The microstructure,micro-hardness,and tensile properties of interface between hot isostatic pressing densified low alloy steel and Inconel 690 cladding were investigated during the aging process at 600℃.The results s...The microstructure,micro-hardness,and tensile properties of interface between hot isostatic pressing densified low alloy steel and Inconel 690 cladding were investigated during the aging process at 600℃.The results show that the interface region can be divided into four zones from base metal to deposited metal:carbon-depleted zone(CDZ),partial melting zone(PMZ),planar growth zone(PGZ),and brownish feature zone(BFZ).Dimensions of these zones do not significantly change during aging.However,type I carbides noticeably increase in size in the PMZ,and precipitates clearly occur in the PGZ.The main reason for their growth and occurrence is continuous carbon migration.The highest micro-hardness appears in the PGZ and BFZ regions,which is related to carbon accumulation and precipitates in these regions.Tensile failure occurs on the base metal side due to the high strength mismatch between these two materials.The CDZ,composed of only ferrite,has lower strength and fractures at the boundary between CDZ and base metal.The ultimate tensile strength decreases by only 50 MPa after aging for 1500 h,and the interface region maintains high strength without significant deformation.展开更多
The unclear interfacial characteristics of Ag/Cu interface during diffusion welding limit the improvement of mechanical properties of Ag/Cu bimetallic strips.The growth orientation and evolution of Ag and Cu crystals ...The unclear interfacial characteristics of Ag/Cu interface during diffusion welding limit the improvement of mechanical properties of Ag/Cu bimetallic strips.The growth orientation and evolution of Ag and Cu crystals between Ag and Cu strips were investigated by electron backscatter diffraction(EBSD)analysis,and the interfacial properties of various Ag/Cu interfacial configurations were calculated using first-principles calculations to elucidate the diversified interfacial characteristics.Three interface bonding states,including Ag(100)/Cu(100),Ag(110)/Cu(110)and Ag(111)/Cu(111),were preferentially formed in Ag/Cu bimetallic strips during roll bonding.The intensity of Ag(100)/Cu(100)interface increases with the increasing deformation amounts during cold rolling,accompanied by the decreased intensity of Ag(110)/Cu(110)and Ag(111)/Cu(111)interfaces.The largest adsorption work and lowest interface energy of Ag(100)/Cu(100)interface at the“center”position reveal the transition from Ag(110)/Cu(110)and Ag(111)/Cu(111)interfaces to Ag(100)/Cu(100)interface.展开更多
Micron-sized silicon anodes offer significant industrial advantages over nanoscale counterparts due to their cost-effectiveness and scalability.However,their practical applications are significantly hindered by severe...Micron-sized silicon anodes offer significant industrial advantages over nanoscale counterparts due to their cost-effectiveness and scalability.However,their practical applications are significantly hindered by severe stress-induced fragmentation,leading to rapid capacity decay.Addressing this challenge,we introduce a novel dual-conformal encapsulated micron-sized porous Si(μm-pSi)anode by utilizingμm-Si recycled from the photovoltaic industry as the Si precursor.This encapsulation design of the internal conformal SiO_(x)/C layer and external Ti_(3)C_(2)Tx MXene layer forms intergranular and intragranular protective skins onμm-pSi,ensuring simultaneous mechanical and electrochemical stability for efficient Li+storage.As a result,the fabricated WpSi@SiO_(x)/C@MXene anode demonstrates an exceptional cycling performance,delivering 535.1 mA h g^(−1)after 1500 cycles at 5 A g^(−1)with a minimal capacity decay of 0.003%per cycle.Chemo-mechanical modeling and SEI analysis reveal that the dual-conformal coating achieves exceptional mechanical and electrochemical stability through robust mechanical confinement and ultra-fast Li+diffusion kinetics during lithiation,coupled with a Li_(2)CO_(3)/LiF-rich hybrid SEI that facilitates Li+transport,collectively enabling rate-insensitive stress evolution,long-term structural durability,and stable cycling under high-rate conditions.This work provides a compelling design strategy for leveraging sustainableμm-Si to achieve high-rate and long-life lithium-ion batteries.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
The heterogeneous multilayer interface of VN/Ag coatings and transition multilayer interface of VN/Ag coatings were prepared on Inconel 781 and Si(100),and the microstructures,mechanical and tribological properties we...The heterogeneous multilayer interface of VN/Ag coatings and transition multilayer interface of VN/Ag coatings were prepared on Inconel 781 and Si(100),and the microstructures,mechanical and tribological properties were investigated from 25 to 700℃.The results showed that the surface roughness and average grain size of VN/Ag coatings with transition multilayer interface are obviously larger than those of VN/Ag coatings with heterogeneous multilayer interface.The coatings with transition multilayer interface have higher adhesion force and hardness than the coatings with heterogeneous multilayer interface,and both coatings can effectively restrict the initiation and propagation of microcracks.Both coatings have excellent self-adaptive lubricating properties with a decrease of friction coefficient as the temperature increases,but their wear rates reveal a drastic increase.The phase composition of the worn area of both coatings was investigated,which indicates that a smooth Ag,Magnéli phase(V2O5)and bimetallic oxides(Ag3VO4 and AgVO3)can be responsible to the excellent lubricity of both coatings.To sum up,the coatings with transition multilayer interface have excellent adaptive lubricating properties and can properly control the diffusion rate and release rate of the lubricating phase,indicating that they have great potential in solving the problem of friction and wear of mechanical parts.展开更多
The atom (Ag,Cu) diffusion behavior and the effect of technology on the interface of rolled Ag/Cu composite contact were investigated. The concentration of Ag and Cu atoms near the interface was determined with electr...The atom (Ag,Cu) diffusion behavior and the effect of technology on the interface of rolled Ag/Cu composite contact were investigated. The concentration of Ag and Cu atoms near the interface was determined with electron probe. The bonding strength of composite interface was tested and the fracture in tensile sample was observed by SEM. The results show that there was inter diffusion of Ag and Cu atoms on the interface, which formed compact layer with high bonding strength of 98 MPa. The practical application proved that the Ag/Cu composite interface is reliable.展开更多
The electroplated(111)-oriented nanotwinned-Cu(nt-Cu) film was utilized as substrate for Ag and Cu sinter joining to improve the weak interface connection between the metal paste and the substrate.It was found that bo...The electroplated(111)-oriented nanotwinned-Cu(nt-Cu) film was utilized as substrate for Ag and Cu sinter joining to improve the weak interface connection between the metal paste and the substrate.It was found that both Cu and Ag sinter joints using(111)-oriented nt-Cu film exhibited a higher bonding strength than that using traditional random-oriented Cu film.Especially,the joints sintered with Cu paste on(111)-oriented nt-Cu film possessed a higher bonding strength of 53.7 MPa at the sintering condition of 300 °C,0.4 MPa in N2 atmosphere,compared to that on random-oriented Cu film with a value of 31.3 MPa.The results show that as metal substrate layer,the(111)-oriented nt-Cu film can improve the connection performance of Ag and Cu sinter joints,which could further promote their application in dieattachment technology for the next-generation power semiconductors.展开更多
Evolution of precipitate and precipitate/matrix interface in artificially aged Al-Zn-Mg-Cu(-Ag)alloys has been systematically studied.In the early stage of ageing,Ag,as a fast diffuser,can promote the formation of sol...Evolution of precipitate and precipitate/matrix interface in artificially aged Al-Zn-Mg-Cu(-Ag)alloys has been systematically studied.In the early stage of ageing,Ag,as a fast diffuser,can promote the formation of solute pairs and small clusters.Solute clusters are further demonstrated to be able to act as precursors forη’precipitates by in-situ STEM heating.With prolonged ageing time,the precipitate/matrix interface evolves from the Zn-dominated interface between early-stageη’and Al matrix to the Zn and Mg co-segregatedη’/Al andη_(2)/Al interfaces.Theη’/Al interfacial layers are shown to precede the formation ofη’,while theη_(2)/Al interfaces are found to be closely related to the thickening process ofη_(2)and the involved particular atomic movements are specified.Experimental observations and DFT calculations re-veal that forη’andη_(2),Ag can dissolve into the precipitate as well as locate at the precipitate/matrix interface without showing preference.For Cu,its dissolution in the precipitate and segregation on the interface mainly occur forη_(2)rather thanη’.The incorporation of Ag and Cu does not change the defined precipitate structure.展开更多
Novel models （2× 1） of Si（001）-SiO2 interface structure have been established. The method of the first-principle General Gradient Approximation （GGA） is employed to structurally optimize the established the...Novel models （2× 1） of Si（001）-SiO2 interface structure have been established. The method of the first-principle General Gradient Approximation （GGA） is employed to structurally optimize the established theoretical models under the K-point space of periodic boundary condition. The structures after optimization have been analyzed, and the results show that the interfaces present in disordered state and both Si-O-Si and Si=O structures exist. Meanwhile, the bonding of surface structure is analyzed via the graphics of electron localization function（ELF）.展开更多
In this work,the sandwich joints were joined by low temperature pressureless sintering Ag paste.The morphology and thermal behavior of Ag nanoparticle paste was characterized and analyzed.The sintered Ag joints with d...In this work,the sandwich joints were joined by low temperature pressureless sintering Ag paste.The morphology and thermal behavior of Ag nanoparticle paste was characterized and analyzed.The sintered Ag joints with different metallization were prepared and tested.The joints with Ag metallization exhibited superior shear strength and interface bonding ratio.However,the joints with Cu metallization showed lowest shear strength and interface delamination.The interfacial microstructures were observed and the diffusion kinetics between Ag and Au atoms were both calculated.The excessive diffusion of Ag atoms towards the Au layer deteriorated the interface bonding ratio and shear strength.This work will help understand the bonding mechanism between sintered Ag and other metallization.展开更多
In order to modify the interface, Si ON coating was introduced on the surface of silicon nitride fiber by perhydropolysilazane conversion method. Si-3N4f/SiO2 and Si-3N4f/Si ONc/SiO2 composites were prepared by sol-ge...In order to modify the interface, Si ON coating was introduced on the surface of silicon nitride fiber by perhydropolysilazane conversion method. Si-3N4f/SiO2 and Si-3N4f/Si ONc/SiO2 composites were prepared by sol-gel method to explore the influence of Si ON coating on the mechanical properties of composites.The results show that with the protection of Si ON coating, Si-3N4fiber enjoys a strength increase of up to 24.1% and Si-3N4f/Si ONc/SiO2 composites have a tensile strength of 170.5 MPa and a modulus of26.9 GPa, respectively. After 1000℃ annealing in air for 1 h, Si-3N4f/Si ONc/SiO2 composites retain 65.0%of their original strength and show a better toughness than Si-3N4f/SiO2 composites. The improvement of mechanical properties is attributing to the healing effect of Si ON coating as well as its intermediate coefficient of thermal expansion between Si-3N4fiber and SiO2 matrix.展开更多
The microstructure of primary Mg_(2)Si and the interface of Mg_(2)Si/α-Mg modified by Sn and Sb elements in an as-cast Mg-5Sn-2Si-1.5Al-1Zn-0.8Sb(wt.%) alloy were investigated.In the primary Mg_(2)Si phase not only t...The microstructure of primary Mg_(2)Si and the interface of Mg_(2)Si/α-Mg modified by Sn and Sb elements in an as-cast Mg-5Sn-2Si-1.5Al-1Zn-0.8Sb(wt.%) alloy were investigated.In the primary Mg_(2)Si phase not only the Si atoms but also the Mg atoms could be substituted by Sn and Sb atoms,resulting in the slightly reduced lattice constant a of 0.627 nm.An OR of Mg_(2)Si phase and α-Mg in the form of[001]Mg_(2)Si‖[01■1]α,(220)Mg_(2)Si‖(0■12)αwas discovered.Between primary Mg_(2)Si phase and α-Mg matrix two transitional nano-particle layers were formed.In the rim region of primary Mg_(2)Si particle,Mg_(2)Sn precipitates sizing from 5 nm to 50 nm were observed.Adjacent to the boundary of primary Mg_(2)Si particle,luxuriant columnar crystals of primary Mg_(2)Sn phase with width of about 25 nm and length of about100 nm were distributed on the α-Mg matrix.The lattice constant of the Mg_(2)Sn precipitate in primary Mg_(2)Si particle was about 0.756 nm.Three ORs between Mg_(2)Sn and Mg_(2)Si were found,in which the Mg_(2)Sn precipitates had strong bonding interfaces with Mg_(2)Si phase.Three new minor ORs between Mg_(2)Sn phase and α-Mg were found.The lattice constant of primary Mg_(2)Sn phase was enlarged to 0.813 nm owing to the solution of Sn and Sb atoms.Primary Mg_(2)Sn had edge-to-edge interfaces with α-Mg.Therefore,the primary Mg_(2)Si particle and α-Mg were united and the interfacial adhesion was improved by the two nano-particles layers of Mg_(2)Sn phase.展开更多
High silicon content Al-Si composites with a composition of Al-40 wt% Si were fabricated via a highenergy ball milling method. The microstructure evolution of Al-40 wt% Si milled powders and sintered composites has be...High silicon content Al-Si composites with a composition of Al-40 wt% Si were fabricated via a highenergy ball milling method. The microstructure evolution of Al-40 wt% Si milled powders and sintered composites has been thoroughly studied by scanning electron microscopy, X-ray diffraction, energydispersive spectrometry and high-resolution transmission electron microscopy. The mechanism of ball milling Al-40 wt% Si powders has been disclosed in detail: fracture mechanism dominating in the early stages, followed by the agglomeration mechanism, finally reaching the balance between the fragments and the agglomerates. It has been found that the average particle sizes of mixed Al-Si powders can be refined to the nanoscale, and the crystallite sizes of Al and Si have been reduced to 10nm and 62nm upon milling for 2h–50h, respectively. The finally formed Al-Si interfaces after ball milling for 50h are wellcohesive. A dense and homogenous Al-40 wt% Si composite have been achieved by solid-state sintering at550?C. The results thus provide an effective support for producing bulk nanostructured Al-Si composites.展开更多
The electron transport behavior across the interface plays an important role in determining the performance of op- toelectronic devices based on heterojunctions. Here through growing CdS thin film on silicon nanoporou...The electron transport behavior across the interface plays an important role in determining the performance of op- toelectronic devices based on heterojunctions. Here through growing CdS thin film on silicon nanoporous pillar array, an untraditional, nonplanar, and multi-interface CdS/Si nanoheterojunction is prepared. The current density versus voltage curve is measured and an obvious rectification effect is observed. Based on the fitting results and model analyses on the forward and reverse conduction characteristics, the electron transport mechanism under low forward bias, high forward bias, and reverse bias are attributed to the Ohmic regime, space-charge-limited current regime, and modified Poole-Frenkel regime respectively. The forward and reverse electrical behaviors are found to be highly related to the distribution of inter- facial trap states and the existence of localized electric field respectively. These results might be helpful for optimizing the preparing procedures to realize high-performance silicon-based CdS optoelectronic devices.展开更多
Self-designed Al8Si0.4Mg0.4Fe aluminium alloy was modified with Sr,followed by solid solution and aging treatments to regulate its microstructure and mechanical/electrical properties.The results show that after the mo...Self-designed Al8Si0.4Mg0.4Fe aluminium alloy was modified with Sr,followed by solid solution and aging treatments to regulate its microstructure and mechanical/electrical properties.The results show that after the modification treatment,the room-temperature tensile strength of the alloy remains nearly unchanged,the elongation at break slightly increases from 1.82%to 3.34%,and the electrical conductivity significantly increases from 40.1%international annealed copper standard(IACS)to 42.0%IACS.After the modification,the alloy was subjected to solid solution treatment at 515℃for 8 h,followed by aging treatment at 180,200,220 and 240℃for 6 h.With increasing aging temperature,the electrical conductivity increases monotonously from 41.4%IACS to 45.5%IACS,while the room-temperature tensile strength initially increases and then decreases.At 200℃,the alloy achieves an optimal balance between electrical conductivity and room-temperature tensile strength:the electrical conductivity is 42.5%IACS,and the room-temperature tensile strength is 282.9 MPa.When the aging temperature continues to rise,the alloy undergoes overaging.Although the conductivity continues to increase,the room-temperature tensile strength drops sharply,and it is only 177.1 MPa at 240℃.展开更多
With an increased utilization of carbon fiber reinforced polymers(CFRPs)in high temperature environments,investigating their effects on materials becomes exceedingly important.This study presents a comparative investi...With an increased utilization of carbon fiber reinforced polymers(CFRPs)in high temperature environments,investigating their effects on materials becomes exceedingly important.This study presents a comparative investigation of thermo-oxidative aging effects on the flexural performance of two carbon fiber reinforced composite laminates(CFRCLs):a quasi-isotropic plain-woven CFRCL and a quasi-isotropic unidirectional layup CFRCL(designated as PW-CFRCL and UD-CFRCL,respectively).The CFRCLs were subjected to thermo-oxidative aging for specific durations,and their flexural strength was evaluated through three-point bending tests.The flexural strength of the laminates decreased with the prolonged aging duration.Despite having lower fiber content,PW-CFRCLs showed higher flexural strength than UD-CFRCLs.After eight days of aging,the flexural strength of PW-CFRCLs decreased by merely 4%-5%,while that of UD-CFRCLs decreased by 11%-14%.After 32 days of aging,the thinner PW-CFRCL with the lowest fiber content exhibited the highest flexural strength(595.52 MPa),followed by the thinner UD-CFRCL(549.83 MPa),then the thicker PW-CFRCL(445.29 MPa)and finally,the thicker UD-CFRCL(393.90 MPa).The decline in flexural properties of the laminates was primarily attributed to matrix cracking and interface debonding resulting from matrix oxidation.To validate the universality of this result,the finite element method was employed,showing a good correlation with the experimental findings.展开更多
Efficient thermal management is critical to the reliability and performance of nanoscale electronic and photonic devices,particularly those incorporating multilayer structures.In this study,non-equilibrium molecular d...Efficient thermal management is critical to the reliability and performance of nanoscale electronic and photonic devices,particularly those incorporating multilayer structures.In this study,non-equilibrium molecular dynamics simulations were conducted to systematically investigate the effects of temperature,penetration depth,and Si layer thickness on the interfacial thermal resistance(ITR)in nanometer-scale Mo/Si multilayers,widely employed in extreme ultraviolet lithography.The results indicate that:(i)temperature variations exert a negligible influence on the ITR of amorphous Mo/Si interfaces,which remains stable across the range of 200-900 K;(ii)increasing penetration depth enhances the overlap of phonon density of states,thereby significantly reducing ITR;(iii)the ITR decreases with increasing Si thickness up to4.2 nm due to quasi-ballistic phonon transport,but rises again as phonon scattering becomes more pronounced at larger thicknesses.This study provides quantitative insights into heat transfer mechanisms at amorphous interfaces and also offers a feasible strategy for tailoring interfacial thermal transport through structural design.展开更多
Interfaces and surfaces of YBa_2Cu_3O_(7-x)(YBCO)-Ag have been studied by SEM-EDX and AES.No effect of Ag on 123 structure in X-ray diffraction pattern was observed for 0.4 mol Ag doped YBCO.AES analysis indicated tha...Interfaces and surfaces of YBa_2Cu_3O_(7-x)(YBCO)-Ag have been studied by SEM-EDX and AES.No effect of Ag on 123 structure in X-ray diffraction pattern was observed for 0.4 mol Ag doped YBCO.AES analysis indicated that Ag segregated on surface of YBCO and resulted in decrease of YBCO-metal lead resistance.In addition,solution and segregation of Ag as elemental state were often appeared on interfaces and surfaces of high temperature annealed YBCO,whether elemental Ag or compound Ag_2O and AgNO_3 adopted as doping material.展开更多
AIM： To evaluate the vitreomacular interface in cases with wet age-related macular degeneration（AMD） and to compare them to eyes with dry AMD and normal eyes.METHODS： This was a cross-sectional comparative study t...AIM： To evaluate the vitreomacular interface in cases with wet age-related macular degeneration（AMD） and to compare them to eyes with dry AMD and normal eyes.METHODS： This was a cross-sectional comparative study that included 87 eyes with wet AMD,42 eyes with dry AMD and 40 eyes without AMD as a control group.Optical coherence tomography（OCT） examination was performed for all patients to assess the vitreomacular interface.RESULTS： In the wet AMD group,34.5% of cases had vitreomacular adhesion（VMA）.Only 14.3% of dry AMD cases and 10% of control cases had VMA.There was a significant difference between the control group and the wet AMD group（P=0.004） as well as the dry and wet AMD group（P=0.017）.There was also a significant difference between the incidence of VMA in patients with subretinal choroidal neovascularization（CNV,type 1） and intraretinal CNV（type 2 or type 3）（P=0.020）.CONCLUSION： There is an association between posterior vitreous attachment and AMD.There is also an increased incidence of VMA with intra-retinal CNV.展开更多
The holes induced by ionizing radiation or carrier injection can depassivate saturated interface defects.The depassivation of these defects suggests that the deep levels associated with the defects are reactivated,aff...The holes induced by ionizing radiation or carrier injection can depassivate saturated interface defects.The depassivation of these defects suggests that the deep levels associated with the defects are reactivated,affecting the performance of devices.This work simulates the depassivation reactions between holes and passivated amorphous-SiO_(2)/Si interface defects(HP_(b)+h→P_(b)+H^(+)).The climbing image nudged elastic band method is used to calculate the reaction curves and the barriers.In addition,the atomic charges of the initial and final structures are analyzed by the Bader charge method.It is shown that more than one hole is trapped by the defects,which is implied by the reduction in the total number of valence electrons on the active atoms.The results indicate that the depassivation of the defects by the holes actually occurs in three steps.In the first step,a hole is captured by the passivated defect,resulting in the stretching of the Si-H bond.In the second step,the defect captures one more hole,which may contribute to the breaking of the Si-H bond.The H atom is released as a proton and the Si atom is three-coordinated and positively charged.In the third step,an electron is captured by the Si atom,and the Si atom becomes neutral.In this step,a Pb-type defect is reactivated.展开更多
基金Major Scientific and Technological Project of Gansu(22ZD6GA008)Excellent Doctorate Project of Gansu(23JRRA806)National Natural Science Foundation of China(52175325,51961024,52071170)。
文摘The microstructure,micro-hardness,and tensile properties of interface between hot isostatic pressing densified low alloy steel and Inconel 690 cladding were investigated during the aging process at 600℃.The results show that the interface region can be divided into four zones from base metal to deposited metal:carbon-depleted zone(CDZ),partial melting zone(PMZ),planar growth zone(PGZ),and brownish feature zone(BFZ).Dimensions of these zones do not significantly change during aging.However,type I carbides noticeably increase in size in the PMZ,and precipitates clearly occur in the PGZ.The main reason for their growth and occurrence is continuous carbon migration.The highest micro-hardness appears in the PGZ and BFZ regions,which is related to carbon accumulation and precipitates in these regions.Tensile failure occurs on the base metal side due to the high strength mismatch between these two materials.The CDZ,composed of only ferrite,has lower strength and fractures at the boundary between CDZ and base metal.The ultimate tensile strength decreases by only 50 MPa after aging for 1500 h,and the interface region maintains high strength without significant deformation.
基金supported by the National Natural Science Foundation of China(No.52474401)the Project funded by the China Postdoctoral Science Foundation(No.2022M712919)+1 种基金Open Project of State Key Laboratory of Advanced Brazing Filler Metals and Technology(SKLABFMT-2021-03)Guangdong Basic and Applied Basic Research Foundation(2023A1515140124).
文摘The unclear interfacial characteristics of Ag/Cu interface during diffusion welding limit the improvement of mechanical properties of Ag/Cu bimetallic strips.The growth orientation and evolution of Ag and Cu crystals between Ag and Cu strips were investigated by electron backscatter diffraction(EBSD)analysis,and the interfacial properties of various Ag/Cu interfacial configurations were calculated using first-principles calculations to elucidate the diversified interfacial characteristics.Three interface bonding states,including Ag(100)/Cu(100),Ag(110)/Cu(110)and Ag(111)/Cu(111),were preferentially formed in Ag/Cu bimetallic strips during roll bonding.The intensity of Ag(100)/Cu(100)interface increases with the increasing deformation amounts during cold rolling,accompanied by the decreased intensity of Ag(110)/Cu(110)and Ag(111)/Cu(111)interfaces.The largest adsorption work and lowest interface energy of Ag(100)/Cu(100)interface at the“center”position reveal the transition from Ag(110)/Cu(110)and Ag(111)/Cu(111)interfaces to Ag(100)/Cu(100)interface.
基金the financial support from the Natural Science Foundation of Shanghai(23ZR1423800)Open Research Fund of Shanghai Key Laboratory of Green Chemistry and Chemical Processes(East China Normal University,202503)+1 种基金State Key Laboratory of Advanced Fiber Materials(Donghua University,KF2406)Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Nankai University。
文摘Micron-sized silicon anodes offer significant industrial advantages over nanoscale counterparts due to their cost-effectiveness and scalability.However,their practical applications are significantly hindered by severe stress-induced fragmentation,leading to rapid capacity decay.Addressing this challenge,we introduce a novel dual-conformal encapsulated micron-sized porous Si(μm-pSi)anode by utilizingμm-Si recycled from the photovoltaic industry as the Si precursor.This encapsulation design of the internal conformal SiO_(x)/C layer and external Ti_(3)C_(2)Tx MXene layer forms intergranular and intragranular protective skins onμm-pSi,ensuring simultaneous mechanical and electrochemical stability for efficient Li+storage.As a result,the fabricated WpSi@SiO_(x)/C@MXene anode demonstrates an exceptional cycling performance,delivering 535.1 mA h g^(−1)after 1500 cycles at 5 A g^(−1)with a minimal capacity decay of 0.003%per cycle.Chemo-mechanical modeling and SEI analysis reveal that the dual-conformal coating achieves exceptional mechanical and electrochemical stability through robust mechanical confinement and ultra-fast Li+diffusion kinetics during lithiation,coupled with a Li_(2)CO_(3)/LiF-rich hybrid SEI that facilitates Li+transport,collectively enabling rate-insensitive stress evolution,long-term structural durability,and stable cycling under high-rate conditions.This work provides a compelling design strategy for leveraging sustainableμm-Si to achieve high-rate and long-life lithium-ion batteries.
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Project(51505100)supported by the National Natural Science Foundation of China
文摘The heterogeneous multilayer interface of VN/Ag coatings and transition multilayer interface of VN/Ag coatings were prepared on Inconel 781 and Si(100),and the microstructures,mechanical and tribological properties were investigated from 25 to 700℃.The results showed that the surface roughness and average grain size of VN/Ag coatings with transition multilayer interface are obviously larger than those of VN/Ag coatings with heterogeneous multilayer interface.The coatings with transition multilayer interface have higher adhesion force and hardness than the coatings with heterogeneous multilayer interface,and both coatings can effectively restrict the initiation and propagation of microcracks.Both coatings have excellent self-adaptive lubricating properties with a decrease of friction coefficient as the temperature increases,but their wear rates reveal a drastic increase.The phase composition of the worn area of both coatings was investigated,which indicates that a smooth Ag,Magnéli phase(V2O5)and bimetallic oxides(Ag3VO4 and AgVO3)can be responsible to the excellent lubricity of both coatings.To sum up,the coatings with transition multilayer interface have excellent adaptive lubricating properties and can properly control the diffusion rate and release rate of the lubricating phase,indicating that they have great potential in solving the problem of friction and wear of mechanical parts.
文摘The atom (Ag,Cu) diffusion behavior and the effect of technology on the interface of rolled Ag/Cu composite contact were investigated. The concentration of Ag and Cu atoms near the interface was determined with electron probe. The bonding strength of composite interface was tested and the fracture in tensile sample was observed by SEM. The results show that there was inter diffusion of Ag and Cu atoms on the interface, which formed compact layer with high bonding strength of 98 MPa. The practical application proved that the Ag/Cu composite interface is reliable.
文摘The electroplated(111)-oriented nanotwinned-Cu(nt-Cu) film was utilized as substrate for Ag and Cu sinter joining to improve the weak interface connection between the metal paste and the substrate.It was found that both Cu and Ag sinter joints using(111)-oriented nt-Cu film exhibited a higher bonding strength than that using traditional random-oriented Cu film.Especially,the joints sintered with Cu paste on(111)-oriented nt-Cu film possessed a higher bonding strength of 53.7 MPa at the sintering condition of 300 °C,0.4 MPa in N2 atmosphere,compared to that on random-oriented Cu film with a value of 31.3 MPa.The results show that as metal substrate layer,the(111)-oriented nt-Cu film can improve the connection performance of Ag and Cu sinter joints,which could further promote their application in dieattachment technology for the next-generation power semiconductors.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.52071284 and 51771172)the Zhejiang Provincial Natural Science Foundation of China(No.LQ22E010003).
文摘Evolution of precipitate and precipitate/matrix interface in artificially aged Al-Zn-Mg-Cu(-Ag)alloys has been systematically studied.In the early stage of ageing,Ag,as a fast diffuser,can promote the formation of solute pairs and small clusters.Solute clusters are further demonstrated to be able to act as precursors forη’precipitates by in-situ STEM heating.With prolonged ageing time,the precipitate/matrix interface evolves from the Zn-dominated interface between early-stageη’and Al matrix to the Zn and Mg co-segregatedη’/Al andη_(2)/Al interfaces.Theη’/Al interfacial layers are shown to precede the formation ofη’,while theη_(2)/Al interfaces are found to be closely related to the thickening process ofη_(2)and the involved particular atomic movements are specified.Experimental observations and DFT calculations re-veal that forη’andη_(2),Ag can dissolve into the precipitate as well as locate at the precipitate/matrix interface without showing preference.For Cu,its dissolution in the precipitate and segregation on the interface mainly occur forη_(2)rather thanη’.The incorporation of Ag and Cu does not change the defined precipitate structure.
基金Supported by the National Grand Fundamental Research 973 Program of China (No. 51310Z07-3) and the Research Program of Application of Sichuan Department of Science and Technology (No. 02GY029-006)
文摘Novel models （2× 1） of Si（001）-SiO2 interface structure have been established. The method of the first-principle General Gradient Approximation （GGA） is employed to structurally optimize the established theoretical models under the K-point space of periodic boundary condition. The structures after optimization have been analyzed, and the results show that the interfaces present in disordered state and both Si-O-Si and Si=O structures exist. Meanwhile, the bonding of surface structure is analyzed via the graphics of electron localization function（ELF）.
基金supported by the Shenzhen Science and Technology innovation committee (Grant No. JCYJ.0180306172006392)。
文摘In this work,the sandwich joints were joined by low temperature pressureless sintering Ag paste.The morphology and thermal behavior of Ag nanoparticle paste was characterized and analyzed.The sintered Ag joints with different metallization were prepared and tested.The joints with Ag metallization exhibited superior shear strength and interface bonding ratio.However,the joints with Cu metallization showed lowest shear strength and interface delamination.The interfacial microstructures were observed and the diffusion kinetics between Ag and Au atoms were both calculated.The excessive diffusion of Ag atoms towards the Au layer deteriorated the interface bonding ratio and shear strength.This work will help understand the bonding mechanism between sintered Ag and other metallization.
基金the financial support from the National Natural Science Foundation of China (Grant No. 51702361)the Natural Science Foundation of Hunan Province (Grant No. 2017JJ3353)
文摘In order to modify the interface, Si ON coating was introduced on the surface of silicon nitride fiber by perhydropolysilazane conversion method. Si-3N4f/SiO2 and Si-3N4f/Si ONc/SiO2 composites were prepared by sol-gel method to explore the influence of Si ON coating on the mechanical properties of composites.The results show that with the protection of Si ON coating, Si-3N4fiber enjoys a strength increase of up to 24.1% and Si-3N4f/Si ONc/SiO2 composites have a tensile strength of 170.5 MPa and a modulus of26.9 GPa, respectively. After 1000℃ annealing in air for 1 h, Si-3N4f/Si ONc/SiO2 composites retain 65.0%of their original strength and show a better toughness than Si-3N4f/SiO2 composites. The improvement of mechanical properties is attributing to the healing effect of Si ON coating as well as its intermediate coefficient of thermal expansion between Si-3N4fiber and SiO2 matrix.
基金supported by the National Natural Science Foundation of China [51571086]Research Fund for Doctoral Program of Henan Polytechnic University [B2015-14]。
文摘The microstructure of primary Mg_(2)Si and the interface of Mg_(2)Si/α-Mg modified by Sn and Sb elements in an as-cast Mg-5Sn-2Si-1.5Al-1Zn-0.8Sb(wt.%) alloy were investigated.In the primary Mg_(2)Si phase not only the Si atoms but also the Mg atoms could be substituted by Sn and Sb atoms,resulting in the slightly reduced lattice constant a of 0.627 nm.An OR of Mg_(2)Si phase and α-Mg in the form of[001]Mg_(2)Si‖[01■1]α,(220)Mg_(2)Si‖(0■12)αwas discovered.Between primary Mg_(2)Si phase and α-Mg matrix two transitional nano-particle layers were formed.In the rim region of primary Mg_(2)Si particle,Mg_(2)Sn precipitates sizing from 5 nm to 50 nm were observed.Adjacent to the boundary of primary Mg_(2)Si particle,luxuriant columnar crystals of primary Mg_(2)Sn phase with width of about 25 nm and length of about100 nm were distributed on the α-Mg matrix.The lattice constant of the Mg_(2)Sn precipitate in primary Mg_(2)Si particle was about 0.756 nm.Three ORs between Mg_(2)Sn and Mg_(2)Si were found,in which the Mg_(2)Sn precipitates had strong bonding interfaces with Mg_(2)Si phase.Three new minor ORs between Mg_(2)Sn phase and α-Mg were found.The lattice constant of primary Mg_(2)Sn phase was enlarged to 0.813 nm owing to the solution of Sn and Sb atoms.Primary Mg_(2)Sn had edge-to-edge interfaces with α-Mg.Therefore,the primary Mg_(2)Si particle and α-Mg were united and the interfacial adhesion was improved by the two nano-particles layers of Mg_(2)Sn phase.
基金financially supported by the National Natural Science Foundation of China (No.51571148)the National Key Research and Development Program of China (No.2017YFE0302600 and No.2017YFB0701801)the Thousand Talents Program for Distinguished Young Scholars of China
文摘High silicon content Al-Si composites with a composition of Al-40 wt% Si were fabricated via a highenergy ball milling method. The microstructure evolution of Al-40 wt% Si milled powders and sintered composites has been thoroughly studied by scanning electron microscopy, X-ray diffraction, energydispersive spectrometry and high-resolution transmission electron microscopy. The mechanism of ball milling Al-40 wt% Si powders has been disclosed in detail: fracture mechanism dominating in the early stages, followed by the agglomeration mechanism, finally reaching the balance between the fragments and the agglomerates. It has been found that the average particle sizes of mixed Al-Si powders can be refined to the nanoscale, and the crystallite sizes of Al and Si have been reduced to 10nm and 62nm upon milling for 2h–50h, respectively. The finally formed Al-Si interfaces after ball milling for 50h are wellcohesive. A dense and homogenous Al-40 wt% Si composite have been achieved by solid-state sintering at550?C. The results thus provide an effective support for producing bulk nanostructured Al-Si composites.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61176044 and 11074224)the Science and Technology Project for Innovative Scientist of Henan Province,China(Grant No.1142002510017)the Science and Technology Project on Key Problems of Henan Province,China(Grant No.082101510007)
文摘The electron transport behavior across the interface plays an important role in determining the performance of op- toelectronic devices based on heterojunctions. Here through growing CdS thin film on silicon nanoporous pillar array, an untraditional, nonplanar, and multi-interface CdS/Si nanoheterojunction is prepared. The current density versus voltage curve is measured and an obvious rectification effect is observed. Based on the fitting results and model analyses on the forward and reverse conduction characteristics, the electron transport mechanism under low forward bias, high forward bias, and reverse bias are attributed to the Ohmic regime, space-charge-limited current regime, and modified Poole-Frenkel regime respectively. The forward and reverse electrical behaviors are found to be highly related to the distribution of inter- facial trap states and the existence of localized electric field respectively. These results might be helpful for optimizing the preparing procedures to realize high-performance silicon-based CdS optoelectronic devices.
基金Applied Basic Research Program of Liaoning Province(CN)(2022JH2/101300078)。
文摘Self-designed Al8Si0.4Mg0.4Fe aluminium alloy was modified with Sr,followed by solid solution and aging treatments to regulate its microstructure and mechanical/electrical properties.The results show that after the modification treatment,the room-temperature tensile strength of the alloy remains nearly unchanged,the elongation at break slightly increases from 1.82%to 3.34%,and the electrical conductivity significantly increases from 40.1%international annealed copper standard(IACS)to 42.0%IACS.After the modification,the alloy was subjected to solid solution treatment at 515℃for 8 h,followed by aging treatment at 180,200,220 and 240℃for 6 h.With increasing aging temperature,the electrical conductivity increases monotonously from 41.4%IACS to 45.5%IACS,while the room-temperature tensile strength initially increases and then decreases.At 200℃,the alloy achieves an optimal balance between electrical conductivity and room-temperature tensile strength:the electrical conductivity is 42.5%IACS,and the room-temperature tensile strength is 282.9 MPa.When the aging temperature continues to rise,the alloy undergoes overaging.Although the conductivity continues to increase,the room-temperature tensile strength drops sharply,and it is only 177.1 MPa at 240℃.
基金National Natural Science Foundation of China(No.12372130)。
文摘With an increased utilization of carbon fiber reinforced polymers(CFRPs)in high temperature environments,investigating their effects on materials becomes exceedingly important.This study presents a comparative investigation of thermo-oxidative aging effects on the flexural performance of two carbon fiber reinforced composite laminates(CFRCLs):a quasi-isotropic plain-woven CFRCL and a quasi-isotropic unidirectional layup CFRCL(designated as PW-CFRCL and UD-CFRCL,respectively).The CFRCLs were subjected to thermo-oxidative aging for specific durations,and their flexural strength was evaluated through three-point bending tests.The flexural strength of the laminates decreased with the prolonged aging duration.Despite having lower fiber content,PW-CFRCLs showed higher flexural strength than UD-CFRCLs.After eight days of aging,the flexural strength of PW-CFRCLs decreased by merely 4%-5%,while that of UD-CFRCLs decreased by 11%-14%.After 32 days of aging,the thinner PW-CFRCL with the lowest fiber content exhibited the highest flexural strength(595.52 MPa),followed by the thinner UD-CFRCL(549.83 MPa),then the thicker PW-CFRCL(445.29 MPa)and finally,the thicker UD-CFRCL(393.90 MPa).The decline in flexural properties of the laminates was primarily attributed to matrix cracking and interface debonding resulting from matrix oxidation.To validate the universality of this result,the finite element method was employed,showing a good correlation with the experimental findings.
基金supported by the National Natural Science Foundation of China(Grant No.52206092)the National Key R&D Program of China(Grant No.2024YFF0508900)+1 种基金the Big Data Computing Center of Southeast Universitythe Center for Fundamental and Interdisciplinary Sciences of Southeast University。
文摘Efficient thermal management is critical to the reliability and performance of nanoscale electronic and photonic devices,particularly those incorporating multilayer structures.In this study,non-equilibrium molecular dynamics simulations were conducted to systematically investigate the effects of temperature,penetration depth,and Si layer thickness on the interfacial thermal resistance(ITR)in nanometer-scale Mo/Si multilayers,widely employed in extreme ultraviolet lithography.The results indicate that:(i)temperature variations exert a negligible influence on the ITR of amorphous Mo/Si interfaces,which remains stable across the range of 200-900 K;(ii)increasing penetration depth enhances the overlap of phonon density of states,thereby significantly reducing ITR;(iii)the ITR decreases with increasing Si thickness up to4.2 nm due to quasi-ballistic phonon transport,but rises again as phonon scattering becomes more pronounced at larger thicknesses.This study provides quantitative insights into heat transfer mechanisms at amorphous interfaces and also offers a feasible strategy for tailoring interfacial thermal transport through structural design.
文摘Interfaces and surfaces of YBa_2Cu_3O_(7-x)(YBCO)-Ag have been studied by SEM-EDX and AES.No effect of Ag on 123 structure in X-ray diffraction pattern was observed for 0.4 mol Ag doped YBCO.AES analysis indicated that Ag segregated on surface of YBCO and resulted in decrease of YBCO-metal lead resistance.In addition,solution and segregation of Ag as elemental state were often appeared on interfaces and surfaces of high temperature annealed YBCO,whether elemental Ag or compound Ag_2O and AgNO_3 adopted as doping material.
文摘AIM： To evaluate the vitreomacular interface in cases with wet age-related macular degeneration（AMD） and to compare them to eyes with dry AMD and normal eyes.METHODS： This was a cross-sectional comparative study that included 87 eyes with wet AMD,42 eyes with dry AMD and 40 eyes without AMD as a control group.Optical coherence tomography（OCT） examination was performed for all patients to assess the vitreomacular interface.RESULTS： In the wet AMD group,34.5% of cases had vitreomacular adhesion（VMA）.Only 14.3% of dry AMD cases and 10% of control cases had VMA.There was a significant difference between the control group and the wet AMD group（P=0.004） as well as the dry and wet AMD group（P=0.017）.There was also a significant difference between the incidence of VMA in patients with subretinal choroidal neovascularization（CNV,type 1） and intraretinal CNV（type 2 or type 3）（P=0.020）.CONCLUSION： There is an association between posterior vitreous attachment and AMD.There is also an increased incidence of VMA with intra-retinal CNV.
基金Project supported by the Science Challenge Project(Grant No.TZ2016003-1-105)Tianjin Natural Science Foundation,China(Grant No.20JCZDJC00750)the Fundamental Research Funds for the Central Universities—Nankai University(Grant Nos.63211107 and 63201182)。
文摘The holes induced by ionizing radiation or carrier injection can depassivate saturated interface defects.The depassivation of these defects suggests that the deep levels associated with the defects are reactivated,affecting the performance of devices.This work simulates the depassivation reactions between holes and passivated amorphous-SiO_(2)/Si interface defects(HP_(b)+h→P_(b)+H^(+)).The climbing image nudged elastic band method is used to calculate the reaction curves and the barriers.In addition,the atomic charges of the initial and final structures are analyzed by the Bader charge method.It is shown that more than one hole is trapped by the defects,which is implied by the reduction in the total number of valence electrons on the active atoms.The results indicate that the depassivation of the defects by the holes actually occurs in three steps.In the first step,a hole is captured by the passivated defect,resulting in the stretching of the Si-H bond.In the second step,the defect captures one more hole,which may contribute to the breaking of the Si-H bond.The H atom is released as a proton and the Si atom is three-coordinated and positively charged.In the third step,an electron is captured by the Si atom,and the Si atom becomes neutral.In this step,a Pb-type defect is reactivated.
