Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is con...Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is considered an effective means to achieve high-efficiency EMW absorption.However,interface modulation engineering has not been fully discussed and has great potential in the field of EMW absorption.In this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal reduction.By utilizing the different properties of different substances,rich heterogeneous interfaces are constructed.This effectively promotes charge transfer and enhances interfacial polarization and conduction loss.The prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy resin.The minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 GHz.Moreover,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel surfaces.Therefore,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.展开更多
The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggre...The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggregate was analyzed by molecular dynamics simulation.The diffusion coefficient and concentration distribution of SBS modified asphalt on aggregate surface are included.The simulation results show that the diffusion coefficient of the aggregate surface of SBS modified asphalt is increased by 47.6%and 70.5%respectively after 110#asphalt and 130#asphalt are pre-wetted.The concentration distribution of SBS modified asphalt on the aggregate surface after pre-wetting is more uniform.According to the results of interface energy calculation,the interface energy of SBS modified bitumen and aggregate can be increased by about 5%after pre-wetting.According to the results of molecular dynamics simulation,the pre-wetting technology can effectively improve the interface workability of SBS modified bitumen and aggregate,so as to improve the interface performance.展开更多
In order to solve the problem of poor formability caused by different materials and properties in the process of tailor-welded sheets forming,a forming method was proposed to change the stress state of tailor-welded s...In order to solve the problem of poor formability caused by different materials and properties in the process of tailor-welded sheets forming,a forming method was proposed to change the stress state of tailor-welded sheets by covering the tailor-welded sheets with better plastic properties overlapping sheets.At the same time,the interface friction effect between the overlapping and tailor-welded sheets was utilized to control the stress magnitude and further improve the formability and quality of the tailor-welded sheets.In this work,the bulging process of the tailor-welded overlapping sheets was taken as the research object.Aluminum alloy tailor-welded overlapping sheets bulging specimens were studied by a combination of finite element analysis and experimental verification.The results show that the appropriate use of interface friction between tailor-welded and overlapping sheets can improve the formability of tailor-welded sheets and control the flow of weld seam to improve the forming quality.When increasing the interface friction coefficient on the side of tailor-welded sheets with higher strength and decreasing that on the side of tailor-welded sheets with lower strength,the deformation of the tailor-welded sheets are more uniform,the offset of the weld seam is minimal,the limit bulging height is maximal,and the forming quality is optimal.展开更多
As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal...As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal materials at various scales and dimensions.Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and interfaces.However,fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal materials.From the perspective of two-dimensional planes and three-dimensional curved surfaces,this paper reviews the current research status of the fractal analysis of metal precipitate interfaces,metal grain boundary interfaces,metal-deposited film surfaces,metal fracture surfaces,metal machined surfaces,and metal wear surfaces.The relationship between the fractal dimensions and properties of metal material surfaces and interfaces is summarized.Starting from three perspectives of fractal analysis,namely,research scope,image acquisition methods,and calculation methods,this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be developed.It is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future.展开更多
Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and...Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.展开更多
Bionic interfaces exhibit multiscale features with various functions that reduce energy consumption and produce renewable resources to support life,triggering them an emerging area of technological revolution in many ...Bionic interfaces exhibit multiscale features with various functions that reduce energy consumption and produce renewable resources to support life,triggering them an emerging area of technological revolution in many disciplines.To improve the design and fabrication flexibility,additive manufacturing(AM)technology has been attempted to achieve multiscale structures and reconstruct biological functions at interfaces.Emerging AM of bionic interfaces has led to substantial advancements in renewable energy applications in recent years,but some challenges remain to be overcome.This review first presents a basic understanding of bionic mechanisms and typical manufacturing techniques especially AM.Subsequently,it emphasizes the latest progress of the bionic interfaces and AM on various renewable energy applications,such as those for wetting-controlled surfaces,energy harvesting,water treatment,batteries,and catalysts.Finally,it discusses some challenges and provides insights on how bionic interfaces and AM provide innovative solutions for next-generation renewable energy applications.展开更多
Cleat serves as the primary flow pathway for coalbed methane(CBM)and water.However,few studies consider the impact of local contact on two-phase flow within cleats.A visual generalized model of endogenous cleats was c...Cleat serves as the primary flow pathway for coalbed methane(CBM)and water.However,few studies consider the impact of local contact on two-phase flow within cleats.A visual generalized model of endogenous cleats was constructed based on microfluidics.A microscopic and mesoscopic observation technique was proposed to simultaneously capture gas-liquid interface morphology of pores and throat and the two-phase flow characteristics in entire cleat system.The local contact characteristics of cleats reduced absolute permeability,which resulted in a sharp increase in the starting pressure.The reduced gas flow capacity narrowed the co-infiltration area and decreased water saturation at the isotonic point in a hydrophilic environment.The increased local contact area of cleats weakened gas phase flow capacity and narrowed the co-infiltration area.Jumping events occurred in methane-water flow due to altered porosity caused by local contact in cleats.The distribution of residual phases changed the jumping direction on the micro-scale as well as the dominant channel on the mesoscale.Besides,jumping events caused additional energy dissipation,which was ignored in traditional two-phase flow models.This might contribute to the overestimation of relative permeability.The work provides new methods and insights for investigating unsaturated flow in complex porous media.展开更多
Global interest in lithium-sulfur batteries as one of the most promising energy storage technologies has been sparked by their low sulfur cathode cost,high gravimetric,volumetric energy densities,abundant resources,an...Global interest in lithium-sulfur batteries as one of the most promising energy storage technologies has been sparked by their low sulfur cathode cost,high gravimetric,volumetric energy densities,abundant resources,and environmental friendliness.However,their practical application is significantly impeded by several serious issues that arise at the cathode-electrolyte interface,such as interface structure degradation including the uneven deposition of Li_(2)S,unstable cathode-electrolyte interphase(CEI)layer and intermediate polysulfide shuttle effect.Thus,an optimized cathode-electrolyte interface along with optimized electrodes is required for overall improvement.Herein,we comprehensively outline the challenges and corresponding strategies,including electrolyte optimization to create a dense CEI layer,regulating the Li_(2)S deposition pattern,and inhibiting the shuttle effect with regard to the solid-liquid-solid pathway,the transformation from solid-liquid-solid to solid-solid pathway,and solid-solid pathway at the cathode-electrolyte interface.In order to spur more perceptive research and hasten the widespread use of lithium-sulfur batteries,viewpoints on designing a stable interface with a deep comprehension are also put forth.展开更多
Electrochemical nitrate(NO_(3)^(-))reduction offers a promising route for ammonia(NH_(3))synthesis from industrial wastewater using renewable energy.However,achieving selective and active NO_(3)^(-)to NH_(3)conversion...Electrochemical nitrate(NO_(3)^(-))reduction offers a promising route for ammonia(NH_(3))synthesis from industrial wastewater using renewable energy.However,achieving selective and active NO_(3)^(-)to NH_(3)conversion at low potentials remains challenging due to complex multi-electron transfer processes and competing reactions.Herein,we tackle this challenge by developing a cascade catalysis approach using synergistic active sites at Cu-Fe_(2)O_(3)interfaces,significantly reducing the NO_(3)^(-)to NH_(3)at a low onset potential to about+0.4 V_(RHE).Specifically,Cu optimizes^(*)NO_(3)adsorption,facilitating NO_(3)^(-)to nitrite(NO_(2)-)conversion,while adjacent Fe species in Fe_(2)O_(3)promote the subsequent NO_(2)-reduction to NH_(3)with favorable^(*)NO_(2)adsorption.Electrochemical operating experiments,in situ Raman spectroscopy,and in situ infrared spectroscopy consolidate this improved onset potential and reduction kinetics via cascade catalysis.An NH_(3)partial current density of~423 mA cm^(-2)and an NH_(3)Faradaic efficiency(FENH_(3))of 99.4%were achieved at-0.6 V_(RHE),with a maximum NH_(3)production rate of 2.71 mmol h^(-1)cm^(-2)at-0.8 V_(RHE).Remarkably,the half-cell energy efficiency exceeded 35%at-0.27 V_(RHE)(80%iR corrected),maintaining an FENH_(3)above 90%across a wide range of NO_(3)^(-)concentrations(0.05^(-1)mol L^(-1)).Using 15N isotopic tracing,we confirmed NO_(3)^(-)as the sole nitrogen source and attained a 98%NO_(3)^(-)removal efficiency.The catalyst exhibit stability over 106-h of continuous operation without noticeable degradation.This work highlights distinctive active sites in Cu-Fe_(2)O_(3)for promoting the cascade NO_(3)^(-)to NO_(2)^(-)and NO_(2)^(-)to NH_(3)electrolysis at industrial relevant current densities.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
Transition metal-carbonate interfaces often act as active sites in heterogeneous catalytic reactions.The interface between transition metal and metal carbonate exhibits a dynamic equilibrium during the CO_(2)hydrogena...Transition metal-carbonate interfaces often act as active sites in heterogeneous catalytic reactions.The interface between transition metal and metal carbonate exhibits a dynamic equilibrium during the CO_(2)hydrogenation reaction,involving surface carbonate hydrogenation and CO_(2)chemisorption.Nonetheless,there have been few reports on engineering the activity of the interface between transition metal and alkaline earth metal carbonate for catalytic CO_(2)conversion.This work demonstrated that the incorporation of CaH_(2)in Ni/CaCO_(3)enhances the CO_(2)methanation activity of the catalysts.The CO_(2)conversion for Ni/CaH_(2)-CaCO_(3)reached 68.5%at 400°C,which was much higher than that of the Ni/CaCO_(3)(31.6%) and Ni/CaH_(2)-CaO (42.4%) catalysts.Furthermore,the Ni/CaH_(2)-CaCO_(3)catalysts remained stable during the stability test for 24 h at 400°C and 8 bar.Our research revealed that CaH_(2)played a crucial role in promoting the activity of the Ni-carbonate interface for CO_(2)methanation.CaH_(2)could modify the electronic structure of Ni and tune the structural properties of CaCO_(3)to generate medium basic sites (OH groups),which are favorable for the activation of H2and CO_(2).In-situ Fourier transform infrared spectroscopy (FTIR) analysis combined with density functional theory calculations demonstrated that CO_(2)activation occurs at the hydroxyl group (OH) on the CaH_(2)-modified Ni-carbonate surface,leading to the formation of CO_(3)H*species.Furthermore,our study has confirmed that CO_(2)methanation over the Ni/CaH_(2)-CaCO_(3)catalysts proceeds via the formate pathway.展开更多
Understanding the factors triggering slope failure is essential to ensure the safety of buildings and transportation infrastructure on slopes. Specifically,the failure of stabilizing piles due to groundwater migration...Understanding the factors triggering slope failure is essential to ensure the safety of buildings and transportation infrastructure on slopes. Specifically,the failure of stabilizing piles due to groundwater migration and freeze–thaw(FT) cycles is a significant factor causing slope failure. This study aims to investigate the transmedia seepage characteristics at slope–concrete stabilizing pile interface systems by using silty clay and concrete with varying microstructure characteristics under FT cycles. To this end, a self-developed indoor test device for transmedia water migration, combined with a macro-meso-micro multiscale testing approach, was used to analyze the laws and mechanisms of transmedia seepage at the interface systems. The effect of the medium's microstructure characteristics on the transmedia seepage behavior at the interface systems under FT cycles was also assessed. Results indicated that the transmedia water migration exhibited particularity due to the migration of soil particles and the low permeability characteristics of concrete. The water content in the media increased significantly within the range of 1/3–2/3 of the height from the interface for soil and within 5 mm from the interface for concrete.FT cycles promoted the increase and penetration of cracks within the medium, enhancing the permeability of the slope-concrete stabilizing pile interface systems.With the increase in FT cycles, the porosity inside the medium first decreased and then increased, and the porosity reached the minimum after 25 FT cycles and the maximum after 75 FT cycles, and the water content of the medium after water migration was positively correlated with the porosity. FT cycles also significantly influenced the temporal variation characteristics of soil moisture and the migration path of water in concrete. The study results could serve as a reference for related research on slope stability assessment.展开更多
The growth of dendrites and the side reactions occurring at the Zn anode pose significant challenges to the commercialization of aqueous Zn-ion batteries(AZIBs). These challenges arise from the inherent conflict betwe...The growth of dendrites and the side reactions occurring at the Zn anode pose significant challenges to the commercialization of aqueous Zn-ion batteries(AZIBs). These challenges arise from the inherent conflict between mass transfer and electrochemical kinetics. In this study, we propose the use of a multifunctional electrolyte additive based on the xylose(Xylo) molecule to address these issues by modulating the solvation structure and electrode/electrolyte interface, thereby stabilizing the Zn anode. The introduction of the additive alters the solvation structure, creating steric hindrance that impedes charge transfer and then reduces electrochemical kinetics. Furthermore, in-situ analyses demonstrate that the reconstructed electrode/electrolyte interface facilitates stable and rapid Zn^(2+)ion migration and suppresses corrosion and hydrogen evolution reactions. As a result, symmetric cells incorporating the Xylo additive exhibit significantly enhanced reversibility during the Zn plating/stripping process, with an impressively long lifespan of up to 1986 h, compared to cells using pure ZnSO4electrolyte. When combined with a polyaniline cathode, the full cells demonstrate improved capacity and long-term cyclic stability. This work offers an effective direction for improving the stability of Zn anode via electrolyte design, as well as highperformance AZIBs.展开更多
The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of ...The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of adsorbent and catalyst.Herein,we engineered a series of RuNa/γ-Al_(2)O_(3)materials,varying the size of ruthenium from single atoms to clusters/nanoparticles.The coordination environment and structure sensitivity of ruthenium were quantitatively investigated at atomic scale.Our findings reveal that the reduced Ru nanoparticles,approximately 7.1 nm in diameter with a Ru-Ru coordination number of 5.9,exhibit high methane formation activity and selectivity at 340°C.The Ru-Na interfacial sites facilitate CO_(2)migration through a deoxygenation pathway,involving carbonate dissociation,carbonyl formation,and hydrogenation.In-situ experiments and theoretical calculations show that stable carbonyl intermediates on metallic Ru nanoparticles facilitate heterolytic C–O scission and C–H bonding,significantly lowering the energy barrier for activating stored CO_(2).展开更多
The oviduct epithelium is the initial maternal contact site for embryos after fertilization,offering the microenviron-ment before implantation.This early gestation period is particularly sensitive to stress,which can ...The oviduct epithelium is the initial maternal contact site for embryos after fertilization,offering the microenviron-ment before implantation.This early gestation period is particularly sensitive to stress,which can cause reduced fertil-ity and reproductive disorders in mammals.Nevertheless,the local impact of elevated stress hormones on the ovi-duct epithelium has received limited attention to date,except for a few reports on polyovulatory species like mice and pigs.In this study,we focused on the effects of chronic maternal stress on cattle,given its association with infertil-ity issues in this monoovulatory species.Bovine oviduct epithelial cells(BOEC)differentiated at the air–liquid interface(ALI)were stimulated with 250 nmol/L cortisol for 1 or 3 weeks.Subsequently,they were assessed for morphology,bioelectrical properties,and gene expression related to oviduct function,glucocorticoid pathway,cortisol metabo-lism,inflammation,and apoptosis.Results revealed adverse effects of cortisol on epithelium structure,featured by deciliation,vacuole formation,and multilayering.Additionally,cortisol exposure led to an increase in transepithelial potential difference,downregulated mRNA expression of the major glucocorticoid receptor(NR3C1),upregulated the expression of cortisol-responsive genes(FKBP5,TSC22D3),and significant downregulation of oviductal glycopro-tein 1(OVGP1)and steroid receptors PGR and ESR1.The systematic comparison to a similar experiment previously performed by us in porcine oviduct epithelial cells,indicated that bovine cultures were more susceptible to elevated cortisol levels than porcine.The distinct responses between both species are likely linked to their divergence in the cortisol-induced expression changes of HSD11B2,an enzyme controlling the cellular capacity to metabolise cortisol.These findings provide insights into the species-specific reactions and reproductive consequences triggered by maternal stress.展开更多
In an aging society,the interface design of smart home products is crucial to the quality of life of the elderly.This paper combines Quality Function Deployment(QFD)and Human-Computer Interaction(HCI)theories,taking s...In an aging society,the interface design of smart home products is crucial to the quality of life of the elderly.This paper combines Quality Function Deployment(QFD)and Human-Computer Interaction(HCI)theories,taking smart washing machines as an example,to explore new paths for the interface design of smart home products for the elderly.An interdisciplinary approach is adopted to construct a design process centered on elderly users,introduce the Kano model to classify requirements,realize the mapping and sorting of requirements to design parameters,and adopt the PUGH model for comprehensive evaluation.This study provides practical and theoretical support for the interface design of smart home products for the elderly.展开更多
As an important and effective indicator of contact heat transfer,thermal contact resistance is a widespread phenomenon in engineering.It can directly affect product reliability,full-load performance,power consumption ...As an important and effective indicator of contact heat transfer,thermal contact resistance is a widespread phenomenon in engineering.It can directly affect product reliability,full-load performance,power consumption and even life cycle in energy,aerospace,electronic packaging,cryogenic refrigeration,etc.Therefore,enhancing the interface heat transfer and suppressing thermal contact resistance have become increasingly important.Against this background,this paper seeks to elaborate on conceptions of thermal contact resistance and the ways to reduce it.After reviewing the existing methods of measuring thermal contact resistance and characterizing the interface morphology,we highlight the theoretical underpinnings of thermal contact resistance,including the two-dimensional mathematic characteristics of the contact interface and the theoretical and empirical models for quantifying it.Three categories of influencing factors,i.e.,thermal,geometrical and mechanical states,are then presented.Based on the macroscopic formation mechanism,the paper summarizes the existing methods for suppressing thermal contact resistance,with close attention paid to polymer composite thermal interfacial materials and metal interfacial materials filled with high thermal conductivity filler.In light of the findings,this review provides five promising directions for future research on thermal contact resistance.It suggests that the failure modes and service life of interface materials are essential to apply such technologies to suppress thermal contact resistance in practice.This review will be a guide for future research in thermal contact resistance and for the widespread use of composite interface materials.展开更多
Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently...Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top priority.Herein,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening process.Benefiting from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated temperature.Therefore,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 K.This study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.展开更多
Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT...Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.展开更多
In this paper,we study the one-dimensional motion of viscous gas near a vacuum,with the gas connecting to a vacuum state with a jump in density.The interface behavior,the pointwise decay rates of the density function ...In this paper,we study the one-dimensional motion of viscous gas near a vacuum,with the gas connecting to a vacuum state with a jump in density.The interface behavior,the pointwise decay rates of the density function and the expanding rates of the interface are obtained with the viscosity coefficientμ(ρ)=ρ^(α)for any 0<α<1;this includes the timeweighted boundedness from below and above.The smoothness of the solution is discussed.Moreover,we construct a class of self-similar classical solutions which exhibit some interesting properties,such as optimal estimates.The present paper extends the results in[Luo T,Xin Z P,Yang T.SIAM J Math Anal,2000,31(6):1175-1191]to the jump boundary conditions case with density-dependent viscosity.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52377026 and No.52301192)Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+4 种基金Postdoctoral Fellowship Program of CPSF under Grant Number(No.GZB20240327)Shandong Postdoctoral Science Foundation(No.SDCXZG-202400275)Qingdao Postdoctoral Application Research Project(No.QDBSH20240102023)China Postdoctoral Science Foundation(No.2024M751563)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites).
文摘Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is considered an effective means to achieve high-efficiency EMW absorption.However,interface modulation engineering has not been fully discussed and has great potential in the field of EMW absorption.In this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal reduction.By utilizing the different properties of different substances,rich heterogeneous interfaces are constructed.This effectively promotes charge transfer and enhances interfacial polarization and conduction loss.The prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy resin.The minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 GHz.Moreover,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel surfaces.Therefore,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.
基金Funded by the Research Funds of China University of Mining and Technology(No.102523215)。
文摘The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggregate was analyzed by molecular dynamics simulation.The diffusion coefficient and concentration distribution of SBS modified asphalt on aggregate surface are included.The simulation results show that the diffusion coefficient of the aggregate surface of SBS modified asphalt is increased by 47.6%and 70.5%respectively after 110#asphalt and 130#asphalt are pre-wetted.The concentration distribution of SBS modified asphalt on the aggregate surface after pre-wetting is more uniform.According to the results of interface energy calculation,the interface energy of SBS modified bitumen and aggregate can be increased by about 5%after pre-wetting.According to the results of molecular dynamics simulation,the pre-wetting technology can effectively improve the interface workability of SBS modified bitumen and aggregate,so as to improve the interface performance.
基金Funded by the National Natural Science Foundation of China(Nos.52075347,51575364)and the Natural Science Foundation of Liaoning Provincial(No.2022-MS-295)。
文摘In order to solve the problem of poor formability caused by different materials and properties in the process of tailor-welded sheets forming,a forming method was proposed to change the stress state of tailor-welded sheets by covering the tailor-welded sheets with better plastic properties overlapping sheets.At the same time,the interface friction effect between the overlapping and tailor-welded sheets was utilized to control the stress magnitude and further improve the formability and quality of the tailor-welded sheets.In this work,the bulging process of the tailor-welded overlapping sheets was taken as the research object.Aluminum alloy tailor-welded overlapping sheets bulging specimens were studied by a combination of finite element analysis and experimental verification.The results show that the appropriate use of interface friction between tailor-welded and overlapping sheets can improve the formability of tailor-welded sheets and control the flow of weld seam to improve the forming quality.When increasing the interface friction coefficient on the side of tailor-welded sheets with higher strength and decreasing that on the side of tailor-welded sheets with lower strength,the deformation of the tailor-welded sheets are more uniform,the offset of the weld seam is minimal,the limit bulging height is maximal,and the forming quality is optimal.
基金financially supported by the National Key R&D Program of China(No.2022YFE0121300)the National Natural Science Foundation of China(No.52374376)the Introduction Plan for High-end Foreign Experts(No.G2023105001L)。
文摘As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal materials at various scales and dimensions.Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and interfaces.However,fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal materials.From the perspective of two-dimensional planes and three-dimensional curved surfaces,this paper reviews the current research status of the fractal analysis of metal precipitate interfaces,metal grain boundary interfaces,metal-deposited film surfaces,metal fracture surfaces,metal machined surfaces,and metal wear surfaces.The relationship between the fractal dimensions and properties of metal material surfaces and interfaces is summarized.Starting from three perspectives of fractal analysis,namely,research scope,image acquisition methods,and calculation methods,this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be developed.It is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future.
基金National Natural Science Foundation of China(32201491)Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)The authors extend their appreciation to the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through the project number“NBU-FPEJ-2024-1101-02”.
文摘Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.
基金supported by the Guangdong Province Science and Technology Plan Project 2023B1212120008Shenzhen Science and Technology Program JCYJ20220818101204010+1 种基金RGC Theme-based Research Scheme AoE/M-402/20Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Materials Engineering Research Center.
文摘Bionic interfaces exhibit multiscale features with various functions that reduce energy consumption and produce renewable resources to support life,triggering them an emerging area of technological revolution in many disciplines.To improve the design and fabrication flexibility,additive manufacturing(AM)technology has been attempted to achieve multiscale structures and reconstruct biological functions at interfaces.Emerging AM of bionic interfaces has led to substantial advancements in renewable energy applications in recent years,but some challenges remain to be overcome.This review first presents a basic understanding of bionic mechanisms and typical manufacturing techniques especially AM.Subsequently,it emphasizes the latest progress of the bionic interfaces and AM on various renewable energy applications,such as those for wetting-controlled surfaces,energy harvesting,water treatment,batteries,and catalysts.Finally,it discusses some challenges and provides insights on how bionic interfaces and AM provide innovative solutions for next-generation renewable energy applications.
基金the financial support from the National Natural Science Foundation of China (No.42102127)the Postdoctoral Research Foundation of China (No.2024 M751860)。
文摘Cleat serves as the primary flow pathway for coalbed methane(CBM)and water.However,few studies consider the impact of local contact on two-phase flow within cleats.A visual generalized model of endogenous cleats was constructed based on microfluidics.A microscopic and mesoscopic observation technique was proposed to simultaneously capture gas-liquid interface morphology of pores and throat and the two-phase flow characteristics in entire cleat system.The local contact characteristics of cleats reduced absolute permeability,which resulted in a sharp increase in the starting pressure.The reduced gas flow capacity narrowed the co-infiltration area and decreased water saturation at the isotonic point in a hydrophilic environment.The increased local contact area of cleats weakened gas phase flow capacity and narrowed the co-infiltration area.Jumping events occurred in methane-water flow due to altered porosity caused by local contact in cleats.The distribution of residual phases changed the jumping direction on the micro-scale as well as the dominant channel on the mesoscale.Besides,jumping events caused additional energy dissipation,which was ignored in traditional two-phase flow models.This might contribute to the overestimation of relative permeability.The work provides new methods and insights for investigating unsaturated flow in complex porous media.
基金supported by the National Natural Science Foundation of China(Grant Nos.52102302,22409161 and 52472249)the Young Talent Support Plan of Xi’an Jiaotong University(Grant No.DQ6J011)+4 种基金the Natural Science Foundation of Shaanxi Province(2023-JC-QN-0115)the China Postdoctoral Science Foundation(2022M712499)Beilin District Science and Technology Plan(GX2328)the support from Young Elite Scientists Sponsorship Program by Chinese Association for Science and Technologythe“High-Level Talent Introduction Plan”of Shaanxi Province and Siyuan Scholar of Xi’an Jiaotong University。
文摘Global interest in lithium-sulfur batteries as one of the most promising energy storage technologies has been sparked by their low sulfur cathode cost,high gravimetric,volumetric energy densities,abundant resources,and environmental friendliness.However,their practical application is significantly impeded by several serious issues that arise at the cathode-electrolyte interface,such as interface structure degradation including the uneven deposition of Li_(2)S,unstable cathode-electrolyte interphase(CEI)layer and intermediate polysulfide shuttle effect.Thus,an optimized cathode-electrolyte interface along with optimized electrodes is required for overall improvement.Herein,we comprehensively outline the challenges and corresponding strategies,including electrolyte optimization to create a dense CEI layer,regulating the Li_(2)S deposition pattern,and inhibiting the shuttle effect with regard to the solid-liquid-solid pathway,the transformation from solid-liquid-solid to solid-solid pathway,and solid-solid pathway at the cathode-electrolyte interface.In order to spur more perceptive research and hasten the widespread use of lithium-sulfur batteries,viewpoints on designing a stable interface with a deep comprehension are also put forth.
文摘Electrochemical nitrate(NO_(3)^(-))reduction offers a promising route for ammonia(NH_(3))synthesis from industrial wastewater using renewable energy.However,achieving selective and active NO_(3)^(-)to NH_(3)conversion at low potentials remains challenging due to complex multi-electron transfer processes and competing reactions.Herein,we tackle this challenge by developing a cascade catalysis approach using synergistic active sites at Cu-Fe_(2)O_(3)interfaces,significantly reducing the NO_(3)^(-)to NH_(3)at a low onset potential to about+0.4 V_(RHE).Specifically,Cu optimizes^(*)NO_(3)adsorption,facilitating NO_(3)^(-)to nitrite(NO_(2)-)conversion,while adjacent Fe species in Fe_(2)O_(3)promote the subsequent NO_(2)-reduction to NH_(3)with favorable^(*)NO_(2)adsorption.Electrochemical operating experiments,in situ Raman spectroscopy,and in situ infrared spectroscopy consolidate this improved onset potential and reduction kinetics via cascade catalysis.An NH_(3)partial current density of~423 mA cm^(-2)and an NH_(3)Faradaic efficiency(FENH_(3))of 99.4%were achieved at-0.6 V_(RHE),with a maximum NH_(3)production rate of 2.71 mmol h^(-1)cm^(-2)at-0.8 V_(RHE).Remarkably,the half-cell energy efficiency exceeded 35%at-0.27 V_(RHE)(80%iR corrected),maintaining an FENH_(3)above 90%across a wide range of NO_(3)^(-)concentrations(0.05^(-1)mol L^(-1)).Using 15N isotopic tracing,we confirmed NO_(3)^(-)as the sole nitrogen source and attained a 98%NO_(3)^(-)removal efficiency.The catalyst exhibit stability over 106-h of continuous operation without noticeable degradation.This work highlights distinctive active sites in Cu-Fe_(2)O_(3)for promoting the cascade NO_(3)^(-)to NO_(2)^(-)and NO_(2)^(-)to NH_(3)electrolysis at industrial relevant current densities.
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National Natural Science Foundation of China (Nos. 22371244 and 21573192)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_3463)。
文摘Transition metal-carbonate interfaces often act as active sites in heterogeneous catalytic reactions.The interface between transition metal and metal carbonate exhibits a dynamic equilibrium during the CO_(2)hydrogenation reaction,involving surface carbonate hydrogenation and CO_(2)chemisorption.Nonetheless,there have been few reports on engineering the activity of the interface between transition metal and alkaline earth metal carbonate for catalytic CO_(2)conversion.This work demonstrated that the incorporation of CaH_(2)in Ni/CaCO_(3)enhances the CO_(2)methanation activity of the catalysts.The CO_(2)conversion for Ni/CaH_(2)-CaCO_(3)reached 68.5%at 400°C,which was much higher than that of the Ni/CaCO_(3)(31.6%) and Ni/CaH_(2)-CaO (42.4%) catalysts.Furthermore,the Ni/CaH_(2)-CaCO_(3)catalysts remained stable during the stability test for 24 h at 400°C and 8 bar.Our research revealed that CaH_(2)played a crucial role in promoting the activity of the Ni-carbonate interface for CO_(2)methanation.CaH_(2)could modify the electronic structure of Ni and tune the structural properties of CaCO_(3)to generate medium basic sites (OH groups),which are favorable for the activation of H2and CO_(2).In-situ Fourier transform infrared spectroscopy (FTIR) analysis combined with density functional theory calculations demonstrated that CO_(2)activation occurs at the hydroxyl group (OH) on the CaH_(2)-modified Ni-carbonate surface,leading to the formation of CO_(3)H*species.Furthermore,our study has confirmed that CO_(2)methanation over the Ni/CaH_(2)-CaCO_(3)catalysts proceeds via the formate pathway.
基金financially supported by Jilin Provincial Natural Science Foundation (No.20220101164JC)。
文摘Understanding the factors triggering slope failure is essential to ensure the safety of buildings and transportation infrastructure on slopes. Specifically,the failure of stabilizing piles due to groundwater migration and freeze–thaw(FT) cycles is a significant factor causing slope failure. This study aims to investigate the transmedia seepage characteristics at slope–concrete stabilizing pile interface systems by using silty clay and concrete with varying microstructure characteristics under FT cycles. To this end, a self-developed indoor test device for transmedia water migration, combined with a macro-meso-micro multiscale testing approach, was used to analyze the laws and mechanisms of transmedia seepage at the interface systems. The effect of the medium's microstructure characteristics on the transmedia seepage behavior at the interface systems under FT cycles was also assessed. Results indicated that the transmedia water migration exhibited particularity due to the migration of soil particles and the low permeability characteristics of concrete. The water content in the media increased significantly within the range of 1/3–2/3 of the height from the interface for soil and within 5 mm from the interface for concrete.FT cycles promoted the increase and penetration of cracks within the medium, enhancing the permeability of the slope-concrete stabilizing pile interface systems.With the increase in FT cycles, the porosity inside the medium first decreased and then increased, and the porosity reached the minimum after 25 FT cycles and the maximum after 75 FT cycles, and the water content of the medium after water migration was positively correlated with the porosity. FT cycles also significantly influenced the temporal variation characteristics of soil moisture and the migration path of water in concrete. The study results could serve as a reference for related research on slope stability assessment.
文摘The growth of dendrites and the side reactions occurring at the Zn anode pose significant challenges to the commercialization of aqueous Zn-ion batteries(AZIBs). These challenges arise from the inherent conflict between mass transfer and electrochemical kinetics. In this study, we propose the use of a multifunctional electrolyte additive based on the xylose(Xylo) molecule to address these issues by modulating the solvation structure and electrode/electrolyte interface, thereby stabilizing the Zn anode. The introduction of the additive alters the solvation structure, creating steric hindrance that impedes charge transfer and then reduces electrochemical kinetics. Furthermore, in-situ analyses demonstrate that the reconstructed electrode/electrolyte interface facilitates stable and rapid Zn^(2+)ion migration and suppresses corrosion and hydrogen evolution reactions. As a result, symmetric cells incorporating the Xylo additive exhibit significantly enhanced reversibility during the Zn plating/stripping process, with an impressively long lifespan of up to 1986 h, compared to cells using pure ZnSO4electrolyte. When combined with a polyaniline cathode, the full cells demonstrate improved capacity and long-term cyclic stability. This work offers an effective direction for improving the stability of Zn anode via electrolyte design, as well as highperformance AZIBs.
基金National Key R&D Program of China(2022YFE0105900)National Natural Science Foundation of China(52306179)+1 种基金Science and Technology Innovation Program of Hunan Province(2021RC4006)High Performance Computing Center of Central South University。
文摘The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of adsorbent and catalyst.Herein,we engineered a series of RuNa/γ-Al_(2)O_(3)materials,varying the size of ruthenium from single atoms to clusters/nanoparticles.The coordination environment and structure sensitivity of ruthenium were quantitatively investigated at atomic scale.Our findings reveal that the reduced Ru nanoparticles,approximately 7.1 nm in diameter with a Ru-Ru coordination number of 5.9,exhibit high methane formation activity and selectivity at 340°C.The Ru-Na interfacial sites facilitate CO_(2)migration through a deoxygenation pathway,involving carbonate dissociation,carbonyl formation,and hydrogenation.In-situ experiments and theoretical calculations show that stable carbonyl intermediates on metallic Ru nanoparticles facilitate heterolytic C–O scission and C–H bonding,significantly lowering the energy barrier for activating stored CO_(2).
基金German research Foundation(DFG,grant numbers:CH2321/1–1 and SCHO1231/7–1)JH has received a scholarship from the Chinese Scholarship Council(CSC No.:201908350115).
文摘The oviduct epithelium is the initial maternal contact site for embryos after fertilization,offering the microenviron-ment before implantation.This early gestation period is particularly sensitive to stress,which can cause reduced fertil-ity and reproductive disorders in mammals.Nevertheless,the local impact of elevated stress hormones on the ovi-duct epithelium has received limited attention to date,except for a few reports on polyovulatory species like mice and pigs.In this study,we focused on the effects of chronic maternal stress on cattle,given its association with infertil-ity issues in this monoovulatory species.Bovine oviduct epithelial cells(BOEC)differentiated at the air–liquid interface(ALI)were stimulated with 250 nmol/L cortisol for 1 or 3 weeks.Subsequently,they were assessed for morphology,bioelectrical properties,and gene expression related to oviduct function,glucocorticoid pathway,cortisol metabo-lism,inflammation,and apoptosis.Results revealed adverse effects of cortisol on epithelium structure,featured by deciliation,vacuole formation,and multilayering.Additionally,cortisol exposure led to an increase in transepithelial potential difference,downregulated mRNA expression of the major glucocorticoid receptor(NR3C1),upregulated the expression of cortisol-responsive genes(FKBP5,TSC22D3),and significant downregulation of oviductal glycopro-tein 1(OVGP1)and steroid receptors PGR and ESR1.The systematic comparison to a similar experiment previously performed by us in porcine oviduct epithelial cells,indicated that bovine cultures were more susceptible to elevated cortisol levels than porcine.The distinct responses between both species are likely linked to their divergence in the cortisol-induced expression changes of HSD11B2,an enzyme controlling the cellular capacity to metabolise cortisol.These findings provide insights into the species-specific reactions and reproductive consequences triggered by maternal stress.
文摘In an aging society,the interface design of smart home products is crucial to the quality of life of the elderly.This paper combines Quality Function Deployment(QFD)and Human-Computer Interaction(HCI)theories,taking smart washing machines as an example,to explore new paths for the interface design of smart home products for the elderly.An interdisciplinary approach is adopted to construct a design process centered on elderly users,introduce the Kano model to classify requirements,realize the mapping and sorting of requirements to design parameters,and adopt the PUGH model for comprehensive evaluation.This study provides practical and theoretical support for the interface design of smart home products for the elderly.
基金supported by the National Natural Science Foundation of China(Grant No.52102445)。
文摘As an important and effective indicator of contact heat transfer,thermal contact resistance is a widespread phenomenon in engineering.It can directly affect product reliability,full-load performance,power consumption and even life cycle in energy,aerospace,electronic packaging,cryogenic refrigeration,etc.Therefore,enhancing the interface heat transfer and suppressing thermal contact resistance have become increasingly important.Against this background,this paper seeks to elaborate on conceptions of thermal contact resistance and the ways to reduce it.After reviewing the existing methods of measuring thermal contact resistance and characterizing the interface morphology,we highlight the theoretical underpinnings of thermal contact resistance,including the two-dimensional mathematic characteristics of the contact interface and the theoretical and empirical models for quantifying it.Three categories of influencing factors,i.e.,thermal,geometrical and mechanical states,are then presented.Based on the macroscopic formation mechanism,the paper summarizes the existing methods for suppressing thermal contact resistance,with close attention paid to polymer composite thermal interfacial materials and metal interfacial materials filled with high thermal conductivity filler.In light of the findings,this review provides five promising directions for future research on thermal contact resistance.It suggests that the failure modes and service life of interface materials are essential to apply such technologies to suppress thermal contact resistance in practice.This review will be a guide for future research in thermal contact resistance and for the widespread use of composite interface materials.
基金the National Nature Science Foundation of China(No.22305066).
文摘Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top priority.Herein,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening process.Benefiting from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated temperature.Therefore,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 K.This study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.
基金the National Natural Science Foundation(No.52073187)NSAF Foundation(No.U2230202)for their financial support of this project+3 种基金National Natural Science Foundation(No.51721091)Programme of Introducing Talents of Discipline to Universities(No.B13040)State Key Laboratory of Polymer Materials Engineering(No.sklpme2022-2-03)support of China Scholarship Council
文摘Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.
基金supported by the NSFC(11931013)the GXNSF(2022GXNSFDA035078)。
文摘In this paper,we study the one-dimensional motion of viscous gas near a vacuum,with the gas connecting to a vacuum state with a jump in density.The interface behavior,the pointwise decay rates of the density function and the expanding rates of the interface are obtained with the viscosity coefficientμ(ρ)=ρ^(α)for any 0<α<1;this includes the timeweighted boundedness from below and above.The smoothness of the solution is discussed.Moreover,we construct a class of self-similar classical solutions which exhibit some interesting properties,such as optimal estimates.The present paper extends the results in[Luo T,Xin Z P,Yang T.SIAM J Math Anal,2000,31(6):1175-1191]to the jump boundary conditions case with density-dependent viscosity.
