(NbZrHfTi)C high-entropy ceramics,as an emerging class of ultra-high-temperature materials,have garnered significant interest due to their unique multi-principal-element crystal structure and exceptional hightemperatu...(NbZrHfTi)C high-entropy ceramics,as an emerging class of ultra-high-temperature materials,have garnered significant interest due to their unique multi-principal-element crystal structure and exceptional hightemperature properties.This study systematically investigates the mechanical properties of(NbZrHfTi)C high-entropy ceramics by employing first-principles density functional theory,combined with the Debye-Grüneisen model,to explore the variations in their thermophysical properties with temperature(0–2000 K)and pressure(0–30 GPa).Thermodynamically,the calculated mixing enthalpy and Gibbs free energy confirm the feasibility of forming a stable single-phase solid solution in(NbZrHfTi)C.The calculated results of the elastic stiffness constant indicate that the material meets the mechanical stability criteria of the cubic crystal system,further confirming the structural stability.Through evaluation of key mechanical parameters—bulk modulus,shear modulus,Young’s modulus,and Poisson’s ratio—we provide comprehensive insight into the macro-mechanical behaviour of the material and its correlation with the underlying microstructure.Notably,compared to traditional binary carbides and their average properties,(NbZrHfTi)C exhibits higher Vickers hardness(Approximately 28.5 GPa)and fracture toughness(Approximately 3.4 MPa⋅m^(1/2)),which can be primarily attributed to the lattice distortion and solid-solution strengthening mechanism.The study also utilizes the quasi-harmonic approximation method to predict the material’s thermophysical properties,including Debye temperature(initial value around 563 K),thermal expansion coefficient(approximately 8.9×10^(−6) K−1 at 2000 K),and other key parameters such as heat capacity at constant volume.The results show that within the studied pressure and temperature ranges,(NbZrHfTi)C consistently maintains a stable phase structure and good thermomechanical properties.The thermal expansion coefficient increasing with temperature,while heat capacity approaches the Dulong-Petit limit at elevated temperatures.These findings underscore the potential of(NbZrHfTi)C applications in ultra-high temperature thermal protection systems,cutting tool coatings,and nuclear structural materials.展开更多
Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separ...Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separability of iron-based carriers require further enhancement.This study investigates the effect of the concentration of Mn doping on reactivity,elastic properties and magnetic properties based on density functional theory(DFT)calculations.Theoretical results demonstrate that Mn doping effectively enhances reactivity by reducing the oxygen vacancy formation energy(E_(vac))from 2.33 to 0.87 eV.However,Mn doping introduces HV/EV Ms lattice distortions that deteriorate elastic properties,thereby reducing wear resistance,as evidenced by a 54.54%decrease in the hardness-to-Young's modulus ratio(H_(v)/E_(v))forα-Fe_(2)O_(3)and an 83.33%reduction for Fe_(3)O_(4).Furthermore,Mn doping also modifies magnetic properties.The maximum of saturation magnetization(M_(s))of Fe_(3)O_(4)reaches 121.02 emu/g at 33.33%Mn doping concentration.Finally,systematic evaluation identifies 33.33%as the optimal Mn doping concentration,achieving a balance in enhanced reactivity,superior magnetic performance,and retained elastic stability.展开更多
This study investigates the properties of high-purity starches extracted from Polygonum multiflorum(PMS)and Smilax glabra(SGS).The starches were characterized by scanning electron microscopy,Fouriertransform infrared ...This study investigates the properties of high-purity starches extracted from Polygonum multiflorum(PMS)and Smilax glabra(SGS).The starches were characterized by scanning electron microscopy,Fouriertransform infrared spectroscopy,X-ray diffraction,high-performance anion-exchange chromatography,and differential scanning calorimetry.Significant differences were observed in their morphological,physicochemical,and functional properties.PMS had a smaller particle size(13.68 μm),irregular polygonal shape,A-type,lower water absorption(62.67 %),and higher oil absorption(51.17 %).In contrast,SGS exhibited larger particles(31.75 μm),a nearly spherical shape,B-type,higher crystallinity(50.66 %),and greater amylose content(21.54 %),with superior thermal stability,shear resistance,and gelatinization enthalpy.SGS also contained higher resistant starch(83.28 %) and longer average chain length(20.58 %),but showed lower solubility,swelling power,light transmittance,and freeze-thaw stability.The physicochemical properties differences in crystal pattern and particle morphology between PMS and SGS lead to distinct behaviors during in vitro digestion and fermentation.These findings highlight the potential of medicinal plant starches in functional ingredients and industrial processes.展开更多
Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been construc...Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been constructed hydrothermally at 160℃ using H_(3)tpta([1,1':3',1″-terphenyl]-4,4',5'-tricarboxylic acid),py(pyridine),H_(2)biim(2,2'-biimidazole),dpe(1,2-di(4-pyridyl)ethylene),and zinc,nickel and cadmium chlorides,resulting in the formation of stable crystalline solids which were subsequently analyzed using infrared spectroscopy,element analysis,thermogravimetric analysis,as well as structural analyses conducted via single-crystal X-ray diffraction.The findings from these single-crystal Xray diffraction studies indicate that complexes 1-3 form crystals within the monoclinic system P2_(1)/c space group(1)or triclinic system P1 space group(2 and 3),and possess 1D,0D,and 3D structures,respectively.Complex 1 demonstrated substantial catalytic efficiency and excellent reusability as a heterogeneous catalyst in the reaction of Knoevenagel condensation under ambient temperature conditions.In addition,complex 1 also showcased notable anti-wear performance when used in polyalphaolefin synthetic lubricants.CCDC:2449810,1;2449811,2;2449812,3.展开更多
The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt%Nb addition after various plastic deformation and heat treatment processes were investigated.Through Vickers hardness tests,free resonance You...The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt%Nb addition after various plastic deformation and heat treatment processes were investigated.Through Vickers hardness tests,free resonance Young's modulus measurements,and microstructure analysis,the effects of dislocation density,vacancy formation,and recrystallization on the alloy performance were clarified.Results indicate that increasing the rolling reduction enhances damping property due to higher dislocation density,whereas aging below the recrystallization temperature reduces damping property via dislocation pinning by the Suzuki effect.Recrystallization heat treatment restores the original structure and damping level.This alloy possesses tensile strength of approximately 1500 MPa and logarithmic decrement valueδ^(-1) in the range of 2×10^(-4)–3×10^(-4),demonstrating superior mechanical properties compared with the Ti-based alloys,which makes it an excellent candidate material for ultrasonic tools and medical applications.展开更多
Dissimilar AZ31B magnesium alloy and DC56D steel were welded via AA1060 aluminum alloy by magnetic pulse welding.The effects of primary and secondary welding processes on the welded interface were comparatively invest...Dissimilar AZ31B magnesium alloy and DC56D steel were welded via AA1060 aluminum alloy by magnetic pulse welding.The effects of primary and secondary welding processes on the welded interface were comparatively investigated.Macroscopic morphology,microstructure,and interfacial structure of the joints were analyzed using scanning electron microscope,energy dispersive spectrometer,and X-ray diffractometer(XRD).The results show that magnetic pulse welding of dissimilar Mg/Fe metals is achieved using an Al interlayer,which acts as a bridge for deformation and diffusion.Specifically,the AZ31B/AA1060 interface exhibits a typical wavy morphology,and a transition zone exists at the joint interface,which may result in an extremely complex microstructure.The microstructure of this transition zone differs from that of AZ31B magnesium and 1060 Al alloys,and it is identified as brittle intermetallic compounds(IMCs)Al_(3)Mg_(2) and Al_(12)Mg_(17).The transition zone is mainly distributed on the Al side,with the maximum thickness of Al-side transition layer reaching approximately 13.53μm.Incomplete melting layers with varying thicknesses are observed at the primary weld interface,while micron-sized hole defects appear in the transition zone of the secondary weld interface.The AA1060/DC56D interface is mainly straight,with only a small number of discontinuous transition zones distributed intermittently along the interface.These transition zones are characterized by the presence of the brittle IMC FeAl_(3),with a maximum thickness of about 4μm.展开更多
To maintain soil quality under long-term saline water irrigation,the influence of manure on soil physical properties was examined.Long-term saline irrigation has been conducted from 2015 to 2024 at the Nanpi Eco-Agric...To maintain soil quality under long-term saline water irrigation,the influence of manure on soil physical properties was examined.Long-term saline irrigation has been conducted from 2015 to 2024 at the Nanpi Eco-Agricultural Experimental Station of Chinese Academy Sciences in the Low Plain of the North China Plain,comprising four irrigation treatments:irrigation once at the jointing stage for winter wheat with irrigation water containing salt at fresh water,3,4 and 5 g·L^(–1),and maize irrigation at sowing using fresh water.Manure application was conducted under all irrigation treatments,with treatments without manure application used as controls.The results showed that under long-term irrigation with saline water,the application of manure increased the soil organic matter content,exchangeable potassium,available phosphorus,and total nitrogen content in the 0–20 cm soil layer by 46.8%,117.0%,75.7%,and 45.5%,respectively,compared to treatments without manure application.The application of manure reduced soil bulk density.It also increased the proportion of water-stable aggregates and the abundance of bacteria,fungi,and actinomycetes in the tillage soil layer compared to the controls.Because of the salt contained in the manure,the application of manure had dual effects on soil salt content.During the winter wheat season,manure application increased soil salt content.The salt content was significantly reduced during the summer maize season,owing to the strong salt-leaching effects under manure application,resulting in a smaller difference in salt content between the manure and non-manure treatments.During the summer rainfall season,improvements in soil structure under manure application increased the soil desalination rate for the 1 m top soil layer.The desalination rate for 0–40 cm and 40–100 cm was averagely by 39.1%and 18.9%higher,respectively,under manure application as compared with that under the nomanure treatments.The yield of winter wheat under manure application was 0.12%lower than that of the control,owing to the higher salt content during the winter wheat season.In contrast,the yield of summer maize improved by 3.9%under manure application,owing to the increased soil nutrient content and effective salt leaching.The results of this study indicated that manure application helped maintain the soil physical structure,which is important for the long-term use of saline water.In practice,using manure with a low salt content is suggested to reduce the adverse effects of saline water irrigation on soil properties and achieve sustainable saline water use.展开更多
The precise control of stereochemistry in organic π-conjugated chiral foldamers remains a fundamental challenge in synthetic chemistry due to the lack of universal design principles.Herein,we establish a versatile st...The precise control of stereochemistry in organic π-conjugated chiral foldamers remains a fundamental challenge in synthetic chemistry due to the lack of universal design principles.Herein,we establish a versatile strategy through cascade integration using a chiral building block Ⅰ-1 as a stereochemical template.Sequential imide functionalization yields Ⅰ-2,followed by parallel π-layer installation and structural expansion to construct foldamers Ⅱ-1,Ⅱ-2,Ⅲ-1,and Ⅲ-2,featuring naphthalimide bridges that interconnect distinct layers with preserved chirality.X-ray crystallography and electrostatic potential analysis conclusively resolve the layered architecture,multi-chiral elements and absolute configurations of this novel folding system.Frontier molecular orbitals and photophysical studies reveal unique luminescent properties arising from the naphthalimide core.The performance characterization indicates that both PLQY and the dissymmetry factors(g_(abs)/g_(lum))of chiroptical properties exhibit significant dependence on spatial modulation.Racemization kinetics and theoretical simulation show that π-layer incorporation significantly enhances interlayer van der Waals interactions,elevating the racemization Gibbs free energy to 41 kcal/mol for Ⅱ-1,which improvement over reported analogues.This work establishes a rational design platform for π-conjugated chiral foldamers,enabling the construction of configurationally stable,geometrically precise architectures with tailored optical properties.展开更多
Cryogenic rolling impacts on microstructure and mechanical properties of spray-formed 7055(SF-7055)Al alloy were investigated.Results show that with the increase of the reduction from 20%to 80%,the grain of cryogenic ...Cryogenic rolling impacts on microstructure and mechanical properties of spray-formed 7055(SF-7055)Al alloy were investigated.Results show that with the increase of the reduction from 20%to 80%,the grain of cryogenic rolled SF-7055 Al alloy is elongated to form a fiber texture.Numerous proliferating dislocations in the microstructure accumulate into dislocation walls and cells,and eventually form subgrains.These subgrain boundaries divide the original grain,thereby reducing the grain size.Under severe deformation conditions,they even enable the formation of nanograins.Meanwhile,the Cu-rich precipitates in the matrix are also broken and refined under the action of large rolling stress.In the process of cryogenic rolling,the tensile strength and hardness of SF-7055 Al alloy gradually increase,while the plasticity decreases.Moreover,the fracture morphology of cryogenic rolled SF-7055 Al alloy gradually transforms to the ductile and quasi-cleavage hybrid fracture characteristics with increased reduction.展开更多
The microstructure of high Nb-TiAl alloys was optimized by the addition of a small amount of Ta elements to further improve their properties.A series of Ti46Al1.5Cr8Nb-xTa(x=0.2,0.4,0.6,0.8,1.0,at.%)alloys were prepar...The microstructure of high Nb-TiAl alloys was optimized by the addition of a small amount of Ta elements to further improve their properties.A series of Ti46Al1.5Cr8Nb-xTa(x=0.2,0.4,0.6,0.8,1.0,at.%)alloys were prepared by vacuum arc melting.The microstructure,mechanical properties,and related influencing mechanisms were systematically investigated.The results indicate that the solidification microstructure of the Ti46Al1.5Cr8Nb-xTa alloys comprises theγ-TiAl phase,α_(2)-Ti_(3)Al phase,and B2 phase.As the Ta content increases from 0.2 at.%to 1.0 at.%,the content ofα_(2)phase and B2 phase increases,while theγphase content decreases.Among them,the B2 phase shows the most pronounced change,being significantly refined,with its content increasing from 12.49%to 21.91%.In addition,the average size of the lamellar colony decreases from 160.65 to 94.44μm.The addition of the Ta element shifts the solidification path toward lower aluminum concentrations,leading to changes in phase content.The tantalum-induced increase in the B2 phase and enhanced supercooling at the solidification front provide the basis for lamellar colony refinement.Compressive testing at room temperature reveals that the Ti46 Al1.5 Cr8 Nb0.4 Ta alloy exhibits optimal compressive properties,achieving a compressive strength of 2,434 MPa and a compressive strain of 33.1%.The improvement of its properties is attributed to a combination of lamellar colony refinement,solid solution strengthening resulting from the incorporation of Ta element,and a reduction in the c/a of theγphase.展开更多
Current thermochromic materials for smart windows suffer from poor environmental stability,lack of self-healing and recyclability,and susceptibility to contamination.In this study,thermochromic supramolecular ionogels...Current thermochromic materials for smart windows suffer from poor environmental stability,lack of self-healing and recyclability,and susceptibility to contamination.In this study,thermochromic supramolecular ionogels with excellent environmental stability,efficient room-temperature self-healing and recyclability properties,as well as amphiphobic slippery surfaces,are fabricated by incorporating binary ionic liquids into a rationally designed self-healing polyurethane with perfluoroalkyl side chains.The outstanding and stable thermochromic performance of the resulting ionogels stems from the hydrogen bond-mediated,confined,and reversible phase separation of ionic liquids within the polyurethane network,enabling the ionogels to effectively reduce indoor temperatures and enhance the comfort of occupants.The surface-enriched perfluoroalkyl side chains enable various liquids,including water,alkanes,and edible oils,to easily slide off the ionogel surface without leaving any residue,preventing the transmittance decrease and thermochromic performance degradation caused by contaminations.The dynamic hydrogen bonds within the polyurethane network enable the ionogels to repeatedly heal physical and chemical damages,as well as to be recycled multiple times without performance loss,thereby reducing maintenance costs and minimizing material waste.This study provides a novel approach to developing advanced thermochromic materials for smart windows,potentially improving the building energy efficiency and sustainability.展开更多
The magnetic properties and Kondo effect in Ce_(3)TiBi_(5) with a quasi-one-dimensional structure were investigated using in situ high-pressure resistivity measurements up to 48 GPa.At ambient pressure,Ce_(3)TiBi_(5) ...The magnetic properties and Kondo effect in Ce_(3)TiBi_(5) with a quasi-one-dimensional structure were investigated using in situ high-pressure resistivity measurements up to 48 GPa.At ambient pressure,Ce_(3)TiBi_(5) undergoes an antiferromagnetic(AFM)transition at T_(N)∼5 K.Under high pressures within 8.9 GPa,we find that Kondo scattering contributes differently to the high-temperature resistance,R(T),depending on the applied current direction,demonstrating a significantly anisotropic Kondo effect.The complete P–T phase diagram has been constructed,in which the pressure dependence of T_(N) exhibits a dome-like shape.The AFM order remains robust under pressure,even when the coherence temperature T^(*) far exceeds 300 K.We attribute the observed anisotropic Kondo effect and the robust AFM to the underlying anisotropy in electronic hybridization under high pressure.展开更多
The commercial AM60(Mg−6Al−0.3Mn)die-casting alloy was modified through Mn,Ce,and La micro-alloying,each at a content below 0.2 wt.%.SEM,TEM,and Micro-CT were employed to characterize the microstructures and propertie...The commercial AM60(Mg−6Al−0.3Mn)die-casting alloy was modified through Mn,Ce,and La micro-alloying,each at a content below 0.2 wt.%.SEM,TEM,and Micro-CT were employed to characterize the microstructures and properties of AM60 based alloys.AM60-0.2La alloy showed excellent mechanical properties.The ultimate tensile strength,yield strength,and elongation of(288.0±1.7)MPa,(158.0±1.0)MPa,and(22.0±3.0)%were achieved in AM60-0.2La alloy.Besides,AM60-0.2La alloy exhibited the best corrosion resistance(0.29 mm/a)and fluidity among the investigated four alloys.The excellent mechanical properties and corrosion resistance are mainly attributed to the grain refinement strengthening,low porosity,and low content of large shrinkage porosity,promising for super-sized integrated automotive components.展开更多
The Cu-12Fe alloy has attracted significant attention due to its excellent electrical conductivity and electromagnetic shielding capability,high strength,cost-effectiveness,and recyclability.In the present work,the Cu...The Cu-12Fe alloy has attracted significant attention due to its excellent electrical conductivity and electromagnetic shielding capability,high strength,cost-effectiveness,and recyclability.In the present work,the Cu-12Fe alloy strip with the thickness of 2.4 mm was successfully produced by twin-roll strip casting.The microstructure and properties of the Cu-12Fe alloy were tailored by cold rolling and aging treatment.The tensile strength of the as-cast strip is approximately 328 MPa and its elongation is 25%.The Fe phase randomly dispersed in the matrix,and the average size of Fe-rich phase is 2μm.Besides,enrichment of Fe phase is observed in the central layer of the strip,results in the formation of the“sandwich structure”.Moreover,the as-cast strip of Cu-12Fe was directly cold-rolled from 2.4 to 0.12 mm.The directly cold-rolled sample after aging at 450℃for 16 h(ProcessⅠ)shows excellent electrical conductivity of 69.5%IACS,the tensile strength and elongation are 513 MPa and 3.8%,the saturation magnetic flux density is 20.1 emu·g^(-1),and the coercive force is 25.2 Oe.In ProcessⅡ,the as-cast strip firstly cold-rolled to 1.2 mm,then aged at 500℃for 1.5 h,followed by cold rolling to 0.12 mm,finally aged at 450℃for 16 h.The sample after ProcessⅡshows the electrical conductivity of 66.3%IACS,the tensile strength of 533 MPa,an elongation of 3.5%,saturation magnetic flux density of 21.4 emu·g^(-1),and the coercive force of 22.3 Oe.展开更多
Developing precision forming of magnesium alloy micro-grooved heat pipes is of great significance for improving the lightweight level of aerospace thermal management systems.In this paper,the electrically-assisted ext...Developing precision forming of magnesium alloy micro-grooved heat pipes is of great significance for improving the lightweight level of aerospace thermal management systems.In this paper,the electrically-assisted extrusion of magnesium alloy heat pipes is explored,and the effects of extrusion and electrical parameters on the forming accuracy,microstructures,and mechanical properties are studied.Finite element simulation found that electrifying the extrusion ram and preheating the extrusion cylinder could effectively ensure the billet temperature,and an extrusion window(30-60 s)could be obtained.Reducing the extrusion velocity and increasing the current could both reduce the extrusion load.Within the range of the studied parameters,the micro-grooved heat pipes are relatively fully formed.It is found that increasing the extrusion velocity and electrical parameters would increase the grain size of the magnesium alloy.While the electrical parameter increases from 0 to 300 A,the grain size increases from~5.9 to~12.6μm,and the tensile strength and yield strength of the extruded profiles are also 20.7%and 16.8%lower than those without current.The tensile fracture surface shows that under the parameters of high extrusion velocity and high current,the fracture morphology changes from dimples and cleavage planes to large-area river patterns,and the fracture mode changes from the mixed ductile-brittle fracture to the brittle fracture.Under the extrusion parameters of 0.5 mm/s and 100 A,the extrusion load is reduced by 1.0-1.6 T,the cross-sectional filling rate is as high as 97.5%,and the size deviation of the micro-ribs(0.8 mm)is only±5μm.Simultaneously,under these parameters,the grain size does not significantly coarsen,and the strength and plasticity of the heat pipe increase slightly.This work provides theoretical and technical support for the development of precision forming technology of lightweight aerospace heat pipes.展开更多
The composition−property relationship of 18 quaternary high entropy diborides(HEBs)consisting of boron and IVB,VB and VIB transition metals(TM)was investigated using first-principles calculations.A valence electron co...The composition−property relationship of 18 quaternary high entropy diborides(HEBs)consisting of boron and IVB,VB and VIB transition metals(TM)was investigated using first-principles calculations.A valence electron concentration−relative electronegativity(VEC−REN)composite descriptor was developed to effectively predict the mechanical properties of HEBs.The results demonstrate that with a fixed VEC,the rise of the REN makes HEBs harder but more brittle when the electronegativity of doped TM atoms is lower than that of boron atoms.However,HEBs become softer and more ductile as REN increases if the doped TM atoms have higher electronegativity than boron atoms.The VEC−REN composite descriptor can accurately classify and predict the mechanical properties of HEBs with different components,which provides important theoretical guidance for the rapid design and development of novel high-entropy ceramic materials.展开更多
Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of re...Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of recycled coral aggregate on concrete properties,this study performed a comprehensive analysis of the physical properties of recycled coral aggregate and the basic mechanical properties and microstructure of RCAC.The test results indicate that,compared to coral debris,the crushing index of recycled coral aggregate was reduced by 9.4%,while porosity decreased by 33.5%.Furthermore,RCAC retained the early strength characteristics of coral concrete,with compressive strength and flexural strength exhibiting a notable increase as the water-cement ratio decreased.Under identical conditions,the compressive strength and flexural strength of RCAC were 12.7% and 2.5% higher than coral concrete's,respectively,with porosity correspondingly reduced from 3.13% to 5.11%.This enhancement could be attributed to the new mortar filling the recycled coral aggregate.Scanning electron microscopy(SEM)analysis revealed three distinct interface transition zones within RCAC,with the‘new mortar-old mortar’interface identified as the weakest.The above findings provided a reference for the sustainable use of coral concrete in constructing offshore islands.展开更多
A new method was proposed for preparing AZ31/1060 composite plates with a corrugated interface,which involved cold-pressing a corrugated surface on the Al plate and then hot-pressing the assembled Mg/Al plate.The resu...A new method was proposed for preparing AZ31/1060 composite plates with a corrugated interface,which involved cold-pressing a corrugated surface on the Al plate and then hot-pressing the assembled Mg/Al plate.The results show that cold-pressing produces intense plastic deformation near the corrugated surface of the Al plate,which promotes dynamic recrystallization of the Al substrate near the interface during the subsequent hot-pressing.In addition,the initial corrugation on the surface of the Al plate also changes the local stress state near the interface during hot pressing,which has a large effect on the texture components of the substrates near the corrugated interface.The construction of the corrugated interface can greatly enhance the shear strength by 2−4 times due to the increased contact area and the strong“mechanical gearing”effect.Moreover,the mechanical properties are largely depended on the orientation relationship between corrugated direction and loading direction.展开更多
基金supported by the National Natural Science Foundation of China(Nos.92166105 and 52005053)High-Tech Industry Science and Technology Innovation Leading Program of Hunan Province(No.2020GK2085)the Science and Technology Innovation Program of Hunan Province(No.2021RC3096).
文摘(NbZrHfTi)C high-entropy ceramics,as an emerging class of ultra-high-temperature materials,have garnered significant interest due to their unique multi-principal-element crystal structure and exceptional hightemperature properties.This study systematically investigates the mechanical properties of(NbZrHfTi)C high-entropy ceramics by employing first-principles density functional theory,combined with the Debye-Grüneisen model,to explore the variations in their thermophysical properties with temperature(0–2000 K)and pressure(0–30 GPa).Thermodynamically,the calculated mixing enthalpy and Gibbs free energy confirm the feasibility of forming a stable single-phase solid solution in(NbZrHfTi)C.The calculated results of the elastic stiffness constant indicate that the material meets the mechanical stability criteria of the cubic crystal system,further confirming the structural stability.Through evaluation of key mechanical parameters—bulk modulus,shear modulus,Young’s modulus,and Poisson’s ratio—we provide comprehensive insight into the macro-mechanical behaviour of the material and its correlation with the underlying microstructure.Notably,compared to traditional binary carbides and their average properties,(NbZrHfTi)C exhibits higher Vickers hardness(Approximately 28.5 GPa)and fracture toughness(Approximately 3.4 MPa⋅m^(1/2)),which can be primarily attributed to the lattice distortion and solid-solution strengthening mechanism.The study also utilizes the quasi-harmonic approximation method to predict the material’s thermophysical properties,including Debye temperature(initial value around 563 K),thermal expansion coefficient(approximately 8.9×10^(−6) K−1 at 2000 K),and other key parameters such as heat capacity at constant volume.The results show that within the studied pressure and temperature ranges,(NbZrHfTi)C consistently maintains a stable phase structure and good thermomechanical properties.The thermal expansion coefficient increasing with temperature,while heat capacity approaches the Dulong-Petit limit at elevated temperatures.These findings underscore the potential of(NbZrHfTi)C applications in ultra-high temperature thermal protection systems,cutting tool coatings,and nuclear structural materials.
基金Supported by National Natural Science Foundation of China(50976032,51776070)。
文摘Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separability of iron-based carriers require further enhancement.This study investigates the effect of the concentration of Mn doping on reactivity,elastic properties and magnetic properties based on density functional theory(DFT)calculations.Theoretical results demonstrate that Mn doping effectively enhances reactivity by reducing the oxygen vacancy formation energy(E_(vac))from 2.33 to 0.87 eV.However,Mn doping introduces HV/EV Ms lattice distortions that deteriorate elastic properties,thereby reducing wear resistance,as evidenced by a 54.54%decrease in the hardness-to-Young's modulus ratio(H_(v)/E_(v))forα-Fe_(2)O_(3)and an 83.33%reduction for Fe_(3)O_(4).Furthermore,Mn doping also modifies magnetic properties.The maximum of saturation magnetization(M_(s))of Fe_(3)O_(4)reaches 121.02 emu/g at 33.33%Mn doping concentration.Finally,systematic evaluation identifies 33.33%as the optimal Mn doping concentration,achieving a balance in enhanced reactivity,superior magnetic performance,and retained elastic stability.
基金supported by the National Natural Science Foundation of China (No.82174074)。
文摘This study investigates the properties of high-purity starches extracted from Polygonum multiflorum(PMS)and Smilax glabra(SGS).The starches were characterized by scanning electron microscopy,Fouriertransform infrared spectroscopy,X-ray diffraction,high-performance anion-exchange chromatography,and differential scanning calorimetry.Significant differences were observed in their morphological,physicochemical,and functional properties.PMS had a smaller particle size(13.68 μm),irregular polygonal shape,A-type,lower water absorption(62.67 %),and higher oil absorption(51.17 %).In contrast,SGS exhibited larger particles(31.75 μm),a nearly spherical shape,B-type,higher crystallinity(50.66 %),and greater amylose content(21.54 %),with superior thermal stability,shear resistance,and gelatinization enthalpy.SGS also contained higher resistant starch(83.28 %) and longer average chain length(20.58 %),but showed lower solubility,swelling power,light transmittance,and freeze-thaw stability.The physicochemical properties differences in crystal pattern and particle morphology between PMS and SGS lead to distinct behaviors during in vitro digestion and fermentation.These findings highlight the potential of medicinal plant starches in functional ingredients and industrial processes.
文摘Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been constructed hydrothermally at 160℃ using H_(3)tpta([1,1':3',1″-terphenyl]-4,4',5'-tricarboxylic acid),py(pyridine),H_(2)biim(2,2'-biimidazole),dpe(1,2-di(4-pyridyl)ethylene),and zinc,nickel and cadmium chlorides,resulting in the formation of stable crystalline solids which were subsequently analyzed using infrared spectroscopy,element analysis,thermogravimetric analysis,as well as structural analyses conducted via single-crystal X-ray diffraction.The findings from these single-crystal Xray diffraction studies indicate that complexes 1-3 form crystals within the monoclinic system P2_(1)/c space group(1)or triclinic system P1 space group(2 and 3),and possess 1D,0D,and 3D structures,respectively.Complex 1 demonstrated substantial catalytic efficiency and excellent reusability as a heterogeneous catalyst in the reaction of Knoevenagel condensation under ambient temperature conditions.In addition,complex 1 also showcased notable anti-wear performance when used in polyalphaolefin synthetic lubricants.CCDC:2449810,1;2449811,2;2449812,3.
文摘The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt%Nb addition after various plastic deformation and heat treatment processes were investigated.Through Vickers hardness tests,free resonance Young's modulus measurements,and microstructure analysis,the effects of dislocation density,vacancy formation,and recrystallization on the alloy performance were clarified.Results indicate that increasing the rolling reduction enhances damping property due to higher dislocation density,whereas aging below the recrystallization temperature reduces damping property via dislocation pinning by the Suzuki effect.Recrystallization heat treatment restores the original structure and damping level.This alloy possesses tensile strength of approximately 1500 MPa and logarithmic decrement valueδ^(-1) in the range of 2×10^(-4)–3×10^(-4),demonstrating superior mechanical properties compared with the Ti-based alloys,which makes it an excellent candidate material for ultrasonic tools and medical applications.
文摘Dissimilar AZ31B magnesium alloy and DC56D steel were welded via AA1060 aluminum alloy by magnetic pulse welding.The effects of primary and secondary welding processes on the welded interface were comparatively investigated.Macroscopic morphology,microstructure,and interfacial structure of the joints were analyzed using scanning electron microscope,energy dispersive spectrometer,and X-ray diffractometer(XRD).The results show that magnetic pulse welding of dissimilar Mg/Fe metals is achieved using an Al interlayer,which acts as a bridge for deformation and diffusion.Specifically,the AZ31B/AA1060 interface exhibits a typical wavy morphology,and a transition zone exists at the joint interface,which may result in an extremely complex microstructure.The microstructure of this transition zone differs from that of AZ31B magnesium and 1060 Al alloys,and it is identified as brittle intermetallic compounds(IMCs)Al_(3)Mg_(2) and Al_(12)Mg_(17).The transition zone is mainly distributed on the Al side,with the maximum thickness of Al-side transition layer reaching approximately 13.53μm.Incomplete melting layers with varying thicknesses are observed at the primary weld interface,while micron-sized hole defects appear in the transition zone of the secondary weld interface.The AA1060/DC56D interface is mainly straight,with only a small number of discontinuous transition zones distributed intermittently along the interface.These transition zones are characterized by the presence of the brittle IMC FeAl_(3),with a maximum thickness of about 4μm.
基金supported by National Key R&D Program of China (2022YFD1900104)。
文摘To maintain soil quality under long-term saline water irrigation,the influence of manure on soil physical properties was examined.Long-term saline irrigation has been conducted from 2015 to 2024 at the Nanpi Eco-Agricultural Experimental Station of Chinese Academy Sciences in the Low Plain of the North China Plain,comprising four irrigation treatments:irrigation once at the jointing stage for winter wheat with irrigation water containing salt at fresh water,3,4 and 5 g·L^(–1),and maize irrigation at sowing using fresh water.Manure application was conducted under all irrigation treatments,with treatments without manure application used as controls.The results showed that under long-term irrigation with saline water,the application of manure increased the soil organic matter content,exchangeable potassium,available phosphorus,and total nitrogen content in the 0–20 cm soil layer by 46.8%,117.0%,75.7%,and 45.5%,respectively,compared to treatments without manure application.The application of manure reduced soil bulk density.It also increased the proportion of water-stable aggregates and the abundance of bacteria,fungi,and actinomycetes in the tillage soil layer compared to the controls.Because of the salt contained in the manure,the application of manure had dual effects on soil salt content.During the winter wheat season,manure application increased soil salt content.The salt content was significantly reduced during the summer maize season,owing to the strong salt-leaching effects under manure application,resulting in a smaller difference in salt content between the manure and non-manure treatments.During the summer rainfall season,improvements in soil structure under manure application increased the soil desalination rate for the 1 m top soil layer.The desalination rate for 0–40 cm and 40–100 cm was averagely by 39.1%and 18.9%higher,respectively,under manure application as compared with that under the nomanure treatments.The yield of winter wheat under manure application was 0.12%lower than that of the control,owing to the higher salt content during the winter wheat season.In contrast,the yield of summer maize improved by 3.9%under manure application,owing to the increased soil nutrient content and effective salt leaching.The results of this study indicated that manure application helped maintain the soil physical structure,which is important for the long-term use of saline water.In practice,using manure with a low salt content is suggested to reduce the adverse effects of saline water irrigation on soil properties and achieve sustainable saline water use.
基金supported by the National Natural Science Foundation of China(22161017,22161016)。
文摘The precise control of stereochemistry in organic π-conjugated chiral foldamers remains a fundamental challenge in synthetic chemistry due to the lack of universal design principles.Herein,we establish a versatile strategy through cascade integration using a chiral building block Ⅰ-1 as a stereochemical template.Sequential imide functionalization yields Ⅰ-2,followed by parallel π-layer installation and structural expansion to construct foldamers Ⅱ-1,Ⅱ-2,Ⅲ-1,and Ⅲ-2,featuring naphthalimide bridges that interconnect distinct layers with preserved chirality.X-ray crystallography and electrostatic potential analysis conclusively resolve the layered architecture,multi-chiral elements and absolute configurations of this novel folding system.Frontier molecular orbitals and photophysical studies reveal unique luminescent properties arising from the naphthalimide core.The performance characterization indicates that both PLQY and the dissymmetry factors(g_(abs)/g_(lum))of chiroptical properties exhibit significant dependence on spatial modulation.Racemization kinetics and theoretical simulation show that π-layer incorporation significantly enhances interlayer van der Waals interactions,elevating the racemization Gibbs free energy to 41 kcal/mol for Ⅱ-1,which improvement over reported analogues.This work establishes a rational design platform for π-conjugated chiral foldamers,enabling the construction of configurationally stable,geometrically precise architectures with tailored optical properties.
基金financially and technically supported by the National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact,Beijing Institute of Technology,China(No.WDZC2024-1)。
文摘Cryogenic rolling impacts on microstructure and mechanical properties of spray-formed 7055(SF-7055)Al alloy were investigated.Results show that with the increase of the reduction from 20%to 80%,the grain of cryogenic rolled SF-7055 Al alloy is elongated to form a fiber texture.Numerous proliferating dislocations in the microstructure accumulate into dislocation walls and cells,and eventually form subgrains.These subgrain boundaries divide the original grain,thereby reducing the grain size.Under severe deformation conditions,they even enable the formation of nanograins.Meanwhile,the Cu-rich precipitates in the matrix are also broken and refined under the action of large rolling stress.In the process of cryogenic rolling,the tensile strength and hardness of SF-7055 Al alloy gradually increase,while the plasticity decreases.Moreover,the fracture morphology of cryogenic rolled SF-7055 Al alloy gradually transforms to the ductile and quasi-cleavage hybrid fracture characteristics with increased reduction.
基金the financial support by the Major Science and Technology Achievement Transformation Project in Heilongjiang Province(No.ZC2023SH0075)the National Natural Science Foundation of China(Nos.52425401,U2441255,52474377,and 52371015)+1 种基金the Young Elite Scientists Sponsorship·Program by CAST(No.2021QNRC001)the Henan Provincial Key Research and Development&Promotion Special Program(No.251111231400)。
文摘The microstructure of high Nb-TiAl alloys was optimized by the addition of a small amount of Ta elements to further improve their properties.A series of Ti46Al1.5Cr8Nb-xTa(x=0.2,0.4,0.6,0.8,1.0,at.%)alloys were prepared by vacuum arc melting.The microstructure,mechanical properties,and related influencing mechanisms were systematically investigated.The results indicate that the solidification microstructure of the Ti46Al1.5Cr8Nb-xTa alloys comprises theγ-TiAl phase,α_(2)-Ti_(3)Al phase,and B2 phase.As the Ta content increases from 0.2 at.%to 1.0 at.%,the content ofα_(2)phase and B2 phase increases,while theγphase content decreases.Among them,the B2 phase shows the most pronounced change,being significantly refined,with its content increasing from 12.49%to 21.91%.In addition,the average size of the lamellar colony decreases from 160.65 to 94.44μm.The addition of the Ta element shifts the solidification path toward lower aluminum concentrations,leading to changes in phase content.The tantalum-induced increase in the B2 phase and enhanced supercooling at the solidification front provide the basis for lamellar colony refinement.Compressive testing at room temperature reveals that the Ti46 Al1.5 Cr8 Nb0.4 Ta alloy exhibits optimal compressive properties,achieving a compressive strength of 2,434 MPa and a compressive strain of 33.1%.The improvement of its properties is attributed to a combination of lamellar colony refinement,solid solution strengthening resulting from the incorporation of Ta element,and a reduction in the c/a of theγphase.
基金supported by the National Natural Science Foundation of China(22475082,21971083)。
文摘Current thermochromic materials for smart windows suffer from poor environmental stability,lack of self-healing and recyclability,and susceptibility to contamination.In this study,thermochromic supramolecular ionogels with excellent environmental stability,efficient room-temperature self-healing and recyclability properties,as well as amphiphobic slippery surfaces,are fabricated by incorporating binary ionic liquids into a rationally designed self-healing polyurethane with perfluoroalkyl side chains.The outstanding and stable thermochromic performance of the resulting ionogels stems from the hydrogen bond-mediated,confined,and reversible phase separation of ionic liquids within the polyurethane network,enabling the ionogels to effectively reduce indoor temperatures and enhance the comfort of occupants.The surface-enriched perfluoroalkyl side chains enable various liquids,including water,alkanes,and edible oils,to easily slide off the ionogel surface without leaving any residue,preventing the transmittance decrease and thermochromic performance degradation caused by contaminations.The dynamic hydrogen bonds within the polyurethane network enable the ionogels to repeatedly heal physical and chemical damages,as well as to be recycled multiple times without performance loss,thereby reducing maintenance costs and minimizing material waste.This study provides a novel approach to developing advanced thermochromic materials for smart windows,potentially improving the building energy efficiency and sustainability.
基金supported by the National Key Research and Development Program of Chinathe National Natural Science Foundation of China (Grant Nos.2024YFA1408000,12474097,and2023YFA1406001)+2 种基金the Guangdong Provincial Quantum Science Strategic Initiative (Grant No.GDZX2201001)the Center for Computational Science and Engineering at Southern University of Science and Technology,the Major Science and Technology Infrastructure Project of Material Genome Big-science Facilities Platform supported by Municipal Development and Reform Commission of Shenzhen(for J.L.Z.and Y.L.)the Chinese funding sources applied via HPSTAR。
文摘The magnetic properties and Kondo effect in Ce_(3)TiBi_(5) with a quasi-one-dimensional structure were investigated using in situ high-pressure resistivity measurements up to 48 GPa.At ambient pressure,Ce_(3)TiBi_(5) undergoes an antiferromagnetic(AFM)transition at T_(N)∼5 K.Under high pressures within 8.9 GPa,we find that Kondo scattering contributes differently to the high-temperature resistance,R(T),depending on the applied current direction,demonstrating a significantly anisotropic Kondo effect.The complete P–T phase diagram has been constructed,in which the pressure dependence of T_(N) exhibits a dome-like shape.The AFM order remains robust under pressure,even when the coherence temperature T^(*) far exceeds 300 K.We attribute the observed anisotropic Kondo effect and the robust AFM to the underlying anisotropy in electronic hybridization under high pressure.
基金financially supported by the National Key Research and Development Program of China(Nos.2022YFB3709300,2021YFB3701000)the National Natural Science Foundation of China(Nos.52271090,52071036,U2037601,U21A2048)+1 种基金Chongqing Science and Technology Commission,China(Nos.CSTB2022TIAD-KPX0021,CSTC2024YCJHBGZXM0164,CSTB2024TIAD-KPX0001)the Fundamental Research Funds for the Central Universities,China(No.2022CDJDX-002)。
文摘The commercial AM60(Mg−6Al−0.3Mn)die-casting alloy was modified through Mn,Ce,and La micro-alloying,each at a content below 0.2 wt.%.SEM,TEM,and Micro-CT were employed to characterize the microstructures and properties of AM60 based alloys.AM60-0.2La alloy showed excellent mechanical properties.The ultimate tensile strength,yield strength,and elongation of(288.0±1.7)MPa,(158.0±1.0)MPa,and(22.0±3.0)%were achieved in AM60-0.2La alloy.Besides,AM60-0.2La alloy exhibited the best corrosion resistance(0.29 mm/a)and fluidity among the investigated four alloys.The excellent mechanical properties and corrosion resistance are mainly attributed to the grain refinement strengthening,low porosity,and low content of large shrinkage porosity,promising for super-sized integrated automotive components.
基金financially supported by the Natural Science Foundation of Liaoning Province of China(2022-MS-109)the Key Research and Development Program of Liaoning Province(2023JH2/101800045)the Ministry of Science and Technology of the Peoples Republic of China(ZZ2021006).
文摘The Cu-12Fe alloy has attracted significant attention due to its excellent electrical conductivity and electromagnetic shielding capability,high strength,cost-effectiveness,and recyclability.In the present work,the Cu-12Fe alloy strip with the thickness of 2.4 mm was successfully produced by twin-roll strip casting.The microstructure and properties of the Cu-12Fe alloy were tailored by cold rolling and aging treatment.The tensile strength of the as-cast strip is approximately 328 MPa and its elongation is 25%.The Fe phase randomly dispersed in the matrix,and the average size of Fe-rich phase is 2μm.Besides,enrichment of Fe phase is observed in the central layer of the strip,results in the formation of the“sandwich structure”.Moreover,the as-cast strip of Cu-12Fe was directly cold-rolled from 2.4 to 0.12 mm.The directly cold-rolled sample after aging at 450℃for 16 h(ProcessⅠ)shows excellent electrical conductivity of 69.5%IACS,the tensile strength and elongation are 513 MPa and 3.8%,the saturation magnetic flux density is 20.1 emu·g^(-1),and the coercive force is 25.2 Oe.In ProcessⅡ,the as-cast strip firstly cold-rolled to 1.2 mm,then aged at 500℃for 1.5 h,followed by cold rolling to 0.12 mm,finally aged at 450℃for 16 h.The sample after ProcessⅡshows the electrical conductivity of 66.3%IACS,the tensile strength of 533 MPa,an elongation of 3.5%,saturation magnetic flux density of 21.4 emu·g^(-1),and the coercive force of 22.3 Oe.
基金supported by the National Natural Science Foundation of China(Grant Nos.U24B2056,52505361)China Postdoctoral Science Foundation(Grant No.2025M774308)。
文摘Developing precision forming of magnesium alloy micro-grooved heat pipes is of great significance for improving the lightweight level of aerospace thermal management systems.In this paper,the electrically-assisted extrusion of magnesium alloy heat pipes is explored,and the effects of extrusion and electrical parameters on the forming accuracy,microstructures,and mechanical properties are studied.Finite element simulation found that electrifying the extrusion ram and preheating the extrusion cylinder could effectively ensure the billet temperature,and an extrusion window(30-60 s)could be obtained.Reducing the extrusion velocity and increasing the current could both reduce the extrusion load.Within the range of the studied parameters,the micro-grooved heat pipes are relatively fully formed.It is found that increasing the extrusion velocity and electrical parameters would increase the grain size of the magnesium alloy.While the electrical parameter increases from 0 to 300 A,the grain size increases from~5.9 to~12.6μm,and the tensile strength and yield strength of the extruded profiles are also 20.7%and 16.8%lower than those without current.The tensile fracture surface shows that under the parameters of high extrusion velocity and high current,the fracture morphology changes from dimples and cleavage planes to large-area river patterns,and the fracture mode changes from the mixed ductile-brittle fracture to the brittle fracture.Under the extrusion parameters of 0.5 mm/s and 100 A,the extrusion load is reduced by 1.0-1.6 T,the cross-sectional filling rate is as high as 97.5%,and the size deviation of the micro-ribs(0.8 mm)is only±5μm.Simultaneously,under these parameters,the grain size does not significantly coarsen,and the strength and plasticity of the heat pipe increase slightly.This work provides theoretical and technical support for the development of precision forming technology of lightweight aerospace heat pipes.
基金the National Natural Science Foundation of China (Nos. 52071179, 52271033)the Key Program of National Natural Science Foundation of China (No. 51931003)+2 种基金the Natural Science Foundation of Jiangsu Province, China (No. BK20221493)the Jiangsu Province Leading Edge Technology Basic Research Major Project, China (No. BK20222014)the Foundation of “Qinglan Project” for Colleges and Universities in Jiangsu Province, China。
文摘The composition−property relationship of 18 quaternary high entropy diborides(HEBs)consisting of boron and IVB,VB and VIB transition metals(TM)was investigated using first-principles calculations.A valence electron concentration−relative electronegativity(VEC−REN)composite descriptor was developed to effectively predict the mechanical properties of HEBs.The results demonstrate that with a fixed VEC,the rise of the REN makes HEBs harder but more brittle when the electronegativity of doped TM atoms is lower than that of boron atoms.However,HEBs become softer and more ductile as REN increases if the doped TM atoms have higher electronegativity than boron atoms.The VEC−REN composite descriptor can accurately classify and predict the mechanical properties of HEBs with different components,which provides important theoretical guidance for the rapid design and development of novel high-entropy ceramic materials.
基金Funded by Natural Science Foundation of Guangxi(No.2025GXNSFBA069565)Guangxi Science and Technology Program(No.AD25069101)Guangxi Bagui Scholars Fund。
文摘Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of recycled coral aggregate on concrete properties,this study performed a comprehensive analysis of the physical properties of recycled coral aggregate and the basic mechanical properties and microstructure of RCAC.The test results indicate that,compared to coral debris,the crushing index of recycled coral aggregate was reduced by 9.4%,while porosity decreased by 33.5%.Furthermore,RCAC retained the early strength characteristics of coral concrete,with compressive strength and flexural strength exhibiting a notable increase as the water-cement ratio decreased.Under identical conditions,the compressive strength and flexural strength of RCAC were 12.7% and 2.5% higher than coral concrete's,respectively,with porosity correspondingly reduced from 3.13% to 5.11%.This enhancement could be attributed to the new mortar filling the recycled coral aggregate.Scanning electron microscopy(SEM)analysis revealed three distinct interface transition zones within RCAC,with the‘new mortar-old mortar’interface identified as the weakest.The above findings provided a reference for the sustainable use of coral concrete in constructing offshore islands.
基金supported by Guangdong Major Project of Basic and Applied Basic Research, China (No. 2020B0301030006)Fundamental Research Funds for the Central Universities, China (No. SWU-XDJH202313)+1 种基金Chongqing Postdoctoral Science Foundation Funded Project, China (No. 2112012728014435)the Chongqing Postgraduate Research and Innovation Project, China (No. CYS23197)。
文摘A new method was proposed for preparing AZ31/1060 composite plates with a corrugated interface,which involved cold-pressing a corrugated surface on the Al plate and then hot-pressing the assembled Mg/Al plate.The results show that cold-pressing produces intense plastic deformation near the corrugated surface of the Al plate,which promotes dynamic recrystallization of the Al substrate near the interface during the subsequent hot-pressing.In addition,the initial corrugation on the surface of the Al plate also changes the local stress state near the interface during hot pressing,which has a large effect on the texture components of the substrates near the corrugated interface.The construction of the corrugated interface can greatly enhance the shear strength by 2−4 times due to the increased contact area and the strong“mechanical gearing”effect.Moreover,the mechanical properties are largely depended on the orientation relationship between corrugated direction and loading direction.
