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
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
Subsurface rocks,as complex porous media,exhibit multiscale pore structures and intricate physical properties.Digital rock physics technology has become increasingly influential in the study of subsurface rock propert...Subsurface rocks,as complex porous media,exhibit multiscale pore structures and intricate physical properties.Digital rock physics technology has become increasingly influential in the study of subsurface rock properties.Given the multiscale characteristics of rock pore structures,direct three-dimensional imaging at sub-micrometer and nanometer scales is typically infeasible.This study introduces a method for reconstructing porous media using multidimensional data,which combines one-dimensional pore structure parameters with two-dimensional images to reconstruct three-dimensional models.The pore network model(PNM)is stochastically reconstructed using one-dimensional parameters,and a generative adversarial network(GAN)is utilized to equip the PNM with pore morphologies derived from two-dimensional images.The digital rocks generated by this method possess excellent controllability.Using Berea sandstone and Grosmont carbonate samples,we performed digital rock reconstructions based on PNM extracted by the maximum ball algorithm and compared them with stochastically reconstructed PNM.Pore structure parameters,permeability,and formation factors were calculated.The results show that the generated samples exhibit good consistency with real samples in terms of pore morphology,pore structure,and physical properties.Furthermore,our method effectively supplements the micropores not captured in CT images,demonstrating its potential in multiscale carbonate samples.Thus,the proposed reconstruction method is promising for advancing porous media property research.展开更多
Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiv...Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiveness,and environ-mental friendliness.The pyrolysis method affects the microstructure of the material,and ultimately its so-dium storage performance.Our previous work has shown that pyrolysis in a sealed graphite vessel im-proved the sodium storage performance of the car-bon,however the changes in its microstructure and the way this influences the sodium storage are still unclear.A series of hard carbon materials derived from corncobs(CCG-T,where T is the pyrolysis temperature)were pyrolyzed in a sealed graphite vessel at different temperatures.As the pyrolysis temperature increased from 1000 to 1400℃ small carbon domains gradually transformed into long and curved domains.At the same time,a greater number of large open pores with uniform apertures,as well as more closed pores,were formed.With the further increase of pyrolysis temperature to 1600℃,the long and curved domains became longer and straighter,and some closed pores gradually became open.CCG-1400,with abundant closed pores,had a superior SIB performance,with an initial reversible ca-pacity of 320.73 mAh g^(-1) at a current density of 30 mA g^(-1),an initial Coulomb efficiency(ICE)of 84.34%,and a capacity re-tention of 96.70%after 100 cycles.This study provides a method for the precise regulation of the microcrystalline and pore structures of hard carbon materials.展开更多
To obtain materials capable of efficiently separating acetylene(C_(2)H_(2))from carbon dioxide(CO_(2))and eth-ylene(C_(2)H_(4)),In this work,based on the pore space partition strategy,a pacs-metal-organic framework(MO...To obtain materials capable of efficiently separating acetylene(C_(2)H_(2))from carbon dioxide(CO_(2))and eth-ylene(C_(2)H_(4)),In this work,based on the pore space partition strategy,a pacs-metal-organic framework(MOF):(NH_(2)Me_(2))_(2)[Fe_(3)(μ_(3)-O)(bdc)_(3)][In(FA)_(3)Cl_(3)](Fe‑FAIn‑bdc)was synthesized successfully by using the metal-formate com-plex[In(FA)_(3)Cl_(3)]^(3-)as the pore partition units,where bdc^(2-)=terephthalate,FA-=formate.Owing to the pore partition effect of this metal-organic building block,fruitful confined spaces are formed in the network of Fe‑FAIn‑bdc,endowing this MOF with superior separation performance of acetylene and carbon dioxide.According to the adsorp-tion test,this MOF exhibited a high adsorption capacity for C_(2)H_(2)(50.79 cm^(3)·g^(-1))at 298 K and 100 kPa,which was much higher than that for CO_(2)(29.99 cm^(3)·g^(-1))and C_(2)H_(4)(30.94 cm^(3)·g^(-1))under the same conditions.Ideal adsorbed solution theory(IAST)calculations demonstrate that the adsorption selectivity of Fe‑FAIn‑bdc for the mixture of C_(2)H_(2)/CO_(2)and C_(2)H_(2)/C_(2)H_(4)in a volume ratio of 50∶50 was 3.08 and 3.65,respectively,which was higher than some reported MOFs such as NUM-11 and SNNU-18.CCDC:_(2)453954.展开更多
As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD ...As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD cycles.X-ray micro-computed tomography(micro-CT)was used as a non-destructive tool to quantitatively analyze microstructural changes of the mudstone due to the first cycle of WD.The test results show that WD leads to an increase of pore volume and pore connectivity in the mudstone.The porosity and fractal dimension of each slice of mudstone not only increase in value,but also in fluctuation amplitude.The pattern of variation in the frequency distribution of the equivalent radii of connected,isolated pores and pore throats in mudstone under WD effect satisfies the Gaussian distribution.Under the effect of WD,pores and pore throats with relatively small sizes increase the most.The sphericity of the pores in mudstones is positively correlated with the pore radius.The WD effect transforms the originally angular and flat pores into round and regular pores.This paper can provide a reference for the study of the deterioration and catastrophic mechanisms of mudstone under wetting and drying cycles.展开更多
Marine organic-rich marl is not only a high-quality hydrocarbon source of conventional oil and gas,but also a new type and field of unconventional oil and gas exploration.An understanding of its pore structure evoluti...Marine organic-rich marl is not only a high-quality hydrocarbon source of conventional oil and gas,but also a new type and field of unconventional oil and gas exploration.An understanding of its pore structure evolution characteristics during a hydrocarbon generation process is theoretically significant and has application prospects for the exploration and development of this special type of natural gas reservoirs.This study conducted thermal simulation of hydrocarbon generation under near-geological conditions during a whole process for cylinder samples of low mature marine organic-rich marl in the Middle Devonian of Luquan,Yunnan Province,China.During this process,hydrocarbon products at different evolution stages were quantified and corresponding geochemical properties were analyzed.Simultaneously,field emission scanning electron microscopy(FE-SEM)and low-pressure gas adsorption(CO_(2),N_(2))tests were applied to the corresponding cylinder residue samples to reveal the mechanisms of different types of pore formation and evolution,and clarify the dynamic evolution processes of their pore systems.The results show that with an increase in temperature and pressure,the total oil yield peaks at an equivalent vitrinite reflectance(VR_(o))of 1.03%and is at the maximum retention stage of liquid hydrocarbons,which are 367.51 mg/g TOC and 211.67 mg/g TOC,respectively.The hydrocarbon gas yield increases continuously with an increase in maturity.The high retained oil rate at the peak of oil generation provides an abundant material basis for gas formation at high maturity and over-maturity stage.The lower limit of VR_(o)for organic matter(OM)pore mass development is about 1.6%,and bitumen pores,organic-clay complex pores together with intergranular pores,grain edge seams and dissolution pores constitute a complicated pore-seam-network system,which is the main reservoir space for unconventional carbonate gas.Pore formation and evolution are controlled synergistically by hydrocarbon generation,diagenesis and organic-inorganic interactions,and the pattern of pore structure evolution can be divided into four stages.A pore volume(PV)and a specific surface area(SSA)are at their highest values within the maturity range of 1.9%to 2.5%,which is conducive to exploring unconventional natural gas.展开更多
The water adsorption performance of shale gas reservoirs is a very important factor affecting their gas in place(GIP)contents,but the water-holding capacity and mechanism of over-mature shale,especially organic pores,...The water adsorption performance of shale gas reservoirs is a very important factor affecting their gas in place(GIP)contents,but the water-holding capacity and mechanism of over-mature shale,especially organic pores,are still not fully understood.In this study,systematic water vapor adsorption(WVA)experiments were carried out on the Lower Cambrian over-mature shale and its kerogen from the Sichuan Basin,China to characterize their WVA behaviors,and combined with the low-pressure gas(N_(2) and CO_(2))adsorption experiments,the main influencing factors of WVA capacity of the shale and the absorbed-water distribution in its organic and inorganic nanopores were investigated.The results show that the WVA isotherms of shale and kerogen are all typeⅡ,with an obvious hysteresis loop in the multilayer adsorption range,and that the positive relationship of the shale TOC content with the WVA capacity(including total adsorption capacity,primary adsorption capacity and secondary adsorption capacity)and WVA hysteresis index(AHIW),and the greater adsorption capacity and AHIW of kerogen than the shale,all indicate that the hydrophilicity of organic matter(OM)in the over-mature shale was underestimated in previous research.Although both the shale OM and clay minerals have a significant positive effect on the WVA,the former has a stronger adsorption ability than the latter.The WVA capacity of the studied Lower Cambrian shale is significantly greater than that of the Longmaxi shale reported in literatures,which was believed to be mainly attributed to its higher maturity,with a significant graphitization of OM.The shale micropores and non-micropores play an important role in WVA,especially OM pores.There are primary and secondary adsorption for water vapor in both the micropores and non-micropores of OM,while these adsorptions of minerals mainly occur in their non-micropores.These results have important guides for understanding the gas storage mechanism and exploration and development potential of marine over-mature shale in southern China,especially the Lower Cambrian shale.展开更多
Zeolites are crystalline microporous materials widely used in catalysis,adsorption,and ion exchange owing to their tunable pore structures and acid centers[1].Traditional zeolites,however,often suffer from limitations...Zeolites are crystalline microporous materials widely used in catalysis,adsorption,and ion exchange owing to their tunable pore structures and acid centers[1].Traditional zeolites,however,often suffer from limitations such as restricted molecular diffusion and rapid coking,which hinder their efficiency in processing large molecules.展开更多
Carbonate,tight sandstone,and shale reservoirs have many pore types,and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape.This paper presents a method for...Carbonate,tight sandstone,and shale reservoirs have many pore types,and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape.This paper presents a method for predicting reservoir pore types based on pore shape substitution.The pore shape substitution allows for accurately characterizing the changes in the elastic properties of the rock with the changes in pore shape,assuming there are no changes in terms of minerals,porosity,or fl uids.By employing a multiple-porosity variable critical porosity model,the eff ective pore aspect ratio could be inverted from the velocities of the rock.To perform pore shape substitution,we could replace the eff ective pore aspect ratio with another pore aspect ratio or increase/decrease the volume content of diff erent pore shapes.The reservoir pore types could be evaluated by comparing the differences in the reservoir velocities before and after the substitution of the pore shape.The test results pertaining to the theoretical model and the well logging data indicated that the pore shape substitution method could be applied to characterize pore types in terms of separating the eff ects of the pore shapes from the eff ects of the minerals,porosity,or fl uids on the velocities.展开更多
A comprehensive analysis of the microstructure and defects of a thixomolded AZ91D alloy was conducted to elucidate their influences on mechanical properties.Samples were made at injection temperatures ranging from 580...A comprehensive analysis of the microstructure and defects of a thixomolded AZ91D alloy was conducted to elucidate their influences on mechanical properties.Samples were made at injection temperatures ranging from 580 to 640℃.X-ray computed tomography was used to visualize pores,and crystal plasticity finite element simulation was adopted for deformation analysis.The microstructure characterizations reveal a hierarchical cell feature composed of α-Mg and eutectic phases.With the increase of injection temperature,large cell content in the material decreases,while the strength of the alloy increases.The underlying mechanism about strength change is that coarse-grained solids experience smaller stress even in hard orientations.The sample fabricated at a moderate temperature of 620℃ exhibits the highest elongation,least quantity and lower local concentration of pores.The detachment and tearing cracks formed at lower injection temperature and defect bands formed at higher injection temperature add additional crack sources and deteriorate the ductility of the materials.展开更多
Forced imbibition,the invasion of a wetting fluid into porous rocks,plays an important role in the effective exploitation of hydrocarbon resources and the geological sequestration of carbon dioxide.However,the interfa...Forced imbibition,the invasion of a wetting fluid into porous rocks,plays an important role in the effective exploitation of hydrocarbon resources and the geological sequestration of carbon dioxide.However,the interface dynamics influenced by complex topology commonly leads to non-wetting fluid trapping.Particularly,the underlying mechanisms under viscously unfavorable conditions remain unclear.This study employs a direct numerical simulation method to simulate forced imbibition through the reconstructed digital rocks of sandstone.The interface dynamics and fluid–fluid interactions are investigated through transient simulations,while the pore topology metrics are introduced to analyze the impact on steady-state residual fluid distribution obtained by a pseudo-transient scheme.The results show that the cooperative pore-filling process promoted by corner flow is dominant at low capillary numbers.This leads to unstable inlet pressure,mass flow,and interface curvature,which correspond to complicated interface dynamics and higher residual fluid saturation.During forced imbibition,the interface curvature gradually increases,with the pore-filling mechanisms involving the cooperation of main terminal meniscus movement and arc menisci filling.Complex topology with small diameter pores may result in the destabilization of interface curvature.The residual fluid saturation is negatively correlated with porosity and pore throat size,and positively correlated with tortuosity and aspect ratio.A large mean coordination number characterizing global connectivity promotes imbibition.However,high connectivity characterized by the standardized Euler number corresponding to small pores is associated with a high probability of non-wetting fluid trapping.展开更多
Clayey-silt natural gas hydrate reservoirs in the South China Sea exhibit loose and unconsolidated structures, heterogeneous pore structures, high clay mineral contents, and strong hydrophilicity. These characteristic...Clayey-silt natural gas hydrate reservoirs in the South China Sea exhibit loose and unconsolidated structures, heterogeneous pore structures, high clay mineral contents, and strong hydrophilicity. These characteristics complicate the gas-water two-phase flow process in porous media following hydrate decomposition, posing challenges for efficient development. This study examines the transport response of clayey-silt reservoir samples from the Shenhu area using gas-water two-phase flow experiments and CT scanning to explore changes in pore structure, gas-water distribution, and relative permeability under varying flow conditions. The results indicate that pore heterogeneity significantly influences flow characteristics. Gas preferentially displaces water in larger pores, forming fracture-like pores, which serve as preferential flow channels for gas migration. The preferential flow channels enhance gas-phase permeability up to 19 times that of the water phase when fluid pressures exceed total stresses. However,small pores retain liquid, leading to a high residual water saturation of 0.561. CT imaging reveals that these hydro-fractures improve gas permeability but also confine gas flow to specific channels. Pore network analysis shows that gas injection expands the pore-throat network, enhancing connectivity and forming fracture-like pores. Residual water remains trapped in smaller pores and throats, while structural changes, including new fractures, improve gas flow pathways and overall connectivity. Relative permeability curves demonstrate a narrow gas-water cocurrent-flow zone, a right-shifted iso-permeability point and high reservoir capillary pressure, indicating a strong "water-blocking" effect. The findings suggest that optimizing reservoir stimulation techniques to enhance fracture formation, reduce residual water saturation, and improve gas flow capacity is critical for efficient hydrate reservoir development.展开更多
Background:Enzyme fragility remains a major challenge in research and applications.Free enzymes are highly unstable,inactivated by heat,acid,alkali,or organic solvents,and often lose activity even under optimal storag...Background:Enzyme fragility remains a major challenge in research and applications.Free enzymes are highly unstable,inactivated by heat,acid,alkali,or organic solvents,and often lose activity even under optimal storage conditions.Limiting their use in cosmetics.Few commercial products combine acids and enzymes effectively.Objective:To investigate the physicochemical properties,in vitro exfoliation efficacy,and effects on facial skin parameters of a supramolecular acid-enzyme complex(SAE)composed of mandelic acid(MAN),betaine(BET),and composite enzymes(CE;papain and bromelain),thereby establishing a theoretical foundation for cosmetic applications.Methods:The supramolecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy and proton nuclear magnetic resonance(1H NMR)spectroscopy.Dissolution experiments were conducted to compare the solubility of SAE and CE in aqueous solutions.Enzymatic activity assays evaluated the stabilizing effect of supramolecular deep eutectic technology on enzymes.In vitro exfoliation tests assessed acid-enzyme synergy in keratin removal.A 4-week clinical trial evaluated the efficacy of a 2%SAE essence aqueous solution on facial skin parameters.Results:Dissolution experiments confirmed that supramolecular deep eutectic technology significantly improved enzyme solubility.Enzymatic activity tests demonstrated that this technology effectively preserved protease activity,substantially enhancing its practical applicability.Furthermore,in vitro exfoliation efficacy tests revealed that this technology strengthened the synergistic interaction between acids and enzymes and exhibited superior stratum corneum-removing capability of the SAE.In clinical evaluations of efficacy,after 7 days of using the essence containing SAE,the formulation significantly enhanced cheek gloss(+8.08%),while reducing comedones volume(-16.25%).after 28 days,significantly enhanced cheek hydration(+25.0%,SCH),gloss(+15.93%),and smoothness(−7.78%SEsm),while reducing TEWL(−6.86%),sebum(−15.54%),roughness(+16.24%SEr),and pore metrics(volume:−39.98%;count:−30.64%),and decreased comedones(blackheads:−70.33%;Whiteheads:−52.42%;all p<0.05).Conclusion:The supramolecular acid-enzyme complex demonstrates enhanced stability,improved solubility,and superior exfoliation efficacy compared to free enzymes.Clinical results further confirm its multifunctional benefits,including enhancing skin hydration,sebum regulation,barrier repair,pore refinement,and comedolytic effects.This study provides both theoretical and practical foundations for developing stable acid-enzyme combinations in dermatological applications.展开更多
Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the ...Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the relationship between pore throat structure and crude oil mobility characteristics of full particle sequence reservoirs in the Lower Permian Fengcheng Formation of Mahu Sag,Junggar Basin,are revealed.(1)With the decrease of reservoir particle size,the volume of pores connected by large throats and the volume of large pores show a decreasing trend,and the distribution and peak ranges of throat and pore radius shift to smaller size in an orderly manner.The upper limits of throat radius,porosity and permeability of unconventional reservoirs in Fengcheng Formation are approximately 0.7μm,8%and 0.1×10^(−3)μm^(2),respectively.(2)As the reservoir particle size decreases,the distribution and peak ranges of pores hosting retained oil and movable oil are shifted to a smaller size in an orderly manner.With the increase of driving pressure,the amount of retained and movable oil of the larger particle reservoir samples shows a more obvious trend of decreasing and increasing,respectively.(3)With the increase of throat radius,the driving pressure of reservoir with different particle levels presents three stages,namely rapid decrease,slow decrease and stabilization.The oil driving pressures of various reservoirs and the differences of them decrease with the increase of temperature and obviously decrease with the increase of throat radius.According to the above experimental analysis,it is concluded that the deep shale oil of Fengcheng Formation in Mahu Sag has great potential for production under geological conditions.展开更多
Changes to the microstructure of a hard carbon(HC)and its solid electrolyte interface(SEI)can be effective in improving the electrode kinetics.However,achieving fast charging using a simple and inexpensive strategy wi...Changes to the microstructure of a hard carbon(HC)and its solid electrolyte interface(SEI)can be effective in improving the electrode kinetics.However,achieving fast charging using a simple and inexpensive strategy without sacrificing its initial Coulombic efficiency remains a challenge in sodium ion batteries.A simple liquid-phase coating approach has been used to generate a pitch-derived soft carbon layer on the HC surface,and its effect on the porosity of HC and SEI chemistry has been studied.A variety of structural characterizations show a soft carbon coating can increase the defect and ultra-micropore contents.The increase in ultra-micropore comes from both the soft carbon coatings and the larger pores within the HC that are partially filled by pitch,which provides more Na+storage sites.In-situ FTIR/EIS and ex-situ XPS showed that the soft carbon coating induced the formation of thinner SEI that is richer in NaF from the electrolyte,which stabilized the interface and promoted the charge transfer process.As a result,the anode produced fastcharging(329.8 mAh g^(−1)at 30 mA g^(−1)and 198.6 mAh g^(−1)at 300 mA g^(−1))and had a better cycling performance(a high capacity retention of 81.4%after 100 cycles at 150 mA g^(−1)).This work reveals the critical role of coating layer in changing the pore structure,SEI chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced fast charging capability.展开更多
The development of sustainable electrode materials for energy storage systems has become very important and porous carbons derived from biomass have become an important candidate because of their tunable pore structur...The development of sustainable electrode materials for energy storage systems has become very important and porous carbons derived from biomass have become an important candidate because of their tunable pore structure,environmental friendliness,and cost-effectiveness.Recent advances in controlling the pore structure of these carbons and its relationship between to is energy storage performance are discussed,emphasizing the critical role of a balanced distribution of micropores,mesopores and macropores in determining electrochemical behavior.Particular attention is given to how the intrinsic components of biomass precursors(lignin,cellulose,and hemicellulose)influence pore formation during carbonization.Carbonization and activation strategies to precisely control the pore structure are introduced.Finally,key challenges in the industrial production of these carbons are outlined,and future research directions are proposed.These include the establishment of a database of biomass intrinsic structures and machine learning-assisted pore structure engineering,aimed at providing guidance for the design of high-performance carbon materials for next-generation energy storage devices.展开更多
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
Four types of Mg-5Zn porous scaffolds with different pore geometries,including body-centered cubic(bcc),the rhombic dodecahedron(RD),gyroid(G),and primitive(P)types,were designed and fabricated using selective laser m...Four types of Mg-5Zn porous scaffolds with different pore geometries,including body-centered cubic(bcc),the rhombic dodecahedron(RD),gyroid(G),and primitive(P)types,were designed and fabricated using selective laser melting.Their forming quality,compression mechanical properties,and degradation behavior were investigated.Results indicate that the fabricated scaffolds exhibit good dimensional accuracy,and the surface chemical polishing treatment significantly improves the forming quality and reduces porosity error in porous scaffolds.Compared to the ones with rod structures(bcc,RD),the scaffolds with surface structures(G,P)have less powder particle adhesion.The G porous scaffold exhibits the best forming quality for the same design porosity.The predominant failure mode of scaffolds during compression is a 45°shear fracture.At a porosity of 75%,the compression property of all scaffolds meets the compressive property requirements of cancellous bone,while bcc and G structures show relatively better compression property.After immersion in Hank's solution for 168 h,the B-2-75% pore structure scaffold exhibits severe localized corrosion,with fractures in partial pillar connections.In contrast,the G-3-75% pore structure scaffold mainly undergoes uniform corrosion,maintaining structural integrity,and its corrosion rate and loss of compressive properties are less than those of the B-2-75%structure.After comparison,the G-pore structure scaffold is preferred.展开更多
This study introduces the“mineral-pore integration”paradigm to address unresolved challenges in understanding flow characteristics within heterogeneous tight oil reservoirs.By analyzing the complementary relationshi...This study introduces the“mineral-pore integration”paradigm to address unresolved challenges in understanding flow characteristics within heterogeneous tight oil reservoirs.By analyzing the complementary relationship between minerals and pore-fractures,we highlight the critical role of mineralogical composition in regulating fluid flow dynamics.Existing research has focused on the qualitative pore morphology and size characterization,neglecting the quantitative dependency between minerals and pore structures.To bridge this gap,we propose the development of quantitative discrimination models using machine learning algorithms to decode mineral-pore coupling mechanisms.Additionally,we advocate for multiscale experimental and numerical approaches,including multi-physics field coupling simulations and microscale visualization experiments,to quantify flow disparities in pores formed by different minerals(e.g.,feldspar,clay,carbonate).The integration of these methods aims to reveal novel flow behaviors,optimize displacement strategies,and enhance residual oil recovery.This framework provides a foundational basis for precise reservoir management by linking mineralogy to pore-scale flow mechanisms,offering actionable insights for tight oil exploitation.展开更多
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 Shandong Provincial Natural Science Foundation(ZR2024MD116)National Natural Science Foundation of China(Grant Nos.42174143,42004098)Technology Innovation Leading Program of Shaanxi(No.2024 ZC-YYDP-27).
文摘Subsurface rocks,as complex porous media,exhibit multiscale pore structures and intricate physical properties.Digital rock physics technology has become increasingly influential in the study of subsurface rock properties.Given the multiscale characteristics of rock pore structures,direct three-dimensional imaging at sub-micrometer and nanometer scales is typically infeasible.This study introduces a method for reconstructing porous media using multidimensional data,which combines one-dimensional pore structure parameters with two-dimensional images to reconstruct three-dimensional models.The pore network model(PNM)is stochastically reconstructed using one-dimensional parameters,and a generative adversarial network(GAN)is utilized to equip the PNM with pore morphologies derived from two-dimensional images.The digital rocks generated by this method possess excellent controllability.Using Berea sandstone and Grosmont carbonate samples,we performed digital rock reconstructions based on PNM extracted by the maximum ball algorithm and compared them with stochastically reconstructed PNM.Pore structure parameters,permeability,and formation factors were calculated.The results show that the generated samples exhibit good consistency with real samples in terms of pore morphology,pore structure,and physical properties.Furthermore,our method effectively supplements the micropores not captured in CT images,demonstrating its potential in multiscale carbonate samples.Thus,the proposed reconstruction method is promising for advancing porous media property research.
文摘Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiveness,and environ-mental friendliness.The pyrolysis method affects the microstructure of the material,and ultimately its so-dium storage performance.Our previous work has shown that pyrolysis in a sealed graphite vessel im-proved the sodium storage performance of the car-bon,however the changes in its microstructure and the way this influences the sodium storage are still unclear.A series of hard carbon materials derived from corncobs(CCG-T,where T is the pyrolysis temperature)were pyrolyzed in a sealed graphite vessel at different temperatures.As the pyrolysis temperature increased from 1000 to 1400℃ small carbon domains gradually transformed into long and curved domains.At the same time,a greater number of large open pores with uniform apertures,as well as more closed pores,were formed.With the further increase of pyrolysis temperature to 1600℃,the long and curved domains became longer and straighter,and some closed pores gradually became open.CCG-1400,with abundant closed pores,had a superior SIB performance,with an initial reversible ca-pacity of 320.73 mAh g^(-1) at a current density of 30 mA g^(-1),an initial Coulomb efficiency(ICE)of 84.34%,and a capacity re-tention of 96.70%after 100 cycles.This study provides a method for the precise regulation of the microcrystalline and pore structures of hard carbon materials.
文摘To obtain materials capable of efficiently separating acetylene(C_(2)H_(2))from carbon dioxide(CO_(2))and eth-ylene(C_(2)H_(4)),In this work,based on the pore space partition strategy,a pacs-metal-organic framework(MOF):(NH_(2)Me_(2))_(2)[Fe_(3)(μ_(3)-O)(bdc)_(3)][In(FA)_(3)Cl_(3)](Fe‑FAIn‑bdc)was synthesized successfully by using the metal-formate com-plex[In(FA)_(3)Cl_(3)]^(3-)as the pore partition units,where bdc^(2-)=terephthalate,FA-=formate.Owing to the pore partition effect of this metal-organic building block,fruitful confined spaces are formed in the network of Fe‑FAIn‑bdc,endowing this MOF with superior separation performance of acetylene and carbon dioxide.According to the adsorp-tion test,this MOF exhibited a high adsorption capacity for C_(2)H_(2)(50.79 cm^(3)·g^(-1))at 298 K and 100 kPa,which was much higher than that for CO_(2)(29.99 cm^(3)·g^(-1))and C_(2)H_(4)(30.94 cm^(3)·g^(-1))under the same conditions.Ideal adsorbed solution theory(IAST)calculations demonstrate that the adsorption selectivity of Fe‑FAIn‑bdc for the mixture of C_(2)H_(2)/CO_(2)and C_(2)H_(2)/C_(2)H_(4)in a volume ratio of 50∶50 was 3.08 and 3.65,respectively,which was higher than some reported MOFs such as NUM-11 and SNNU-18.CCDC:_(2)453954.
基金Project(41877240)supported by the National Natural Science Foundation of China。
文摘As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD cycles.X-ray micro-computed tomography(micro-CT)was used as a non-destructive tool to quantitatively analyze microstructural changes of the mudstone due to the first cycle of WD.The test results show that WD leads to an increase of pore volume and pore connectivity in the mudstone.The porosity and fractal dimension of each slice of mudstone not only increase in value,but also in fluctuation amplitude.The pattern of variation in the frequency distribution of the equivalent radii of connected,isolated pores and pore throats in mudstone under WD effect satisfies the Gaussian distribution.Under the effect of WD,pores and pore throats with relatively small sizes increase the most.The sphericity of the pores in mudstones is positively correlated with the pore radius.The WD effect transforms the originally angular and flat pores into round and regular pores.This paper can provide a reference for the study of the deterioration and catastrophic mechanisms of mudstone under wetting and drying cycles.
基金supported by the National Natural Science Foundation of China(Grant No.41930426)。
文摘Marine organic-rich marl is not only a high-quality hydrocarbon source of conventional oil and gas,but also a new type and field of unconventional oil and gas exploration.An understanding of its pore structure evolution characteristics during a hydrocarbon generation process is theoretically significant and has application prospects for the exploration and development of this special type of natural gas reservoirs.This study conducted thermal simulation of hydrocarbon generation under near-geological conditions during a whole process for cylinder samples of low mature marine organic-rich marl in the Middle Devonian of Luquan,Yunnan Province,China.During this process,hydrocarbon products at different evolution stages were quantified and corresponding geochemical properties were analyzed.Simultaneously,field emission scanning electron microscopy(FE-SEM)and low-pressure gas adsorption(CO_(2),N_(2))tests were applied to the corresponding cylinder residue samples to reveal the mechanisms of different types of pore formation and evolution,and clarify the dynamic evolution processes of their pore systems.The results show that with an increase in temperature and pressure,the total oil yield peaks at an equivalent vitrinite reflectance(VR_(o))of 1.03%and is at the maximum retention stage of liquid hydrocarbons,which are 367.51 mg/g TOC and 211.67 mg/g TOC,respectively.The hydrocarbon gas yield increases continuously with an increase in maturity.The high retained oil rate at the peak of oil generation provides an abundant material basis for gas formation at high maturity and over-maturity stage.The lower limit of VR_(o)for organic matter(OM)pore mass development is about 1.6%,and bitumen pores,organic-clay complex pores together with intergranular pores,grain edge seams and dissolution pores constitute a complicated pore-seam-network system,which is the main reservoir space for unconventional carbonate gas.Pore formation and evolution are controlled synergistically by hydrocarbon generation,diagenesis and organic-inorganic interactions,and the pattern of pore structure evolution can be divided into four stages.A pore volume(PV)and a specific surface area(SSA)are at their highest values within the maturity range of 1.9%to 2.5%,which is conducive to exploring unconventional natural gas.
基金supported by the National Natural Science Foundation of China(42030804,42330811)the“Deep-time Digital Earth”Science and Technology Leading Talents Team Funds for the Central Universities for the Frontiers Science Center for Deep-time Digital Earth,China University of Geosciences(Fundamental Research Funds for the Central Universities,grant number:2652023001).
文摘The water adsorption performance of shale gas reservoirs is a very important factor affecting their gas in place(GIP)contents,but the water-holding capacity and mechanism of over-mature shale,especially organic pores,are still not fully understood.In this study,systematic water vapor adsorption(WVA)experiments were carried out on the Lower Cambrian over-mature shale and its kerogen from the Sichuan Basin,China to characterize their WVA behaviors,and combined with the low-pressure gas(N_(2) and CO_(2))adsorption experiments,the main influencing factors of WVA capacity of the shale and the absorbed-water distribution in its organic and inorganic nanopores were investigated.The results show that the WVA isotherms of shale and kerogen are all typeⅡ,with an obvious hysteresis loop in the multilayer adsorption range,and that the positive relationship of the shale TOC content with the WVA capacity(including total adsorption capacity,primary adsorption capacity and secondary adsorption capacity)and WVA hysteresis index(AHIW),and the greater adsorption capacity and AHIW of kerogen than the shale,all indicate that the hydrophilicity of organic matter(OM)in the over-mature shale was underestimated in previous research.Although both the shale OM and clay minerals have a significant positive effect on the WVA,the former has a stronger adsorption ability than the latter.The WVA capacity of the studied Lower Cambrian shale is significantly greater than that of the Longmaxi shale reported in literatures,which was believed to be mainly attributed to its higher maturity,with a significant graphitization of OM.The shale micropores and non-micropores play an important role in WVA,especially OM pores.There are primary and secondary adsorption for water vapor in both the micropores and non-micropores of OM,while these adsorptions of minerals mainly occur in their non-micropores.These results have important guides for understanding the gas storage mechanism and exploration and development potential of marine over-mature shale in southern China,especially the Lower Cambrian shale.
基金the support of the National Natural Science Foundation of China(Nos.22205207 and 22378369).
文摘Zeolites are crystalline microporous materials widely used in catalysis,adsorption,and ion exchange owing to their tunable pore structures and acid centers[1].Traditional zeolites,however,often suffer from limitations such as restricted molecular diffusion and rapid coking,which hinder their efficiency in processing large molecules.
基金the National Natural Science Foundation of China(Nos.42074136,41674130)National Key S&T Special Project of China(No.2016ZX05027-004-001)the Fundamental Research Funds for the Central University(No.18CX02061A).
文摘Carbonate,tight sandstone,and shale reservoirs have many pore types,and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape.This paper presents a method for predicting reservoir pore types based on pore shape substitution.The pore shape substitution allows for accurately characterizing the changes in the elastic properties of the rock with the changes in pore shape,assuming there are no changes in terms of minerals,porosity,or fl uids.By employing a multiple-porosity variable critical porosity model,the eff ective pore aspect ratio could be inverted from the velocities of the rock.To perform pore shape substitution,we could replace the eff ective pore aspect ratio with another pore aspect ratio or increase/decrease the volume content of diff erent pore shapes.The reservoir pore types could be evaluated by comparing the differences in the reservoir velocities before and after the substitution of the pore shape.The test results pertaining to the theoretical model and the well logging data indicated that the pore shape substitution method could be applied to characterize pore types in terms of separating the eff ects of the pore shapes from the eff ects of the minerals,porosity,or fl uids on the velocities.
基金supported by the National Natural Science Foundation of China(Nos.51825101,52001202)the National Key Research and Development Program of China(No.2021YFA1600900)。
文摘A comprehensive analysis of the microstructure and defects of a thixomolded AZ91D alloy was conducted to elucidate their influences on mechanical properties.Samples were made at injection temperatures ranging from 580 to 640℃.X-ray computed tomography was used to visualize pores,and crystal plasticity finite element simulation was adopted for deformation analysis.The microstructure characterizations reveal a hierarchical cell feature composed of α-Mg and eutectic phases.With the increase of injection temperature,large cell content in the material decreases,while the strength of the alloy increases.The underlying mechanism about strength change is that coarse-grained solids experience smaller stress even in hard orientations.The sample fabricated at a moderate temperature of 620℃ exhibits the highest elongation,least quantity and lower local concentration of pores.The detachment and tearing cracks formed at lower injection temperature and defect bands formed at higher injection temperature add additional crack sources and deteriorate the ductility of the materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.42172159 and 42302143)the Postdoctora Fellowship Program of the China Postdoctoral Science Foundation(CPSF)(Grant No.GZB20230864).
文摘Forced imbibition,the invasion of a wetting fluid into porous rocks,plays an important role in the effective exploitation of hydrocarbon resources and the geological sequestration of carbon dioxide.However,the interface dynamics influenced by complex topology commonly leads to non-wetting fluid trapping.Particularly,the underlying mechanisms under viscously unfavorable conditions remain unclear.This study employs a direct numerical simulation method to simulate forced imbibition through the reconstructed digital rocks of sandstone.The interface dynamics and fluid–fluid interactions are investigated through transient simulations,while the pore topology metrics are introduced to analyze the impact on steady-state residual fluid distribution obtained by a pseudo-transient scheme.The results show that the cooperative pore-filling process promoted by corner flow is dominant at low capillary numbers.This leads to unstable inlet pressure,mass flow,and interface curvature,which correspond to complicated interface dynamics and higher residual fluid saturation.During forced imbibition,the interface curvature gradually increases,with the pore-filling mechanisms involving the cooperation of main terminal meniscus movement and arc menisci filling.Complex topology with small diameter pores may result in the destabilization of interface curvature.The residual fluid saturation is negatively correlated with porosity and pore throat size,and positively correlated with tortuosity and aspect ratio.A large mean coordination number characterizing global connectivity promotes imbibition.However,high connectivity characterized by the standardized Euler number corresponding to small pores is associated with a high probability of non-wetting fluid trapping.
基金the National Natural Science Foundation of China (Nos. 42302143, 42172159)China Geological Survey Project (No. DD20211350)support from the G. Albert Shoemaker endowment
文摘Clayey-silt natural gas hydrate reservoirs in the South China Sea exhibit loose and unconsolidated structures, heterogeneous pore structures, high clay mineral contents, and strong hydrophilicity. These characteristics complicate the gas-water two-phase flow process in porous media following hydrate decomposition, posing challenges for efficient development. This study examines the transport response of clayey-silt reservoir samples from the Shenhu area using gas-water two-phase flow experiments and CT scanning to explore changes in pore structure, gas-water distribution, and relative permeability under varying flow conditions. The results indicate that pore heterogeneity significantly influences flow characteristics. Gas preferentially displaces water in larger pores, forming fracture-like pores, which serve as preferential flow channels for gas migration. The preferential flow channels enhance gas-phase permeability up to 19 times that of the water phase when fluid pressures exceed total stresses. However,small pores retain liquid, leading to a high residual water saturation of 0.561. CT imaging reveals that these hydro-fractures improve gas permeability but also confine gas flow to specific channels. Pore network analysis shows that gas injection expands the pore-throat network, enhancing connectivity and forming fracture-like pores. Residual water remains trapped in smaller pores and throats, while structural changes, including new fractures, improve gas flow pathways and overall connectivity. Relative permeability curves demonstrate a narrow gas-water cocurrent-flow zone, a right-shifted iso-permeability point and high reservoir capillary pressure, indicating a strong "water-blocking" effect. The findings suggest that optimizing reservoir stimulation techniques to enhance fracture formation, reduce residual water saturation, and improve gas flow capacity is critical for efficient hydrate reservoir development.
文摘Background:Enzyme fragility remains a major challenge in research and applications.Free enzymes are highly unstable,inactivated by heat,acid,alkali,or organic solvents,and often lose activity even under optimal storage conditions.Limiting their use in cosmetics.Few commercial products combine acids and enzymes effectively.Objective:To investigate the physicochemical properties,in vitro exfoliation efficacy,and effects on facial skin parameters of a supramolecular acid-enzyme complex(SAE)composed of mandelic acid(MAN),betaine(BET),and composite enzymes(CE;papain and bromelain),thereby establishing a theoretical foundation for cosmetic applications.Methods:The supramolecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy and proton nuclear magnetic resonance(1H NMR)spectroscopy.Dissolution experiments were conducted to compare the solubility of SAE and CE in aqueous solutions.Enzymatic activity assays evaluated the stabilizing effect of supramolecular deep eutectic technology on enzymes.In vitro exfoliation tests assessed acid-enzyme synergy in keratin removal.A 4-week clinical trial evaluated the efficacy of a 2%SAE essence aqueous solution on facial skin parameters.Results:Dissolution experiments confirmed that supramolecular deep eutectic technology significantly improved enzyme solubility.Enzymatic activity tests demonstrated that this technology effectively preserved protease activity,substantially enhancing its practical applicability.Furthermore,in vitro exfoliation efficacy tests revealed that this technology strengthened the synergistic interaction between acids and enzymes and exhibited superior stratum corneum-removing capability of the SAE.In clinical evaluations of efficacy,after 7 days of using the essence containing SAE,the formulation significantly enhanced cheek gloss(+8.08%),while reducing comedones volume(-16.25%).after 28 days,significantly enhanced cheek hydration(+25.0%,SCH),gloss(+15.93%),and smoothness(−7.78%SEsm),while reducing TEWL(−6.86%),sebum(−15.54%),roughness(+16.24%SEr),and pore metrics(volume:−39.98%;count:−30.64%),and decreased comedones(blackheads:−70.33%;Whiteheads:−52.42%;all p<0.05).Conclusion:The supramolecular acid-enzyme complex demonstrates enhanced stability,improved solubility,and superior exfoliation efficacy compared to free enzymes.Clinical results further confirm its multifunctional benefits,including enhancing skin hydration,sebum regulation,barrier repair,pore refinement,and comedolytic effects.This study provides both theoretical and practical foundations for developing stable acid-enzyme combinations in dermatological applications.
基金Supported by Leading Talent Program of Autonomous Region(2022TSYCLJ0070)PetroChina Prospective and Basic Technological Project(2021DJ0108)Natural Science Foundation for Outstanding Young People in Shandong Province(ZR2022YQ30).
文摘Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the relationship between pore throat structure and crude oil mobility characteristics of full particle sequence reservoirs in the Lower Permian Fengcheng Formation of Mahu Sag,Junggar Basin,are revealed.(1)With the decrease of reservoir particle size,the volume of pores connected by large throats and the volume of large pores show a decreasing trend,and the distribution and peak ranges of throat and pore radius shift to smaller size in an orderly manner.The upper limits of throat radius,porosity and permeability of unconventional reservoirs in Fengcheng Formation are approximately 0.7μm,8%and 0.1×10^(−3)μm^(2),respectively.(2)As the reservoir particle size decreases,the distribution and peak ranges of pores hosting retained oil and movable oil are shifted to a smaller size in an orderly manner.With the increase of driving pressure,the amount of retained and movable oil of the larger particle reservoir samples shows a more obvious trend of decreasing and increasing,respectively.(3)With the increase of throat radius,the driving pressure of reservoir with different particle levels presents three stages,namely rapid decrease,slow decrease and stabilization.The oil driving pressures of various reservoirs and the differences of them decrease with the increase of temperature and obviously decrease with the increase of throat radius.According to the above experimental analysis,it is concluded that the deep shale oil of Fengcheng Formation in Mahu Sag has great potential for production under geological conditions.
基金National Key Research and Development Program of China(2022YFE0206300)National Natural Science Foundation of China(U21A2081,22075074,22209047)+2 种基金Guangdong Basic and Applied Basic Research Foundation(2024A1515011620)Hunan Provincial Natural Science Foundation of China(2024JJ5068)Foundation of Yuelushan Center for Industrial Innovation(2023YCII0119)。
文摘Changes to the microstructure of a hard carbon(HC)and its solid electrolyte interface(SEI)can be effective in improving the electrode kinetics.However,achieving fast charging using a simple and inexpensive strategy without sacrificing its initial Coulombic efficiency remains a challenge in sodium ion batteries.A simple liquid-phase coating approach has been used to generate a pitch-derived soft carbon layer on the HC surface,and its effect on the porosity of HC and SEI chemistry has been studied.A variety of structural characterizations show a soft carbon coating can increase the defect and ultra-micropore contents.The increase in ultra-micropore comes from both the soft carbon coatings and the larger pores within the HC that are partially filled by pitch,which provides more Na+storage sites.In-situ FTIR/EIS and ex-situ XPS showed that the soft carbon coating induced the formation of thinner SEI that is richer in NaF from the electrolyte,which stabilized the interface and promoted the charge transfer process.As a result,the anode produced fastcharging(329.8 mAh g^(−1)at 30 mA g^(−1)and 198.6 mAh g^(−1)at 300 mA g^(−1))and had a better cycling performance(a high capacity retention of 81.4%after 100 cycles at 150 mA g^(−1)).This work reveals the critical role of coating layer in changing the pore structure,SEI chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced fast charging capability.
文摘The development of sustainable electrode materials for energy storage systems has become very important and porous carbons derived from biomass have become an important candidate because of their tunable pore structure,environmental friendliness,and cost-effectiveness.Recent advances in controlling the pore structure of these carbons and its relationship between to is energy storage performance are discussed,emphasizing the critical role of a balanced distribution of micropores,mesopores and macropores in determining electrochemical behavior.Particular attention is given to how the intrinsic components of biomass precursors(lignin,cellulose,and hemicellulose)influence pore formation during carbonization.Carbonization and activation strategies to precisely control the pore structure are introduced.Finally,key challenges in the industrial production of these carbons are outlined,and future research directions are proposed.These include the establishment of a database of biomass intrinsic structures and machine learning-assisted pore structure engineering,aimed at providing guidance for the design of high-performance carbon materials for next-generation energy storage devices.
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Science and Technology Planning Project of Inner Mongolia Science and Technology Department(2022YFSH0021)Key Research and Development Program of Shaanxi Province(2024SF2-GJHX-14,2021SF-296)。
文摘Four types of Mg-5Zn porous scaffolds with different pore geometries,including body-centered cubic(bcc),the rhombic dodecahedron(RD),gyroid(G),and primitive(P)types,were designed and fabricated using selective laser melting.Their forming quality,compression mechanical properties,and degradation behavior were investigated.Results indicate that the fabricated scaffolds exhibit good dimensional accuracy,and the surface chemical polishing treatment significantly improves the forming quality and reduces porosity error in porous scaffolds.Compared to the ones with rod structures(bcc,RD),the scaffolds with surface structures(G,P)have less powder particle adhesion.The G porous scaffold exhibits the best forming quality for the same design porosity.The predominant failure mode of scaffolds during compression is a 45°shear fracture.At a porosity of 75%,the compression property of all scaffolds meets the compressive property requirements of cancellous bone,while bcc and G structures show relatively better compression property.After immersion in Hank's solution for 168 h,the B-2-75% pore structure scaffold exhibits severe localized corrosion,with fractures in partial pillar connections.In contrast,the G-3-75% pore structure scaffold mainly undergoes uniform corrosion,maintaining structural integrity,and its corrosion rate and loss of compressive properties are less than those of the B-2-75%structure.After comparison,the G-pore structure scaffold is preferred.
基金supported by Youth Innovation Promotion Association CAS,2023021,Shuheng DuYoung Elite Scientists Sponsorship Program by CAST,YESS20220094,Shuheng Du+2 种基金Young Elite Scientists Sponsorship Program by BAST,BYESS2023182,Shuheng DuBeijing Natural Science Foundation,8232054,Shuheng DuNational Natural Science Foundation of China,41902132,Shuheng Du.
文摘This study introduces the“mineral-pore integration”paradigm to address unresolved challenges in understanding flow characteristics within heterogeneous tight oil reservoirs.By analyzing the complementary relationship between minerals and pore-fractures,we highlight the critical role of mineralogical composition in regulating fluid flow dynamics.Existing research has focused on the qualitative pore morphology and size characterization,neglecting the quantitative dependency between minerals and pore structures.To bridge this gap,we propose the development of quantitative discrimination models using machine learning algorithms to decode mineral-pore coupling mechanisms.Additionally,we advocate for multiscale experimental and numerical approaches,including multi-physics field coupling simulations and microscale visualization experiments,to quantify flow disparities in pores formed by different minerals(e.g.,feldspar,clay,carbonate).The integration of these methods aims to reveal novel flow behaviors,optimize displacement strategies,and enhance residual oil recovery.This framework provides a foundational basis for precise reservoir management by linking mineralogy to pore-scale flow mechanisms,offering actionable insights for tight oil exploitation.
