The present work provides a facile and efficient method for producing ultrafine copper powders.Ultrafine copper powders were synthesized through a solvothermal method,utilizing ethanol both as a solvent and a reducing...The present work provides a facile and efficient method for producing ultrafine copper powders.Ultrafine copper powders were synthesized through a solvothermal method,utilizing ethanol both as a solvent and a reducing agent.Specifically,by exploiting the weak reducing property of ethanol,the copper precursor is first converted to copper oxide and then further reduced to cuprous oxide and pure copper.Such a method can effectively control the morphology and particle size of the copper powder,reduce particle aggregation,and enhance oxidation resistance.It is cost-effective and produces fewer toxic by-products.Spherical copper particles with an average particle size of about 180 nm were obtained.The initial oxidation temperature is approximately 150℃,and the resulting copper powders can be stored stably under ambient conditions for at least 5 months,demonstrating excellent oxidation resistance and thermal stability.展开更多
A dual-phase synergistic enhancement method was adopted to strengthen the Al-Mn-Mg-Sc-Zr alloy fabricated by laser powder bed fusion(LPBF)by leveraging the unique advantages of Er and TiB_(2).Spherical powders of 0.5w...A dual-phase synergistic enhancement method was adopted to strengthen the Al-Mn-Mg-Sc-Zr alloy fabricated by laser powder bed fusion(LPBF)by leveraging the unique advantages of Er and TiB_(2).Spherical powders of 0.5wt%Er-1wt%TiB_(2)/Al-Mn-Mg-Sc-Zr nanocomposite were prepared using vacuum homogenization technique,and the density of samples prepared through the LPBF process reached 99.8%.The strengthening and toughening mechanisms of Er-TiB_(2)were investigated.The results show that Al_(3)Er diffraction peaks are detected by X-ray diffraction analysis,and texture strength decreases according to electron backscatter diffraction results.The added Er and TiB_(2)nano-reinforcing phases act as heterogeneous nucleation sites during the LPBF forming process,hindering grain growth and effectively refining the grains.After incorporating the Er-TiB_(2)dual-phase nano-reinforcing phases,the tensile strength and elongation at break of the LPBF-deposited samples reach 550 MPa and 18.7%,which are 13.4%and 26.4%higher than those of the matrix material,respectively.展开更多
The application and promotion of waste glass powder concrete(WGPC)cansignificantly alleviate the pressure of concrete material scarcity and environmental pollution.Compressive strength(CS)is a critical parameter for e...The application and promotion of waste glass powder concrete(WGPC)cansignificantly alleviate the pressure of concrete material scarcity and environmental pollution.Compressive strength(CS)is a critical parameter for evaluating the efficacy of WGPC.Unlike conventional testing methods,machine learning techniques offer precise and reliable predictions of concrete’s compressive strength,especially in its long-term mechanical properties.In this work,four models,namely Multiple Linear Regression(MLR),Back Propagation Neural Network(BPNN),Support Vector Regression(SVR),and Random Forest Regression(RFR)were employed.Furthermore,particle swarm optimization(PSO)algorithm and cross-validation techniques were applied to fine-tune the model parameters,striving for peak prediction performance.The results indicated that optimized models generally exhibit enhanced predictive accuracy compared to their basic counterparts.Notably,the PSO-RFR model excels among all evaluated models,showcasing superior performance on the testing dataset.It achieves a coefficient of determination(R^(2))of 0.9231,a mean absolute error(MAE)of 2.1073,and a root mean square error(RMSE)of 3.6903.When compared to experimental results,the PSO-RFR and PSO-BPNN models demonstrate exceptional predictive accuracy.Notably,the PSO-BPNN model exhibits the closest R^(2)values between its training and test sets.This close alignment of R^(2)values between the training and testing sets reflects the PSO-BPNN model’s superior generalization ability for unseen data.The findings present an efficient method for predicting concrete’s compressive strength,contributing to the sustainable development of concrete materials,and providing theoretical support for their research and application.展开更多
Laser powder bed fusion(LPBF)is highly suitable for forming 18Ni300 mold steel,thanks to its excellent capability in manufacturing complex shapes and outstanding capacity for regulating microstructures.It is widely us...Laser powder bed fusion(LPBF)is highly suitable for forming 18Ni300 mold steel,thanks to its excellent capability in manufacturing complex shapes and outstanding capacity for regulating microstructures.It is widely used in fields such as injection molding,die casting,and stamping dies.Adding reinforcing particles into steel is an effective means to improve its performance.Nb/18Ni300 composites were fabricated by LPBF using two kinds of Nb powders with different particle sizes,and their microstructures and properties were studied.The results show that the unmelted Nb particles are uniformly distributed in the 18Ni300 matrix and the grains are refined,which is particularly pronounced with fine Nb particles.In addition,element diffusion occurs between the particles and the matrix.The main phases of the base alloy are α-Fe and a small amount of γ-Fe.With the addition of Nb,part of the α-Fe is transformed into γ-Fe,and unmelted Nb phases appear.The addition of Nb also enhances the hardness and wear resistance of the composites but slightly reduces their tensile properties.After aging treatment,the molten pools and grain boundaries become blurred,grains are further refined,and the interfaces around the particles are thinned.The aging treatment also promotes the formation of reverted austenite.The hardness,ultimate tensile strength,and volumetric wear rate of the base alloy reach 51.9 HRC,1704 MPa,and 17.8×10^(-6) mm^(3)/(N·m),respectively.In contrast,the sample added with fine Nb particles has the highest hardness(56.1 HRC),ultimate tensile strength(1892 MPa)and yield strength(1842 MPa),and the volume wear rate of the sample added with coarse Nb particles is reduced by 90%to 1.7×10^(-6) mm^(3)/(N·m).展开更多
Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the eff...Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the effects of strengthening phases on Cu,Cu-carbon nanotubes(CNTs)composites were prepared using LPBF technique with Cu-CNTs mixed powder as the matrix.The formability,microstructure,mechanical properties,electrical conductivity,and thermal properties were studied.The result shows that the prepared composites have high relative density.The addition of CNTs results in inhomogeneous equiaxed grains at the edges of the molten pool and columnar grains at the center.Compared with pure copper,the overall mechanical properties of the composite are improved:tensile strength increases by 52.8%and elongation increases by 146.4%;the electrical and thermal properties are also enhanced:thermal conductivity increases by 10.8%and electrical conductivity increases by 12.7%.展开更多
Seaweed was fermented using Bifidobacterium,and its high-density fermentation conditions were investigated through single-factor experiments.The optimized fermentation conditions were determined as follows:Ulva powder...Seaweed was fermented using Bifidobacterium,and its high-density fermentation conditions were investigated through single-factor experiments.The optimized fermentation conditions were determined as follows:Ulva powder as the fermentation algal body,Ulva powder addition at 2%,fermented nitrogen source as 1%soy peptone,fermentation time of 26 h,and fermentation temperature of 37℃.The Ulva powder ferment broth was subjected to the Hen’s Egg Test-Chorioallantoic Membrane(HET-CAM)assay and acute cell toxicity testing to evaluate its irritancy and safety.Additionally,cell-based experiments for firming and anti-wrinking efficacy,soothing effect,whitening potency,and antioxidant activity were conducted to assess its cosmetic functionalities.The results indicated that the obtained Ulva powder ferment broth was non-irritating and exhibited a high non-cytotoxic concentration.A 5%concentration of the Ulva powder ferment broth promoted the upregulation of Type Ⅰ collagen by 32.58%±1.33%.A 10%concentration of the ferment broth achieved relative inhibition rates of 67.64%±3.99%for nitric oxide(NO)and 55.76%±0.11%for melanin,respectively.Furthermore,a 6.25%concentration of the ferment broth demonstrated an ABTS radical scavenging rate of 58.29%±4.92%.These findings suggest that the Ulva powder ferment broth is a fermentation product characterized by high safety,excellent anti-wrinking,soothing,and whitening efficacies,along with potent in vitro antioxidant capacity.This study demonstrates its value-added development and significant potential for application in industries such as cosmetics and food.展开更多
Received:06 December 2025;Accepted:25 February 2026;Published:30 March 2026 ABSTRACT:In the last decade,the importance of sustainable construction and artificial intelligence(AI)in civil engineering has been underline...Received:06 December 2025;Accepted:25 February 2026;Published:30 March 2026 ABSTRACT:In the last decade,the importance of sustainable construction and artificial intelligence(AI)in civil engineering has been underlined in many studies.Numerous studies highlighted the superiority of AI techniques over simple and mathematical regression analyses,which suffer from relatively poor generalization and an inability to capture highly non-linear relationships among inputs and output(s)parameters.In this study,to evaluate the compressive strength of concrete with glass powder(GP)and recycled aggregates,600 concrete samples were tested in the laboratory,and their results were evaluated.For intelligent assessment of concrete compressive strength(CCS),the study utilized an improved artificial neural network(ANN)with particle swarm optimization(PSO)algorithm and imperialist competitive algorithm(ICA).For training the models,the experimentally obtained data were used.The concrete ingredients formed the inputs of the AI-based predictive models of CCS.The experimental findings reveal that the implementation of recycled coarse aggregates in concrete from a sustainable construction point of view is advantageous and can enhance the CCS by 11.43%.Apart from that,findings indicate that utilization of 10%GP can lead to a nearly 20%increase in CCS(from 44.6 to 54.1 MPa).Additionally,the experimental observations show almost 40%improvement of CCS when 5%micro silica was used in the concrete mixture.Based on the findings,the study suggests the utilization of waste glass powder to partially replace cement in concrete,which can reduce the amount of cement production.This reduction from economic,energy-saving,and environmental(reduction in greenhouse gas emissions)points of view is of interest.On the other hand,the AI results show that the PSO-based ANN model outperforms the ICA-based ANN for the utilized dataset.According to the findings,the PSO-based ANN predictive model(with a coefficient of determination value of 0.939 and root mean square value of 0.113 for testing data)is a capable tool in predicting the CCS.Hence,this study recommends the implementation of AI-based models in CCS assessment.展开更多
Boron has attracted increasing attention in the field of high-energy explosives and propellants due to its high volume calorific value and mass calorific value.However,the complicated combustion process and low combus...Boron has attracted increasing attention in the field of high-energy explosives and propellants due to its high volume calorific value and mass calorific value.However,the complicated combustion process and low combustion efficiency hinder its wide application.To tackle this challenge,bioinspired polydopamine(PDA)interface reinforced boron-Viton composites,with high structure stability and excellent energy releasing efficiency,are designed and prepared,combining the interface regulation of PDA biomimetic materials and combustion promotion of fluoropolymers.Firstly,the stronger adsorption energy of PDA with boron compared to Viton is demonstrated by molecular dynamics simulations.Next,B@PDA@Viton is prepared by the combination of in-situ dopamine polymerization and solvent/nonsolvent method,and the double-layer core-shell structure is confirmed by XPS,FTIR,and TEM characterizations.TG-DSC analysis shows that B@PDA@Viton possesses superior thermal properties,with a 55.48%increase in oxidation heat compared to raw B.Furthermore,ignition and combustion performance tests indicate that B@PDA@Viton reduces ignition delay by 57.56%and increases heat of combustion by 68.63%relative to raw B.These findings elucidate the ignition and combustion mechanisms of B@PDA@Viton.This work not only developed high-performance boron-based composite fuels but also provided insights into the development of boron-based fuels.展开更多
The hydrogen reduction kinetics of tungsten trioxide(WO_(3))was investigated via non-isothermal thermogravimetric analysis.Under the local gas-solid reduction conditions,the particle morphology of tungsten powders was...The hydrogen reduction kinetics of tungsten trioxide(WO_(3))was investigated via non-isothermal thermogravimetric analysis.Under the local gas-solid reduction conditions,the particle morphology of tungsten powders was found to be consistent with that of raw material WO_(3).The removal of oxygen from tungsten oxide during hydrogen reduction led to the formation of porous structures between the reduced particles,which were obviously different from the polyhedral single-crystal configuration of tungsten powders obtained via chemical vapor deposition.Moreover,the two-stage hydrogen reduction mechanisms of WO_(3) under the local gas-solid reduction conditions can be described using the composite autocatalytic function.The activation energies of the first and second stages of the hydrogen reduction of WO_(3) were determined to be 121 and 135 kJ/mol,respectively.展开更多
Adding magnesite flotation concentrate powder in the production of fused magnesia has become an important method for reducing costs and improving the yield.However,the extensive use of concentrate powder also reduces ...Adding magnesite flotation concentrate powder in the production of fused magnesia has become an important method for reducing costs and improving the yield.However,the extensive use of concentrate powder also reduces the quality of fused magnesia raw materials,which is a major cause of the reduced slag corrosion resistance and service life of magnesia-carbon refractories.The effects of concentrate powder additions(0,30%,60%,and 90%,by mass)on the chemical composition,phase composition,microstructure,bulk density,and apparent porosity of the produced 97-grade fused magnesia were investigated.The results show that as the concentrate powder addition increases,the bulk density first increases and then decreases,while the apparent porosity first decreases and then increases.The crystal size of the fused magnesia increases,and the pores at the grain boundaries become larger.The CaO/SiO_(2)molar ratio(C/S ratio)in the fused magnesia increases from 1.17 to 4.17.The bonding phases between the fused magnesia grains change from low-melting-point phases such as CMS(CaMgSiO_(4))and C_(3)MS_(2)(3CaO·MgO·2SiO_(2))to high-melting-point phases like C_(2)S(2CaO·SiO_(2)),C_(3)S(3CaO·SiO_(2)),and CaO,which is beneficial for improving the high-temperature performance of the fused magnesia.However,during production,the volume effects resulting from the polymorphic transformation of dicalcium silicate(C_(2)S)and the low-temperature decomposition of tricalcium silicate(C_(3)S)create significant voids around the fused magnesia grains.These voids can provide pathways for slag corrosion in subsequent magnesia-carbon products,which is likely the primary reason for the decline in the slag corrosion resistance and service life of carbon-containing refractories made from this type of fused magnesia.展开更多
The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbi...The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbide nanowires using lignite and waste silicon powder as raw materials through carbothermal reduction.The staggered structure of nanowires promotes the creation of interfacial polarization,impedance matching,and multiple loss mechanisms,leading to enhanced electromagnetic absorption performance.The silicon carbide nanowires demonstrate outstanding electromagnetic absorption capabilities with the minimum reflection loss of-48.09 d B at10.08 GHz and an effective absorption bandwidth(the reflection loss less than-10 d B)ranging from 8.54 to 16.68 GHz with a thickness of 2.17 mm.This research presents an innovative approach for utilizing solid waste in an environmentally friendly manner to produce broadband silicon carbide composite absorbers.展开更多
A full-sectional microstructure characterization method was developed to investigate the formation of coarse slag rims during the continuous casting of hypo-peritectic steel.The cross-sectional microstructural analysi...A full-sectional microstructure characterization method was developed to investigate the formation of coarse slag rims during the continuous casting of hypo-peritectic steel.The cross-sectional microstructural analysis of typical slag rims for two highly crystalline powders revealed that their formation was primarily driven by the solidification of the liquid slag.Distinct differences were observed in the microstructures of slag rims from the two powders.Powder A(characterized by a higher breaking temperature and viscosity)displayed alternating lamellar microstructures of coarse and fine phases,with the coarse phases composed of akermanite-gehlenite transition phases.In contrast,powder B(with a lower breaking temperature and viscosity)predominantly comprised regular akermanite-gehlenite crystals interspersed with a certain amount of glassy phases.Numerical simulations of a three-phase fluid flow coupled with heat transfer indicate that slag rim formation correlates with mold oscillation.Solidification of the liquid slag at the slag rim front predominantly occurs during the negative stroke of the mold oscillation.The average heating rate during the ascending stage of the mold reaches approximately 100 K·s^(−1),whereas the average cooling rate during the descending stage attains 400 K·s^(−1).This temperature variation leads to the formation of lamellar microstructures,whereas the ascending stage promotes the formation of coarse structures and thicker slag rims.Based on the powder properties,two distinct formation pathways exist for highly crystalline mold powders.For the powders with a higher breaking temperature,higher viscosity,and narrower solidification range(powder A),coarse microstructures and thicker slag rims were preferentially formed.For powders with lower breaking temperature and viscosity and wider solidification ranges(powder B),the liquid slag resisted rapid solidification,and the extended mushy zone allowed the partial liquid slag to persist at the slag rim front,promoting the formation of a thin slag rim.This study enhances the understanding of slag rim formation in highly crystalline mold powders and provides critical insights into the control of longitudinal surface cracks in hypo-peritectic steel.展开更多
High-moisture meat analogues(HMMAs)offer sustainable protein alternatives to conventional meat and become a research hotspot in recent years.This study systematically investigated the impact of nori powder(NP)incorpor...High-moisture meat analogues(HMMAs)offer sustainable protein alternatives to conventional meat and become a research hotspot in recent years.This study systematically investigated the impact of nori powder(NP)incorporation(0.5%–2.0%)on the physicochemical and structural properties of HMMAs.Rheological analysis revealed that NP reduced the viscosity(consistency coefficient K decreased from 65.67 Pa⋅s to 16.66–19.99 Pa⋅s)and enhanced the fluidity(flow behavior index n increased from 0.25 to 0.33–0.38)of raw material.NP addition progressively decreased the redness values(a*),except for 0.5%NP level.At 1.0%NP level,HMMAs exhibited a denser microstructure with reduced water mobility,resulting in the lowest water holding capacity(2.07 g/g).Conversely,2.0%NP promoted highly oriented fibrous structures,achieving a maximal texturization degree of 1.51.Secondary structure analysis indicated NP facilitated a shift fromα-helix toβ-sheet conformations(β-sheet content increased from 26.06%to 29.92%at 2.0%NP),resulting in stabilized protein networks.These modifications were attributed to NP-induced hydrophobic interactions and polysaccharide-protein crosslinking.The study demonstrates NP's role in modulating HMMA texture and nutrition,providing critical insights for developing fiber-enhanced,nutrient-fortified HMMAs.展开更多
Zn's natural degradability and biocompatibility make it a promising candidate for implants,however,its mechanical properties remain insufficient for bone applications.In this study,the performance of Zn was enhanc...Zn's natural degradability and biocompatibility make it a promising candidate for implants,however,its mechanical properties remain insufficient for bone applications.In this study,the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion(LPBF).Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed.Under optimized conditions of 100 W and 100 mm/s,high density(99.58%)Zn-Cu alloys with improved hardness(68.2 HV)and yield strength(160 MPa)were achieved.These improvements are attributed to solid solution strengthening,segregation strengthening,and grain refinement.The Zn-Cu alloys also demonstrated favorable degradation behavior,with a rate of 0.16 mm/year.This degradation is primarily driven by micro-galvanic corrosion between the CuZn 5 phase and Zn matrix,along with refined grains and increased grain boundary density.This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.展开更多
The presence of a surface oxide film(B_(2)O_(3))on boron(B)particles significantly compromises their combustion efficiency and kinetic performance in fuel-rich solid propellants.This study proposes an innovative conti...The presence of a surface oxide film(B_(2)O_(3))on boron(B)particles significantly compromises their combustion efficiency and kinetic performance in fuel-rich solid propellants.This study proposes an innovative continuous modification strategy combining non-thermal plasma(NTP)etching with fluorocarbon passivation.Characterization and kinetic analysis revealed that reactive plasma species—including atomic hydrogen(H),electronically excited molecular hydrogen(H_(2)^(*)),vibrationally excited molecular hydrogen(H_(2)v),and hydrogen ions(H^(+))—dominate the reduction of B_(2)O_(3)through lowering the transition energy barrier and shifting the reaction spontaneity.Subsequent argon plasma fragmentation of C_(8)F_(18)generates fluorocarbon radicals that form conformal passivation coatings(thickness:7 nm)on purified boron surfaces.The modified boron particles exhibit 37.5℃lower exothermic peak temperature and 27.2%higher heat release(14.8 kJ/g vs.11.6 kJ/g)compared to untreated counterparts.Combustion diagnostics reveal 194%increase in maximum flame height(135.10 mm vs.46.03 mm)and 134%enhancement in flame propagation rate(4.44 cm/s vs.1.90 cm/s).This NTP-based surface engineering approach establishes a scalable pathway for developing highperformance boron-based energetic composites.展开更多
The leaching mechanism of gallium(Ga)and germanium(Ge)from zinc powder replacement residue(ZPRR)was investigated through ultrasonic-assisted sulfuric acid leaching.Characterization via XRD,SEM,XPS,and FT-IR revealed t...The leaching mechanism of gallium(Ga)and germanium(Ge)from zinc powder replacement residue(ZPRR)was investigated through ultrasonic-assisted sulfuric acid leaching.Characterization via XRD,SEM,XPS,and FT-IR revealed that ultrasonic treatment promotes the dehydration of H_(4)SiO_(4)colloids,thereby reducing their adsorption capacities for Ga and Ge complexes.Additionally,ultrasound enhances the dissolution of CaS in H_(2)SO_(4),increasing H_(2)S production,which aids in the reduction of Fe^(3+)and mitigates iron precipitate formation.Process parameters including ultrasonic power(0-450 W),temperature(100-120℃),and leaching time(30-120 min)were systematically optimized,achieving optimal leaching efficiencies of Ga and Ge at 95.7%and 94.5%,respectively.展开更多
As the primary functional component of a fusion reactor,the fusion blanket pebble bed,composed of numerous particles,is crucial for tritium breeding,neutron multiplication,and radiation shielding.Particles within trit...As the primary functional component of a fusion reactor,the fusion blanket pebble bed,composed of numerous particles,is crucial for tritium breeding,neutron multiplication,and radiation shielding.Particles within tritium-breeding pebble beds are subjected to prolonged neutron irradiation,high thermal loads,and strong magnetic fields in fusion environments.Such conditions render them susceptible to pulverization and fragmentation.The resulting fragments and powders migrate and are deposited into the gas channel,driven by the purge gas.The reduction in the effective flow area of the gas increases the flow resistance,resulting in tritium retention,degraded heat transfer,and other adverse effects.These conditions impair the thermodynamic properties of the pebble beds and hinder the self-maintenance of tritium.Limited information exists on powder migration and clogging mechanisms in fusion blanket pebble beds,particularly under diverse physical conditions.The aim of this study was to use a computational fluid dynamics model coupled with the discrete element method(CFD-DEM)to numerically explore powder migration and clogging in pebble beds.The model considers factors such as breeder orientation,purge velocity,powder size distribution,and friction coefficient.We propose two migration and clogging mechanisms.One involves powder with a large particle size,and the other does not.The results indicate that the powder migration velocity progresses through three stages:rapid decay,linear decay,and stability.Pebble-bed clogging manifests in two forms:extensive superficial clogging and uniform internal clogging.Two fitted curves were used to depict the migration and clogging tendencies.The powder size distribution significantly influenced the powder migration.The breeder orientation,powder size,and friction coefficient affected the distribution of the clogging powders.However,the impact of the purge velocity on powder migration and clogging in pebble beds was limited,and this effect varied significantly with different particle size ratios.Based on the analysis,a formula is proposed to characterize the behavior of the powder in the pebble beds.The results of this study can aid in analyzing and predicting powder dynamics in pebble beds.展开更多
Laser additively manufactured microscale metallic lattices show great potential for high-performance applications,yet trade-offs among geometric precision,structural integrity,and computational efficiency still persis...Laser additively manufactured microscale metallic lattices show great potential for high-performance applications,yet trade-offs among geometric precision,structural integrity,and computational efficiency still persist.Here,we introduce a stereolithography file format-free(STL-free)hybrid toolpath generation method for laser-based powder bed fusion(PBF-LB)that synergizes implicit geometric modeling with optimized laser scanning strategy,overcoming these limitations.By circumventing traditional mesh-based workflows,our method directly translates implicit lattice geometries into laser toolpaths while precisely regulating energy deposition trajectories.This mesh-free process enables the fabrication of complex shell lattices with ultra-thin walls and enhanced surface quality.In addition to reducing memory usage and processing time by up to 90%,the method yields a synergistic enhancement in mechanical performance,notably improving both strength and toughness.By bridging computational design and fabrication,this framework enables the scalable production of high-performance microscale lattices and unlocks their potential for industrial applications.展开更多
Targeting Chang'E-8 mission'in-situ resource utilization(ISRU)for sustainable lunar habitats,laser powder bed fusion(LPBF)provides a viable pathway for in-situ additive manufacturing of lunar regolith.To eluci...Targeting Chang'E-8 mission'in-situ resource utilization(ISRU)for sustainable lunar habitats,laser powder bed fusion(LPBF)provides a viable pathway for in-situ additive manufacturing of lunar regolith.To elucidate mission relevant mechanical behavior and failure mechanisms of LPBF fabricated lunar regolith simulants,mare type and highland type simulant specimens were produced.Microstructural characterization,mechanical test coupled with three-dimensional digital image correlation(3D-DIC),and an energy-dissipation framework were employed for comprehensive analysis.The pristine highland specimens achieved 5.79 MPa and a peak strain of 0.13(50 mm×50 mm×30 mm),significantly outperforming their mare counterparts.Wire-cutting to 20 mm×20 mm×20 mm lowered strength by~20%and peak strain to 0.04,indicating cutting-induced defects reduce ductility.All specimens displayed multipeaked stress–strain curves.3D-DIC revealed band-type strain localization in pristine highland samples,diffuse strain patterns in cut highland samples,and highly tortuous,network-type bands in mare samples;the anisotropy index was also quantified.Fragmented particles exhibited fractal dimensions ranging from 1.6 to 2.0(size 1.25–9 mm).Energy evolution progressed through three distinct stages:elastic energy storage,progressive energy dissipation delaying crack propagation,and final unstable collapse.An energy-based damage model was established and validated.The data and methods developed support Chang'E-8 missions'ISRU demonstrations and establish a transferable framework toward sustainable lunar habitats.展开更多
The strength-ductility synergy in heterogeneous materials offers significant advantages,though their scalable and controlled fabrication remains challenging.This study introduces an in situ fabrication strategy for he...The strength-ductility synergy in heterogeneous materials offers significant advantages,though their scalable and controlled fabrication remains challenging.This study introduces an in situ fabrication strategy for heterogeneous lamellar titanium(HLT)alloy via laser powder bed fusion of a powder mixture consisting of Ti6Al4V(TC4)and 3 wt%Fe.By periodically varying the scanning velocity between layers,a heterogeneous lamellar microstructure is achieved due to the unique Fe distribution originating from the various volumetric energy densities(VEDs).Consequently,the HLT achieves high yield strength(1036 MPa)and ultimate tensile strength(1419 MPa)without compromising uniform elongation(UE),surpassing most TC4 alloys.The high strength may be attributed to precipitation strengthening originating from the nano-sizedαandωprecipitates,while the high UE and work hardening arise from the strain-induced martensite(SIM)and strong hetero-deformation induced(HDI)stress.The denser dual-phase interfaces and smaller grains in the low VED layers contribute to the higher sensitivity to the SIM.A strain gradient between soft and hard layers evolves during loading,and it further enhances the HDI strengthening and SIM behavior.Through this work,the in situ fabrication method and the deformation mechanism of lamellar heterostructure could offer valuable reference for the optimization and application of heterogeneous materials.展开更多
文摘The present work provides a facile and efficient method for producing ultrafine copper powders.Ultrafine copper powders were synthesized through a solvothermal method,utilizing ethanol both as a solvent and a reducing agent.Specifically,by exploiting the weak reducing property of ethanol,the copper precursor is first converted to copper oxide and then further reduced to cuprous oxide and pure copper.Such a method can effectively control the morphology and particle size of the copper powder,reduce particle aggregation,and enhance oxidation resistance.It is cost-effective and produces fewer toxic by-products.Spherical copper particles with an average particle size of about 180 nm were obtained.The initial oxidation temperature is approximately 150℃,and the resulting copper powders can be stored stably under ambient conditions for at least 5 months,demonstrating excellent oxidation resistance and thermal stability.
基金Shaanxi Province Qin Chuangyuan“Scientist+Engineer”Team Construction Project(2022KXJ-071)2022 Qin Chuangyuan Achievement Transformation Incubation Capacity Improvement Project(2022JH-ZHFHTS-0012)+8 种基金Shaanxi Province Key Research and Development Plan-“Two Chains”Integration Key Project-Qin Chuangyuan General Window Industrial Cluster Project(2023QCY-LL-02)Xixian New Area Science and Technology Plan(2022-YXYJ-003,2022-XXCY-010)2024 Scientific Research Project of Shaanxi National Defense Industry Vocational and Technical College(Gfy24-07)Shaanxi Vocational and Technical Education Association 2024 Vocational Education Teaching Reform Research Topic(2024SZX354)National Natural Science Foundation of China(U24A20115)2024 Shaanxi Provincial Education Department Service Local Special Scientific Research Program Project-Industrialization Cultivation Project(24JC005,24JC063)Shaanxi Province“14th Five-Year Plan”Education Science Plan,2024 Project(SGH24Y3181)National Key Research and Development Program of China(2023YFB4606400)Longmen Laboratory Frontier Exploration Topics Project(LMQYTSKT003)。
文摘A dual-phase synergistic enhancement method was adopted to strengthen the Al-Mn-Mg-Sc-Zr alloy fabricated by laser powder bed fusion(LPBF)by leveraging the unique advantages of Er and TiB_(2).Spherical powders of 0.5wt%Er-1wt%TiB_(2)/Al-Mn-Mg-Sc-Zr nanocomposite were prepared using vacuum homogenization technique,and the density of samples prepared through the LPBF process reached 99.8%.The strengthening and toughening mechanisms of Er-TiB_(2)were investigated.The results show that Al_(3)Er diffraction peaks are detected by X-ray diffraction analysis,and texture strength decreases according to electron backscatter diffraction results.The added Er and TiB_(2)nano-reinforcing phases act as heterogeneous nucleation sites during the LPBF forming process,hindering grain growth and effectively refining the grains.After incorporating the Er-TiB_(2)dual-phase nano-reinforcing phases,the tensile strength and elongation at break of the LPBF-deposited samples reach 550 MPa and 18.7%,which are 13.4%and 26.4%higher than those of the matrix material,respectively.
文摘The application and promotion of waste glass powder concrete(WGPC)cansignificantly alleviate the pressure of concrete material scarcity and environmental pollution.Compressive strength(CS)is a critical parameter for evaluating the efficacy of WGPC.Unlike conventional testing methods,machine learning techniques offer precise and reliable predictions of concrete’s compressive strength,especially in its long-term mechanical properties.In this work,four models,namely Multiple Linear Regression(MLR),Back Propagation Neural Network(BPNN),Support Vector Regression(SVR),and Random Forest Regression(RFR)were employed.Furthermore,particle swarm optimization(PSO)algorithm and cross-validation techniques were applied to fine-tune the model parameters,striving for peak prediction performance.The results indicated that optimized models generally exhibit enhanced predictive accuracy compared to their basic counterparts.Notably,the PSO-RFR model excels among all evaluated models,showcasing superior performance on the testing dataset.It achieves a coefficient of determination(R^(2))of 0.9231,a mean absolute error(MAE)of 2.1073,and a root mean square error(RMSE)of 3.6903.When compared to experimental results,the PSO-RFR and PSO-BPNN models demonstrate exceptional predictive accuracy.Notably,the PSO-BPNN model exhibits the closest R^(2)values between its training and test sets.This close alignment of R^(2)values between the training and testing sets reflects the PSO-BPNN model’s superior generalization ability for unseen data.The findings present an efficient method for predicting concrete’s compressive strength,contributing to the sustainable development of concrete materials,and providing theoretical support for their research and application.
基金Key-Area Research and Development Program of Guangdong Province(2023B0909020004)Project of Innovation Research Team in Zhongshan(CXTD2023006)+1 种基金Natural Science Foundation of Guangdong Province(2023A1515011573)Zhongshan Social Welfare Science and Technology Research Project(2024B2022)。
文摘Laser powder bed fusion(LPBF)is highly suitable for forming 18Ni300 mold steel,thanks to its excellent capability in manufacturing complex shapes and outstanding capacity for regulating microstructures.It is widely used in fields such as injection molding,die casting,and stamping dies.Adding reinforcing particles into steel is an effective means to improve its performance.Nb/18Ni300 composites were fabricated by LPBF using two kinds of Nb powders with different particle sizes,and their microstructures and properties were studied.The results show that the unmelted Nb particles are uniformly distributed in the 18Ni300 matrix and the grains are refined,which is particularly pronounced with fine Nb particles.In addition,element diffusion occurs between the particles and the matrix.The main phases of the base alloy are α-Fe and a small amount of γ-Fe.With the addition of Nb,part of the α-Fe is transformed into γ-Fe,and unmelted Nb phases appear.The addition of Nb also enhances the hardness and wear resistance of the composites but slightly reduces their tensile properties.After aging treatment,the molten pools and grain boundaries become blurred,grains are further refined,and the interfaces around the particles are thinned.The aging treatment also promotes the formation of reverted austenite.The hardness,ultimate tensile strength,and volumetric wear rate of the base alloy reach 51.9 HRC,1704 MPa,and 17.8×10^(-6) mm^(3)/(N·m),respectively.In contrast,the sample added with fine Nb particles has the highest hardness(56.1 HRC),ultimate tensile strength(1892 MPa)and yield strength(1842 MPa),and the volume wear rate of the sample added with coarse Nb particles is reduced by 90%to 1.7×10^(-6) mm^(3)/(N·m).
基金National Key Research and Development Program of China(2023YFB4606400)Supported by Longmen Laboratory Frontier Exploration Topics(LMQYTSKT003)。
文摘Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the effects of strengthening phases on Cu,Cu-carbon nanotubes(CNTs)composites were prepared using LPBF technique with Cu-CNTs mixed powder as the matrix.The formability,microstructure,mechanical properties,electrical conductivity,and thermal properties were studied.The result shows that the prepared composites have high relative density.The addition of CNTs results in inhomogeneous equiaxed grains at the edges of the molten pool and columnar grains at the center.Compared with pure copper,the overall mechanical properties of the composite are improved:tensile strength increases by 52.8%and elongation increases by 146.4%;the electrical and thermal properties are also enhanced:thermal conductivity increases by 10.8%and electrical conductivity increases by 12.7%.
文摘Seaweed was fermented using Bifidobacterium,and its high-density fermentation conditions were investigated through single-factor experiments.The optimized fermentation conditions were determined as follows:Ulva powder as the fermentation algal body,Ulva powder addition at 2%,fermented nitrogen source as 1%soy peptone,fermentation time of 26 h,and fermentation temperature of 37℃.The Ulva powder ferment broth was subjected to the Hen’s Egg Test-Chorioallantoic Membrane(HET-CAM)assay and acute cell toxicity testing to evaluate its irritancy and safety.Additionally,cell-based experiments for firming and anti-wrinking efficacy,soothing effect,whitening potency,and antioxidant activity were conducted to assess its cosmetic functionalities.The results indicated that the obtained Ulva powder ferment broth was non-irritating and exhibited a high non-cytotoxic concentration.A 5%concentration of the Ulva powder ferment broth promoted the upregulation of Type Ⅰ collagen by 32.58%±1.33%.A 10%concentration of the ferment broth achieved relative inhibition rates of 67.64%±3.99%for nitric oxide(NO)and 55.76%±0.11%for melanin,respectively.Furthermore,a 6.25%concentration of the ferment broth demonstrated an ABTS radical scavenging rate of 58.29%±4.92%.These findings suggest that the Ulva powder ferment broth is a fermentation product characterized by high safety,excellent anti-wrinking,soothing,and whitening efficacies,along with potent in vitro antioxidant capacity.This study demonstrates its value-added development and significant potential for application in industries such as cosmetics and food.
文摘Received:06 December 2025;Accepted:25 February 2026;Published:30 March 2026 ABSTRACT:In the last decade,the importance of sustainable construction and artificial intelligence(AI)in civil engineering has been underlined in many studies.Numerous studies highlighted the superiority of AI techniques over simple and mathematical regression analyses,which suffer from relatively poor generalization and an inability to capture highly non-linear relationships among inputs and output(s)parameters.In this study,to evaluate the compressive strength of concrete with glass powder(GP)and recycled aggregates,600 concrete samples were tested in the laboratory,and their results were evaluated.For intelligent assessment of concrete compressive strength(CCS),the study utilized an improved artificial neural network(ANN)with particle swarm optimization(PSO)algorithm and imperialist competitive algorithm(ICA).For training the models,the experimentally obtained data were used.The concrete ingredients formed the inputs of the AI-based predictive models of CCS.The experimental findings reveal that the implementation of recycled coarse aggregates in concrete from a sustainable construction point of view is advantageous and can enhance the CCS by 11.43%.Apart from that,findings indicate that utilization of 10%GP can lead to a nearly 20%increase in CCS(from 44.6 to 54.1 MPa).Additionally,the experimental observations show almost 40%improvement of CCS when 5%micro silica was used in the concrete mixture.Based on the findings,the study suggests the utilization of waste glass powder to partially replace cement in concrete,which can reduce the amount of cement production.This reduction from economic,energy-saving,and environmental(reduction in greenhouse gas emissions)points of view is of interest.On the other hand,the AI results show that the PSO-based ANN model outperforms the ICA-based ANN for the utilized dataset.According to the findings,the PSO-based ANN predictive model(with a coefficient of determination value of 0.939 and root mean square value of 0.113 for testing data)is a capable tool in predicting the CCS.Hence,this study recommends the implementation of AI-based models in CCS assessment.
基金funded by the National Natural Science Foundation of China,Grant No.22405208。
文摘Boron has attracted increasing attention in the field of high-energy explosives and propellants due to its high volume calorific value and mass calorific value.However,the complicated combustion process and low combustion efficiency hinder its wide application.To tackle this challenge,bioinspired polydopamine(PDA)interface reinforced boron-Viton composites,with high structure stability and excellent energy releasing efficiency,are designed and prepared,combining the interface regulation of PDA biomimetic materials and combustion promotion of fluoropolymers.Firstly,the stronger adsorption energy of PDA with boron compared to Viton is demonstrated by molecular dynamics simulations.Next,B@PDA@Viton is prepared by the combination of in-situ dopamine polymerization and solvent/nonsolvent method,and the double-layer core-shell structure is confirmed by XPS,FTIR,and TEM characterizations.TG-DSC analysis shows that B@PDA@Viton possesses superior thermal properties,with a 55.48%increase in oxidation heat compared to raw B.Furthermore,ignition and combustion performance tests indicate that B@PDA@Viton reduces ignition delay by 57.56%and increases heat of combustion by 68.63%relative to raw B.These findings elucidate the ignition and combustion mechanisms of B@PDA@Viton.This work not only developed high-performance boron-based composite fuels but also provided insights into the development of boron-based fuels.
基金supported by the National Key Research&Development Program of China(No.2022YFC2904905)the National Natural Science Foundation of China(No.52274400)+1 种基金the Project of Zhongyuan Critical Metals Laboratory,China(No.GJJSGFZD202302)the Science and Technology Project of Henan Province,China(No.232102230044)。
文摘The hydrogen reduction kinetics of tungsten trioxide(WO_(3))was investigated via non-isothermal thermogravimetric analysis.Under the local gas-solid reduction conditions,the particle morphology of tungsten powders was found to be consistent with that of raw material WO_(3).The removal of oxygen from tungsten oxide during hydrogen reduction led to the formation of porous structures between the reduced particles,which were obviously different from the polyhedral single-crystal configuration of tungsten powders obtained via chemical vapor deposition.Moreover,the two-stage hydrogen reduction mechanisms of WO_(3) under the local gas-solid reduction conditions can be described using the composite autocatalytic function.The activation energies of the first and second stages of the hydrogen reduction of WO_(3) were determined to be 121 and 135 kJ/mol,respectively.
基金support from the National Natural Science Foundation of China(U20A20239 and U1908227).
文摘Adding magnesite flotation concentrate powder in the production of fused magnesia has become an important method for reducing costs and improving the yield.However,the extensive use of concentrate powder also reduces the quality of fused magnesia raw materials,which is a major cause of the reduced slag corrosion resistance and service life of magnesia-carbon refractories.The effects of concentrate powder additions(0,30%,60%,and 90%,by mass)on the chemical composition,phase composition,microstructure,bulk density,and apparent porosity of the produced 97-grade fused magnesia were investigated.The results show that as the concentrate powder addition increases,the bulk density first increases and then decreases,while the apparent porosity first decreases and then increases.The crystal size of the fused magnesia increases,and the pores at the grain boundaries become larger.The CaO/SiO_(2)molar ratio(C/S ratio)in the fused magnesia increases from 1.17 to 4.17.The bonding phases between the fused magnesia grains change from low-melting-point phases such as CMS(CaMgSiO_(4))and C_(3)MS_(2)(3CaO·MgO·2SiO_(2))to high-melting-point phases like C_(2)S(2CaO·SiO_(2)),C_(3)S(3CaO·SiO_(2)),and CaO,which is beneficial for improving the high-temperature performance of the fused magnesia.However,during production,the volume effects resulting from the polymorphic transformation of dicalcium silicate(C_(2)S)and the low-temperature decomposition of tricalcium silicate(C_(3)S)create significant voids around the fused magnesia grains.These voids can provide pathways for slag corrosion in subsequent magnesia-carbon products,which is likely the primary reason for the decline in the slag corrosion resistance and service life of carbon-containing refractories made from this type of fused magnesia.
基金supported by the National Natural Science Foundation of China(No.52436008)the Inner Mongolia Science and Technology Projects,China(Nos.JMRHZX20210003 and 2023YFCY0009)+3 种基金the Huaneng Group Co Ltd.,China(No.HNKJ23-H50)the National Natural Science Foundation of China(No.22408044)the China Postdoctoral Science Foundation(No.2024M761877)the National Key R&D Program of China(No.SQ2024YFD2200039)。
文摘The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbide nanowires using lignite and waste silicon powder as raw materials through carbothermal reduction.The staggered structure of nanowires promotes the creation of interfacial polarization,impedance matching,and multiple loss mechanisms,leading to enhanced electromagnetic absorption performance.The silicon carbide nanowires demonstrate outstanding electromagnetic absorption capabilities with the minimum reflection loss of-48.09 d B at10.08 GHz and an effective absorption bandwidth(the reflection loss less than-10 d B)ranging from 8.54 to 16.68 GHz with a thickness of 2.17 mm.This research presents an innovative approach for utilizing solid waste in an environmentally friendly manner to produce broadband silicon carbide composite absorbers.
基金supported by the National Natural Science Foundation of China(No.52274318).
文摘A full-sectional microstructure characterization method was developed to investigate the formation of coarse slag rims during the continuous casting of hypo-peritectic steel.The cross-sectional microstructural analysis of typical slag rims for two highly crystalline powders revealed that their formation was primarily driven by the solidification of the liquid slag.Distinct differences were observed in the microstructures of slag rims from the two powders.Powder A(characterized by a higher breaking temperature and viscosity)displayed alternating lamellar microstructures of coarse and fine phases,with the coarse phases composed of akermanite-gehlenite transition phases.In contrast,powder B(with a lower breaking temperature and viscosity)predominantly comprised regular akermanite-gehlenite crystals interspersed with a certain amount of glassy phases.Numerical simulations of a three-phase fluid flow coupled with heat transfer indicate that slag rim formation correlates with mold oscillation.Solidification of the liquid slag at the slag rim front predominantly occurs during the negative stroke of the mold oscillation.The average heating rate during the ascending stage of the mold reaches approximately 100 K·s^(−1),whereas the average cooling rate during the descending stage attains 400 K·s^(−1).This temperature variation leads to the formation of lamellar microstructures,whereas the ascending stage promotes the formation of coarse structures and thicker slag rims.Based on the powder properties,two distinct formation pathways exist for highly crystalline mold powders.For the powders with a higher breaking temperature,higher viscosity,and narrower solidification range(powder A),coarse microstructures and thicker slag rims were preferentially formed.For powders with lower breaking temperature and viscosity and wider solidification ranges(powder B),the liquid slag resisted rapid solidification,and the extended mushy zone allowed the partial liquid slag to persist at the slag rim front,promoting the formation of a thin slag rim.This study enhances the understanding of slag rim formation in highly crystalline mold powders and provides critical insights into the control of longitudinal surface cracks in hypo-peritectic steel.
基金funded by The Science Foundation of Henan University of Technology(2021BS038)The Open Project Program of National Engineering Re-search Center of Wheat and Corn Further Processing(NL2022014)Henan Province Science and Technology R&D Program Joint Fund(Application Research and De-velopment Category)(242103810082).
文摘High-moisture meat analogues(HMMAs)offer sustainable protein alternatives to conventional meat and become a research hotspot in recent years.This study systematically investigated the impact of nori powder(NP)incorporation(0.5%–2.0%)on the physicochemical and structural properties of HMMAs.Rheological analysis revealed that NP reduced the viscosity(consistency coefficient K decreased from 65.67 Pa⋅s to 16.66–19.99 Pa⋅s)and enhanced the fluidity(flow behavior index n increased from 0.25 to 0.33–0.38)of raw material.NP addition progressively decreased the redness values(a*),except for 0.5%NP level.At 1.0%NP level,HMMAs exhibited a denser microstructure with reduced water mobility,resulting in the lowest water holding capacity(2.07 g/g).Conversely,2.0%NP promoted highly oriented fibrous structures,achieving a maximal texturization degree of 1.51.Secondary structure analysis indicated NP facilitated a shift fromα-helix toβ-sheet conformations(β-sheet content increased from 26.06%to 29.92%at 2.0%NP),resulting in stabilized protein networks.These modifications were attributed to NP-induced hydrophobic interactions and polysaccharide-protein crosslinking.The study demonstrates NP's role in modulating HMMA texture and nutrition,providing critical insights for developing fiber-enhanced,nutrient-fortified HMMAs.
基金Projects(52571276,52275395,U24A20120,52475362)supported by the National Natural Science Foundation of ChinaProject(2025JJ30015)supported by the Hunan Provincial Natural Science Foundation,China+3 种基金Project(2023RC3046)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(2023YFB4605800)supported by National Key Research and Development Program of ChinaProject(2023CXQD023)supported by the Central South University Innovation-Driven Research Programme,ChinaProject supported by the State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University,China。
文摘Zn's natural degradability and biocompatibility make it a promising candidate for implants,however,its mechanical properties remain insufficient for bone applications.In this study,the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion(LPBF).Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed.Under optimized conditions of 100 W and 100 mm/s,high density(99.58%)Zn-Cu alloys with improved hardness(68.2 HV)and yield strength(160 MPa)were achieved.These improvements are attributed to solid solution strengthening,segregation strengthening,and grain refinement.The Zn-Cu alloys also demonstrated favorable degradation behavior,with a rate of 0.16 mm/year.This degradation is primarily driven by micro-galvanic corrosion between the CuZn 5 phase and Zn matrix,along with refined grains and increased grain boundary density.This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.
基金supported by the National Natural Science Foundation of China(Nos.U2341249,12005076,22205112)the Fundamental Research Funds for the Central Universities(No.2025201012)。
文摘The presence of a surface oxide film(B_(2)O_(3))on boron(B)particles significantly compromises their combustion efficiency and kinetic performance in fuel-rich solid propellants.This study proposes an innovative continuous modification strategy combining non-thermal plasma(NTP)etching with fluorocarbon passivation.Characterization and kinetic analysis revealed that reactive plasma species—including atomic hydrogen(H),electronically excited molecular hydrogen(H_(2)^(*)),vibrationally excited molecular hydrogen(H_(2)v),and hydrogen ions(H^(+))—dominate the reduction of B_(2)O_(3)through lowering the transition energy barrier and shifting the reaction spontaneity.Subsequent argon plasma fragmentation of C_(8)F_(18)generates fluorocarbon radicals that form conformal passivation coatings(thickness:7 nm)on purified boron surfaces.The modified boron particles exhibit 37.5℃lower exothermic peak temperature and 27.2%higher heat release(14.8 kJ/g vs.11.6 kJ/g)compared to untreated counterparts.Combustion diagnostics reveal 194%increase in maximum flame height(135.10 mm vs.46.03 mm)and 134%enhancement in flame propagation rate(4.44 cm/s vs.1.90 cm/s).This NTP-based surface engineering approach establishes a scalable pathway for developing highperformance boron-based energetic composites.
基金financially supported by the National Key Research and Development Program of China(No.2022YFC2904900)the National Natural Science Foundation of China(Nos.52204392,52274385,52204347)the Young Elite Scientists Sponsorship Program by CAST,China(No.2022QNRC001)。
文摘The leaching mechanism of gallium(Ga)and germanium(Ge)from zinc powder replacement residue(ZPRR)was investigated through ultrasonic-assisted sulfuric acid leaching.Characterization via XRD,SEM,XPS,and FT-IR revealed that ultrasonic treatment promotes the dehydration of H_(4)SiO_(4)colloids,thereby reducing their adsorption capacities for Ga and Ge complexes.Additionally,ultrasound enhances the dissolution of CaS in H_(2)SO_(4),increasing H_(2)S production,which aids in the reduction of Fe^(3+)and mitigates iron precipitate formation.Process parameters including ultrasonic power(0-450 W),temperature(100-120℃),and leaching time(30-120 min)were systematically optimized,achieving optimal leaching efficiencies of Ga and Ge at 95.7%and 94.5%,respectively.
文摘As the primary functional component of a fusion reactor,the fusion blanket pebble bed,composed of numerous particles,is crucial for tritium breeding,neutron multiplication,and radiation shielding.Particles within tritium-breeding pebble beds are subjected to prolonged neutron irradiation,high thermal loads,and strong magnetic fields in fusion environments.Such conditions render them susceptible to pulverization and fragmentation.The resulting fragments and powders migrate and are deposited into the gas channel,driven by the purge gas.The reduction in the effective flow area of the gas increases the flow resistance,resulting in tritium retention,degraded heat transfer,and other adverse effects.These conditions impair the thermodynamic properties of the pebble beds and hinder the self-maintenance of tritium.Limited information exists on powder migration and clogging mechanisms in fusion blanket pebble beds,particularly under diverse physical conditions.The aim of this study was to use a computational fluid dynamics model coupled with the discrete element method(CFD-DEM)to numerically explore powder migration and clogging in pebble beds.The model considers factors such as breeder orientation,purge velocity,powder size distribution,and friction coefficient.We propose two migration and clogging mechanisms.One involves powder with a large particle size,and the other does not.The results indicate that the powder migration velocity progresses through three stages:rapid decay,linear decay,and stability.Pebble-bed clogging manifests in two forms:extensive superficial clogging and uniform internal clogging.Two fitted curves were used to depict the migration and clogging tendencies.The powder size distribution significantly influenced the powder migration.The breeder orientation,powder size,and friction coefficient affected the distribution of the clogging powders.However,the impact of the purge velocity on powder migration and clogging in pebble beds was limited,and this effect varied significantly with different particle size ratios.Based on the analysis,a formula is proposed to characterize the behavior of the powder in the pebble beds.The results of this study can aid in analyzing and predicting powder dynamics in pebble beds.
基金financial support of the Hong Kong Special Administrative Region University Grants Committee—General Research Fund CUHK14209523Collaborative Research Fund C4074-22G,C4002-22Y and C7074-23Gsupport by the University of Massachusetts Amherst。
文摘Laser additively manufactured microscale metallic lattices show great potential for high-performance applications,yet trade-offs among geometric precision,structural integrity,and computational efficiency still persist.Here,we introduce a stereolithography file format-free(STL-free)hybrid toolpath generation method for laser-based powder bed fusion(PBF-LB)that synergizes implicit geometric modeling with optimized laser scanning strategy,overcoming these limitations.By circumventing traditional mesh-based workflows,our method directly translates implicit lattice geometries into laser toolpaths while precisely regulating energy deposition trajectories.This mesh-free process enables the fabrication of complex shell lattices with ultra-thin walls and enhanced surface quality.In addition to reducing memory usage and processing time by up to 90%,the method yields a synergistic enhancement in mechanical performance,notably improving both strength and toughness.By bridging computational design and fabrication,this framework enables the scalable production of high-performance microscale lattices and unlocks their potential for industrial applications.
基金supported by the Young Student Project of National Natural Science Foundation of China(No.525B2139)the National Key Research and Development Program of China(Nos.2023YFB3711300 and 2021YFF0500301)the Space Application System of China Manned Space Program(No.KJZ-YYWCL404)。
文摘Targeting Chang'E-8 mission'in-situ resource utilization(ISRU)for sustainable lunar habitats,laser powder bed fusion(LPBF)provides a viable pathway for in-situ additive manufacturing of lunar regolith.To elucidate mission relevant mechanical behavior and failure mechanisms of LPBF fabricated lunar regolith simulants,mare type and highland type simulant specimens were produced.Microstructural characterization,mechanical test coupled with three-dimensional digital image correlation(3D-DIC),and an energy-dissipation framework were employed for comprehensive analysis.The pristine highland specimens achieved 5.79 MPa and a peak strain of 0.13(50 mm×50 mm×30 mm),significantly outperforming their mare counterparts.Wire-cutting to 20 mm×20 mm×20 mm lowered strength by~20%and peak strain to 0.04,indicating cutting-induced defects reduce ductility.All specimens displayed multipeaked stress–strain curves.3D-DIC revealed band-type strain localization in pristine highland samples,diffuse strain patterns in cut highland samples,and highly tortuous,network-type bands in mare samples;the anisotropy index was also quantified.Fragmented particles exhibited fractal dimensions ranging from 1.6 to 2.0(size 1.25–9 mm).Energy evolution progressed through three distinct stages:elastic energy storage,progressive energy dissipation delaying crack propagation,and final unstable collapse.An energy-based damage model was established and validated.The data and methods developed support Chang'E-8 missions'ISRU demonstrations and establish a transferable framework toward sustainable lunar habitats.
基金financially supported by the National Natural Science Foundation of China(No.52375347)Shanghai Pujiang Programme(No.8003PJD023)Natural Science Foundation of Ningbo(Grant No.2023J008)。
文摘The strength-ductility synergy in heterogeneous materials offers significant advantages,though their scalable and controlled fabrication remains challenging.This study introduces an in situ fabrication strategy for heterogeneous lamellar titanium(HLT)alloy via laser powder bed fusion of a powder mixture consisting of Ti6Al4V(TC4)and 3 wt%Fe.By periodically varying the scanning velocity between layers,a heterogeneous lamellar microstructure is achieved due to the unique Fe distribution originating from the various volumetric energy densities(VEDs).Consequently,the HLT achieves high yield strength(1036 MPa)and ultimate tensile strength(1419 MPa)without compromising uniform elongation(UE),surpassing most TC4 alloys.The high strength may be attributed to precipitation strengthening originating from the nano-sizedαandωprecipitates,while the high UE and work hardening arise from the strain-induced martensite(SIM)and strong hetero-deformation induced(HDI)stress.The denser dual-phase interfaces and smaller grains in the low VED layers contribute to the higher sensitivity to the SIM.A strain gradient between soft and hard layers evolves during loading,and it further enhances the HDI strengthening and SIM behavior.Through this work,the in situ fabrication method and the deformation mechanism of lamellar heterostructure could offer valuable reference for the optimization and application of heterogeneous materials.
