLLS/RLLS recipients but remained within acceptable limits.Meta-analysis revealed no significant differences in survivability between graft types.CONCLUSION HRLLS and MSG techniques enable successful liver transplantation in small pediatric recipients,achieving longterm outcomes comparable to standard approaches.These graft modification strategies expand donor pool utilization and optimize patient survival while mitigating large-for-size complications.
基金supported by the National Natural Science Foundation of China(No.61904073)Spring City Plan-Special Program for Young Talents(No.K202005007)+4 种基金Yunnan Talents Support Plan for Yong Talents(No.XDYC-QNRC-20220482)Yunnan Local Colleges Applied Basic Research Projects(No.202101BA070001-138)Scientific Research Fund of Yunnan Education Department(No.2023Y0883)Frontier Research Team of Kunming University 2023Key Laboratory of Artificial Microstructures in Yunnan Higher Education。
文摘Silicon-air batteries(SABs),a new type of semiconductor air battery,have a high energy density.However,some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge,and the anode utilization rate is low.In this work,reduced graphene oxide(RGO)fabricated via high-temperature annealing or L-ascorbic acid(L.AA)reduction was first used to obtain Si nanowires/RGO-1000(Si NWs/RGO-1000)and Si nanowires/RGO-L.AA(Si NWs/RGO-L.AA)composite anodes for SABs.It was found that RGO suppressed the passivation and self-corrosion reactions and that SABs using Si NWs/RGO-L.AA as the anode can discharge for more than 700 h,breaking the previous performance of SABs,and that the specific capacity was increased by 90.8%compared to bare Si.This work provides a new solution for the design of high specific capacity SABs with nanostructures and anode protective layers.
基金support of the Key Science Research Project in Colleges and Universities of Anhui Province,China(No.2022AH050813)the Medical Special Cultivation Project of Anhui University of Science and Technology,China(No.YZ2023H2A002).
文摘Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption materials.In this study,a flake-like nickel cobaltate/re-duced graphene oxide/melamine-derived carbon foam(FNC/RGO/MDCF)was successfully fabricated through a combination of solvo-thermal treatment and high-temperature pyrolysis.Results indicated that RGO was evenly distributed in the MDCF skeleton,providing ef-fective support for the load growth of FNC on its surface.Sample S3,the FNC/RGO/MDCF composite prepared by solvothermal method for 16 h,exhibited a minimum reflection loss(RL_(min))of-66.44 dB at a thickness of 2.29 mm.When the thickness was reduced to 1.50 mm,the optimal effective absorption bandwidth was 3.84 GHz.Analysis of the absorption mechanism of FNC/RGO/MDCF revealed that its excellent absorption performance was primarily attributed to the combined effects of conduction loss,multiple reflection,scattering,in-terface polarization,and dipole polarization.
基金support by the National Key R&D Program of China(Grant No.2023YFA1008901)the National Natural Science Foundation of China(Grant Nos.11988102,12172009)is gratefully acknowledged.
文摘In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational homogenization.The method is based on the reduced-order homogenization(ROH)approach.The ROH method typically involves solving multiple finite element problems under periodic conditions to evaluate elastic strain and eigenstrain influence functions in an‘off-line’stage,which offers substantial cost savings compared to direct computational homogenization methods.Due to the unique structure of the fibrous unit cell,“off-line”stage calculation can be eliminated by influence functions obtained analytically.Introducing the standard solid model to the ROH method enables the creation of a comprehensive analytical homogeneous viscoelastic constitutive model.This method treats fibrous composite materials as homogeneous,anisotropic viscoelastic materials,significantly reducing computational time due to its analytical nature.This approach also enables precise determination of a homogenized anisotropic relaxation modulus and accurate capture of various viscoelastic responses under different loading conditions.Three sets of numerical examples,including unit cell tests,three-point beam bending tests,and torsion tests,are given to demonstrate the predictive performance of the homogenized viscoelastic model.Furthermore,the model is validated against experimental measurements,confirming its accuracy and reliability.
基金Supported by the National Natural Science Foundation of China (Grant No. 52171298)the National Foreign Experts Program (G2023180006L)+1 种基金the Natural Science Foundation of Heilongjiang Province of China (Grant No. ZD2019E003)the Fundamental Research Funds for the Central Universities (Grant No. 3072022TS0303)。
文摘Biodiesel is a clean and renewable energy,and it is an effective measure to optimize engine combustion fueled with biodiesel to meet the increasingly strict toxic and CO_(2) emission regulations of internal combustion engines.A suitable-scale chemical kinetic mechanism is very crucial for the accurate and rapid prediction of engine combustion and emissions.However,most previous researchers developed the mechanism of blend fuels through the separate simplification and merging of the reduced mechanisms of diesel and biodiesel rather than considering their cross-reaction.In this study,a new reduced chemical reaction kinetics mechanism of diesel and biodiesel was constructed through the adoption of directed relationship graph (DRG),directed relationship graph with error propagation,and full-species sensitivity analysis (FSSA).N-heptane and methyl decanoate (MD) were selected as surrogates of traditional diesel and biodiesel,respectively.In this mechanism,the interactions between the intermediate products of both fuels were considered based on the cross-reaction theory.Reaction pathways were revealed,and the key species involved in the oxidation of n-heptane and MD were identified through sensitivity analyses.The reduced mechanism of n-heptane/MD consisting of 288 species and 800 reactions was developed and sufficiently verified by published experimental data.Prediction maps of ignition delay time were established at a wide range of parameter matrices (temperature from 600 to 1 700 K,pressure from 10 bar to 80 bar,equivalence ratio from 0.5 to 1.5) and different substitution ratios to identify the occurrence regions of the crossreaction.Concentration and sensitivity analyses were then conducted to further investigate the effects of cross-reactions.The results indicate temperature as the primary factor causing cross-reactivity.In addition,the reduced mechanism with cross-reactions was more accurate than that without cross-reactions.At 700–1 000 K,the cross-reactions inhibited the consumption of n-heptane/MD,which resulted in a prolonged ignition delay time.At this point,the elementary reaction,NC_(7)H_(16)+OH<=>C_(7)H_(15)-2+H_(2)O,played a dominant role in fuel consumption.Specifically,the contribution of the MD consumption reaction to ignition decreased,and the increased generation time of OH,HO_(2),and H_(2)O_(2) was directly responsible for the increased ignition delay.
基金funded by the National Key Research and Development Program of China(No.20022YFC3102405)the National Natural Science Foundation of China(Nos.42425004,32371665)the Natural Science Foundation of Guangdong Province(Nos.2022A1515011461,2022A1515011831)。
文摘Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological information associated with environmental changes as it reflects their growth potential.To evaluate the effects of the changes in salinity and nutrients,the photosynthetic efficiency of a green macroalga Ulva fasciata from the Daya Bay was tested at a range of salinity(i.e.,31 to 10 psu)and nitrogen content(i.e.,5 to 60μmol L^(-1)).The results showed that cellular chlorophyll a(Chl a),carbohydrate and protein contents of U.fasciata were increased due to reduced salinity,and were decreased by interactive nitrogen enrichment.Within a short culture period(i.e.,18 h),the reduced salinity decreased the maximum photosynthetic efficiency(rETRmax and Pmax)derived from the rapid light response curve and photosynthetic oxygen evolution rate versus irradiance curve,respectively,as well as the saturation irradiance(E_(K)).This reducing effect diminished with enlonged cultivation time and reversed to a stimulating effect after 24 h of cultivation.The nitrogen enrichment stimulated the rETRmax and Pmax,as well as the E_(K),regardless of salinity,especially within short-term cultivation period(i.e.,<24 h).In addition,our results indicate that seawater freshening lowers the photosynthetic efficiency of U.fasciata in the short term,which is mitigated by nitrogen enrichment,but stimulates it in the long term,providing insight into how macroalgae thrive in coastal or estuarine waters where salinity and nutrients normally covary strongly.
基金support from Basic research project of Education Department of Liaoning Province(LJKZ0256)Special Fund for Basic Scientific Research of Liaoning Province(LJKZSYLUGX027).
文摘The indiscriminate use and disposal of ciprofloxacin(CIP)have led to its detection in water globally,which pose a huge risk to public health and water environment.Herein,(Zn-Al)LDHs modified 3D reduced graphene oxide nanocomposite((Zn-Al)LDHs/3D-rGO)was synthesized through a feasible onepot hydrothermal method for CIP removal.The highly distributed(Zn-Al)LDHs flakes on the surface of 3D-rGO endow the resulted(Zn-Al)LDHs/3D-rGO with an excellent adsorption performance for CIP.The adsorption results showed that the adsorption process could be well interpreted by Temkin isothermal model and the pseudo second-order kinetics model.The maximal adsorption capacity of 20.01 mg·g^(-1)for CIP could be achieved under the optimal conditions optimized by response surface methodology(RSM).The inhibitory effect of co-existing ions on CIP adsorption were also discussed.The probable adsorption mechanism might be ascribed toπ-πinteractions,hydrogen bonding,electrostatic,and surface complexation.Regeneration tests showed that the obtained 3D porous material also possessed pronounced recyclability.The obtained(Zn-Al)LDHs/3D-rGO holds a great potential for removal of CIP from actual wastewater.
基金supported by the‘Double First-Class’Key Scientific Research Project of Education Department in Gansu Province,China(GSSYLXM-02)the National Natural Science Foundation of China(U21A20218 and 32160765)+3 种基金the earmarked fund for China Agriculture Research System(CARS-22-G-12)the Science and Technology Project of Gansu Province,China(20JR5RA037 and 21JR7RA836)the Postdoctoral Research Start-up Foundation of Gansu Province,China(03824034)the Postdoctoral Research Start-up Foundation of Gansu Agricultural University,China(202403)。
文摘A critical challenge for global food security and sustainable agriculture is enhancing crop yields while reducing chemical N inputs.Improving N use efficiency in crops is essential for increasing agricultural productivity.The aim of this study was to evaluate the impacts of intercropping maize with leguminous green manure on grain yield and N utilization under reduced N-fertilization conditions.A field experiment with a split-plot design was conducted in northwestern China from 2018 to 2021.The main plots consisted of two cropping systems:maize-common vetch intercropping(IM)and sole maize(SM).The subplots had three N levels:zero N application(N0,0 kg ha^(-1)),a 25%reduction from the traditional chemical N supply(N1,270 kg ha^(-1)),and the traditional chemical N supply(N2,360 kg ha^(-1)).The results showed that the negative effects of N reduction on maize grain yield and N uptake were compensated by intercropping leguminous green manure,and the improvements increased with cultivation years.The integrated system involving maize-leguminous green manure intercropping and a reduced N supply enhanced N translocation from maize vegetative organs to grains and increased the nitrate reductase and glutamine synthetase activities in maize leaves.The supercompensatory effect in maize leaves increased year by year,reaching values of 16.1,21.3,and 25.5%in 2019,2020,and 2021,respectively.These findings suggest that intercropping maize with leguminous green manure under reduced chemical N input can enhance N assimilation and uptake in maize.By using this strategy,chemical fertilizer is effectively replaced by leguminous green manure,thereby improving N use efficiency and maintaining stable yields in the maize-based intercropping system.
基金supported by the National Key R&D Program of China(No.2021YFB3700103).
文摘The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene oxide(HPAN/rGO)composite aerogel was prepared by combining electrospinning and unidirectional freeze-drying.The anisotropic HPAN/rGO composite aerogel exhibited a honeycomb morphology in the direction perpendicular to the growth of ice crystals,and a through-well structure of directed microchannels in the direction parallel to the temperature gradient.By varying the mass ratio of HPAN/rGO,a composite aerogel with an ultra-low density of 5.34-7.81 mg·cm^(-3) and an ultra-high porosity of 98%-99%was obtained.Benefiting from the anisotropic structure,the radial and axial thermal conductivities of HPAN/rGO-3 composite aerogel were 29.37 and 44.35 mW·m^(-1)·K^(-1),respectively.A combination of software simulation and experiments was used to analyze the effect of anisotropic structures on the thermal insulation properties of aerogels.Moreover,due to the intrinsic self-extinguishing properties of heterocyclic para-aramid and the protection of the graphene carbon layer,the composite aerogel also exhibits excellent flame retardancy properties,and its total heat release rate(THR)was only 5.8 kJ·g^(-1),which is far superior to many reported aerogels.Therefore,ultralight anisotropic HPAN/rGO composite aerogels with excellent high-temperature thermal insulation and flame retardancy properties have broad application prospects in complex environments such as aerospace.
基金supported by the following funds:The National Natural Science Foundation of China(Nos.52275393,51935014,and 82072084)Jiangxi Provincial Natural Science Foundation of China(No.20224ACB204013)+2 种基金The Project of State Key Laboratory of Precision Manufacturing for Extreme Service Performancethe National Key Research and Development Program of China(No.2023YFB4605800)the Independent Exploration and Innovation Project of Central South University(No.1053320221707).
文摘Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect repair.In this study,TiO_(2)@reduced graphene oxide(rGO)composites were synthesized using a hydrothermal method in which rGO,which possesses very high electrical conductivity,promotes the separation of photoelectron-hole pairs of TiO_(2),thus improving the efficiency of photocatalytic production of reactive oxygen species(ROS).Subsequently,TiO_(2)@rGO composites were introduced into poly-L-lactic acid(PLLA)to prepare bone scaffolds with photocatalytic antibacterial function via selective laser sintering.The results showed that TiO_(2)grew on the surface of rGO and formed a covalent bond connection(Ti-O-C)with rGO.A decreased electrochemical impedance of TiO_(2)@rGO composites was observed,and the transient photocurrent intensity increased from 0.05 to 0.5μA/cm^(2).Analysis of electron spin resonance found that the photocatalytic products of TiO_(2)were·OH and·O^(2-),two kinds of ROS capable of killing bacteria via disrupting the structure of the bacterial membrane in vitro.Antibacterial experiments showed that the PLLA/TiO_(2)@rGO scaffolds had good antibacterial properties against Escherichia coli and Staphylococcus aureus.Finally,we report that these scaffolds exhibited both enhanced mechanical properties due to the addition of TiO_(2)@rGO as a reinforcement material and good biocompatibility during cell proliferation.
基金supported by the National Natural Science Foundation of China(No.52171152).
文摘The present work investigates the microstructural evolution and mechanical properties in a novel medium-Si 12%Cr reduced activation ferritic/martensitic steel cladding tube(Fe-11.8Cr-0.2C-1.4W-0.17Ta-0.2V-0.55Si-0.5Mn,wt%)during multipass cold rolling and annealing.The initial hot-extruded tube exhibited a full martensitic matrix with the prior austenite grain size of~32μm.After annealing,Cr_(23)C_(6) and TaC particles were precipitated,which are basically unchanged(152-183 nm and 84-113 nm,respectively)during the manufacturing process.Meanwhile,with the cold-rolling strain(ε)increasing and subsequent annealing,the martensitic lath gradually diminishes,and the recrystallization volume fraction(f_(r))is increased.Based on the static recrystallization kinetics model,a clear relationship between f_(r) andεis established,in which the newly proposed kinetic equation demonstrates a strong correlation with the experimental results.Furthermore,the yield strength(σ_(YS)=362 MPa)of the final annealed state was much lower than that(σ_(YS)=482 MPa)of the initial annealed state,which can be attributed to the recrystallization from the martensitic matrix to ferritic matrix.Various strengthening mechanisms are further discussed,and the calculated strengths are in good agreement with the experimental results.This work provides a guidance for the optimization of cold-rolling and annealing treatments in the manufacture of cladding tube.
基金supported by the faculty research fund of Sejong Universityfunding from the National Research Foundation of Korea(NRF)under grant number NRF-2022R1F1A1071444+2 种基金funding from NRF under grant numbers NRF-2022R1A2B5B03001781Funding provided by the Department of Energy Office of Energy EfficiencyRenewable Energy Vehicles Technology Office。
文摘Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the wo rld.In general,it is thought that the electrochemical performance of recha rgeable batteries is mostly determined by the electrodes within them and that the electrolyte plays a relatively passive role.However,ion transport and storage can be greatly influenced by the electrolyte solution structure,specifically,ion solvation within the bulk and ion desolvation across the electrode/electrolyte interfaces.Herein,we studied the role of the electrolyte as an active component of electrochemical energy storage devices.We found that with an appropriate electrolyte formulation,ion storage in disordered carbonaceous anode materials can occur spontaneously without externally supplied electrical energy.Reduced graphene oxide(RGO)in an ether-based electrolyte demonstrates'spontaneous'ion storage behaviors of adsorbing and inserting the solvated ions utilizing facilitated permeability and wettability of RGO,which results in Coulombic efficiency of~145%due to additional charging capacity of~180 mAh g^(-1)during electrochemical processes.The unexpected spontaneous ion storage behavior was extensively investigated using a combination of electrochemical analyses and diagnostics,advanced characterizations,and computational simulation.We believe the spontaneous ion storage behavior offers a new way to further improve the energy efficiency of practical rechargeable batteries.
基金financial support from the National Natural Science Foundation of China(No.52174328)the Fundamental Research Funds for the Central Universities of Central South University(No.2024ZZTS0062).
文摘The iron and steel industry,standing as a quintessential manufacture example with high consumption,pollution and emissions,faces significant environmental and sustainable development challenges.Electric arc furnace(EAF)steelmaking process mainly uses scrap as raw material and is characterized by environmentally friendly and recyclable process.However,the further development of EAF route in China is limited by the reserve,supply,availability and quality of scrap resource.Direct reduced iron(DRI)is one of typical low-carbon and clean charges,which can effectively make up for the adverse effects caused by the lack of scrap.The physical and chemical properties,classifications,and production technologies of DRI are firstly reviewed.In particular,the reducing gas types,reduction temperature,and reduction mechanism of the DRI production with gas-based shaft furnace(SF)technology are detailed.Considering the crucial role played by DRI application in EAF,the influences of DRI addition on EAF smelting rules and operations including the blending and charging process,heat transfer and melting in molten bath,slag formation operation,refractory corrosion,and slag system evolution are then further discussed.Finally,the comparative analysis and assessment of the consumption level of material and energy as well as the cleaner production both covering the clean chemical composition of molten steel and the clean environment impact in EAF steelmaking with DRI charged are conducted.From perspectives of metallurgical process engineering,a suitable route of hydrogen generation and application(from coke oven gas,methanol,and clean energy power),CO_(2) capture and utilization integrated with SF–EAF process is proposed.In view of the difficulties in large-scale DRI application in EAF,the follow-up work should focus on the investigation of DRI charging and melting,slag system evolution and molten pool reaction rules,as well as the developments of the DRI standardized use technology and intelligent batching and control models.
文摘Accurate traffic flow prediction(TFP)is vital for efficient and sustainable transportation management and the development of intelligent traffic systems.However,missing data in real-world traffic datasets poses a significant challenge to maintaining prediction precision.This study introduces REPTF-TMDI,a novel method that combines a Reduced Error Pruning Tree Forest(REPTree Forest)with a newly proposed Time-based Missing Data Imputation(TMDI)approach.The REP Tree Forest,an ensemble learning approach,is tailored for time-related traffic data to enhance predictive accuracy and support the evolution of sustainable urbanmobility solutions.Meanwhile,the TMDI approach exploits temporal patterns to estimate missing values reliably whenever empty fields are encountered.The proposed method was evaluated using hourly traffic flow data from a major U.S.roadway spanning 2012-2018,incorporating temporal features(e.g.,hour,day,month,year,weekday),holiday indicator,and weather conditions(temperature,rain,snow,and cloud coverage).Experimental results demonstrated that the REPTF-TMDI method outperformed conventional imputation techniques across various missing data ratios by achieving an average 11.76%improvement in terms of correlation coefficient(R).Furthermore,REPTree Forest achieved improvements of 68.62%in RMSE and 70.52%in MAE compared to existing state-of-the-art models.These findings highlight the method’s ability to significantly boost traffic flow prediction accuracy,even in the presence of missing data,thereby contributing to the broader objectives of sustainable urban transportation systems.
基金The authors are grateful to the National Natural Science Foundation of China(Grant Nos.52034004 and 52271111)the National Key R&D Program of China(2022YFB3705300)for grant and financial support.
文摘Interfacial evolution and bonding mechanism of reduced activation ferritic/martensitic(RAFM)steel were systematically investigated through a series of hot compression tests conducted at various strains(0.15-0.8),strain rates(0.001-1 s^(-1)),and temperatures(950-1050℃).Interfacial microstructural analysis revealed that plastic deformation of surface asperities effectively removes interfacial voids,and the evolution of dynamic recrystallization(DRX)aids in achieving a joint characterized by homogeneously refined microstructure and adequate interfacial grain boundary(IGB)migration.Electron backscattered diffraction analysis demonstrated that the continuous dynamic recrystallization,characterized by progressive subgrain rotation,is the prevailing DRX nucleation mechanism in RAFM steel during hot compression bonding.During DRX evolution,emerging DRX grains in the interfacial region expand into adjacent areas,transforming T-type triple junction grain boundaries into equal form,and resulting in a serrated and intricate interface.Elevated temperatures and strains,coupled with reduced strain rates,augment DRX grain nucleation and IGB migration,thus enhancing RAFM joint quality with regard to the interface bonding ratio and the interface migration ratio.
基金supported by the National Natural Science Foundation of China(no.22109023,no.22179022,and no.22209027)the Youth Innovation Fund of Fujian Province(no.2021J05043 and no.2022J05046)+5 种基金the National Key Research and Development Program of China(2023YFC3906300)the FuXiaQuan National Independent Innovation Demonstration Zone Collaborative Innovation Platform(no.2022-P-027)the·“Hundred Talents·Plan”of Fujian Provincethe“Top Young Talents of Young Eagle”Program of Fujian Provincethe Award Program for Fujian Minjiang Scholar Professorshipthe Talent Fund Program of Fujian Normal University.
文摘Sodium-ion batteries have garnered significant attention as a cost-effective alternative to lithium-ion batteries due to the abundance and affordability of sodium precursors.However,the lack of suitable electrode materials with both high capacity and excellent stability continues to hinder their practical viability.Herein,we couple lattice strain and sulfur deficiency effects in a tin monosulfide/reduced graphene oxide composite to enhance sodium storage performance.Experimental results and theoretical calculations reveal that the synergistic effects of lattice strain and sulfur vacancies in tin monosulfide promote rapid(de)intercalation near the surface/edge of the material,thereby enhancing its pseudocapacitive sodium storage properties.Consequently,the strained and defective tin monosulfide/reduced graphene oxide composite demonstrates a high reversible capacity of 511.82 mAh g^(-1) at 1 A g^(-1) and an outstanding rate capability of 450.60 mAh g^(-1) at 3 A g^(-1).This study offers an effective strategy for improving sodium storage performance through lattice strain and defect engineering.
基金financially supported by National Natural Science Foundation of China(Grant Nos.12025205 and 12141203)Natural Science Basic Research Program of Shaanxi(Program No.S2023-JC-QN-0614)Fund for Basic Research(No.2021T019)from the Analytical&Testing Center of Northwestern Polytechnical University.
文摘The tensile properties and deformation mechanisms of the reduced activation ferritic/martensitic steel—China low activation martensitic(CLAM)steel are determined from tests carried out over a wider range of strain rate and temperature.During high-temperature deformation,the plastic deformation modes involve dynamic recrystallization(DRX)and dynamic recovery(DRV)processes,which govern the mechanical behaviors of CLAM steel under different loading conditions.This work systematically explored the effects of increasing strain rates and temperatures,finding that the microstructure evolution process is facilitated by nano-sized M_(23)C_(6)precipitates and the grain boundaries of the initial microstructure.Under quasi-static loading conditions,DRX grains preferentially nucleate around M_(23)C_(6) precipitates,and the dominant deformation mechanism is DRX.However,under dynamic loading conditions,the number of DRX grains decreases significantly,and the dominant deformation mechanism converts to DRV.It was concluded that the coupling effects of strain rates and temperatures strongly influence DRX and DRV processes,which ultimately determine the mechanical properties and microstructure evolution.Moreover,dynamic deformation at elevated temperatures achieves much finer grain sizes,offering a novel method for grain refinement through dynamic straining processes.
文摘The production of hydrogen peroxide(H_(2)O_(2))via artificial photosynthesis using single-atom semiconductor photocatalysts represents a promising green and sustainable technology.However,its efficiency is still limited by sluggish water oxidation kinetics,poor photogenerated charge separation,and insufficient O_(2)adsorption and activation capabilities.Herein,uniformly dispersed single-atom catalysts(SACs)with a Co-N_(4)coordination structure have been synthesized by thermally transforming cobalt phthalocyanine(CoPc)assemblies pre-anchored on phosphate functionalized reduced graphene oxide(Co@rGO-P),and then used to construct heterojunctions with perylenetetracarboxylic acid(PTA)nanosheets for photocatalytic H_(2)O_(2)production by an in-situ growth method.The optimized Co@rGO-P/PTA achieved an H_(2)O_(2)production rate of 1.4 mmol g^(-1)h^(-1)in pure water,with a 12.9-fold enhancement compared to pristine PTA nanosheets exhibiting competitive photoactivity among reported perylene-based materials.Femtosecond transient absorption spectra,in-situ diffuse reflectance infrared Fourier transform spectra and theoretical calculations reveal that the exceptional performance is attributed to the enhanced electron transfer from PTA to rGO via the phosphate bridge and then to the Co-N_(4),and to the promoted O_(2)adsorption and activation at Co-N_(4)active sites.This work provides a feasible and effective strategy for designing highly efficient single-atom semiconductor heterojunction photocatalysts for H_(2)O_(2)production.
基金supported by the National Natural Science Foundation of China(Grant No.12361052)the Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region(Grant No.NMGIRT2414)+3 种基金the Fundamental Research Funds for the Inner Mongolia Normal University,China(Grant Nos.2022JBTD007,2022JBXC013)Graduate Students'Research and Innovation Fund of Inner Mongolia Autonomous Region(Grant No.B20231053Z)the Key Laboratory of Infinite-Dimensional Hamiltonian System and Its Algorithm Application(Inner Mongolia Normal University),the Ministry of Education(Grant Nos.2023KFZR01,2023KFZR02)the First-Class Disciplines Project,Inner Mongolia Autonomous Region,China(Grant No.YLXKZX-NSD-001)。
文摘In this paper,the nonlinearization of the Lax pair and the Darboux transformation method are used to construct the rogue wave on the elliptic function background in the reduced Maxwell–Bloch system,which is described by four component nonlinear evolution equations(NLEEs).On the background of the Jacobian elliptic function,we obtain the admissible eigenvalues and the corresponding non-periodic eigenfunctions of the model spectrum problem.Then,with the help of the one-fold Darboux transformation and two-fold Darboux transformation,rogue waves on a dn-periodic background and cn-periodic background are derived,respectively.Finally,the corresponding complex dynamical properties and evolutions of the four components are illustrated graphically by choosing suitable parameters.
基金provided by Guizhou Provincial Science and Technology Projects for Platform and Talent Team Plan(GCC[2023]007)Fok Ying Tung Education Foundation(171095)National Natural Science Foundation of China(11964006).
文摘Considering the serious electromagnetic wave(EMW)pollution problems and complex application condition,there is a pressing need to amalgamate multiple functionalities within a single substance.However,the effective integration of diverse functions into designed EMW absorption materials still faces the huge challenges.Herein,reduced graphene oxide/carbon foams(RGO/CFs)with two-dimensional/three-dimensional(2D/3D)van der Waals(vdWs)heterostructures were meticulously engineered and synthesized utilizing an efficient methodology involving freeze-drying,immersing absorption,secondary freeze-drying,followed by carbonization treatment.Thanks to their excellent linkage effect of amplified dielectric loss and optimized impedance matching,the designed 2D/3D RGO/CFs vdWs heterostructures demonstrated commendable EMW absorption performances,achieving a broad absorption bandwidth of 6.2 GHz and a reflection loss of-50.58 dB with the low matching thicknesses.Furthermore,the obtained 2D/3D RGO/CFs vdWs heterostructures also displayed the significant radar stealth properties,good corrosion resistance performances as well as outstanding thermal insulation capabilities,displaying the great potential in complex and variable environments.Accordingly,this work not only demonstrated a straightforward method for fabricating 2D/3D vdWs heterostructures,but also outlined a powerful mixeddimensional assembly strategy for engineering multifunctional foams for electromagnetic protection,aerospace and other complex conditions.
