Coal cinder is an abundant byproduct of the extensive consumption of coal in industrial production and daily life.Making full use of the cinder is conducive to a low-carbon economy.In this study,inspired by the burnin...Coal cinder is an abundant byproduct of the extensive consumption of coal in industrial production and daily life.Making full use of the cinder is conducive to a low-carbon economy.In this study,inspired by the burning of coal,a new method for constructing a silica-based composite porous material(SiO_(2)-CPM)was developed by combusting a siloxane-modified anthracite coal gel(CSiO_(2) gel).During this process,the combustion product was directly converted into a porous material,and the calorific value of the coal remained nearly unchanged(~98%of the original calorific value was retained),demonstrating the viability of this method for energy-efficient applications.The SiO_(2)-CPM exhibited an ultra-low thermal conductivity(0.036 W/(m·K)at room temperature),outperforming conventional insulation materials(e.g.,cotton~0.05 W/(m·K)).Additionally,it showed enhanced mechanical strength(fracture stress of 41.8 kPa)compared to the powder state of the coal cinder.Experimental results indicate that the amount of siloxane,structure-directing agent,and an acidic environment were critical for mechanical enhancement.The SiO_(2)-CPM showed good dimensional stability against thermal expansion and exhibited excellent thermal insulation and fire resistance even at 900℃.Meanwhile,the SiO_(2)-CPM with complex geometry could be easily fabricated using this method owing to the excellent shaping ability of the CSiO_(2) gel.Compared to conventional methods such as sol-gel synthesis or freeze-drying,this approach for fabricating SiO_(2)-CPM is simpler and cost-effective and allows the direct utilization of coal cinder post-combustion.展开更多
Nanoconfinement is a promising approach to simultaneously enhance the thermodynamics,kinetics,and cycling stability of hydrogen storage materials.The introduction of supporting scaffolds usually causes a reduction in ...Nanoconfinement is a promising approach to simultaneously enhance the thermodynamics,kinetics,and cycling stability of hydrogen storage materials.The introduction of supporting scaffolds usually causes a reduction in the total hydrogen storage capacity due to“dead weight.”Here,we synthesize an optimized N-doped porous carbon(rN-pC)without heavy metal as supporting scaffold to confine Mg/MgH_(2) nanoparticles(Mg/MgH_(2)@rN-pC).rN-pC with 60 wt%loading capacity of Mg(denoted as 60 Mg@rN-pC)can adsorb and desorb 0.62 wt%H_(2) on the rN-pC scaffold.The nanoconfined MgH_(2) can be chemically dehydrided at 175℃,providing~3.59 wt%H_(2) with fast kinetics(fully dehydrogenated at 300℃ within 15 min).This study presents the first realization of nanoconfined Mg-based system with adsorption-active scaffolds.Besides,the nanoconfined MgH_(2) formation enthalpy is reduced to~68 kJ mol^(−1) H_(2) from~75 kJ mol^(−1) H_(2) for pure MgH_(2).The composite can be also compressed to nanostructured pellets,with volumetric H_(2) density reaching 33.4 g L^(−1) after 500 MPa compression pressure,which surpasses the 24 g L^(−1) volumetric capacity of 350 bar compressed H_(2).Our approach can be implemented to the design of hybrid H_(2) storage materials with enhanced capacity and desorption rate.展开更多
Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via lo...Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.展开更多
The three-dimensional(3D) Pd-based nanoflower structures,assembled from two-dimensional(2D)nanosheets,are characterized by their stable and ordered configurations.These structures have been extensively designed as ano...The three-dimensional(3D) Pd-based nanoflower structures,assembled from two-dimensional(2D)nanosheets,are characterized by their stable and ordered configurations.These structures have been extensively designed as anode materials for fuel cells.However,the exploration of trimetallic nanoflowers with porous architectures remains limited.In this study,we present a straightforward one-step solvothermal method for the synthesis of trimetallic Pd Cu Ni porous nanoflowers(PNFs).Leveraging several unique advantages,such as an open superstructure,high porosity,and enhanced electronic interactions among the trimetals,the resulting Pd Cu Ni PNFs demonstrate significantly improved electrochemical performance,with mass activities reaching 5.94 and 10.14 A/mg for the ethanol oxidation reaction(EOR)and the ethylene glycol oxidation reaction(EGOR),respectively.Furthermore,the Pd Cu Ni PNFs exhibit optimized d-band centers and the most negative onset oxidation potential,indicating enhanced antitoxicity and stability.This study not only provides a novel perspective on the synthesis of 3D porous nanomaterials but also highlights the potential application value of trimetallic nanoalloys in catalysis.展开更多
The tire acoustic cavity resonance(TACR)noise is a significant source of the structure-borne noise inside a vehicle in the low-frequency range.This paper studies the noise dissipation effect of porous materials in red...The tire acoustic cavity resonance(TACR)noise is a significant source of the structure-borne noise inside a vehicle in the low-frequency range.This paper studies the noise dissipation effect of porous materials in reducing the TACR noise,an attempt to clarify the acoustic reduction mechanism and improve the accompanying vehicle interior noise level.A numerical model of a simplified tire cavity with rigid boundaries and acoustic excitation is established and further validated by the experiment.The effects of porous parameters on TACR frequency and sound pressure are then investigated and compared.The result reveals that the most influential material parameters are the porosity and material volume.It is also shown that the effectiveness of porous material in the mitigation of noise originates from the curliness of the material,which results in much larger acoustic impedance near the excitation position.Therefore,the sound absorption performance of the cavity attached with porous material proves to be excellent compared to that of the porous material itself.For further studying the damping effects of structural coupling,the flexible boundary of the tire tread is introduced.The results show that the porosity,material volume and structural loss factor of the tread all play important roles in reducing TACR noise.展开更多
Porous carbon microspheres are widely regarded as a superior CO_(2) adsorbent due to their exceptional efficiency and affordability.However,better adsorption performance is very attractive for porous carbon microspher...Porous carbon microspheres are widely regarded as a superior CO_(2) adsorbent due to their exceptional efficiency and affordability.However,better adsorption performance is very attractive for porous carbon microspheres.And modification of the pore structure is one of the effective strategies.In this study,multi-cavity mesoporous carbon microspheres were successfully synthesized by the synergistic method of soft and hard templates,during which a phenolic resin with superior thermal stability was employed as the carbon precursor and a mixture of silica sol and F108 as the mesoporous template.Carbon microspheres with multi-cavity mesoporous structures were prepared,and all the samples showed highly even mesopores,with diameters around 12 nm.The diameter of these microspheres decreased from 396.8 nm to about 182.5 nm with the increase of silica sol.After CO_(2) activation,these novel carbon microspheres(APCF0.5-S1.75)demonstrated high specific surface area(983.3 m^(2)/g)and remarkable CO_(2) uptake of 4.93 mmol/g at 0℃ and1 bar.This could be attributed to the unique multi-cavity structure,which offers uniform mesoporous pore channels,minimal CO_(2) transport of and a greater number of active sites for CO_(2) adsorption.展开更多
In the present work,the porous Ti particle reinforced Mg-based bulk metallic glass matrix composites(BMGCs)have been successfully fabricated via a novel in-situ dealloying method in metallic melt.A dual reinforcing st...In the present work,the porous Ti particle reinforced Mg-based bulk metallic glass matrix composites(BMGCs)have been successfully fabricated via a novel in-situ dealloying method in metallic melt.A dual reinforcing structure,including large-scale between porous particles and fine-scale inside one particle,was induced to further overcome the strength-plasticity tradeoff.The microstructure and mechanical properties of such dual-scale structure-reinforced BMGCs with various volume fractions and diameters of porous Ti particles were investigated in detail.It is found that with more and finer porous Ti particles,the BMGC showed both high fracture strength(1131.9±39.1 MPa)and good plastic deformability(1.48±0.38%).The characteristic of the reinforcing structure(0.48μm)inside the porous particles was close to the plastic processing zone size of the matrix(0.1~0.2μm),which generated a locally ideal reinforcing structure.Such dual-scale reinforcing structures with more interfaces can effectively promote the multiplication of shear bands at the interfaces.Due to the size effect,the refined submicron matrix between the Ti ligaments inside the porous particles should exhibit homogeneous shearing events.Such delocalization behavior from the dual-scale reinforcing structures should help to enhance the role of the interactions between shear bands,thus improving the yield strength of the composites.Based on the in-situ dealloying method,the dual-scale structure design provides a novel approach to fabricate various BMGCs with both high strength and good plasticity.展开更多
When a porous rock is subjected to overall compressive loading,either increasing pore pressure or decreasing confining pressure could result in rock failure.The stress path and the applied pressure change rate may aff...When a porous rock is subjected to overall compressive loading,either increasing pore pressure or decreasing confining pressure could result in rock failure.The stress path and the applied pressure change rate may affect the initiation and propagation of fractures within brittle materials.Understanding the physical mechanisms leading to failure is crucial for underground engineering applications and geo-energy exploration and storage.We conducted triaxial compression experiments on porous Bentheim sandstone samples at different stress paths and pressure change rates.First,at a constant confining pressure of 35 MPa and pore pressure of 5 MPa,intact cylindrical samples were axially loaded up to about 85%of the peak strength.Subsequently,the axial piston position was fixed,and then either the pore pressure was increased or the confining pressure was decreased at two different rates(0.5 MPa/min or 2 MPa/min),leading to final catastrophic failure.The mechanical results revealed that samples subjected to higher rates of decreasing effective confining pressure exhibited larger stress drop rates,higher slip rates,higher total breakdown work,higher rates of acoustic emissions(AEs)before failure,and higher post-failure AE decay rates.In contrast,the applied stress path did not significantly affect rock failure characteristics.Comparison of located AE events with post-mortem microstructures of deformed samples shows a good agreement.The AE source type determined from the P-wave first-motion polarity shows that shear failure dominated the fracture process when approaching failure.Gutenberg-Richter b-values revealed a significant decrease before failure in all tests.Our results indicate that,in contrast to the stress path,the rate of effective stress change strongly affects fracturing behavior and AE rate changes.展开更多
With the continuous increase in performance requirements for power systems in the aerospace and low-altitude economy sectors,designing lightweight and highstrength blade structures with excellent dynamic characteristi...With the continuous increase in performance requirements for power systems in the aerospace and low-altitude economy sectors,designing lightweight and highstrength blade structures with excellent dynamic characteristics has become critical.This paper puts forward a dynamic model for a rotating functionally graded graphenereinforced(FG-GPR)sandwich metal porous cantilever pre-twisted plate(PTP),aiming to analyze its natural vibration characteristics.To this end,the mixture principle and the revised Halpin-Tsai model are used to determine the parameters of graphene and porosity distributions in the core layer.With the classical plate theory,the Rayleigh-Ritz method,and the polynomials,the dynamic equations are derived to solve for the free vibration mode shapes and frequencies of the rotating FG-GPR sandwich metal porous cantilever PTP.The comparison of natural frequencies and mode shapes with available literature results confirms the precision of the theoretical formulation and numerical computations.The bending stiffnesses are analyzed.Finally,the effects of different graphene/pore distributions,length-to-thickness/width ratios,layer thickness ratios,twist angles,and rotational speeds on the natural frequencies of the system are systematically investigated.展开更多
Solid polymer electrolytes(SPEs)are considered promising candidates for all-solid-state lithium metal batteries because of their easy preparation and good compatibility with lithium metal.However,their applications ar...Solid polymer electrolytes(SPEs)are considered promising candidates for all-solid-state lithium metal batteries because of their easy preparation and good compatibility with lithium metal.However,their applications are restricted by their low ionic conductivity and poor mechanical properties.In this study,a composite solid polymer electrolyte composed of poly(ethylene oxide)(PEO),poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP),plasticizer succinonitrile(SN),and polytetrafluoroethylene(PTFE)fibrous porous membranes was prepared.The PTFE fibrous membrane significantly enhanced the mechanical strength of the electrolyte as a supporting framework.SN reduced the crystalline regions of PEO and facilitated rapid lithium-ion transport.PVDF-HFP promoted lithium salt dissolution and improved the electrochemical stability of the electrolyte.Accordingly,the optimized PTFE/PEO/PVDF-HFP/SN polymer electrolyte exhibited a tensile strength of 3.31 MPa at 352%elongation and demonstrated an ionic conductivity of 7.6×10^(-4)S·cm^(-1)at 60℃.Lithium symmetric cells maintained stable cycling for over 2500 h at 0.15 m A·cm^(-2),and Li//Li Fe PO_(4) full cells showed a high capacity retention of 91.6%after 300 cycles at 0.5 C,with coulombic efficiency consistently exceeding 99.9%throughout cycling.展开更多
With growing concerns regarding electromagnetic pollution,low-cost,environmentally friendly,and high-performance electromagnetic wave absorption(EWA)materials have attracted significant attention.This paper reports on...With growing concerns regarding electromagnetic pollution,low-cost,environmentally friendly,and high-performance electromagnetic wave absorption(EWA)materials have attracted significant attention.This paper reports on the synthesis of porous Fe_(3)O_(4)/C composites that incorporate dielectric and magnetic loss mechanisms via the carbothermal reduction method and optimization of waste ratio to enhance EWA performance.The Fe_(3)O_(4)/C composites with 10wt%soybean residues(Fe_(3)O_(4)/C-10),demonstrated the best EWA performance,achieving the minimum reflection loss of−56.4 dB and a bandwidth of 2.14 GHz at a thickness of 2.23 mm.This enhanced EWA performance is primarily attributable to improved impedance matching and the synergistic effect between dielectric and magnetic losses.Furthermore,radar cross-sectional simulations confirmed the practical feasibility of the porous Fe_(3)O_(4)/C composites.This study proposes a viable strategy for utilizing soybean residue and electrolytic manganese residue,highlighting their potential applications in EWA.展开更多
As a class of crystalline porous materials,metal-organic frameworks(MOFs)have shown unique advantages in the fields of catalysis,gas storage and separation,but their inherent microporous structure(pore diameter<2 n...As a class of crystalline porous materials,metal-organic frameworks(MOFs)have shown unique advantages in the fields of catalysis,gas storage and separation,but their inherent microporous structure(pore diameter<2 nm)severely limits their application in scenarios such as macromolecular mass transfer and so on.In order to overcome this re-striction,mesoporous MOFs(meso-MOFs)with a larger aperture(2-50 nm)have attracted much attention due to their potential applications in biological macromolecular catalysis,energy storage and other fields.To date,how to accurately regulate its mesopore topology and pore ordering still faces important technical challenges.展开更多
Following the fundamental characteristics of the porosity windbreak,this study suggests a new numerical investigation method for the wind field of the windbreak based on the porous medium physical model.This method ca...Following the fundamental characteristics of the porosity windbreak,this study suggests a new numerical investigation method for the wind field of the windbreak based on the porous medium physical model.This method can transform the reasonable matching problem of the porosity and windproof performance of the windbreak into a study of the relationship between the resistance coefficient of the porous medium and the aerodynamic load of the train.This study examines the influence of the hole type on the wind field behind the porosity windbreak.Then,the relationship between the resistance coefficient of the porous medium,the porosity of the windbreak,and the aerodynamic loads of the train is investigated.The results show that the porous media physical model can be used instead of the windbreak geometry to study the windbreak-train aerodynamic performance,and the process of using this method is suggested.展开更多
The study considers numerical findings regarding magneto-thermosolutal-aided natural convective flow of alumina/water-based nanofluid filled in a non-Darcian porous horizontal concentric annulus.Two equations are assu...The study considers numerical findings regarding magneto-thermosolutal-aided natural convective flow of alumina/water-based nanofluid filled in a non-Darcian porous horizontal concentric annulus.Two equations are assumed to evaluate the thermal fields in the porous medium under Local Thermal Non-Equilibrium(LTNE)conditions,along with the Darcy-Brinkman-Forchheimer model for the flow.By imposing distinct and constant temperatures and concentrations on both internal and external cylinders,thermosolutal natural convection is induced in the annulus.We apply the finite volume method to solve the dimensionless governing equations numerically.The thermal conductivity and viscosity of the nanofluid mixture are determined utilizing Corcione’s empirical correlations,incorporating the effects of Brownian diffusion of nanoparticles.Steady-state findings are provided for a range of significant parameters,including buoyancy ratio(N=1 to 5),Lewis(Le=0 to 10),Rayleigh(Ra=102 to 105),Hartmann(Ha=0 to 50),and heat generation in the nanofluid and solid phases(Q=0 to 20)when the nanofluid flow is driven by aiding thermal and mass buoyancies at given porous medium characteristics(porosity(ε),Darcy number(Da),porous interfacial heat transfer coefficient(H),and thermal conductivity ratio(γ),to assess the thermosolutal convective circulation beside heat and solutal transfer rates in the annulus.The results reveal that internal heat generation significantly modifies the heat transport mechanism,initially reducing and then enhancing heat transfer rates as Q increases.Interestingly,increasing Le reduces heat transfer at low Q but promotes it when Q>5,while mass transfer consistently increases with Le.The magnetic field represses heat transfer in the absence of internal heat but enhances it when internal heat is present.展开更多
To efficiently address the current high cost associated with preparing pseudo-boehmite from organic aluminum,a low-cost alternative,AlCl_(3),is employed as the raw material.The sol-gel method is utilized,and H_(2)O_(2...To efficiently address the current high cost associated with preparing pseudo-boehmite from organic aluminum,a low-cost alternative,AlCl_(3),is employed as the raw material.The sol-gel method is utilized,and H_(2)O_(2)is incorporated for the modification of pseudo-boehmite.The modification mechanism is thoroughly investigated through the use of X-ray powder diffractometer,scanning electron microscope,and BET data analysis,as well as molecular dynamics simulations.Under specific conditions(temperature at 80°C,pH=7,and H_(2)O_(2)volume ratios of 0.5:1,1:1,and 2:1),mesoporous pseudo-boehmite is synthesized with a specific surface area of 227 m^(2)/g,a pore volume of 0.281 cm^(3)/g,a pore size of 6.78 nm,and a peptizing index of 99.47%.A novel and innovative methodology for the cost-effective production of high-performance alumina is offered through the approach.展开更多
The use of visible-light responsive photocatalysts for removing heavy metal ions in wastewater has received great attention.However,the development of photocatalysts with high activity and recyclability remains a huge...The use of visible-light responsive photocatalysts for removing heavy metal ions in wastewater has received great attention.However,the development of photocatalysts with high activity and recyclability remains a huge challenge.Herein,a recyclable carbon fiber cloth-supported porous CdS nanorod photocatalyst was fabricated by a two-step hydrothermal treatment using AgVO_(3) nanowires as templates.The results indicated that under visible-light illumination,the carbon cloth-supported porous CdS nanorods showed improved photocatalytic activity for the reduction of Cr(Ⅵ),with an apparent rate constant exceeding that of carbon cloth-supported CdS nanospheres by a factor of 1.65 times.Moreover,the carbon cloth-supported porous CdS nanorods can be easily separated and be reused.This brings a new perspective for developing photocatalysts with high efficiency and recyclability for wastewater treatment.展开更多
This paper gives an overview on nonlinear porous flow in low permeability porous media, reveals the microscopic mechanisms of flows, and clarifies properties of porous flow fluids. It shows that, deviating from Darcy...This paper gives an overview on nonlinear porous flow in low permeability porous media, reveals the microscopic mechanisms of flows, and clarifies properties of porous flow fluids. It shows that, deviating from Darcy＇s linear law, the porous flow characteristics obey a nonlinear law in a low-permeability porous medium, and the viscosity of the porous flow fluid and the permeability values of water and oil are not constants. Based on these characters, a new porous flow model, which can better describe low permeability reservoir~ is established. This model can describe various patterns of porous flow, as Darcy＇s linear law does. All the parameters involved in the model, having definite physical meanings, can be obtained directly from the experiments.展开更多
Large-scale deployment of carbon dioxide(CO_(2))removal technology is an essential step to cope with global warming and achieve carbon neutrality.Direct air capture(DAC)has recently received increasing attention given...Large-scale deployment of carbon dioxide(CO_(2))removal technology is an essential step to cope with global warming and achieve carbon neutrality.Direct air capture(DAC)has recently received increasing attention given the high flexibility to remove CO_(2)from discrete sources.Porous materials with adjustable pore characteristics are promising sorbents with low or no latent heat of vaporization.This review article has summarized the recent development of porous sorbents for DAC,with a focus of pore engineering strategy and adsorption mechanism.Physisorbents such as zeolites,porous carbons,metal-organic frameworks(MOFs),and amine-modified chemisorbents have been discussed and their challenges in practical application have been analyzed.At last,future directions have been proposed,and it is expected to inspire collaborations from chemistry,environment,material science and engineering communities.展开更多
Due to the greenhouse effect caused by carbon dioxide(CO_(2))emission,much attention has been paid for the removal of CO_(2).Porous liquids(PLs),as new type of liquid materials,have obvious advantages in mass and heat...Due to the greenhouse effect caused by carbon dioxide(CO_(2))emission,much attention has been paid for the removal of CO_(2).Porous liquids(PLs),as new type of liquid materials,have obvious advantages in mass and heat transfer,which are widely used in gas adsorption and sep-aration.Metal–organic frameworks(MOFs)with merits like large surface area,inherent porous structure and adjustable topology have been considered as one of the best candidates for PLs construction.This review presents the state-of-the-art status on the fabrication strategy of MOFs-based PLs and their CO_(2) absorption and utilization performance,and the positive effects of porosity and functional modification on the absorption-desorption property,selectivity of target product,and regeneration ability are well summarized.Finally,the challenges and prospects for MOFs-based PLs in the optimization of preparation,the coupling of multiple removal techniques,the in situ characterization methods,the regeneration and cycle stability,the environmental impact as well as expansion of application are proposed.展开更多
The current artificial bone is unable to accurately replicate the inhomogeneity and anisotropy of human cancellous bone.To address this issue,we proposed a personalized approach based on clinical CT images to design m...The current artificial bone is unable to accurately replicate the inhomogeneity and anisotropy of human cancellous bone.To address this issue,we proposed a personalized approach based on clinical CT images to design mechanical equivalent porous structures for artificial femoral heads.Firstly,supported by Micro and clinical CT scans of 21 bone specimens,the anisotropic mechanical parameters of human cancellous bone in the femoral head were characterized using clinical CT values(Hounsfield unit).After that,the equivalent porous structure of cancellous bone was designed based on the gyroid surface,the influence of its degree of anisotropy and volume fraction on the macroscopic mechanical parameters was investigated by finite element analysis.Furthermore,a mapping relationship between CT values and the porous structure was established by jointly solving the mechanical parameters of the porous structure and human cancellous bone,allowing the design of personalized gradient porous structures based on clinical CT images.Finally,to verify the mechanical equivalence,implant press-in tests were conducted on 3D-printed artificial femoral heads and human femoral heads,the influence of the porous structure’s cell size in bone-implant interaction problems was also explored.Results showed that the minimum deviations of press-in stiffness(<15%)and peak load(<5%)both occurred when the cell size was 20%to 30%of the implant diameter.In conclusion,the designed porous structure can replicate the human cancellous bone-implant interaction at a high level,indicating its effectiveness in optimizing the mechanical performance of 3D-printed artificial femoral head.展开更多
基金supported by the National Natural Science Foundation of China(No.52573220)the National Key R&D Program of China(No.2023YFC3404201)+1 种基金the Fundamental Research Funds for the Central Universities(No.FRF-IDRY-GD24-005)the State Key Laboratory of Solid Waste Reuse for Building Materials(No.SWR-2022-009).
文摘Coal cinder is an abundant byproduct of the extensive consumption of coal in industrial production and daily life.Making full use of the cinder is conducive to a low-carbon economy.In this study,inspired by the burning of coal,a new method for constructing a silica-based composite porous material(SiO_(2)-CPM)was developed by combusting a siloxane-modified anthracite coal gel(CSiO_(2) gel).During this process,the combustion product was directly converted into a porous material,and the calorific value of the coal remained nearly unchanged(~98%of the original calorific value was retained),demonstrating the viability of this method for energy-efficient applications.The SiO_(2)-CPM exhibited an ultra-low thermal conductivity(0.036 W/(m·K)at room temperature),outperforming conventional insulation materials(e.g.,cotton~0.05 W/(m·K)).Additionally,it showed enhanced mechanical strength(fracture stress of 41.8 kPa)compared to the powder state of the coal cinder.Experimental results indicate that the amount of siloxane,structure-directing agent,and an acidic environment were critical for mechanical enhancement.The SiO_(2)-CPM showed good dimensional stability against thermal expansion and exhibited excellent thermal insulation and fire resistance even at 900℃.Meanwhile,the SiO_(2)-CPM with complex geometry could be easily fabricated using this method owing to the excellent shaping ability of the CSiO_(2) gel.Compared to conventional methods such as sol-gel synthesis or freeze-drying,this approach for fabricating SiO_(2)-CPM is simpler and cost-effective and allows the direct utilization of coal cinder post-combustion.
基金supported by the National Key R&D Program of China(2022YFB3803700)National Natural Science Foundation of China(52171186)+1 种基金Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)support from“Zhiyuan Honor Program”for doctoral students,Shanghai Jiao Tong University.
文摘Nanoconfinement is a promising approach to simultaneously enhance the thermodynamics,kinetics,and cycling stability of hydrogen storage materials.The introduction of supporting scaffolds usually causes a reduction in the total hydrogen storage capacity due to“dead weight.”Here,we synthesize an optimized N-doped porous carbon(rN-pC)without heavy metal as supporting scaffold to confine Mg/MgH_(2) nanoparticles(Mg/MgH_(2)@rN-pC).rN-pC with 60 wt%loading capacity of Mg(denoted as 60 Mg@rN-pC)can adsorb and desorb 0.62 wt%H_(2) on the rN-pC scaffold.The nanoconfined MgH_(2) can be chemically dehydrided at 175℃,providing~3.59 wt%H_(2) with fast kinetics(fully dehydrogenated at 300℃ within 15 min).This study presents the first realization of nanoconfined Mg-based system with adsorption-active scaffolds.Besides,the nanoconfined MgH_(2) formation enthalpy is reduced to~68 kJ mol^(−1) H_(2) from~75 kJ mol^(−1) H_(2) for pure MgH_(2).The composite can be also compressed to nanostructured pellets,with volumetric H_(2) density reaching 33.4 g L^(−1) after 500 MPa compression pressure,which surpasses the 24 g L^(−1) volumetric capacity of 350 bar compressed H_(2).Our approach can be implemented to the design of hybrid H_(2) storage materials with enhanced capacity and desorption rate.
基金the National Nature Science Foundation of China for Excellent Young Scientists Fund(32222058)Fundamental Research Foundation of CAF(CAFYBB2022QB001).
文摘Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.
基金supported by the National Natural Science Foundation of China (No.52274304)。
文摘The three-dimensional(3D) Pd-based nanoflower structures,assembled from two-dimensional(2D)nanosheets,are characterized by their stable and ordered configurations.These structures have been extensively designed as anode materials for fuel cells.However,the exploration of trimetallic nanoflowers with porous architectures remains limited.In this study,we present a straightforward one-step solvothermal method for the synthesis of trimetallic Pd Cu Ni porous nanoflowers(PNFs).Leveraging several unique advantages,such as an open superstructure,high porosity,and enhanced electronic interactions among the trimetals,the resulting Pd Cu Ni PNFs demonstrate significantly improved electrochemical performance,with mass activities reaching 5.94 and 10.14 A/mg for the ethanol oxidation reaction(EOR)and the ethylene glycol oxidation reaction(EGOR),respectively.Furthermore,the Pd Cu Ni PNFs exhibit optimized d-band centers and the most negative onset oxidation potential,indicating enhanced antitoxicity and stability.This study not only provides a novel perspective on the synthesis of 3D porous nanomaterials but also highlights the potential application value of trimetallic nanoalloys in catalysis.
基金Supported by National Natural Science Foundation of China(Grant No.51675021).
文摘The tire acoustic cavity resonance(TACR)noise is a significant source of the structure-borne noise inside a vehicle in the low-frequency range.This paper studies the noise dissipation effect of porous materials in reducing the TACR noise,an attempt to clarify the acoustic reduction mechanism and improve the accompanying vehicle interior noise level.A numerical model of a simplified tire cavity with rigid boundaries and acoustic excitation is established and further validated by the experiment.The effects of porous parameters on TACR frequency and sound pressure are then investigated and compared.The result reveals that the most influential material parameters are the porosity and material volume.It is also shown that the effectiveness of porous material in the mitigation of noise originates from the curliness of the material,which results in much larger acoustic impedance near the excitation position.Therefore,the sound absorption performance of the cavity attached with porous material proves to be excellent compared to that of the porous material itself.For further studying the damping effects of structural coupling,the flexible boundary of the tire tread is introduced.The results show that the porosity,material volume and structural loss factor of the tread all play important roles in reducing TACR noise.
基金supported by the National Key R&D Program of China(No.2021YFB3501102).
文摘Porous carbon microspheres are widely regarded as a superior CO_(2) adsorbent due to their exceptional efficiency and affordability.However,better adsorption performance is very attractive for porous carbon microspheres.And modification of the pore structure is one of the effective strategies.In this study,multi-cavity mesoporous carbon microspheres were successfully synthesized by the synergistic method of soft and hard templates,during which a phenolic resin with superior thermal stability was employed as the carbon precursor and a mixture of silica sol and F108 as the mesoporous template.Carbon microspheres with multi-cavity mesoporous structures were prepared,and all the samples showed highly even mesopores,with diameters around 12 nm.The diameter of these microspheres decreased from 396.8 nm to about 182.5 nm with the increase of silica sol.After CO_(2) activation,these novel carbon microspheres(APCF0.5-S1.75)demonstrated high specific surface area(983.3 m^(2)/g)and remarkable CO_(2) uptake of 4.93 mmol/g at 0℃ and1 bar.This could be attributed to the unique multi-cavity structure,which offers uniform mesoporous pore channels,minimal CO_(2) transport of and a greater number of active sites for CO_(2) adsorption.
基金supported by National Natural Science Foundation of China(No.52101138)Natural Science Foundation of Hubei Province(No.2023AFB798)+1 种基金Shenzhen Science and Technology Program(No.JCYJ20220530160813032)State Key Laboratory of Solidification Processing in NWPU(No.SKLSP202309).
文摘In the present work,the porous Ti particle reinforced Mg-based bulk metallic glass matrix composites(BMGCs)have been successfully fabricated via a novel in-situ dealloying method in metallic melt.A dual reinforcing structure,including large-scale between porous particles and fine-scale inside one particle,was induced to further overcome the strength-plasticity tradeoff.The microstructure and mechanical properties of such dual-scale structure-reinforced BMGCs with various volume fractions and diameters of porous Ti particles were investigated in detail.It is found that with more and finer porous Ti particles,the BMGC showed both high fracture strength(1131.9±39.1 MPa)and good plastic deformability(1.48±0.38%).The characteristic of the reinforcing structure(0.48μm)inside the porous particles was close to the plastic processing zone size of the matrix(0.1~0.2μm),which generated a locally ideal reinforcing structure.Such dual-scale reinforcing structures with more interfaces can effectively promote the multiplication of shear bands at the interfaces.Due to the size effect,the refined submicron matrix between the Ti ligaments inside the porous particles should exhibit homogeneous shearing events.Such delocalization behavior from the dual-scale reinforcing structures should help to enhance the role of the interactions between shear bands,thus improving the yield strength of the composites.Based on the in-situ dealloying method,the dual-scale structure design provides a novel approach to fabricate various BMGCs with both high strength and good plasticity.
文摘When a porous rock is subjected to overall compressive loading,either increasing pore pressure or decreasing confining pressure could result in rock failure.The stress path and the applied pressure change rate may affect the initiation and propagation of fractures within brittle materials.Understanding the physical mechanisms leading to failure is crucial for underground engineering applications and geo-energy exploration and storage.We conducted triaxial compression experiments on porous Bentheim sandstone samples at different stress paths and pressure change rates.First,at a constant confining pressure of 35 MPa and pore pressure of 5 MPa,intact cylindrical samples were axially loaded up to about 85%of the peak strength.Subsequently,the axial piston position was fixed,and then either the pore pressure was increased or the confining pressure was decreased at two different rates(0.5 MPa/min or 2 MPa/min),leading to final catastrophic failure.The mechanical results revealed that samples subjected to higher rates of decreasing effective confining pressure exhibited larger stress drop rates,higher slip rates,higher total breakdown work,higher rates of acoustic emissions(AEs)before failure,and higher post-failure AE decay rates.In contrast,the applied stress path did not significantly affect rock failure characteristics.Comparison of located AE events with post-mortem microstructures of deformed samples shows a good agreement.The AE source type determined from the P-wave first-motion polarity shows that shear failure dominated the fracture process when approaching failure.Gutenberg-Richter b-values revealed a significant decrease before failure in all tests.Our results indicate that,in contrast to the stress path,the rate of effective stress change strongly affects fracturing behavior and AE rate changes.
基金Project supported by the National Natural Science Foundation of China(Nos.12272056 and 11832002)。
文摘With the continuous increase in performance requirements for power systems in the aerospace and low-altitude economy sectors,designing lightweight and highstrength blade structures with excellent dynamic characteristics has become critical.This paper puts forward a dynamic model for a rotating functionally graded graphenereinforced(FG-GPR)sandwich metal porous cantilever pre-twisted plate(PTP),aiming to analyze its natural vibration characteristics.To this end,the mixture principle and the revised Halpin-Tsai model are used to determine the parameters of graphene and porosity distributions in the core layer.With the classical plate theory,the Rayleigh-Ritz method,and the polynomials,the dynamic equations are derived to solve for the free vibration mode shapes and frequencies of the rotating FG-GPR sandwich metal porous cantilever PTP.The comparison of natural frequencies and mode shapes with available literature results confirms the precision of the theoretical formulation and numerical computations.The bending stiffnesses are analyzed.Finally,the effects of different graphene/pore distributions,length-to-thickness/width ratios,layer thickness ratios,twist angles,and rotational speeds on the natural frequencies of the system are systematically investigated.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3801500)Fundamental Research Funds of Zhejiang Sci-Tech University(No.24202105-Y)。
文摘Solid polymer electrolytes(SPEs)are considered promising candidates for all-solid-state lithium metal batteries because of their easy preparation and good compatibility with lithium metal.However,their applications are restricted by their low ionic conductivity and poor mechanical properties.In this study,a composite solid polymer electrolyte composed of poly(ethylene oxide)(PEO),poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP),plasticizer succinonitrile(SN),and polytetrafluoroethylene(PTFE)fibrous porous membranes was prepared.The PTFE fibrous membrane significantly enhanced the mechanical strength of the electrolyte as a supporting framework.SN reduced the crystalline regions of PEO and facilitated rapid lithium-ion transport.PVDF-HFP promoted lithium salt dissolution and improved the electrochemical stability of the electrolyte.Accordingly,the optimized PTFE/PEO/PVDF-HFP/SN polymer electrolyte exhibited a tensile strength of 3.31 MPa at 352%elongation and demonstrated an ionic conductivity of 7.6×10^(-4)S·cm^(-1)at 60℃.Lithium symmetric cells maintained stable cycling for over 2500 h at 0.15 m A·cm^(-2),and Li//Li Fe PO_(4) full cells showed a high capacity retention of 91.6%after 300 cycles at 0.5 C,with coulombic efficiency consistently exceeding 99.9%throughout cycling.
基金supported by the National Natural Science Foundation of China(No.52471221)the Natural Science Foundation of Hunan Province,China(No.2024JJ7145)the National Sustainable Development Agenda Innovation Demonstration Zone Hunan special project,China(No.2022sfq09).
文摘With growing concerns regarding electromagnetic pollution,low-cost,environmentally friendly,and high-performance electromagnetic wave absorption(EWA)materials have attracted significant attention.This paper reports on the synthesis of porous Fe_(3)O_(4)/C composites that incorporate dielectric and magnetic loss mechanisms via the carbothermal reduction method and optimization of waste ratio to enhance EWA performance.The Fe_(3)O_(4)/C composites with 10wt%soybean residues(Fe_(3)O_(4)/C-10),demonstrated the best EWA performance,achieving the minimum reflection loss of−56.4 dB and a bandwidth of 2.14 GHz at a thickness of 2.23 mm.This enhanced EWA performance is primarily attributable to improved impedance matching and the synergistic effect between dielectric and magnetic losses.Furthermore,radar cross-sectional simulations confirmed the practical feasibility of the porous Fe_(3)O_(4)/C composites.This study proposes a viable strategy for utilizing soybean residue and electrolytic manganese residue,highlighting their potential applications in EWA.
基金support from the National Natural Science Foundation of China(22088101,21733003,22365021,22305132)the Inner Mongolia Autonomous Region“Grassland Talents”Project(2024098)+3 种基金the Inner Mongolia Natural Science Foundation Youth Fund(2023QN02014)The Local Talent Project of Inner Mongolia(12000-15042222)the Basic Research Expenses Supported under 45 Years Old of Inner Mongolia(10000-23112101/036)the“Young Academic Talents”Program of Inner Mongolia University 23600-5233706.
文摘As a class of crystalline porous materials,metal-organic frameworks(MOFs)have shown unique advantages in the fields of catalysis,gas storage and separation,but their inherent microporous structure(pore diameter<2 nm)severely limits their application in scenarios such as macromolecular mass transfer and so on.In order to overcome this re-striction,mesoporous MOFs(meso-MOFs)with a larger aperture(2-50 nm)have attracted much attention due to their potential applications in biological macromolecular catalysis,energy storage and other fields.To date,how to accurately regulate its mesopore topology and pore ordering still faces important technical challenges.
基金Projects(52302447,52388102,52372369)supported by the National Natural Science Foundation of China。
文摘Following the fundamental characteristics of the porosity windbreak,this study suggests a new numerical investigation method for the wind field of the windbreak based on the porous medium physical model.This method can transform the reasonable matching problem of the porosity and windproof performance of the windbreak into a study of the relationship between the resistance coefficient of the porous medium and the aerodynamic load of the train.This study examines the influence of the hole type on the wind field behind the porosity windbreak.Then,the relationship between the resistance coefficient of the porous medium,the porosity of the windbreak,and the aerodynamic loads of the train is investigated.The results show that the porous media physical model can be used instead of the windbreak geometry to study the windbreak-train aerodynamic performance,and the process of using this method is suggested.
基金The authors extend their appreciation to the Deanship of Scientific Research at Northern Border University,Arar,Saudi Arabia,for funding this research work through the project number NBU-FFR-2025-2193-15.
文摘The study considers numerical findings regarding magneto-thermosolutal-aided natural convective flow of alumina/water-based nanofluid filled in a non-Darcian porous horizontal concentric annulus.Two equations are assumed to evaluate the thermal fields in the porous medium under Local Thermal Non-Equilibrium(LTNE)conditions,along with the Darcy-Brinkman-Forchheimer model for the flow.By imposing distinct and constant temperatures and concentrations on both internal and external cylinders,thermosolutal natural convection is induced in the annulus.We apply the finite volume method to solve the dimensionless governing equations numerically.The thermal conductivity and viscosity of the nanofluid mixture are determined utilizing Corcione’s empirical correlations,incorporating the effects of Brownian diffusion of nanoparticles.Steady-state findings are provided for a range of significant parameters,including buoyancy ratio(N=1 to 5),Lewis(Le=0 to 10),Rayleigh(Ra=102 to 105),Hartmann(Ha=0 to 50),and heat generation in the nanofluid and solid phases(Q=0 to 20)when the nanofluid flow is driven by aiding thermal and mass buoyancies at given porous medium characteristics(porosity(ε),Darcy number(Da),porous interfacial heat transfer coefficient(H),and thermal conductivity ratio(γ),to assess the thermosolutal convective circulation beside heat and solutal transfer rates in the annulus.The results reveal that internal heat generation significantly modifies the heat transport mechanism,initially reducing and then enhancing heat transfer rates as Q increases.Interestingly,increasing Le reduces heat transfer at low Q but promotes it when Q>5,while mass transfer consistently increases with Le.The magnetic field represses heat transfer in the absence of internal heat but enhances it when internal heat is present.
基金Funded by the National Natural Science Foundation of China(Nos.22068021 and 52064030)the Yunnan Young and Middle-aged Academic and Technical Leaders Reserve Talent Program of China(No.202305AC160064)the Yunnan Major Scientific and Technological Program of China(Nos.202402AB080004,202202AG050011,and 202202AG050007)。
文摘To efficiently address the current high cost associated with preparing pseudo-boehmite from organic aluminum,a low-cost alternative,AlCl_(3),is employed as the raw material.The sol-gel method is utilized,and H_(2)O_(2)is incorporated for the modification of pseudo-boehmite.The modification mechanism is thoroughly investigated through the use of X-ray powder diffractometer,scanning electron microscope,and BET data analysis,as well as molecular dynamics simulations.Under specific conditions(temperature at 80°C,pH=7,and H_(2)O_(2)volume ratios of 0.5:1,1:1,and 2:1),mesoporous pseudo-boehmite is synthesized with a specific surface area of 227 m^(2)/g,a pore volume of 0.281 cm^(3)/g,a pore size of 6.78 nm,and a peptizing index of 99.47%.A novel and innovative methodology for the cost-effective production of high-performance alumina is offered through the approach.
文摘The use of visible-light responsive photocatalysts for removing heavy metal ions in wastewater has received great attention.However,the development of photocatalysts with high activity and recyclability remains a huge challenge.Herein,a recyclable carbon fiber cloth-supported porous CdS nanorod photocatalyst was fabricated by a two-step hydrothermal treatment using AgVO_(3) nanowires as templates.The results indicated that under visible-light illumination,the carbon cloth-supported porous CdS nanorods showed improved photocatalytic activity for the reduction of Cr(Ⅵ),with an apparent rate constant exceeding that of carbon cloth-supported CdS nanospheres by a factor of 1.65 times.Moreover,the carbon cloth-supported porous CdS nanorods can be easily separated and be reused.This brings a new perspective for developing photocatalysts with high efficiency and recyclability for wastewater treatment.
文摘This paper gives an overview on nonlinear porous flow in low permeability porous media, reveals the microscopic mechanisms of flows, and clarifies properties of porous flow fluids. It shows that, deviating from Darcy＇s linear law, the porous flow characteristics obey a nonlinear law in a low-permeability porous medium, and the viscosity of the porous flow fluid and the permeability values of water and oil are not constants. Based on these characters, a new porous flow model, which can better describe low permeability reservoir~ is established. This model can describe various patterns of porous flow, as Darcy＇s linear law does. All the parameters involved in the model, having definite physical meanings, can be obtained directly from the experiments.
基金financial support from the National Natural Science Foundation of China(Nos.22278011,22225803,22038001 and 22108007)Beijing Natural Science Foundation(No.Z230023)+1 种基金The Science&Technology Project of Beijing Municipal Education Committee(No.KZ201810005004)Beijing Nova Program(No.Z211100002121094)。
文摘Large-scale deployment of carbon dioxide(CO_(2))removal technology is an essential step to cope with global warming and achieve carbon neutrality.Direct air capture(DAC)has recently received increasing attention given the high flexibility to remove CO_(2)from discrete sources.Porous materials with adjustable pore characteristics are promising sorbents with low or no latent heat of vaporization.This review article has summarized the recent development of porous sorbents for DAC,with a focus of pore engineering strategy and adsorption mechanism.Physisorbents such as zeolites,porous carbons,metal-organic frameworks(MOFs),and amine-modified chemisorbents have been discussed and their challenges in practical application have been analyzed.At last,future directions have been proposed,and it is expected to inspire collaborations from chemistry,environment,material science and engineering communities.
基金supported by the Natural Science Foundation of China(22106007 and U23A20120)Beijing Natural Science Foundation(8244060)+2 种基金China Postdoctoral Science Foundation(2023M730143)R&D Program of BeijingMunicipal Education Commission(KZ202210005011)Natural Science Foundation of Hebei Province(B2021208033).
文摘Due to the greenhouse effect caused by carbon dioxide(CO_(2))emission,much attention has been paid for the removal of CO_(2).Porous liquids(PLs),as new type of liquid materials,have obvious advantages in mass and heat transfer,which are widely used in gas adsorption and sep-aration.Metal–organic frameworks(MOFs)with merits like large surface area,inherent porous structure and adjustable topology have been considered as one of the best candidates for PLs construction.This review presents the state-of-the-art status on the fabrication strategy of MOFs-based PLs and their CO_(2) absorption and utilization performance,and the positive effects of porosity and functional modification on the absorption-desorption property,selectivity of target product,and regeneration ability are well summarized.Finally,the challenges and prospects for MOFs-based PLs in the optimization of preparation,the coupling of multiple removal techniques,the in situ characterization methods,the regeneration and cycle stability,the environmental impact as well as expansion of application are proposed.
基金supported by the National Key R&D Program of China(Grant No.2021YFC2501700).
文摘The current artificial bone is unable to accurately replicate the inhomogeneity and anisotropy of human cancellous bone.To address this issue,we proposed a personalized approach based on clinical CT images to design mechanical equivalent porous structures for artificial femoral heads.Firstly,supported by Micro and clinical CT scans of 21 bone specimens,the anisotropic mechanical parameters of human cancellous bone in the femoral head were characterized using clinical CT values(Hounsfield unit).After that,the equivalent porous structure of cancellous bone was designed based on the gyroid surface,the influence of its degree of anisotropy and volume fraction on the macroscopic mechanical parameters was investigated by finite element analysis.Furthermore,a mapping relationship between CT values and the porous structure was established by jointly solving the mechanical parameters of the porous structure and human cancellous bone,allowing the design of personalized gradient porous structures based on clinical CT images.Finally,to verify the mechanical equivalence,implant press-in tests were conducted on 3D-printed artificial femoral heads and human femoral heads,the influence of the porous structure’s cell size in bone-implant interaction problems was also explored.Results showed that the minimum deviations of press-in stiffness(<15%)and peak load(<5%)both occurred when the cell size was 20%to 30%of the implant diameter.In conclusion,the designed porous structure can replicate the human cancellous bone-implant interaction at a high level,indicating its effectiveness in optimizing the mechanical performance of 3D-printed artificial femoral head.
