This study investigates the microstructure and co-precipitation behavior of multicomponent(Ni(Al,Mn)and Cu)nanoparticles in the weld heat-affected zones of high-strength low-carbon steel.Through thermal simulations,th...This study investigates the microstructure and co-precipitation behavior of multicomponent(Ni(Al,Mn)and Cu)nanoparticles in the weld heat-affected zones of high-strength low-carbon steel.Through thermal simulations,the intercritical,fine-grained,and coarsegrained heat-affected zones were systematically characterized to elucidate the interplay between the microstructure,precipitation,and mechanical properties.At a heat input of 30 kJ·cm^(−1),Ni(Al,Mn)nanoparticles dissolve in the intercritical heat-affected zone,followed by dense reprecipitation coupled with significant coarsening of Cu particles during cooling,thereby retaining high strength but reducing impact toughness to(142±10)J(compared to(205±8)J of the base metal).The fine-grained heat-affected zone,under the same heat input,exhibits a refined ferritic-bainite matrix with a few fine Ni(Al,Mn)and slightly coarsened Cu particles,thus enhancing plastic deformation capacity and resulting in superior impact toughness of(196±7)J.Despite complete dissolution of original precipitates at peak temperatures in the coarse-grained heat-affected zone,re-precipitated nanoparticles provide effective strengthening effect,compensating for grain coarsening and dislocation recovery and resulting in an impressive impact toughness of(186±6)J.The toughening mechanism is primarily attributed to the synergistic actions of the matrix,precipitates,and deformation twins.These findings provide mechanistic and quantitative insights for developing processing-microstructure-property relationships in different welding heat-affected zones,and this framework can be further utilized to optimize welding parameters for tailored applications.展开更多
The complex interactions and conflicting performance demands in multi-component composites pose significant challenges for achieving balanced multi-property optimization through conventional trial-and-error approaches...The complex interactions and conflicting performance demands in multi-component composites pose significant challenges for achieving balanced multi-property optimization through conventional trial-and-error approaches.Machine learning(ML)offers a promising solution,markedly improving materials discovery efficiency.However,the high dimensionality of feature spaces in such systems has long impeded effective ML-driven feature representation and inverse design.To overcome this,we present an Intelligent Screening System(ISS)framework to accelerate the discovery of optimal formulations balancing four key properties in 15-component PTFE-based copper-clad laminate composites(PTFE-CCLCs).ISS adopts modular descriptors based on the physical information of component volume fractions,thereby simplifying the feature representation.By leveraging the inverse prediction capability of ML models and constructing a performance-driven virtual candidate database,ISS significantly reduced the computational complexity associated with high-dimensional spaces.Experimental validation confirmed that ISSoptimized formulations exhibited superior synergy,notably resolving the trade-off between thermal conductivity and peel strength,and outperform many commercial counterparts.Despite limited data and inherent process variability,ISS achieved an average prediction accuracy of 76.5%,with thermal conductivity predictions exceeding 90%,demonstrating robust reliability.This work provides an innovative,efficient strategy for multifunctional optimization and accelerated discovery in ultra-complex composite systems,highlighting the integration of ML and advanced materials design.展开更多
Multicomponent(Hf-Zr-Ta)B_(2)potentially provides improved ablation resistance compared with silicon-based ceramics.Here we deposited(Hf_(0.5-x/2)Zr_(0.5-x/2)Ta_(x))B_(2)(x=0,0.1,and 0.2)coatings onto C/C com-posites,...Multicomponent(Hf-Zr-Ta)B_(2)potentially provides improved ablation resistance compared with silicon-based ceramics.Here we deposited(Hf_(0.5-x/2)Zr_(0.5-x/2)Ta_(x))B_(2)(x=0,0.1,and 0.2)coatings onto C/C com-posites,and investigated their ablation behaviors under an oxyacetylene torch with a heat flux of 2.4 MW m^(-2).It was observed that the x=0.1 oxide scale bulged but was denser,and the x=0.2 oxide scale was blown away due to the formation of excessive liquid.Based on these findings,we further de-veloped a duplex(Hf-Zr-Ta)B_(2)coating that showed a linear recession rate close to zero(0.11μm s^(-1))after two 120-s ablation cycles.It is identified that the resulting oxide scale is mainly composed of(Hf,Zr)_(6)Ta_(2)O_(17)and(Hf,Zr,Ta)O_(2)by performing aberration-corrected(scanning)transmission electron microscopy.The protective mechanism is related to the peritectic transformation of orthorhombic-(Hf,Zr)_(6)Ta_(2)O_(17)to tetragonal-(Hf,Zr,Ta)O_(2)plus Ta-dominated liquid.This study contributes to the develop-ment of Ta-containing multicomponent UHTC bulk and coatings for ultra-high temperature applications.展开更多
Novel hydrogen storage materials have propelled progress in hydrogen storage technologies.Magnesium hydride(MgH_(2))is a highly promising candidate.Nevertheless,several drawbacks,including the need for elevated therma...Novel hydrogen storage materials have propelled progress in hydrogen storage technologies.Magnesium hydride(MgH_(2))is a highly promising candidate.Nevertheless,several drawbacks,including the need for elevated thermal conditions,sluggish dehydrogena-tion kinetics,and high thermodynamic stability,limit its practical application.One effective method of addressing these challenges is cata-lyst doping,which effectively boosts the hydrogen storage capability of Mg-based materials.Herein,we review recent advancements in catalyst-doped MgH_(2) composites,with particular focus on multicomponent and high-entropy catalysts.Structure-property relationships and catalytic mechanisms in these doping strategies are also summarized.Finally,based on existing challenges,we discuss future research directions for the development of Mg-based hydrogen storage systems.展开更多
Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structur...Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structural studies of other physicochemical properties are con-ducted on a series of materials obtained by the sol-gel method with different ratios of Gd and Sm cations.It is documented that changing the x value,and the resulting adjustment of the average ionic radius,have a significant impact on the crystal structure,stability,as well as on the total conductivity and thermomechanical properties of the materials,with the best results obtained for the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)composition.Oxygen electrodes are prepared using the selected compound,allowing to obtain low polarization resistance values,such as 0.086Ω·cm^(2)at 800℃.Systematic studies of electrocatalytic activity are conducted using La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(_(0.2))O_(3−δ)as the electrolyte for all electrodes,and Ce_(0.8)Gd_(0.2)O_(2−δ)electrolyte for the best performing Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes.The electrochemical data are analyzed using the distribution of relaxation times method.Also,the influence of the preparation method of the electrode material is in-ve`stigated using the electrospinning technique.Finally,the performance of the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes is tested in a Ni-YSZ(yttria-stabilized zirconia)anode-supported cell with a Ce_(0.8)Gd_(0.2)O_(2−δ)buffer layer,in the fuel cell and electrolyzer operating modes.With the electrospun electrode,a power density of 462 mW·cm^(−2)is obtained at 700℃,with a current density of ca.0.2 A·cm^(−2)at 1.3 V for the electrolysis at the same temperature,indicating better performance compared to the sol-gel-based electrode.展开更多
Despite their attractive features of high energy density,low cost,and safety,polysulfide/iodide flow batteries(SIFBs)are hampered by the sluggish kinetics of the iodide redox couple,which restricts overall performance...Despite their attractive features of high energy density,low cost,and safety,polysulfide/iodide flow batteries(SIFBs)are hampered by the sluggish kinetics of the iodide redox couple,which restricts overall performance.Multicomponent sulfides are demonstrated as promising catalysts for accelerating I^(-)/I_(3)^(-) redox reactions.Concurrently,the enhanced configurational entropy arising from multinary compositions drives synergistic effects among constituent elements,establishing a viable pathway to optimize catalytic performance.Building on these foundations,this work introduces a targeted orbital hybridization-optimized electron density strategy to enhance the catalytic activity.Implementing this concept,we developed an in-situ solvothermal synthesis process for an entropy-enhanced AgCuZnSnS_(4) loaded graphite felt(ACZTS/GF)electrode.The engineered electrode demonstrates exceptional electrocatalytic performance with improved bulk conductivity and interfacial charge transfer kinetics within a SIFB.The cell achieves a high energy efficiency of 88.5%at 20 mA·cm^(−2) with 10%state-of-charge.Furthermore,the battery delivers a maximum power density of 119.8 mW·cm^(−2) and exhibits excellent long-term cycling stability.These significant results stem from orbital hybridization-driven electronic state optimization and entropy effect-induced synergistic catalysis.展开更多
Double bonds of internal olefins can be efficiently migrated to the terminal carbons and regioselectively hydroesterified with formates in the presence of Pd(OAc)_(2) and 1,2-DTBPMB under mild reaction conditions,prov...Double bonds of internal olefins can be efficiently migrated to the terminal carbons and regioselectively hydroesterified with formates in the presence of Pd(OAc)_(2) and 1,2-DTBPMB under mild reaction conditions,providing a wide variety of corresponding linear carboxylic esters bearing various functional groups in good yields and>20:1 linear/branch ratios.The reaction is optionally simple and does not need to use CO gas and acid co-catalysts.展开更多
Inflammation is often accompanied by glioblastoma cells(GBMs)and is considered a key factor for GBM growth.This feature is believed to be connected with the tryptophan pathway mainly affected by intestinal microbes si...Inflammation is often accompanied by glioblastoma cells(GBMs)and is considered a key factor for GBM growth.This feature is believed to be connected with the tryptophan pathway mainly affected by intestinal microbes since the concept of gut-brain axis(GBA)has been proposed.Here we present a microchip model co-culturing intestinal cells(Caco2),microbes(E.coli),and GBM cells(U87)to study inflammatory responses of GBM by investigating the tryptophan metabolism.E.coli after encapsulating with alginate hydrogel microparticles(AHMPs)was seeded in the microchip where Caco2 was located,forming the simulated system of intestinal physiology and avoiding excessive reproduction of microbes.Continuous flow was applied to maintain the cell viability,induce the morphogenesis,and simulate the tryptophan transportation in GBA.The morphological alterations of Caco2 and U87 were characterized by fluorescence imaging and the tryptophan metabolism,especially the tryptophan-kynurenine pathway,was analyzed by LC-MS.Above these results of molecular analysis and cell behavior,we can conclude that GBM inflammation is induced by tryptophan accumulation.This microchip-based model generally provides an alternative method for in vitro research of interactions in GBA.展开更多
Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great signif...Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.展开更多
Objectives:To assess the effects of a wearable-sensorassisted multicomponent exercise program on physical fitness,cognition and quality of life in a practical setting involving frail older adults.Methods:Frail older a...Objectives:To assess the effects of a wearable-sensorassisted multicomponent exercise program on physical fitness,cognition and quality of life in a practical setting involving frail older adults.Methods:Frail older adults(n=130)were randomly divided into a control(CG,n=68)group and an exercise group(EG,n=62)in a 12-week intervention,which included stride gait training with wearable sensors;aerobic exercise;and resistance,flexibility,balance,and cognitive training.Primary outcomes(physical fitness)were evaluated via the SPPB and SFT.Secondary outcomes(cognitive ability,quality of life and frailty)were evaluated via the MoCA-BC,SF-36 and Fried frailty criteria,respectively.Results:After the 12-week intervention,the EG demonstrated significant improvements(p<0.05)vs.the CG in gait speed(β_(3)=0.424,coefficient of interaction effect between group and time from the generalized linear mixed model),chair stand(β_(3)=0.501)and total score(β_(3)=65.466)of SPPB and all SFT components including 6MWT(walked distance,β_(3)=1.098;walking speed,β_(3)=0.105;stride length,β_(3)=0.041),back scratch(β_(3)=4.926),chair sit and reach(β_(3)=3.762),30s arm curl(β_(3)=6.124),30s sit-to-stand(β_(3)=3.04),and TUG(β_(3)=−6.712).The MoCA-BC total,verbal fluency and delayed recall scores;the physical function,general health,vitality,and mental health scores of the SF-36;and the frailty phenotype in the EG were significantly improved compared with those of the CG.Conclusions:The progressive wearable-sensor-assisted multicomponent exercise program designed in this study enhanced physical fitness,cognitive ability and quality of life and slowed down the progression of frailty in frail older adults,supporting its potential as a feasible communitybased health intervention.展开更多
Exploration of new green polymerization strategies for the construction of conjugated polymers is important but challengeable.In this work,a multicomponent polymerization of acetylarenes,alkynones and ammonium acetate...Exploration of new green polymerization strategies for the construction of conjugated polymers is important but challengeable.In this work,a multicomponent polymerization of acetylarenes,alkynones and ammonium acetate for in situ construction of conjugated poly(triarylpyridine)s was developed.The polymerization reactions of diacetylarenes,aromatic dialkynones and NH_(4)OAc were performed in dimethylsulfoxide(DMSO)under heating in the presence of potassium tert-butoxide(t-BuOK),affording four conjugated poly(2,4,6-triarylpyridine)s(PTAPs)in satisfactory yields.The resulting PTAPs have good solubility in common organic solvents and high thermal stability with 5%weight loss temperatures reaching up to 460℃.They are also electrochemically active.The PTAPs incorporating tetraphenylethene units manifest aggregation-induced emission features.Moreover,through simply being doped into poly(vinyl alcohol)(PVA)matrix,the polymer and model compound containing triphenylamine moieties exhibit room-temperature phosphorescence properties with ultralong lifetimes up to 696.2 ms and high quantum yields up to 28.7%.This work not only provides a facile green synthetic route for conjugated polymers but also offers new insights into the design of advanced materials with unique photophysical properties.展开更多
We demonstrate a case study of Ce-doped yttrium aluminum garnet(YAG)phosphor to illustrate a novel plasma route for the synthesis of multicomponent materials with addressing morphology and structural control.The prese...We demonstrate a case study of Ce-doped yttrium aluminum garnet(YAG)phosphor to illustrate a novel plasma route for the synthesis of multicomponent materials with addressing morphology and structural control.The presented strategy was started directly from liquid precursors without any precipitating agents,and an innovative growth mechanism was proposed to explain the formation of monodispersed spherical particles with an adjusted size distribution.Homogeneous elemental distribution close to that of liquid precursors was also achieved due to the thermal nonequilibrium effect in plasma.Benefiting from the structural feature of the obtained product,a low transformation temperature of 1100℃for YAG phase was obtained and final products exhibit the highest photoluminescence intensity with rather low Ce doping of 0.5 wt.%,together with excellent thermal stability of 92%preservation of initial emission at 473 K.This work well illustrates the advance of plasma strategy in formation of multicomponent com-pounds with excellent performances,and its potential for large-scale production due to the transient and in-flight synthesis process.展开更多
Premature adiabatic shear localization caused by strain softening is a roadblock for the application of body-centered cubic(BCC)structured high-entropy alloy(HEAs)in the impact field.A micron-scale orthorhombic-phase(...Premature adiabatic shear localization caused by strain softening is a roadblock for the application of body-centered cubic(BCC)structured high-entropy alloy(HEAs)in the impact field.A micron-scale orthorhombic-phase(O-phase)strengthened TiZrVNbAl alloy was developed to delay adiabatic shear failure and enhance dynamic ductility.The O-phase can not only reduce the slip length,but also promote the pinning and tangling of the dislocations near the phase boundaries.The introduction of the O-phase transformed the strain hardening rate from negative to positive,resulting in a significantly improved dynamic shear resistance.Meanwhile,slip transfer across the O-phase via dislocation cutting mechanisms and a reduction of slip band spacing guaranteed dynamic deformation uniformity.Benefiting from the introduction of the O-phase,the alloy exhibits an excellent stored energy density(∼446 J/cm^(3),surpass the reported BCC-HEAs and typical titanium alloys),a large dynamic fracture strain(∼42%)and a considerable dynamic specific yield strength(∼241 MPa cm^(3)g^(-1)).The present study presents an effective approach for developing BCC-HEAs with excellent dynamic shear resistance and plasticity.展开更多
Dimethyl sulfoxide(DMSO)possessing strong solvency and high boiling point is a very important aprotic polar solvent in organic and polymer synthesis.Notably,it is also a useful synthon in organic chemistry.However,the...Dimethyl sulfoxide(DMSO)possessing strong solvency and high boiling point is a very important aprotic polar solvent in organic and polymer synthesis.Notably,it is also a useful synthon in organic chemistry.However,the direct incorporation of DMSO in polymer synthesis remains challenging.In this work,DMSO was successfully converted to nitrogen-containing heterocyclic polymers as a monomer via multicomponent polymerizations(MCPs)with dialdehydes and diamines in the presence of K_(2)S_(2)O_(8)/t-BuOK at 120℃in 6 h.A series of poly(phenylquinoline)s with high M_(w)values(up to 5.11×10^(4))were obtained in satisfactory yields(up to 82%),performing good solubility,good thermal and morphological stability as well as excellent film-forming ability.The thin films of poly(phenylquinoline)s exhibit high refractive index value in a wide wavelength range of 400–1700 nm.Thus,this work not only enriches the family of MCPs but also provides an efficient strategy for the conversion of DMSO into functional polymeric materials that are potentially applicable in diverse areas.展开更多
Bubbles are prevalent defects on the oxidized surfaces of ultra-high temperature carbides,compromis-ing structural stability and oxidation resistance.Despite their significance,the formation mechanisms and microstruct...Bubbles are prevalent defects on the oxidized surfaces of ultra-high temperature carbides,compromis-ing structural stability and oxidation resistance.Despite their significance,the formation mechanisms and microstructural evolution of bubbles during ultra-high temperature oxidation remain inadequately understood.To address this gap,the bubble behaviors of multicomponent carbides,including(Hf,Ti)C,(Hf,Zr,Ti)C,(Hf,Zr,Ti,Ta)C,and(Hf,Zr,Ti,Nb)C,were investigated under oxidation conditions at 2500℃.The roles of various elements were elucidated through first-principles calculations.Results show that the for-mation of a dense composite oxide layer is essential for bubble generation,with the release of gaseous products serving as the primary driving force.The microstructure of the bubbles is influenced by the ma-trix composition.The addition of Ti,Ta,and Nb significantly lowers the surface energy of the shell oxides,providing preferential nucleation sites for bubbles.The progressive oxidation of Ti leads to the formation of a“TiO_(2)-TiO-HfO_(2)”multilayerstructureat thebubbletop,which evolvesintoadendriticstructurewith prolonged oxidation.Ta and Nb further modulate the size and number of bubbles by altering the compo-sition and surface energy of the shell oxides.展开更多
Separation of ternary C_(4) olefins(n-butene,iso-butene and 1,3-butadiene)is very challenging but crucial in the petrol-chemical industry due to their similar molecular sizes and properties.Herein,to optimize the sepa...Separation of ternary C_(4) olefins(n-butene,iso-butene and 1,3-butadiene)is very challenging but crucial in the petrol-chemical industry due to their similar molecular sizes and properties.Herein,to optimize the separation efficiency for separation of C_(4) olefins,a new Hofmann-type MOF,[Ni(piz)Ni(CN)_(4)](piz=piperazine)-isostructural to the typical one[Ni(pyz)Ni(CN)_(4)](pyz=pyrazine),has been synthesized by a facile method from aqueous solution.The pore size reduction of[Ni(piz)Ni(CN)_(4)](3.62A,in contrast to 3.85A in[Ni(pyz)Ni(CN)_(4)])results in negligible iso-butene(i-C_(4)H_(8))uptake(from 2.92 to 0.04 mmol g^(-1))whereas retaining significant uptake for 1,3-butadiene(1,3-C_(4)H_(6),1.96 mmol g^(-1))and n-butene(n-C_(4)H_(8),1.47 mmol g^(-1)),showing much higher uptake ratios of 1,3-C_(4)H_(6)/i-C_(4)H_(8)(47)and n-C_(4)H_(8)/i-C_(4)H_(8)(35)that outperform most of the benchmark porous materials for separating C_(4) olefins.Breakthrough experiments demonstrate successful separation of high-purity(99.9999%)i-C_(4)H_(8) and 1,3-C_(4)H_(6) from equimolar 1,3-C_(4)H_(6)/i-C_(4)H_(8),n-C_(4)H_(8)/i-C_(4)H_(8) and 1,3-C_(4)H_(6)/n-C_(4)H_(8)/i-C_(4)H_(8) mixtures.展开更多
The development of human industry inevitably leads to excessive carbon dioxide(CO_(2))emissions.It can cause critical ecological consequences,primarily global warming and ocean acidification.In this regard,close atten...The development of human industry inevitably leads to excessive carbon dioxide(CO_(2))emissions.It can cause critical ecological consequences,primarily global warming and ocean acidification.In this regard,close attention is paid to the carbon capture,utilization,and storage concept.The key component of this concept is the catalytic conversion of CO_(2)into valuable chemical compounds and fuels.Light olefins are one of the most industrially important chemicals,and their sustainable production via CO_(2)hydrogenation could be a prospective way to reach carbon neutrality.Fe-based materials are widely recognized as effective thermocatalysts and photothermal catalysts for that process thanks to their low cost,high activity,and good stability.This review critically examines the most recent progress in the development and optimization of Fe-based catalysts for CO_(2)hydrogenation into light olefins.Particular attention is paid to understanding the roles of catalyst composition,structural properties,and promoters in enhancing catalytic activity,selectivity,and stability.展开更多
With the evolution of nickel-based single crystal superalloys,there is an increase in heavy elements such as Re and Ru.This has made solutal convection more pronounced during the directional solidification process,lea...With the evolution of nickel-based single crystal superalloys,there is an increase in heavy elements such as Re and Ru.This has made solutal convection more pronounced during the directional solidification process,leading to solute redistribution and increasing the risk of casting defects such as low-angle grain boundaries.To avoid casting defects,downward directional solidification(DWS)method is adopted to eliminate solutal convection and change solute redistribution.However,there is currently no in-situ characterization or quantitative simulation studying the solute redistribution during DWS and upward directional solidification(UWS)processes.A multicomponent phase field simulation coupled with lattice Boltzmann method was employed to quantitatively investigate changes in dendrite morphology,solutal convection and deviation of dendrite tips from the perspective of solute redistribution during UWS and DWS processes.The simulation of microstructure agrees well with the experimental results.The mechanism that explains how solutal convection affects side branching behavior is depicted.A novel approach is introduced to characterize dendrite deviation,elucidating the reasons why defects are prone to occur under the influence of natural convection and solute redistribution.展开更多
With the rapid development of economy,the consumption of fossil fuels and excessive emissions of carbon dioxide(CO_(2))have led to many environmental issues.The thermocatalytic conversion of CO_(2) to high value‐adde...With the rapid development of economy,the consumption of fossil fuels and excessive emissions of carbon dioxide(CO_(2))have led to many environmental issues.The thermocatalytic conversion of CO_(2) to high value‐added chemicals is an effective strategy to meet the need of carbon neutralization.Among them,CO_(2) hydrogenation to light olefins has been well researched so that the selectivity of desired products can exceed the Anderson–Schulz–Flory(ASF)distribution to acquire an extremely high yield.However,although huge progress has been made in CO_(2) hydrogenation to produce long‐chain α‐olefins based on Fe catalysts as well,designing efficient catalysts with promoted C‐O dissociation and C‐C coupling remains challenging.In addition,ASF distribution restrains the selectivity of desired long‐chain products,whereas the approaches to breaking it still face issues.In this review,we focus on the design of Fe‐based catalysts for the synthesis of long‐chainα‐olefins through CO_(2) hydrogenation.We have summarized and analyzed the reaction mechanism,design of catalysts,structure–activity relationship,interaction between Fe and promoters,and strategies to break the ASF distribution.At the same time,the issues faced by CO_(2) hydrogenation to long‐chain α‐olefins are proposed and the possible future solutions are prospected.This review aims to provide a recent development on the design of Fe‐based catalysts for CO_(2) hydrogenation to long‐chain α‐olefins while considering the ASF distribution.展开更多
Heavy metal-contaminated sites are primarily treated via solidification and adsorption.Calcium silicate hydrate(C-S-H)is generated during the soil stabilization process and contributes significantly to the strength an...Heavy metal-contaminated sites are primarily treated via solidification and adsorption.Calcium silicate hydrate(C-S-H)is generated during the soil stabilization process and contributes significantly to the strength and durability of the stabilized soil.To understand how the soil moisture content and heavy metal concentration affect the transport of heavy metals and the tensile strength of C-S-H,this study performed molecular dynamics(MD)simulations under different moisture and concentration levels.The results showed that Pb2+presented the highest adsorption to the surface of C-S-H due to its strong electrostatic interaction energy.The adsorption density peaks of Pb2+were 1.5–5 times greater than those of Cd2+and Zn2+.Zn2+and Cd2+ions were more likely to be adsorbed onto water molecules and form a larger hydrated radius than Pb2+.The adsorption of heavy metals onto C-S-H initially increased as the metal concentration increased and then decreased because of the limited sorption sites on C-S-H.The diffusion coefficients of the multicomponent metals in C-S-H showed no consistent trends.The maximum tensile strength of C-S-H decreased with increasing soil moisture and heavy metal concentrations.The tensile stress increased approximately linearly with strain until it reached a peak,after which it gradually declined but remained above zero,indicating good ductility and toughness under unsaturated conditions.These findings offer valuable molecular insights into the interactions between C-S-H and heavy metals and soil moisture,thereby advancing our understanding of their combined effects on soil stabilization.展开更多
基金supported by the National Natural Science Foundation of China(No.U2330110)Youth Science Foundation Project(Category A)of Liaoning Province,China(No.2025JH6/101100006).
文摘This study investigates the microstructure and co-precipitation behavior of multicomponent(Ni(Al,Mn)and Cu)nanoparticles in the weld heat-affected zones of high-strength low-carbon steel.Through thermal simulations,the intercritical,fine-grained,and coarsegrained heat-affected zones were systematically characterized to elucidate the interplay between the microstructure,precipitation,and mechanical properties.At a heat input of 30 kJ·cm^(−1),Ni(Al,Mn)nanoparticles dissolve in the intercritical heat-affected zone,followed by dense reprecipitation coupled with significant coarsening of Cu particles during cooling,thereby retaining high strength but reducing impact toughness to(142±10)J(compared to(205±8)J of the base metal).The fine-grained heat-affected zone,under the same heat input,exhibits a refined ferritic-bainite matrix with a few fine Ni(Al,Mn)and slightly coarsened Cu particles,thus enhancing plastic deformation capacity and resulting in superior impact toughness of(196±7)J.Despite complete dissolution of original precipitates at peak temperatures in the coarse-grained heat-affected zone,re-precipitated nanoparticles provide effective strengthening effect,compensating for grain coarsening and dislocation recovery and resulting in an impressive impact toughness of(186±6)J.The toughening mechanism is primarily attributed to the synergistic actions of the matrix,precipitates,and deformation twins.These findings provide mechanistic and quantitative insights for developing processing-microstructure-property relationships in different welding heat-affected zones,and this framework can be further utilized to optimize welding parameters for tailored applications.
基金financially supported by the National Key Research and Development Project of China(No.2022YFB3806900)。
文摘The complex interactions and conflicting performance demands in multi-component composites pose significant challenges for achieving balanced multi-property optimization through conventional trial-and-error approaches.Machine learning(ML)offers a promising solution,markedly improving materials discovery efficiency.However,the high dimensionality of feature spaces in such systems has long impeded effective ML-driven feature representation and inverse design.To overcome this,we present an Intelligent Screening System(ISS)framework to accelerate the discovery of optimal formulations balancing four key properties in 15-component PTFE-based copper-clad laminate composites(PTFE-CCLCs).ISS adopts modular descriptors based on the physical information of component volume fractions,thereby simplifying the feature representation.By leveraging the inverse prediction capability of ML models and constructing a performance-driven virtual candidate database,ISS significantly reduced the computational complexity associated with high-dimensional spaces.Experimental validation confirmed that ISSoptimized formulations exhibited superior synergy,notably resolving the trade-off between thermal conductivity and peel strength,and outperform many commercial counterparts.Despite limited data and inherent process variability,ISS achieved an average prediction accuracy of 76.5%,with thermal conductivity predictions exceeding 90%,demonstrating robust reliability.This work provides an innovative,efficient strategy for multifunctional optimization and accelerated discovery in ultra-complex composite systems,highlighting the integration of ML and advanced materials design.
基金supported by the National Key R&D Pro-gram of China(Grant No.2021YFA0715803)the National Natural Science Foundation of China(Grant Nos.52293373,52130205,and 52302091)+1 种基金the Joint Fund of Henan Province Science and Technol-ogy R&D Program(No.225200810002)the ND Basic Research Funds of Northwestern Polytechnical University(No.G2022WD).
文摘Multicomponent(Hf-Zr-Ta)B_(2)potentially provides improved ablation resistance compared with silicon-based ceramics.Here we deposited(Hf_(0.5-x/2)Zr_(0.5-x/2)Ta_(x))B_(2)(x=0,0.1,and 0.2)coatings onto C/C com-posites,and investigated their ablation behaviors under an oxyacetylene torch with a heat flux of 2.4 MW m^(-2).It was observed that the x=0.1 oxide scale bulged but was denser,and the x=0.2 oxide scale was blown away due to the formation of excessive liquid.Based on these findings,we further de-veloped a duplex(Hf-Zr-Ta)B_(2)coating that showed a linear recession rate close to zero(0.11μm s^(-1))after two 120-s ablation cycles.It is identified that the resulting oxide scale is mainly composed of(Hf,Zr)_(6)Ta_(2)O_(17)and(Hf,Zr,Ta)O_(2)by performing aberration-corrected(scanning)transmission electron microscopy.The protective mechanism is related to the peritectic transformation of orthorhombic-(Hf,Zr)_(6)Ta_(2)O_(17)to tetragonal-(Hf,Zr,Ta)O_(2)plus Ta-dominated liquid.This study contributes to the develop-ment of Ta-containing multicomponent UHTC bulk and coatings for ultra-high temperature applications.
基金financially supported by the National Key Research and Development Program of China (No. 2021YFB4000604)the National Natural Science Foundation of China (No. 52271220)+2 种基金the 111 Project (No. B12015)the Fundamental Research Funds for the Central UniversitiesHaihe Laboratory of Sustainable Chemical Transformations, Guangxi Collaborative Innovation Centre of Structure and Property for New Energy and Materials, Science Research and Technology Development Project of Guilin (No. 20210102-4)
文摘Novel hydrogen storage materials have propelled progress in hydrogen storage technologies.Magnesium hydride(MgH_(2))is a highly promising candidate.Nevertheless,several drawbacks,including the need for elevated thermal conditions,sluggish dehydrogena-tion kinetics,and high thermodynamic stability,limit its practical application.One effective method of addressing these challenges is cata-lyst doping,which effectively boosts the hydrogen storage capability of Mg-based materials.Herein,we review recent advancements in catalyst-doped MgH_(2) composites,with particular focus on multicomponent and high-entropy catalysts.Structure-property relationships and catalytic mechanisms in these doping strategies are also summarized.Finally,based on existing challenges,we discuss future research directions for the development of Mg-based hydrogen storage systems.
基金funded by the National Science Centre,Poland,on the basis of the decision number UMO-2020/37/B/ST8/02097supported by the program“Excellence Initiative-Research University”for the AGH University of Krakow(IDUB AGH,No.501.696.7996,Action 4,ID 9880).
文摘Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structural studies of other physicochemical properties are con-ducted on a series of materials obtained by the sol-gel method with different ratios of Gd and Sm cations.It is documented that changing the x value,and the resulting adjustment of the average ionic radius,have a significant impact on the crystal structure,stability,as well as on the total conductivity and thermomechanical properties of the materials,with the best results obtained for the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)composition.Oxygen electrodes are prepared using the selected compound,allowing to obtain low polarization resistance values,such as 0.086Ω·cm^(2)at 800℃.Systematic studies of electrocatalytic activity are conducted using La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(_(0.2))O_(3−δ)as the electrolyte for all electrodes,and Ce_(0.8)Gd_(0.2)O_(2−δ)electrolyte for the best performing Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes.The electrochemical data are analyzed using the distribution of relaxation times method.Also,the influence of the preparation method of the electrode material is in-ve`stigated using the electrospinning technique.Finally,the performance of the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes is tested in a Ni-YSZ(yttria-stabilized zirconia)anode-supported cell with a Ce_(0.8)Gd_(0.2)O_(2−δ)buffer layer,in the fuel cell and electrolyzer operating modes.With the electrospun electrode,a power density of 462 mW·cm^(−2)is obtained at 700℃,with a current density of ca.0.2 A·cm^(−2)at 1.3 V for the electrolysis at the same temperature,indicating better performance compared to the sol-gel-based electrode.
基金supported by the National Natural Science Foundation of China(Nos.22171180,22461142137,and 22478242)the Shanghai Municipal Science and Technology Major Project,China.
文摘Despite their attractive features of high energy density,low cost,and safety,polysulfide/iodide flow batteries(SIFBs)are hampered by the sluggish kinetics of the iodide redox couple,which restricts overall performance.Multicomponent sulfides are demonstrated as promising catalysts for accelerating I^(-)/I_(3)^(-) redox reactions.Concurrently,the enhanced configurational entropy arising from multinary compositions drives synergistic effects among constituent elements,establishing a viable pathway to optimize catalytic performance.Building on these foundations,this work introduces a targeted orbital hybridization-optimized electron density strategy to enhance the catalytic activity.Implementing this concept,we developed an in-situ solvothermal synthesis process for an entropy-enhanced AgCuZnSnS_(4) loaded graphite felt(ACZTS/GF)electrode.The engineered electrode demonstrates exceptional electrocatalytic performance with improved bulk conductivity and interfacial charge transfer kinetics within a SIFB.The cell achieves a high energy efficiency of 88.5%at 20 mA·cm^(−2) with 10%state-of-charge.Furthermore,the battery delivers a maximum power density of 119.8 mW·cm^(−2) and exhibits excellent long-term cycling stability.These significant results stem from orbital hybridization-driven electronic state optimization and entropy effect-induced synergistic catalysis.
基金financial support from the National Natural Science Foundation of China(Nos.22271024,21632005)Changzhou University.
文摘Double bonds of internal olefins can be efficiently migrated to the terminal carbons and regioselectively hydroesterified with formates in the presence of Pd(OAc)_(2) and 1,2-DTBPMB under mild reaction conditions,providing a wide variety of corresponding linear carboxylic esters bearing various functional groups in good yields and>20:1 linear/branch ratios.The reaction is optionally simple and does not need to use CO gas and acid co-catalysts.
基金supported by the National Key R&D Program of China(No.2021YFF0600700)the National Natural Science Foundation of China(No.22034005)+1 种基金Research Projects of Putian University(No.2024172)the Startup Fund for Advanced Talents of Putian University(No.2024046)。
文摘Inflammation is often accompanied by glioblastoma cells(GBMs)and is considered a key factor for GBM growth.This feature is believed to be connected with the tryptophan pathway mainly affected by intestinal microbes since the concept of gut-brain axis(GBA)has been proposed.Here we present a microchip model co-culturing intestinal cells(Caco2),microbes(E.coli),and GBM cells(U87)to study inflammatory responses of GBM by investigating the tryptophan metabolism.E.coli after encapsulating with alginate hydrogel microparticles(AHMPs)was seeded in the microchip where Caco2 was located,forming the simulated system of intestinal physiology and avoiding excessive reproduction of microbes.Continuous flow was applied to maintain the cell viability,induce the morphogenesis,and simulate the tryptophan transportation in GBA.The morphological alterations of Caco2 and U87 were characterized by fluorescence imaging and the tryptophan metabolism,especially the tryptophan-kynurenine pathway,was analyzed by LC-MS.Above these results of molecular analysis and cell behavior,we can conclude that GBM inflammation is induced by tryptophan accumulation.This microchip-based model generally provides an alternative method for in vitro research of interactions in GBA.
基金financially supported by the Scientific Research Start-up Fund Project of Anhui Polytechnic University for Introducing Talents(No.2022YQQ081)Natural Science Research Project of Anhui Educational Committee(No.2024AH050133)the National Natural Science Foundation of China(No.22001078).
文摘Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.
基金supported by the project of Guangzhou Sports Science and Technology Collaborative Innovation Center(No.SL2022B04J00034)National Key Research and Development Program of China(No.2020YFC2002900)。
文摘Objectives:To assess the effects of a wearable-sensorassisted multicomponent exercise program on physical fitness,cognition and quality of life in a practical setting involving frail older adults.Methods:Frail older adults(n=130)were randomly divided into a control(CG,n=68)group and an exercise group(EG,n=62)in a 12-week intervention,which included stride gait training with wearable sensors;aerobic exercise;and resistance,flexibility,balance,and cognitive training.Primary outcomes(physical fitness)were evaluated via the SPPB and SFT.Secondary outcomes(cognitive ability,quality of life and frailty)were evaluated via the MoCA-BC,SF-36 and Fried frailty criteria,respectively.Results:After the 12-week intervention,the EG demonstrated significant improvements(p<0.05)vs.the CG in gait speed(β_(3)=0.424,coefficient of interaction effect between group and time from the generalized linear mixed model),chair stand(β_(3)=0.501)and total score(β_(3)=65.466)of SPPB and all SFT components including 6MWT(walked distance,β_(3)=1.098;walking speed,β_(3)=0.105;stride length,β_(3)=0.041),back scratch(β_(3)=4.926),chair sit and reach(β_(3)=3.762),30s arm curl(β_(3)=6.124),30s sit-to-stand(β_(3)=3.04),and TUG(β_(3)=−6.712).The MoCA-BC total,verbal fluency and delayed recall scores;the physical function,general health,vitality,and mental health scores of the SF-36;and the frailty phenotype in the EG were significantly improved compared with those of the CG.Conclusions:The progressive wearable-sensor-assisted multicomponent exercise program designed in this study enhanced physical fitness,cognitive ability and quality of life and slowed down the progression of frailty in frail older adults,supporting its potential as a feasible communitybased health intervention.
基金supported by the National Natural Science Foundation of China(No.22071166)the Priority Academic Program Development of Jiangsu High Education Institutions(PAPD).
文摘Exploration of new green polymerization strategies for the construction of conjugated polymers is important but challengeable.In this work,a multicomponent polymerization of acetylarenes,alkynones and ammonium acetate for in situ construction of conjugated poly(triarylpyridine)s was developed.The polymerization reactions of diacetylarenes,aromatic dialkynones and NH_(4)OAc were performed in dimethylsulfoxide(DMSO)under heating in the presence of potassium tert-butoxide(t-BuOK),affording four conjugated poly(2,4,6-triarylpyridine)s(PTAPs)in satisfactory yields.The resulting PTAPs have good solubility in common organic solvents and high thermal stability with 5%weight loss temperatures reaching up to 460℃.They are also electrochemically active.The PTAPs incorporating tetraphenylethene units manifest aggregation-induced emission features.Moreover,through simply being doped into poly(vinyl alcohol)(PVA)matrix,the polymer and model compound containing triphenylamine moieties exhibit room-temperature phosphorescence properties with ultralong lifetimes up to 696.2 ms and high quantum yields up to 28.7%.This work not only provides a facile green synthetic route for conjugated polymers but also offers new insights into the design of advanced materials with unique photophysical properties.
基金supported by the National Natu-ral Science Foundation of China(No.52174342)the Beijing Nat-ural Science Foundation(No.2232044)the Beijing Munic-ipal Education Commission Research Plan General Project(No.KM202410005009).
文摘We demonstrate a case study of Ce-doped yttrium aluminum garnet(YAG)phosphor to illustrate a novel plasma route for the synthesis of multicomponent materials with addressing morphology and structural control.The presented strategy was started directly from liquid precursors without any precipitating agents,and an innovative growth mechanism was proposed to explain the formation of monodispersed spherical particles with an adjusted size distribution.Homogeneous elemental distribution close to that of liquid precursors was also achieved due to the thermal nonequilibrium effect in plasma.Benefiting from the structural feature of the obtained product,a low transformation temperature of 1100℃for YAG phase was obtained and final products exhibit the highest photoluminescence intensity with rather low Ce doping of 0.5 wt.%,together with excellent thermal stability of 92%preservation of initial emission at 473 K.This work well illustrates the advance of plasma strategy in formation of multicomponent com-pounds with excellent performances,and its potential for large-scale production due to the transient and in-flight synthesis process.
基金supported by the YEQISUN Joint Funds of the National Natural Science Foundation of China(Grant No.U2241234)the National Natural Science Foundation of China(Grant No.52301127).
文摘Premature adiabatic shear localization caused by strain softening is a roadblock for the application of body-centered cubic(BCC)structured high-entropy alloy(HEAs)in the impact field.A micron-scale orthorhombic-phase(O-phase)strengthened TiZrVNbAl alloy was developed to delay adiabatic shear failure and enhance dynamic ductility.The O-phase can not only reduce the slip length,but also promote the pinning and tangling of the dislocations near the phase boundaries.The introduction of the O-phase transformed the strain hardening rate from negative to positive,resulting in a significantly improved dynamic shear resistance.Meanwhile,slip transfer across the O-phase via dislocation cutting mechanisms and a reduction of slip band spacing guaranteed dynamic deformation uniformity.Benefiting from the introduction of the O-phase,the alloy exhibits an excellent stored energy density(∼446 J/cm^(3),surpass the reported BCC-HEAs and typical titanium alloys),a large dynamic fracture strain(∼42%)and a considerable dynamic specific yield strength(∼241 MPa cm^(3)g^(-1)).The present study presents an effective approach for developing BCC-HEAs with excellent dynamic shear resistance and plasticity.
基金supported by the Scientific Research Start-up Fund Project of Anhui Polytechnic University for Introducing Talents(No.2022YQQ081)Natural Science Research Project of the Anhui Educational Committee(No.2024AH050133)the National Natural Science Foundation of China(No.22101088)。
文摘Dimethyl sulfoxide(DMSO)possessing strong solvency and high boiling point is a very important aprotic polar solvent in organic and polymer synthesis.Notably,it is also a useful synthon in organic chemistry.However,the direct incorporation of DMSO in polymer synthesis remains challenging.In this work,DMSO was successfully converted to nitrogen-containing heterocyclic polymers as a monomer via multicomponent polymerizations(MCPs)with dialdehydes and diamines in the presence of K_(2)S_(2)O_(8)/t-BuOK at 120℃in 6 h.A series of poly(phenylquinoline)s with high M_(w)values(up to 5.11×10^(4))were obtained in satisfactory yields(up to 82%),performing good solubility,good thermal and morphological stability as well as excellent film-forming ability.The thin films of poly(phenylquinoline)s exhibit high refractive index value in a wide wavelength range of 400–1700 nm.Thus,this work not only enriches the family of MCPs but also provides an efficient strategy for the conversion of DMSO into functional polymeric materials that are potentially applicable in diverse areas.
基金financially supported by National Natural Science Foundation of China(No.52072410).
文摘Bubbles are prevalent defects on the oxidized surfaces of ultra-high temperature carbides,compromis-ing structural stability and oxidation resistance.Despite their significance,the formation mechanisms and microstructural evolution of bubbles during ultra-high temperature oxidation remain inadequately understood.To address this gap,the bubble behaviors of multicomponent carbides,including(Hf,Ti)C,(Hf,Zr,Ti)C,(Hf,Zr,Ti,Ta)C,and(Hf,Zr,Ti,Nb)C,were investigated under oxidation conditions at 2500℃.The roles of various elements were elucidated through first-principles calculations.Results show that the for-mation of a dense composite oxide layer is essential for bubble generation,with the release of gaseous products serving as the primary driving force.The microstructure of the bubbles is influenced by the ma-trix composition.The addition of Ti,Ta,and Nb significantly lowers the surface energy of the shell oxides,providing preferential nucleation sites for bubbles.The progressive oxidation of Ti leads to the formation of a“TiO_(2)-TiO-HfO_(2)”multilayerstructureat thebubbletop,which evolvesintoadendriticstructurewith prolonged oxidation.Ta and Nb further modulate the size and number of bubbles by altering the compo-sition and surface energy of the shell oxides.
基金supported by National Natural Science Foundation of China(22090061,22375221)Fundamental Research Program of Shanxi Province(No.202203021223004)+1 种基金Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2017ZT07C069)Hundred Talents Program of Sun Yat-Sen University.
文摘Separation of ternary C_(4) olefins(n-butene,iso-butene and 1,3-butadiene)is very challenging but crucial in the petrol-chemical industry due to their similar molecular sizes and properties.Herein,to optimize the separation efficiency for separation of C_(4) olefins,a new Hofmann-type MOF,[Ni(piz)Ni(CN)_(4)](piz=piperazine)-isostructural to the typical one[Ni(pyz)Ni(CN)_(4)](pyz=pyrazine),has been synthesized by a facile method from aqueous solution.The pore size reduction of[Ni(piz)Ni(CN)_(4)](3.62A,in contrast to 3.85A in[Ni(pyz)Ni(CN)_(4)])results in negligible iso-butene(i-C_(4)H_(8))uptake(from 2.92 to 0.04 mmol g^(-1))whereas retaining significant uptake for 1,3-butadiene(1,3-C_(4)H_(6),1.96 mmol g^(-1))and n-butene(n-C_(4)H_(8),1.47 mmol g^(-1)),showing much higher uptake ratios of 1,3-C_(4)H_(6)/i-C_(4)H_(8)(47)and n-C_(4)H_(8)/i-C_(4)H_(8)(35)that outperform most of the benchmark porous materials for separating C_(4) olefins.Breakthrough experiments demonstrate successful separation of high-purity(99.9999%)i-C_(4)H_(8) and 1,3-C_(4)H_(6) from equimolar 1,3-C_(4)H_(6)/i-C_(4)H_(8),n-C_(4)H_(8)/i-C_(4)H_(8) and 1,3-C_(4)H_(6)/n-C_(4)H_(8)/i-C_(4)H_(8) mixtures.
基金supported by the Ministry of Higher Education,Science and Innovation,and the Slovenian Research Agency(ARIS)throughresearch grants J7-4638 and J2-4441.
文摘The development of human industry inevitably leads to excessive carbon dioxide(CO_(2))emissions.It can cause critical ecological consequences,primarily global warming and ocean acidification.In this regard,close attention is paid to the carbon capture,utilization,and storage concept.The key component of this concept is the catalytic conversion of CO_(2)into valuable chemical compounds and fuels.Light olefins are one of the most industrially important chemicals,and their sustainable production via CO_(2)hydrogenation could be a prospective way to reach carbon neutrality.Fe-based materials are widely recognized as effective thermocatalysts and photothermal catalysts for that process thanks to their low cost,high activity,and good stability.This review critically examines the most recent progress in the development and optimization of Fe-based catalysts for CO_(2)hydrogenation into light olefins.Particular attention is paid to understanding the roles of catalyst composition,structural properties,and promoters in enhancing catalytic activity,selectivity,and stability.
基金supported by the stable support project and the Major National Science and Technology Project(2017-VII-0008-0101).
文摘With the evolution of nickel-based single crystal superalloys,there is an increase in heavy elements such as Re and Ru.This has made solutal convection more pronounced during the directional solidification process,leading to solute redistribution and increasing the risk of casting defects such as low-angle grain boundaries.To avoid casting defects,downward directional solidification(DWS)method is adopted to eliminate solutal convection and change solute redistribution.However,there is currently no in-situ characterization or quantitative simulation studying the solute redistribution during DWS and upward directional solidification(UWS)processes.A multicomponent phase field simulation coupled with lattice Boltzmann method was employed to quantitatively investigate changes in dendrite morphology,solutal convection and deviation of dendrite tips from the perspective of solute redistribution during UWS and DWS processes.The simulation of microstructure agrees well with the experimental results.The mechanism that explains how solutal convection affects side branching behavior is depicted.A novel approach is introduced to characterize dendrite deviation,elucidating the reasons why defects are prone to occur under the influence of natural convection and solute redistribution.
基金supported by the CNPC Innovation Found(2021DQ02‐0702).
文摘With the rapid development of economy,the consumption of fossil fuels and excessive emissions of carbon dioxide(CO_(2))have led to many environmental issues.The thermocatalytic conversion of CO_(2) to high value‐added chemicals is an effective strategy to meet the need of carbon neutralization.Among them,CO_(2) hydrogenation to light olefins has been well researched so that the selectivity of desired products can exceed the Anderson–Schulz–Flory(ASF)distribution to acquire an extremely high yield.However,although huge progress has been made in CO_(2) hydrogenation to produce long‐chain α‐olefins based on Fe catalysts as well,designing efficient catalysts with promoted C‐O dissociation and C‐C coupling remains challenging.In addition,ASF distribution restrains the selectivity of desired long‐chain products,whereas the approaches to breaking it still face issues.In this review,we focus on the design of Fe‐based catalysts for the synthesis of long‐chainα‐olefins through CO_(2) hydrogenation.We have summarized and analyzed the reaction mechanism,design of catalysts,structure–activity relationship,interaction between Fe and promoters,and strategies to break the ASF distribution.At the same time,the issues faced by CO_(2) hydrogenation to long‐chain α‐olefins are proposed and the possible future solutions are prospected.This review aims to provide a recent development on the design of Fe‐based catalysts for CO_(2) hydrogenation to long‐chain α‐olefins while considering the ASF distribution.
基金supported by the National Natural Science Foundation of China(Grant Nos.42030710 and 52308345)the National Key Research and Development Program of China(Grant No.2023YFC3707903).
文摘Heavy metal-contaminated sites are primarily treated via solidification and adsorption.Calcium silicate hydrate(C-S-H)is generated during the soil stabilization process and contributes significantly to the strength and durability of the stabilized soil.To understand how the soil moisture content and heavy metal concentration affect the transport of heavy metals and the tensile strength of C-S-H,this study performed molecular dynamics(MD)simulations under different moisture and concentration levels.The results showed that Pb2+presented the highest adsorption to the surface of C-S-H due to its strong electrostatic interaction energy.The adsorption density peaks of Pb2+were 1.5–5 times greater than those of Cd2+and Zn2+.Zn2+and Cd2+ions were more likely to be adsorbed onto water molecules and form a larger hydrated radius than Pb2+.The adsorption of heavy metals onto C-S-H initially increased as the metal concentration increased and then decreased because of the limited sorption sites on C-S-H.The diffusion coefficients of the multicomponent metals in C-S-H showed no consistent trends.The maximum tensile strength of C-S-H decreased with increasing soil moisture and heavy metal concentrations.The tensile stress increased approximately linearly with strain until it reached a peak,after which it gradually declined but remained above zero,indicating good ductility and toughness under unsaturated conditions.These findings offer valuable molecular insights into the interactions between C-S-H and heavy metals and soil moisture,thereby advancing our understanding of their combined effects on soil stabilization.
