The demand for high-energy-density sodium-ion batteries has driven research to increase the hard carbon(HC)plateau capacity(<0.1 V),but the plateau capacity-rate capability trade-off limits performance.We report a ...The demand for high-energy-density sodium-ion batteries has driven research to increase the hard carbon(HC)plateau capacity(<0.1 V),but the plateau capacity-rate capability trade-off limits performance.We report a way to regulate the closed pore structure and improve the rate capability of HC by the addition of graphene oxide using an emulsification process.In a non-emulsion system,graphene oxide not only shortens ion diffusion paths by inducing the formation of flakelike HC but also significantly improves the rate performance by serving as conductive bridges within the carbon matrix.The prepared graphene/phenolic resin carbon composite has reversible capacities of 362,340,319,274,119,86,69 and 48 mAh g^(−1)at current densities of 0.02,0.05,0.1,0.2,0.5,1,2 and 5 A g^(−1),respectively.When emulsification is introduced,the graphene oxide acts as a nano-confinement template,guiding the cross-linking of phenolic resin to form uniformly sized closed pores.This composite electrode material has the highest plateau capacity of 268 mAh g^(−1)at 20 mA g^(−1).展开更多
Mesoporous silica materials with high pore volume were successfully prepared by the chemical precipitation method, with water glass and a biodegradable nonionic surfactant polyethylene glycol （PEG）. The obtained mat...Mesoporous silica materials with high pore volume were successfully prepared by the chemical precipitation method, with water glass and a biodegradable nonionic surfactant polyethylene glycol （PEG）. The obtained materials were characterized by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, thermo gravimetric analyzer and differential scanning calorimetry （TG-DSC）, nitrogen adsorption-desorption measurements, and X-ray diffraction （XRD）. The results showed that the changes of the pore parameters depended on both the surfactant content and heat treatment temperature. When the content of PEG was 10wt% and the obtained PEG/SiO2 composite was heated at 600℃, the mesoporous silica with a pore volume of 2.2 cma/g, a BET specific surface area of 361.55 m^2/g, and a diameter of 2-4 μm could be obtained. The obtained mesoporous silica materials have potential applications in the fields of paint and plastic, as thickening, reinforcing, and flatting agents.展开更多
Through improving the aging process during synthesis of the support, γ-Al2O3 with large pore volume and high surface area was synthesized by a facile secondary reforming method. The synthesis parameters, such as the ...Through improving the aging process during synthesis of the support, γ-Al2O3 with large pore volume and high surface area was synthesized by a facile secondary reforming method. The synthesis parameters, such as the reaction temperature, the first aging temperature and the second aging temperature, were investigated. The textural properties of γ-Al2O3 were characterized by means of N2 adsorption-desorption isotherms, X-ray powder diffractometry （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared （FTIR） spectroscopy and thermogravimetry （TG）. The experimental results indicated that AACH and amorphous A1OOH were the precursors of alumina, which were formed via precipitation from solutions after reaction of aluminum sulphate with ammonium hydrogen carbonate. The precursor nanocrystallites grew and re-assembled during the secondary reforming process, which resulted in an increased pore size and pore volume and a decreased bulk density. The as-synthesized γ-Al2O3 materials featured meso/macroporosity, large pore volume （2.175 cm^3/g）, high surface area （237.8 m^2/g）, and low bulk density （0.284 g/mL）.展开更多
The real pores in digital cores were simplified into three abstractive types,including prolate ellipsoids,oblate ellipsoids and spheroids.The three-dimensional spheroidal-pore model of digital core was established bas...The real pores in digital cores were simplified into three abstractive types,including prolate ellipsoids,oblate ellipsoids and spheroids.The three-dimensional spheroidal-pore model of digital core was established based on mesoscopic mechanical theory.The constitutive relationship of different types of pore microstructure deformation was studied with Eshelby equivalent medium theory,and the effects of pore microstructure on pore volume compressibility under elastic deformation conditions of single and multiple pores of a single type and mixed types of pores were investigated.The results showed that the pore volume compressibility coefficient of digital core is closely related with porosity,pore aspect ratio and volumetric proportions of different types of pores.(1)The compressibility coefficient of prolate ellipsoidal pore is positively correlated with the pore aspect ratio,while that of oblate ellipsoidal pore is negatively correlated with the pore aspect ratio.(2)At the same mean value of pore aspect ratio satisfying Gaussian distribution,the more concentrated the range of pore aspect ratio,the higher the compressibility coefficient of both prolate and oblate ellipsoidal pores will be,and the larger the deformation under the same stress condition.(3)The pore compressibility coefficient increases with porosity.(4)At a constant porosity value,the higher the proportion of oblate ellipsoidal and spherical pores in the rock,the more easier for the rock to deform,and the higher the compressibility coefficient of the rock is,while the higher the proportion of prolate ellipsoidal pores in the rock,the more difficult it is for rock to deform,and the lower the compressibility coefficient of the rock is.By calculating pore compressibility coefficient of ten classical digital rock samples,the presented analytical elliptical-pore model based on real pore structure of digital rocks can be applied to calculation of pore volume compressibility coefficient of digital rock sample.展开更多
Pore volume compressibility is an essential parameter in reservoir studies,as it plays a major role in recovery mechanisms.Over the past decades,many attempts have been made to establish a link between the pore compre...Pore volume compressibility is an essential parameter in reservoir studies,as it plays a major role in recovery mechanisms.Over the past decades,many attempts have been made to establish a link between the pore compressibility and the porosity and other mechanical properties of the rock.Some scholars introduced analytical correlations between pore compressibility and rock mechanical properties,while others developed empirical formulas for estimating pore compressibility based on a porosity calculated by comparing nonlinear models to laboratory data.In this study,pore volume compressibility is measured on 55 carbonate samples and then applied to derive an empirical relationship between pore compressibility and porosity at each stress step,which is useful for predicting pore compressibility based on initial porosity.We take the net stress effect into account and derive an empirical correlation based on net effective stress and initial porosity to predict pore compressibility.In the end,we compare the measured pore compressibility with that predicted by the derived correlation and other non-leaner models,which indicates that the newly proposed non-linear equation outperforms those available in literature。展开更多
Mesoporous silica with tuned pore volume and pore size was yielded with the controllable sol-gel process using inexpensive water glass as silica source and ammonia as an additive.The effects of the parameters of the s...Mesoporous silica with tuned pore volume and pore size was yielded with the controllable sol-gel process using inexpensive water glass as silica source and ammonia as an additive.The effects of the parameters of the sol-gel process have been examined.The results show that the mesoporous silica can be synthesized by controlling the weight ratio of ammonia to silica,concentration of water glass,gelating temperature and the final pH value.The major properties of the obtained mesoporous silica are large pore volumes and controllable pore sizes.展开更多
In this paper,a method composed of gelation of basic skeleton(first step)and skeleton reinforcement process(second step)was introduced to synthesize silica powder with high pore volume through the reaction between wat...In this paper,a method composed of gelation of basic skeleton(first step)and skeleton reinforcement process(second step)was introduced to synthesize silica powder with high pore volume through the reaction between water glass and sulfuric acid.No organic solvents were involved in the entire preparation process and the final product was collected by spray drying.The effect of concentration of base solution,gelation point p H value and skeleton reinforcement time on the BET specific surface area and pore volume of the prepared silica powder were investigated intensively.The results show that,a basic skeleton with good dispersibility and high porosity was obtained when the concentration of base solution was 0.1 mol·L^(-1) and the gelation p H value reached 6.5.Then the basic skeleton grew into a more uniform porous structure after 30 min skeleton reinforcement.Under these optimum conditions,silica powder prepared by skeleton reinforcement method had a BET specific surface area of 358.0 m^(2)·g^(-1),and its pore volume reached 2.18 cm^(3)·g^(-1),which was much higher than that of prepared by skeleton-free method(1.62 cm^(3)·g^(-1))and by direct gelation method(0.31 cm^(3)·g^(-1)).展开更多
Carbon-based materials have gained significant attention in anticancer treatment because of their exceptional biocompatibility,yet critical challenges persist in establishing definitive correlations between their poro...Carbon-based materials have gained significant attention in anticancer treatment because of their exceptional biocompatibility,yet critical challenges persist in establishing definitive correlations between their porous structures and functional performance.We report the use of a silica template to guide pore formation in the design of mesoporous carbon spheres(mC)with tailored pore structures for improved combined photothermal-chemotherapy.The mesopore size of mC has been adjusted by kinetic control of the resin polymerization and silica hydrolysis.Structural characterization showed that 4.4 nm mesopores enabled an exceptional gemcitabine loading of 228 mg g^(−1) and a sustained pH/thermal dual-responsive release with>70%drug release under near-infrared(NIR)irradiation.Finite element analysis demonstrated pore size-dependent heat transfer dynamics,with the improved mC achieving a superior photothermal conversion efficiency of 62%by a combination of N-doping and defect engineering.In vitro evaluations confirmed outstanding biocompatibility with>95%cell viability at 200μg mL^(−1) and potent tumor suppression in pancreatic and biliary cancer models with an~5%cell viability at 25μg mL^(−1) where combined therapy showed a 3.7-fold increased cytotoxicity over monotherapy.The improved structure of mC facilitated cascade therapeutic effects with enhanced tumor permeability derived from NIR-triggered hyperthermia and prolonged therapeutic exposure due to pH-responsive drug release.This pore engineering strategy establishes a structure-function process for next-generation theranostic platforms,addressing the critical limitations of conventional pancreatic and biliary cancer therapies through spatiotemporal control of multimodal treatment.展开更多
Hard carbon(HC)remains a leading anode candidate for sodium-ion storage,yet its application is hindered by low initial Coulombic efficiency(ICE)and limited plateau capacity due to uncontrolled defect density and open ...Hard carbon(HC)remains a leading anode candidate for sodium-ion storage,yet its application is hindered by low initial Coulombic efficiency(ICE)and limited plateau capacity due to uncontrolled defect density and open porosity.Here,we propose a scalable dual-regulation strategy that simultaneously tunes pore mouth size and defect chemistry to enhance sodium storage performance.Using phenol-formaldehyde resin as the carbon precursor and phosphorus pentoxide(P_(2)O_(5))as a bifunctional sacrificial template and dopant source,we synthesize phosphorus-functionalized hard carbon(PF-PHC)featuring a high density of closed pores with well-confined sub-nanometer pore entrances.The in-situ sublimation of P_(2)O_(5) during pyrolysis promotes the formation of closed-pore architectures,while residual phosphorus atoms effectively passivate vacancy-type defects,thereby reducing irreversible Na+adsorption and mitigating excessive solid electrolyte interphase(SEI)formation.As a result,PF-PHC achieves an ICE of 89.3%and a plateau capacity of 289 mAh g^(−1).In-situ characterizations reveal that regulating pore mouth dimensions decouples Na+and solvent access,enabling highly selective ion transport and stable interfacial chemistry.Sodium-ion hybrid capacitors(SIHCs)assembled based on PF-PHC deliver exceptional rate performance and outstanding long-term cycling stability,retaining 98.2%after 10,000 cycles at 2 A g^(−1).This study establishes pore mouth engineering as a robust and scalable design principle for advancing next-generation HC-based sodium storage materials.展开更多
THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between c...THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between crystallographic orientation,grain boundary(GB)proximity,and pore characteristics(size/location).This study compares single-crystal nickel models along[100],[110],and[111]orientations with equiaxed polycrystalline models containing 0,1,and 2.5 nm pores in surface and subsurface configurations.Our results reveal that crystallographic anisotropy manifests as a 24.4%higher elastic modulus and 22.2%greater hardness in[111]-oriented single crystals compared to[100].Pore-GB synergistic effects are found to dominate the deformation behavior:2.5 nm subsurface pores reduce hardness by 25.2%through stress concentration and dislocation annihilation at GBs,whereas surface pores enable mechanical recovery via accelerated dislocation generation post-collapse.Additionally,size-dependent deformation regimes were identified,with 1 nm pores inducing negligible perturbation due to rapid atomic rearrangement,in contrast with persistent softening in 2.5 nm pores.These findings establish atomic-scale design principles for defect engineering in nickel-based aerospace components,demonstrating how crystallographic orientation,pore configuration,and GB interactions collectively govern nanoindentation behavior.展开更多
A debris flow descending through an erodible convex colluvial bed,originating from a landslide dam and its upstream deposits,can entrain massive amounts of sediment,dramatically increasing the debris flow volume.Most ...A debris flow descending through an erodible convex colluvial bed,originating from a landslide dam and its upstream deposits,can entrain massive amounts of sediment,dramatically increasing the debris flow volume.Most existing erosion models assume that bed sediments are fully saturated,although this condition is rarely observed in nature.Therefore,a thorough understanding of debris flow overtopping erosion on a convex unsaturated bed is crucial for quantifying disaster risk.In this study,we experimentally investigated the effects of sediment composition,specifically coarse-grain size distribution and fine particle content,on the pore pressure evolution and entrainment of debris flows overriding a convex unsaturated colluvial bed.The average entrainment rate at convex sites for continuously graded bed sediment was higher than its discontinuous counterpart.The measured pore pressures within the unsaturated bed sediments were primarily generated by the passing debris flows.Furthermore,it was found that these pressures decreased as the fine particle content increased and the coarse-grain size of the erodible substrates decreased.When the coarse-grain size of the debris flow was smaller than that of the bed sediment,only a portion of the eroded material was entrained by the moving debris flow.In contrast,when the coarse-grain size of the debris flow was equal to or greater than that of the bed sediment,nearly all of the eroded material was entrained.The findings of this study could contribute to the assessment of hazard amplification and inform the design of mitigation and prevention strategies.展开更多
The specific surface area(S S)and pore size(D)exhibit an inherent trade-off in the microscale design of bone implants:larger pores typically correlate with reduced surface area and vice versa.This relationship has att...The specific surface area(S S)and pore size(D)exhibit an inherent trade-off in the microscale design of bone implants:larger pores typically correlate with reduced surface area and vice versa.This relationship has attracted notable attention because of its critical role in the regulation of cell adhesion and osteogenesis.However,it remains largely unclear how S S and D affect the generated bone tissue and dynamically change during long-term osteogenesis.Herein,by applying rigorous geometric mapping to minimal surfaces,we constructed precisely partitioned and layer-by-layer thickened tissue models to simulate osteogenesis across different temporal scales and thereby track the dynamic evolution of geometric characteristics,permeability,and mechanobiological tissue differentiation.The high-S S samples were found to facilitate the rapid formation of new bone tissue in the early stages.However,their smaller pores tended to cause occlusions,hindering further tissue development.In contrast,low-S S samples showed slower bone regeneration,but their larger pores provided adequate physical space for tissue regeneration and mass transport,ultimately promoting bone formation in the long term.Mechanobiological regulation suggests that fibrous tissue formation inhibits additional bone formation,establishing a dynamic equilibrium between osteogenesis and pore space to sustain nutrient/waste exchange throughout the regenerative process.Overall,smaller pores are preferable in implants for minimally loaded osteoplasty procedures focused on early-stage bone consolidation,whereas larger pores are preferable in dynamically loaded implants requiring prolonged mechanical stability.展开更多
The vertical heterogeneity of the pore structure in deep coal seams with varying ash yields is a key control for coalbed methane storage and producibility;however,its specific impact on gas adsorption is not clearly d...The vertical heterogeneity of the pore structure in deep coal seams with varying ash yields is a key control for coalbed methane storage and producibility;however,its specific impact on gas adsorption is not clearly defined.The focus of this study is the No.8 coal seam of the Carboniferous Benxi Formation in the Central-Eastern Ordos Basin.By integrating microscopic identification,proximate analysis,gas adsorption(CO_(2),N_(2),and CH_(4)),and the multifractal theory,we quantitatively characterized the nanopore structure(micropores<2 nm and mesopores 2 nm-100 nm)of coal reservoirs with varying ash yields.The results indicate that(1)ash yield is the primary factor that controls the vertical evolution of pore structures in coal seams.In low-ash yield coal seams,the extent of thermal evolution and ash yield jointly constrain the heterogeneity of pore size distribution.In mediumto high-ash yield coal seams,the heterogeneity of pore structure and pore size distribution are predominantly constrained by ash yield.(2)As the ash yield vertically increases,the mesoporous pore volume and specific surface area initially decrease and subsequently increase,while the contribution of micropores to both pore volume and specific surface area continuously diminishes.Consequently,the total pore volume and specific surface area of the coal samples exhibit a two-stage reduction close to an ash yield threshold of approximately 20%.(3)Further,the Langmuir volume for CH_(4)adsorption sharply declines below the 20%threshold,followed by a gradual decrease;in contrast,the Langmuir pressure initially decreases and subsequently increases.Hence,the vertical increase in ash yield constrains the development of pore systems and diminishes pore connectivity,thereby reducing methane adsorption capacity and adversely affecting coalbed methane productivity.(4)Low-ash yield coal reservoirs are characterized by a rapid gas breakthrough and high productivity,whereas medium-ash yield coal reservoirs generally require prolonged depressurization to achieve peak gas production.These findings reveal that in medium-high rank coal,ash yield―and not thermal evolution―is the main factor that controls vertical pore evolution and methane adsorption efficiency.The quantitative ash yield threshold(20%)established in this study provides a practical criterion for evaluating reservoir quality and predicting vertical variations in gas storage potential in the Ordos Basin.展开更多
This study investigated the effects of periodic high-frequency stress disturbances on the creep behavior of sandstone and analyzed the microstructural changes using nuclear magnetic resonance(NMR)technology.High-frequ...This study investigated the effects of periodic high-frequency stress disturbances on the creep behavior of sandstone and analyzed the microstructural changes using nuclear magnetic resonance(NMR)technology.High-frequency disturbance creep experiments were conducted on sandstone under different disturbance frequencies,disturbance cycles and loading stresses,and the following findings were obtained.Firstly,with the increase of loading stress and disturbance cycles,the total porosity increments,and damage value of sandstone increase,while the fractal dimension of sandstone pore structure presents the opposite trend.Secondly,during the disturbance creep process,the volumes of all three types of pores increase,but the proportion of micropores(T_(2)<10 ms)decreases,while the proportion of mesopores(10 ms<T_(2)<100 ms)and macropores(T_(2)>100 ms)increases.Thirdly,the fractal dimension difference has a good linear relationship with the damage,strain and porosity increment of sandstone during the disturbance creep process.Finally,the higher the disturbance frequency,the smaller the creep strain and creep strain rate during the steady-state creep stage.The study offers valuable theoretical insights for understanding rock creep behavior in complex stress environments.展开更多
To investigate the pore structure of graphene oxide modified polymer cement mortar(GOPM)under salt-freeze-thaw(SFT)coupling effects and its impact on deterioration,this study modifies polymer cement mortar(EMCM)with g...To investigate the pore structure of graphene oxide modified polymer cement mortar(GOPM)under salt-freeze-thaw(SFT)coupling effects and its impact on deterioration,this study modifies polymer cement mortar(EMCM)with graphene oxide(GO).The micro-pore structure of GOPM is characterized using LF-NMR and SEM.Fractal theory is applied to calculate the fractal dimension of pore volume,and the deterioration patterns are analyzed based on the evolution characteristics of capillary pores.The experimental results indicate that,after 25 salt-freeze-thaw cycles(SFTc),SO2-4 ions penetrate the matrix,generating corrosion products that fill existing pores and enhance the compactness of the specimen.As the number of cycles increases,the ongoing formation and expansion of corrosion products within the matrix,combined with persistent freezing forces,and result in the degradation of the pore structure.Therefore,the mass loss rate(MLR)of the specimens shows a trend of first decreasing and then increasing,while the relative dynamic elastic modulus(RDEM)initially increases and then decreases.Compared to the PC group specimens,the G3PM group specimens show a 28.71% reduction in MLR and a 31.42% increase in RDEM after 150 SFTc.The fractal dimensions of the transition pores,capillary pores,and macropores in the G3PM specimens first increase and then decrease as the number of SFTc increases.Among them,the capillary pores show the highest correlation with MLR and RDEM,with correlation coefficients of 0.97438 and 0.98555,respectively.展开更多
The rapid advancement of 5G/6G communication and radar technology has exacerbated issues of electromagnetic wave(EMW)leakage,interference,and thermal management.Therefore,developing lightweight EMW absorbers that inte...The rapid advancement of 5G/6G communication and radar technology has exacerbated issues of electromagnetic wave(EMW)leakage,interference,and thermal management.Therefore,developing lightweight EMW absorbers that integrate strong absorption,broad bandwidth,and thermal stability is crucial.Herein,a 3D MXene sponge/NiFe@NC heterostructure with tunable pore architecture is constructed by pyrolyzing a polyurethane(PU)foam template uniformly coated with NiFe-decorated Ti_(3)C_(2)T_(x)MXene nanosheets.The resulting porous dielectric-magnetic network integrates interconnected MXene pathways with uniformly dispersed NiFe@NC nanoparticles,enabling a synergistic effect of dielectric-magnetic loss through conduction loss,dipole/interface polarization,and magnetic loss.Precise pore structure design enhances impedance matching and promotes multi-scattering and internal reflection of EMWs.Notably,an“EMW-pore matching”mechanism is proposed,whereby pore size governs the impedance matching at specific frequencies,enabling tunable absorption performance.The optimized absorber achieves a reflection loss(RL)of-67.84 dB,while radar cross-section(RCS)simulations confirm its exceptional attenuation and stealth potential.Additionally,the 3D skeleton derived from PU foam confers remarkable thermal resistance and flame retardancy.This pore-regulation strategy provides a scalable route to designing lightweight,broadband,and thermally stable EMW absorbers for next-generation communication and stealth applications.展开更多
As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This ...As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses,along with in-situ temperatures,on the mechanical behavior and pore water pressure(PWP)evolution of CPB.Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing,replicating in-situ stress paths and thermal profiles typical of deep mine environments.Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing,reducing porosity,and increasing frictional resistance.Elevated temperatures independently accelerate early-age cement hydration,further improving bond strength and stiffness.When combined,multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength(UCS)and elastic modulus,as confirmed by two-way ANOVA and synergy index analysis.PWP responses were also highly sensitive to thermo-mechanical conditions.The evolution of positive and negative PWP was governed by the interplay of thermal expansion,hydration-induced desaturation,and mechanical compaction.Multiaxial stress amplified early positive PWP and delayed its dissipation,whereas elevated temperature accelerated hydration and reduced pore pressure,leading to enhanced suction at later ages.A transient“stress-induced resaturation”effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures.These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design,binder content,and barricade stability in deep mining applications.展开更多
To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as wel...To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.展开更多
The Micro pore volume in porous materials usually interests many researchers. However, there has been few, if not, direct method to determine it. A strategy of combining mercury porosimetry with pre adsorption is pr...The Micro pore volume in porous materials usually interests many researchers. However, there has been few, if not, direct method to determine it. A strategy of combining mercury porosimetry with pre adsorption is proposed in the present paper. The total pore volume in activated carbon is determined through direct measurements for the first time. The application scope of mercury porosimetry is also enlarged. Besides, the present experiments also confirmed the preference of adsorption to the smaller pores even in the range of meso and macro pores.展开更多
A new nano-assembly approach has been proposed for the preparation of macropore volume mesoporous aluminum oxide supports.Secondary nano-assembly and a frame structure mechanism for large pore volume mesoporous suppor...A new nano-assembly approach has been proposed for the preparation of macropore volume mesoporous aluminum oxide supports.Secondary nano-assembly and a frame structure mechanism for large pore volume mesoporous supports have been proposed.In a primary nano-assembly supersoluble micelle,aluminum hydroxide nanoparticles were precipitated in situ in surfactants with a volume balance(VB)less than 1,followed by secondary nano-assembly in linear and cylindrical shapes.The secondary nano-assembly of cylindrical aluminum hydroxides was calcined to form nano cylindrical aluminum oxides.For the formation of macropore volume mesoporous supports,we utilized a frame structure mechanism of mesoporous support,in which the exterior surface of the carrier may not be continuous.This macropore volume support has been used for the hydrotreatment of a residual oil catalyst,which possesses the following physical characteristics:pore volume 1.8―2.7 mL·g-1,specific surface area 180―429 m2·g-1,average pore diameter 17―57 nm,average pore diameter more than 10 nm(81%―94%),porosity 87%―93%,and crush strength 7.7―25 N·mm-1.展开更多
文摘The demand for high-energy-density sodium-ion batteries has driven research to increase the hard carbon(HC)plateau capacity(<0.1 V),but the plateau capacity-rate capability trade-off limits performance.We report a way to regulate the closed pore structure and improve the rate capability of HC by the addition of graphene oxide using an emulsification process.In a non-emulsion system,graphene oxide not only shortens ion diffusion paths by inducing the formation of flakelike HC but also significantly improves the rate performance by serving as conductive bridges within the carbon matrix.The prepared graphene/phenolic resin carbon composite has reversible capacities of 362,340,319,274,119,86,69 and 48 mAh g^(−1)at current densities of 0.02,0.05,0.1,0.2,0.5,1,2 and 5 A g^(−1),respectively.When emulsification is introduced,the graphene oxide acts as a nano-confinement template,guiding the cross-linking of phenolic resin to form uniformly sized closed pores.This composite electrode material has the highest plateau capacity of 268 mAh g^(−1)at 20 mA g^(−1).
基金the National Natural Science Foundation of China (No.20671010, 20236020, 20325621, 50642042).
文摘Mesoporous silica materials with high pore volume were successfully prepared by the chemical precipitation method, with water glass and a biodegradable nonionic surfactant polyethylene glycol （PEG）. The obtained materials were characterized by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, thermo gravimetric analyzer and differential scanning calorimetry （TG-DSC）, nitrogen adsorption-desorption measurements, and X-ray diffraction （XRD）. The results showed that the changes of the pore parameters depended on both the surfactant content and heat treatment temperature. When the content of PEG was 10wt% and the obtained PEG/SiO2 composite was heated at 600℃, the mesoporous silica with a pore volume of 2.2 cma/g, a BET specific surface area of 361.55 m^2/g, and a diameter of 2-4 μm could be obtained. The obtained mesoporous silica materials have potential applications in the fields of paint and plastic, as thickening, reinforcing, and flatting agents.
基金the financial support by the Natural Science Foundation of Liaoning Province of China (Grant No. 2013020122)the National Natural Science Foundationof China (Grant No. 21076100 and 51308045)the financial support by the PetroChina Company Limited (Grant No. 10-01A-01-01-01)
文摘Through improving the aging process during synthesis of the support, γ-Al2O3 with large pore volume and high surface area was synthesized by a facile secondary reforming method. The synthesis parameters, such as the reaction temperature, the first aging temperature and the second aging temperature, were investigated. The textural properties of γ-Al2O3 were characterized by means of N2 adsorption-desorption isotherms, X-ray powder diffractometry （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared （FTIR） spectroscopy and thermogravimetry （TG）. The experimental results indicated that AACH and amorphous A1OOH were the precursors of alumina, which were formed via precipitation from solutions after reaction of aluminum sulphate with ammonium hydrogen carbonate. The precursor nanocrystallites grew and re-assembled during the secondary reforming process, which resulted in an increased pore size and pore volume and a decreased bulk density. The as-synthesized γ-Al2O3 materials featured meso/macroporosity, large pore volume （2.175 cm^3/g）, high surface area （237.8 m^2/g）, and low bulk density （0.284 g/mL）.
基金Supported by the National Natural Science Foundation of China(51474224)The Shenzhen Peacock Plan(KQTD2017033114582189)The Shenzhen Science and Technology Innovation Committee(JCYJ20170817152743178)
文摘The real pores in digital cores were simplified into three abstractive types,including prolate ellipsoids,oblate ellipsoids and spheroids.The three-dimensional spheroidal-pore model of digital core was established based on mesoscopic mechanical theory.The constitutive relationship of different types of pore microstructure deformation was studied with Eshelby equivalent medium theory,and the effects of pore microstructure on pore volume compressibility under elastic deformation conditions of single and multiple pores of a single type and mixed types of pores were investigated.The results showed that the pore volume compressibility coefficient of digital core is closely related with porosity,pore aspect ratio and volumetric proportions of different types of pores.(1)The compressibility coefficient of prolate ellipsoidal pore is positively correlated with the pore aspect ratio,while that of oblate ellipsoidal pore is negatively correlated with the pore aspect ratio.(2)At the same mean value of pore aspect ratio satisfying Gaussian distribution,the more concentrated the range of pore aspect ratio,the higher the compressibility coefficient of both prolate and oblate ellipsoidal pores will be,and the larger the deformation under the same stress condition.(3)The pore compressibility coefficient increases with porosity.(4)At a constant porosity value,the higher the proportion of oblate ellipsoidal and spherical pores in the rock,the more easier for the rock to deform,and the higher the compressibility coefficient of the rock is,while the higher the proportion of prolate ellipsoidal pores in the rock,the more difficult it is for rock to deform,and the lower the compressibility coefficient of the rock is.By calculating pore compressibility coefficient of ten classical digital rock samples,the presented analytical elliptical-pore model based on real pore structure of digital rocks can be applied to calculation of pore volume compressibility coefficient of digital rock sample.
文摘Pore volume compressibility is an essential parameter in reservoir studies,as it plays a major role in recovery mechanisms.Over the past decades,many attempts have been made to establish a link between the pore compressibility and the porosity and other mechanical properties of the rock.Some scholars introduced analytical correlations between pore compressibility and rock mechanical properties,while others developed empirical formulas for estimating pore compressibility based on a porosity calculated by comparing nonlinear models to laboratory data.In this study,pore volume compressibility is measured on 55 carbonate samples and then applied to derive an empirical relationship between pore compressibility and porosity at each stress step,which is useful for predicting pore compressibility based on initial porosity.We take the net stress effect into account and derive an empirical correlation based on net effective stress and initial porosity to predict pore compressibility.In the end,we compare the measured pore compressibility with that predicted by the derived correlation and other non-leaner models,which indicates that the newly proposed non-linear equation outperforms those available in literature。
基金Supported by the National Natural Science Foundation of China(20671010,20236020,20325621)
文摘Mesoporous silica with tuned pore volume and pore size was yielded with the controllable sol-gel process using inexpensive water glass as silica source and ammonia as an additive.The effects of the parameters of the sol-gel process have been examined.The results show that the mesoporous silica can be synthesized by controlling the weight ratio of ammonia to silica,concentration of water glass,gelating temperature and the final pH value.The major properties of the obtained mesoporous silica are large pore volumes and controllable pore sizes.
基金financially supported by the National Natural Science Foundation of China (21838003, 91834301, 21878092)the Shanghai Scientific and Technological Innovation Project (18JC1410600)+2 种基金the Social Development Program of Shanghai(17DZ1200900, 18DZ2252400)the Innovation Program of Shanghai Municipal Education Commissionthe Fundamental Research Funds for the Central Universities (222201718002)
文摘In this paper,a method composed of gelation of basic skeleton(first step)and skeleton reinforcement process(second step)was introduced to synthesize silica powder with high pore volume through the reaction between water glass and sulfuric acid.No organic solvents were involved in the entire preparation process and the final product was collected by spray drying.The effect of concentration of base solution,gelation point p H value and skeleton reinforcement time on the BET specific surface area and pore volume of the prepared silica powder were investigated intensively.The results show that,a basic skeleton with good dispersibility and high porosity was obtained when the concentration of base solution was 0.1 mol·L^(-1) and the gelation p H value reached 6.5.Then the basic skeleton grew into a more uniform porous structure after 30 min skeleton reinforcement.Under these optimum conditions,silica powder prepared by skeleton reinforcement method had a BET specific surface area of 358.0 m^(2)·g^(-1),and its pore volume reached 2.18 cm^(3)·g^(-1),which was much higher than that of prepared by skeleton-free method(1.62 cm^(3)·g^(-1))and by direct gelation method(0.31 cm^(3)·g^(-1)).
文摘Carbon-based materials have gained significant attention in anticancer treatment because of their exceptional biocompatibility,yet critical challenges persist in establishing definitive correlations between their porous structures and functional performance.We report the use of a silica template to guide pore formation in the design of mesoporous carbon spheres(mC)with tailored pore structures for improved combined photothermal-chemotherapy.The mesopore size of mC has been adjusted by kinetic control of the resin polymerization and silica hydrolysis.Structural characterization showed that 4.4 nm mesopores enabled an exceptional gemcitabine loading of 228 mg g^(−1) and a sustained pH/thermal dual-responsive release with>70%drug release under near-infrared(NIR)irradiation.Finite element analysis demonstrated pore size-dependent heat transfer dynamics,with the improved mC achieving a superior photothermal conversion efficiency of 62%by a combination of N-doping and defect engineering.In vitro evaluations confirmed outstanding biocompatibility with>95%cell viability at 200μg mL^(−1) and potent tumor suppression in pancreatic and biliary cancer models with an~5%cell viability at 25μg mL^(−1) where combined therapy showed a 3.7-fold increased cytotoxicity over monotherapy.The improved structure of mC facilitated cascade therapeutic effects with enhanced tumor permeability derived from NIR-triggered hyperthermia and prolonged therapeutic exposure due to pH-responsive drug release.This pore engineering strategy establishes a structure-function process for next-generation theranostic platforms,addressing the critical limitations of conventional pancreatic and biliary cancer therapies through spatiotemporal control of multimodal treatment.
基金supported by the National Natural Science Foundation of China(22269020,U23A20582,42167068)the Gansu Province Higher Education Industry Support Plan Project(2023CYZC-17)+1 种基金2024 Major Cultivation Project for University Research and Innovation Platforms(2024CXPT-10)the Key Project of the Natural Science Foundation of Gansu Province(25JRRA004).
文摘Hard carbon(HC)remains a leading anode candidate for sodium-ion storage,yet its application is hindered by low initial Coulombic efficiency(ICE)and limited plateau capacity due to uncontrolled defect density and open porosity.Here,we propose a scalable dual-regulation strategy that simultaneously tunes pore mouth size and defect chemistry to enhance sodium storage performance.Using phenol-formaldehyde resin as the carbon precursor and phosphorus pentoxide(P_(2)O_(5))as a bifunctional sacrificial template and dopant source,we synthesize phosphorus-functionalized hard carbon(PF-PHC)featuring a high density of closed pores with well-confined sub-nanometer pore entrances.The in-situ sublimation of P_(2)O_(5) during pyrolysis promotes the formation of closed-pore architectures,while residual phosphorus atoms effectively passivate vacancy-type defects,thereby reducing irreversible Na+adsorption and mitigating excessive solid electrolyte interphase(SEI)formation.As a result,PF-PHC achieves an ICE of 89.3%and a plateau capacity of 289 mAh g^(−1).In-situ characterizations reveal that regulating pore mouth dimensions decouples Na+and solvent access,enabling highly selective ion transport and stable interfacial chemistry.Sodium-ion hybrid capacitors(SIHCs)assembled based on PF-PHC deliver exceptional rate performance and outstanding long-term cycling stability,retaining 98.2%after 10,000 cycles at 2 A g^(−1).This study establishes pore mouth engineering as a robust and scalable design principle for advancing next-generation HC-based sodium storage materials.
基金The National Natural Science Foundation of China(Grant No.12462006)Beijing Institute of Structure and Environment Engineering Joint Innovation Fund(No.BQJJ202414).
文摘THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between crystallographic orientation,grain boundary(GB)proximity,and pore characteristics(size/location).This study compares single-crystal nickel models along[100],[110],and[111]orientations with equiaxed polycrystalline models containing 0,1,and 2.5 nm pores in surface and subsurface configurations.Our results reveal that crystallographic anisotropy manifests as a 24.4%higher elastic modulus and 22.2%greater hardness in[111]-oriented single crystals compared to[100].Pore-GB synergistic effects are found to dominate the deformation behavior:2.5 nm subsurface pores reduce hardness by 25.2%through stress concentration and dislocation annihilation at GBs,whereas surface pores enable mechanical recovery via accelerated dislocation generation post-collapse.Additionally,size-dependent deformation regimes were identified,with 1 nm pores inducing negligible perturbation due to rapid atomic rearrangement,in contrast with persistent softening in 2.5 nm pores.These findings establish atomic-scale design principles for defect engineering in nickel-based aerospace components,demonstrating how crystallographic orientation,pore configuration,and GB interactions collectively govern nanoindentation behavior.
基金supported by the National Key R&D Program of China(Grant No.2018YFC1505205)the Science and Technology Research Program of the Institute of Mountain Hazards and Environment,Chinese Academy of Sciences(Grant No.IMHE-ZDRW-01)Sichuan Science and Technology Program(Grant No.2024NSFSC0781).
文摘A debris flow descending through an erodible convex colluvial bed,originating from a landslide dam and its upstream deposits,can entrain massive amounts of sediment,dramatically increasing the debris flow volume.Most existing erosion models assume that bed sediments are fully saturated,although this condition is rarely observed in nature.Therefore,a thorough understanding of debris flow overtopping erosion on a convex unsaturated bed is crucial for quantifying disaster risk.In this study,we experimentally investigated the effects of sediment composition,specifically coarse-grain size distribution and fine particle content,on the pore pressure evolution and entrainment of debris flows overriding a convex unsaturated colluvial bed.The average entrainment rate at convex sites for continuously graded bed sediment was higher than its discontinuous counterpart.The measured pore pressures within the unsaturated bed sediments were primarily generated by the passing debris flows.Furthermore,it was found that these pressures decreased as the fine particle content increased and the coarse-grain size of the erodible substrates decreased.When the coarse-grain size of the debris flow was smaller than that of the bed sediment,only a portion of the eroded material was entrained by the moving debris flow.In contrast,when the coarse-grain size of the debris flow was equal to or greater than that of the bed sediment,nearly all of the eroded material was entrained.The findings of this study could contribute to the assessment of hazard amplification and inform the design of mitigation and prevention strategies.
基金financial support from the National Natural Science Foundation of China(No.52035012)the Guangdong Basic and Applied Basic Research Foundation(No.2025A1515012203)。
文摘The specific surface area(S S)and pore size(D)exhibit an inherent trade-off in the microscale design of bone implants:larger pores typically correlate with reduced surface area and vice versa.This relationship has attracted notable attention because of its critical role in the regulation of cell adhesion and osteogenesis.However,it remains largely unclear how S S and D affect the generated bone tissue and dynamically change during long-term osteogenesis.Herein,by applying rigorous geometric mapping to minimal surfaces,we constructed precisely partitioned and layer-by-layer thickened tissue models to simulate osteogenesis across different temporal scales and thereby track the dynamic evolution of geometric characteristics,permeability,and mechanobiological tissue differentiation.The high-S S samples were found to facilitate the rapid formation of new bone tissue in the early stages.However,their smaller pores tended to cause occlusions,hindering further tissue development.In contrast,low-S S samples showed slower bone regeneration,but their larger pores provided adequate physical space for tissue regeneration and mass transport,ultimately promoting bone formation in the long term.Mechanobiological regulation suggests that fibrous tissue formation inhibits additional bone formation,establishing a dynamic equilibrium between osteogenesis and pore space to sustain nutrient/waste exchange throughout the regenerative process.Overall,smaller pores are preferable in implants for minimally loaded osteoplasty procedures focused on early-stage bone consolidation,whereas larger pores are preferable in dynamically loaded implants requiring prolonged mechanical stability.
基金sponsored by the National Natural Science Foundation of China(Grant No.42202205)Natural Science Foundation of Shandong Province,China(Grant No.ZR2021QD072).-。
文摘The vertical heterogeneity of the pore structure in deep coal seams with varying ash yields is a key control for coalbed methane storage and producibility;however,its specific impact on gas adsorption is not clearly defined.The focus of this study is the No.8 coal seam of the Carboniferous Benxi Formation in the Central-Eastern Ordos Basin.By integrating microscopic identification,proximate analysis,gas adsorption(CO_(2),N_(2),and CH_(4)),and the multifractal theory,we quantitatively characterized the nanopore structure(micropores<2 nm and mesopores 2 nm-100 nm)of coal reservoirs with varying ash yields.The results indicate that(1)ash yield is the primary factor that controls the vertical evolution of pore structures in coal seams.In low-ash yield coal seams,the extent of thermal evolution and ash yield jointly constrain the heterogeneity of pore size distribution.In mediumto high-ash yield coal seams,the heterogeneity of pore structure and pore size distribution are predominantly constrained by ash yield.(2)As the ash yield vertically increases,the mesoporous pore volume and specific surface area initially decrease and subsequently increase,while the contribution of micropores to both pore volume and specific surface area continuously diminishes.Consequently,the total pore volume and specific surface area of the coal samples exhibit a two-stage reduction close to an ash yield threshold of approximately 20%.(3)Further,the Langmuir volume for CH_(4)adsorption sharply declines below the 20%threshold,followed by a gradual decrease;in contrast,the Langmuir pressure initially decreases and subsequently increases.Hence,the vertical increase in ash yield constrains the development of pore systems and diminishes pore connectivity,thereby reducing methane adsorption capacity and adversely affecting coalbed methane productivity.(4)Low-ash yield coal reservoirs are characterized by a rapid gas breakthrough and high productivity,whereas medium-ash yield coal reservoirs generally require prolonged depressurization to achieve peak gas production.These findings reveal that in medium-high rank coal,ash yield―and not thermal evolution―is the main factor that controls vertical pore evolution and methane adsorption efficiency.The quantitative ash yield threshold(20%)established in this study provides a practical criterion for evaluating reservoir quality and predicting vertical variations in gas storage potential in the Ordos Basin.
基金supported by National Natural Science Foundation of China(Grant No.52404074)the National Key Research and Development Program(Fund for Young Scientists)(Grant No.2021YFC2900400)Postdoctoral Science Foundation of China(Grant No.2024M761706).
文摘This study investigated the effects of periodic high-frequency stress disturbances on the creep behavior of sandstone and analyzed the microstructural changes using nuclear magnetic resonance(NMR)technology.High-frequency disturbance creep experiments were conducted on sandstone under different disturbance frequencies,disturbance cycles and loading stresses,and the following findings were obtained.Firstly,with the increase of loading stress and disturbance cycles,the total porosity increments,and damage value of sandstone increase,while the fractal dimension of sandstone pore structure presents the opposite trend.Secondly,during the disturbance creep process,the volumes of all three types of pores increase,but the proportion of micropores(T_(2)<10 ms)decreases,while the proportion of mesopores(10 ms<T_(2)<100 ms)and macropores(T_(2)>100 ms)increases.Thirdly,the fractal dimension difference has a good linear relationship with the damage,strain and porosity increment of sandstone during the disturbance creep process.Finally,the higher the disturbance frequency,the smaller the creep strain and creep strain rate during the steady-state creep stage.The study offers valuable theoretical insights for understanding rock creep behavior in complex stress environments.
基金Funded by the National Natural Science Foundation of China(Nos.5226804252468035)。
文摘To investigate the pore structure of graphene oxide modified polymer cement mortar(GOPM)under salt-freeze-thaw(SFT)coupling effects and its impact on deterioration,this study modifies polymer cement mortar(EMCM)with graphene oxide(GO).The micro-pore structure of GOPM is characterized using LF-NMR and SEM.Fractal theory is applied to calculate the fractal dimension of pore volume,and the deterioration patterns are analyzed based on the evolution characteristics of capillary pores.The experimental results indicate that,after 25 salt-freeze-thaw cycles(SFTc),SO2-4 ions penetrate the matrix,generating corrosion products that fill existing pores and enhance the compactness of the specimen.As the number of cycles increases,the ongoing formation and expansion of corrosion products within the matrix,combined with persistent freezing forces,and result in the degradation of the pore structure.Therefore,the mass loss rate(MLR)of the specimens shows a trend of first decreasing and then increasing,while the relative dynamic elastic modulus(RDEM)initially increases and then decreases.Compared to the PC group specimens,the G3PM group specimens show a 28.71% reduction in MLR and a 31.42% increase in RDEM after 150 SFTc.The fractal dimensions of the transition pores,capillary pores,and macropores in the G3PM specimens first increase and then decrease as the number of SFTc increases.Among them,the capillary pores show the highest correlation with MLR and RDEM,with correlation coefficients of 0.97438 and 0.98555,respectively.
基金supported by the National Natural Science Foundation of China(52562043)Jiangxi Provincial Natural Science Foundation(20244BAB28050)。
文摘The rapid advancement of 5G/6G communication and radar technology has exacerbated issues of electromagnetic wave(EMW)leakage,interference,and thermal management.Therefore,developing lightweight EMW absorbers that integrate strong absorption,broad bandwidth,and thermal stability is crucial.Herein,a 3D MXene sponge/NiFe@NC heterostructure with tunable pore architecture is constructed by pyrolyzing a polyurethane(PU)foam template uniformly coated with NiFe-decorated Ti_(3)C_(2)T_(x)MXene nanosheets.The resulting porous dielectric-magnetic network integrates interconnected MXene pathways with uniformly dispersed NiFe@NC nanoparticles,enabling a synergistic effect of dielectric-magnetic loss through conduction loss,dipole/interface polarization,and magnetic loss.Precise pore structure design enhances impedance matching and promotes multi-scattering and internal reflection of EMWs.Notably,an“EMW-pore matching”mechanism is proposed,whereby pore size governs the impedance matching at specific frequencies,enabling tunable absorption performance.The optimized absorber achieves a reflection loss(RL)of-67.84 dB,while radar cross-section(RCS)simulations confirm its exceptional attenuation and stealth potential.Additionally,the 3D skeleton derived from PU foam confers remarkable thermal resistance and flame retardancy.This pore-regulation strategy provides a scalable route to designing lightweight,broadband,and thermally stable EMW absorbers for next-generation communication and stealth applications.
基金the University of Ottawa, the China Scholarship Council and the Natural Sciences and Engineering Research Council of Canada (NSERC) for their financial support.
文摘As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses,along with in-situ temperatures,on the mechanical behavior and pore water pressure(PWP)evolution of CPB.Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing,replicating in-situ stress paths and thermal profiles typical of deep mine environments.Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing,reducing porosity,and increasing frictional resistance.Elevated temperatures independently accelerate early-age cement hydration,further improving bond strength and stiffness.When combined,multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength(UCS)and elastic modulus,as confirmed by two-way ANOVA and synergy index analysis.PWP responses were also highly sensitive to thermo-mechanical conditions.The evolution of positive and negative PWP was governed by the interplay of thermal expansion,hydration-induced desaturation,and mechanical compaction.Multiaxial stress amplified early positive PWP and delayed its dissipation,whereas elevated temperature accelerated hydration and reduced pore pressure,leading to enhanced suction at later ages.A transient“stress-induced resaturation”effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures.These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design,binder content,and barricade stability in deep mining applications.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.NRF-2021M3H4A1A02048529)the Ministry of Trade,Industry and Energy(MOTIE)of the Korean government under grant No.RS-2022-00155854support from the DGIST Supercomputing and Big Data Center.
文摘To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.
文摘The Micro pore volume in porous materials usually interests many researchers. However, there has been few, if not, direct method to determine it. A strategy of combining mercury porosimetry with pre adsorption is proposed in the present paper. The total pore volume in activated carbon is determined through direct measurements for the first time. The application scope of mercury porosimetry is also enlarged. Besides, the present experiments also confirmed the preference of adsorption to the smaller pores even in the range of meso and macro pores.
文摘A new nano-assembly approach has been proposed for the preparation of macropore volume mesoporous aluminum oxide supports.Secondary nano-assembly and a frame structure mechanism for large pore volume mesoporous supports have been proposed.In a primary nano-assembly supersoluble micelle,aluminum hydroxide nanoparticles were precipitated in situ in surfactants with a volume balance(VB)less than 1,followed by secondary nano-assembly in linear and cylindrical shapes.The secondary nano-assembly of cylindrical aluminum hydroxides was calcined to form nano cylindrical aluminum oxides.For the formation of macropore volume mesoporous supports,we utilized a frame structure mechanism of mesoporous support,in which the exterior surface of the carrier may not be continuous.This macropore volume support has been used for the hydrotreatment of a residual oil catalyst,which possesses the following physical characteristics:pore volume 1.8―2.7 mL·g-1,specific surface area 180―429 m2·g-1,average pore diameter 17―57 nm,average pore diameter more than 10 nm(81%―94%),porosity 87%―93%,and crush strength 7.7―25 N·mm-1.
