The excellent irradiation resistance,high strength and plasticity exhibited by high-entropy alloys(HEAs)make it candidate for engin-eering applications.Diffusion bonding of Al_(0.3)CoCrFeNi single-phase HEAs was carri...The excellent irradiation resistance,high strength and plasticity exhibited by high-entropy alloys(HEAs)make it candidate for engin-eering applications.Diffusion bonding of Al_(0.3)CoCrFeNi single-phase HEAs was carried out using electric-assisted diffusion bonding(EADB),and the effect of bonding temperature on the evolution of the interfacial microstructure and the mechanical properties was investigated.The results indicate that as the bonding temperature increases,the pores at the interface gradually decrease in size and undergo closure.The electric current significantly promotes the pore closure mechanism dominated by plastic deformation at the diffusion interface and promotes the recrystallisation behavior at the interface,and the fracture mode changes from intergranular fracture at the interface to jagged fracture along the grains spanning the weld parent material.Due to the activation effect of EADB,higher-strength diffusion bonding of high-entropy alloys can be achieved at the same temperature compared with the conventional hot-pressure diffusion bonding(HPDB)process.展开更多
This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ra...This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ratio and thickness of steel tube influence the bond strength characteristics.The results show that as the enhancement of the steel tube wall thickness,the ultimate bond strength at the interface improves significantly,whereas the initial bond strength exhibits only slight variations.The influence of steel fiber volumetric ratio presents a nonlinear trend,with initial bond strength decreasing at low fiber content and increasing significantly as fiber content rises.Additionally,finite element(FE)simulations were applied to replicate the experimental conditions,and the outcomes showed strong correlation with the experimental data,confirming the exactitude of the FE model in predicting the bond behavior at the UHPC-Steel interface.These findings provide valuable insights for optimizing the design of UHPC-Filled steel tubes in high-performance structure.展开更多
Removing H_(2)S and CO_(2)is of great significance for natural gas purification.With excellent gas affinity and tunable structure,ionic liquids(ILs) have been regarded as nontrivial candidates for fabricating polymer-...Removing H_(2)S and CO_(2)is of great significance for natural gas purification.With excellent gas affinity and tunable structure,ionic liquids(ILs) have been regarded as nontrivial candidates for fabricating polymer-based membranes.Herein,we firstly reported the incorporation of protic ILs (PILs) having ether-rich and carboxylate sites (ECPILs) into poly(ether-block-amide)(Pebax) matrix for efficient separation H_(2)S and CO_(2)from CH_(4).Notably,the optimal permeability of H_(2)S reaches up to 4310 Barrer (40C,0.50 bar) in Pebax/ECPIL membranes,along with H_(2)S/CH_(4)and (H_(2)StCO_(2))/CH_(4)selectivity of 97.7 and 112.3,respectively.These values are increased by 1125%,160.8%and 145.9%compared to those in neat Pebax membrane.Additionally,the solubility and diffusion coefficients of the gases were measured,demonstrating that ECPIL can simultaneously strengthen the dissolution and diffusion of H_(2)S and CO_(2),thus elevating the permeability and permselectivity.By using quantum chemical calculations and FT-IR spectroscopy,the highly reversible multi-site hydrogen bonding interaction between ECPILs and H_(2)S was revealed,which is responsible for the fast permeation of H_(2)S and good selectivity.Furthermore,H_(2)S/CO_(2)/CH_(4)(3/3/94 mol/mol) ternary mixed gas can be efficiently and stably separated by Pebax/ECPIL membrane for at least 100 h.Overall,this work not only illustrates that PILs with ether-rich and carboxylate hydrogen bonding sites are outstanding materials for simultaneous removal of H_(2)S and CO_(2),but may also provide a novel insight into the design of membrane materials for natural gas upgrading.展开更多
Information plays a crucial role in guiding behavioral decisions during public health emergencies. Individuals communicate to acquire relevant knowledge about an epidemic, which influences their decisions to adopt pro...Information plays a crucial role in guiding behavioral decisions during public health emergencies. Individuals communicate to acquire relevant knowledge about an epidemic, which influences their decisions to adopt protective measures.However, whether to disseminate specific information is also a behavioral decision. In light of this understanding, we develop a coupled information–vaccination–epidemic model to depict these co-evolutionary dynamics in a three-layer network. Negative information dissemination and vaccination are treated as separate decision-making processes. We then examine the combined effects of herd and risk motives on information dissemination and vaccination decisions through the lens of game theory. The microscopic Markov chain approach(MMCA) is used to describe the dynamic process and to derive the epidemic threshold. Simulation results indicate that increasing the cost of negative information dissemination and providing timely clarification can effectively control the epidemic. Furthermore, a phenomenon of diminishing marginal utility is observed as the cost of dissemination increases, suggesting that authorities do not need to overinvest in suppressing negative information. Conversely, reducing the cost of vaccination and increasing vaccine efficacy emerge as more effective strategies for outbreak control. In addition, we find that the scale of the epidemic is greater when the herd motive dominates behavioral decision-making. In conclusion, this study provides a new perspective for understanding the complexity of epidemic spreading by starting with the construction of different behavioral decisions.展开更多
Surface tension-induced shrinkage of heterogeneously bonded interfaces is a key factor in limiting the performance of nanostructures.Herein,we demonstrate a laser-induced thermo-compression bonding technology to suppr...Surface tension-induced shrinkage of heterogeneously bonded interfaces is a key factor in limiting the performance of nanostructures.Herein,we demonstrate a laser-induced thermo-compression bonding technology to suppress surface tension-induced shrinkage of Cu-Au bonded interface.A focused laser beam is used to apply localized heating and scattering force to the exposed Cu nanowire.The laser-induced scattering force and the heating can be adjusted by regulating the exposure intensity.When the ratio of scattering forces to the gravity of the exposed nanowire reaches 3.6×10^(3),the molten Cu nanowire is compressed into flattened shape rather than shrinking into nanosphere by the surface tension.As a result,the Cu-Au bonding interface is broadened fourfold by the scattering force,leading to a reduction in contact resistance of approximately 56%.This noncontact thermo-compression bonding technology provides significant possibilities for the interconnect packaging and integration of nanodevices.展开更多
Due to its superior nanoscale properties,cobalt(Co)is highly desirable for ultrahigh-density 3D integration into materials through metal/dielectric hybrid bonding.However,this process is very challenging through Co/Si...Due to its superior nanoscale properties,cobalt(Co)is highly desirable for ultrahigh-density 3D integration into materials through metal/dielectric hybrid bonding.However,this process is very challenging through Co/SiO_(2)hybrid bonding,as very hydrophilic SiO_(2)surfaces are needed for bonding during dehydration reactions and oxidation of the Co surfaces must be avoided.Additionally,the substantial coefficient of thermal expansion mismatch between the robust capping layers(Co and SiO_(2)layers)necessitates hybrid bonding with minimal thermal input and compression.In this study,we introduce a ternary plasma activation strategy employing an Ar/NH_(3)/H_(2)O gas mixture to facilitate Co/SiO_(2)hybrid bonding at temperatures as low as~200℃,which is markedly lower than the melting point of Co(~1500℃).Intriguingly,non-oxide metallization at the Co-Co interface can be realized without the hindrance of a bonding barrier,thereby reducing the electrical resistance by over 40%and compression force requirements.Moreover,the enhancement in the SiO_(2)surface energy through active group terminations fosters extensive interfacial hydration and strengthens the mechanical properties.This research paves the way for fine-tuning bonding surfaces using a material-selective strategy which should advance metal/dielectric hybrid bonding for future integration applications.展开更多
Accurate acquisition of the rock stress is crucial for various rock engineering applications.The hollow inclusion (HI) technique is widely used for measuring in-situ rock stress.This technique calculates the stress te...Accurate acquisition of the rock stress is crucial for various rock engineering applications.The hollow inclusion (HI) technique is widely used for measuring in-situ rock stress.This technique calculates the stress tensor by measuring strain using an HI strain cell.However,existing analytical solutions for stress calculation based on an HI strain cell in a double-layer medium are not applicable when an HI strain cell is used in a three-layer medium,leading to erroneous stress calculations.To address this issue,this paper presents a method for calculating stress tensors in a three-layer medium using numerical simulations,specifically by obtaining a constitutive matrix that relates strain measurements to stress tensors in a three-layer medium.Furthermore,using Latin hypercube sampling (LHS) and orthogonal experimental design strategies,764 groups of numerical models encompassing various stress measurement scenarios have been established and calculated using FLAC^(3D)software.Finally,a surrogate model based on artificial neural network (ANN) was developed to predict constitutive matrices,achieving a goodness of fit (R^(2)) of 0.999 and a mean squared error (MSE) of 1.254.A software program has been developed from this surrogate model for ease of use in practical engineering applications.The method’s accuracy was verified through numerical simulations,analytical solution and laboratory experiment,demonstrating its effectiveness in calculating stress in a three-layer medium.The surrogate model was applied to calculate mining-induced stress in the roadway roof rock of a coal mine,a typical case for stress measurement in a three-layer medium.Errors in stress calculations arising from the use of existing analytical solutions were corrected.The study also highlights the significant errors associated with using double-layer analytical solutions in a three-layer medium,which could lead to inappropriate engineering design.展开更多
Surface chemistry plays a critical role in the fields of electrochemistry,heterogeneous catalysis,adsorption,etc.[1–4].The representative D-band center theory reported through Hammer and Nørskov in surface chemi...Surface chemistry plays a critical role in the fields of electrochemistry,heterogeneous catalysis,adsorption,etc.[1–4].The representative D-band center theory reported through Hammer and Nørskov in surface chemistry has been widely used in early studies to predict adsorption strength[5,6].Generally,the adsorption strength of active sites correlates inversely with the downward shift of the D-band center(εd)relative to the Fermi level,as lower-energy positioning increases anti-bonding orbital occupancy,weakening surface interactions(Fig.1(a)).展开更多
Interfacial evolution and bonding mechanism of reduced activation ferritic/martensitic(RAFM)steel were systematically investigated through a series of hot compression tests conducted at various strains(0.15-0.8),strai...Interfacial evolution and bonding mechanism of reduced activation ferritic/martensitic(RAFM)steel were systematically investigated through a series of hot compression tests conducted at various strains(0.15-0.8),strain rates(0.001-1 s^(-1)),and temperatures(950-1050℃).Interfacial microstructural analysis revealed that plastic deformation of surface asperities effectively removes interfacial voids,and the evolution of dynamic recrystallization(DRX)aids in achieving a joint characterized by homogeneously refined microstructure and adequate interfacial grain boundary(IGB)migration.Electron backscattered diffraction analysis demonstrated that the continuous dynamic recrystallization,characterized by progressive subgrain rotation,is the prevailing DRX nucleation mechanism in RAFM steel during hot compression bonding.During DRX evolution,emerging DRX grains in the interfacial region expand into adjacent areas,transforming T-type triple junction grain boundaries into equal form,and resulting in a serrated and intricate interface.Elevated temperatures and strains,coupled with reduced strain rates,augment DRX grain nucleation and IGB migration,thus enhancing RAFM joint quality with regard to the interface bonding ratio and the interface migration ratio.展开更多
This study examines the intricate occurrences of thermal and solutal Marangoni convection in three-layered flows of viscous fluids,with a particular emphasis on their relevance to renewable energy systems.This researc...This study examines the intricate occurrences of thermal and solutal Marangoni convection in three-layered flows of viscous fluids,with a particular emphasis on their relevance to renewable energy systems.This research examines the flow of a three-layered viscous fluid,considering the combined influence of heat and solutal buoyancy driven Rayleigh-Bénard convection,as well as thermal and solutal Marangoni convection.The homotopy perturbation method is used to examine and simulate complex fluid flow and transport phenomena,providing important understanding of the fundamental physics and assisting in the optimization of various battery configurations.The inquiry examines the primary elements that influence Marangoni convection and its impact on battery performance,providing insights on possible enhancements in energy storage devices.The findings indicate that the velocity profiles shown graphically exhibit a prominent core zone characterized by the maximum speed,which progressively decreases as it approaches the walls of the channel.This study enhances our comprehension of fluid dynamics and the transmission of heat and mass in intricate systems,which has substantial ramifications for the advancement of sustainable energy solutions.展开更多
Bonding quality at the interface of solid propellant grains is crucial for the reliability and safety of solid rocket motors.Although bonding reliability is influenced by numerous factors,the lack of quantitative char...Bonding quality at the interface of solid propellant grains is crucial for the reliability and safety of solid rocket motors.Although bonding reliability is influenced by numerous factors,the lack of quantitative characterization of interface debonding mechanisms and the challenge of identifying key factors have made precise control of process variables difficult,resulting in unpredictable failure risks.This paper presents an improved fuzzy failure probability evaluation method that combines fuzzy fault tree analysis with expert knowledge,transforming process data into fuzzy failure probability to accurately assess debonding probabilities.The predictive model is constructed through a general regression neural network and optimized using the particle swarm optimization algorithm.Sensitivity analysis is conducted to identify key decision variables,including normal force,grain rotation speed,and adhesive weight,which are verified experimentally.Compared with classical models,the maximum error margin of the constructed reliability prediction model is only 0.02%,and it has high stability.The experimental results indicate that the main factors affecting debonding are processing roughness and coating uniformity.Controlling the key decision variable as the median resulted in a maximum increase of 200.7%in bonding strength.The feasibility of the improved method has been verified,confirming that identifying key decision variables has the ability to improve bonding reliability.The proposed method simplifies the evaluation of propellant interface bonding reliability under complex conditions by quantifying the relationship between process parameters and failure risk,enabling targeted management of key decision variables.展开更多
This paper examines the role of traumatic bonding in Anita Brookner’s novel Providence.Through the perspective of traumatic bonding theory,this paper explores the true nature of the relationship between Kitty Maule a...This paper examines the role of traumatic bonding in Anita Brookner’s novel Providence.Through the perspective of traumatic bonding theory,this paper explores the true nature of the relationship between Kitty Maule and Maurice Bishop.The paper analyzes the intermittent cycles of affection and neglect that characterize their interactions,highlighting how Bishop’s emotional detachment and sporadic gestures of warmth create a power imbalance that traps Kitty in a cycle of idealization and disillusionment.Drawing on the work of Dutton and Painter(1981)on traumatic bonding,the paper explores how Kitty’s emotional dependence on Maurice mirrors the patterns found in emotionally abusive relationships,revealing how the traumatic bond between Kitty and Bishop shapes her journey toward self-growth.展开更多
Flexible strain sensors have received tremendous attention because of their potential applications as wearable sensing devices.However, the integration of key functions into a single sensor, such as high stretchabilit...Flexible strain sensors have received tremendous attention because of their potential applications as wearable sensing devices.However, the integration of key functions into a single sensor, such as high stretchability, low hysteresis, self-adhesion, andexcellent antifreezing performance, remains an unmet challenge. In this respect, zwitterionic hydrogels have emerged asideal material candidates for breaking through the above dilemma. The mechanical properties of most reported zwitterionichydrogels, however, are relatively poor, significantly restricting their use under load-bearing conditions. Traditional improve-ment approaches often involve complex preparation processes, making large-scale production challenging. Additionally,zwitterionic hydrogels prepared with chemical crosslinkers are typically fragile and prone to irreversible deformation underlarge strains, resulting in the slow recovery of structure and function. To fundamentally enhance the mechanical properties ofpure zwitterionic hydrogels, the most effective approach is the regulation of the chemical structure of zwitterionic monomersthrough a targeted design strategy. This study employed a novel zwitterionic monomer carboxybetaine urethane acrylate(CBUTA), which contained one urethane group and one carboxybetaine group on its side chain. Through the direct polym-erization of ultrahigh concentration monomer solutions without adding any chemical crosslinker, we successfully developedpure zwitterionic supramolecular hydrogels with significantly enhanced mechanical properties, self-adhesive behavior, andantifreezing performance. Most importantly, the resultant zwitterionic hydrogels exhibited high tensile strength and tough-ness and displayed ultralow hysteresis under strain conditions up to 1100%. This outstanding performance was attributedto the unique liquid–liquid phase separation phenomenon induced by the ultrahigh concentration of CBUTA monomers inan aqueous solution, as well as the enhanced polymer chain entanglement and the strong hydrogen bonds between urethanegroups on the side chains. The potential application of hydrogels in strain sensors and high-performance triboelectric nano-generators was further explored. Overall, this work provides a promising strategy for developing pure zwitterionic hydrogelsfor flexible strain sensors and self-powered electronic devices.展开更多
This study focused on the various surface treatments of grinding,Na OH etching,HCl pickling,micro-arc oxidation and anodic oxidation to strengthen adhesive bonding joint of Aluminum(Al)substrate and Carbon Fiber Reinf...This study focused on the various surface treatments of grinding,Na OH etching,HCl pickling,micro-arc oxidation and anodic oxidation to strengthen adhesive bonding joint of Aluminum(Al)substrate and Carbon Fiber Reinforced Plastics(CFRP).Different surface conditions were created by these treatments and simple Resin Pre-Coating(RPC)technique was further used to reduce the potential void defects at the root of those micro-cavities.Carbon Nanotubes(CNTs)were guided into the etched micro-cavities to construct quasi-Z-directional fiber bridging and form the“CNT-reinforced epoxy-pins”.The surface performance testing results imply that anodic oxidation of Al substrate created relatively even and continuous channels with higher hardness and better wettability among these treatments,which could provide quasi-vertical spaces for containing epoxy adhesive or CNTs.The single lap shear test results show combined treatments of anodic oxidation and upgraded RPC with CNTs technique on Al substrate yielded the highest bonding strength of 21.8 MPa(up to 243.3% greater than base strength).The constructed through-the-thickness“epoxy-pins”or“CNT-reinforced epoxy-pins”contributed to failure modes changing from complete debonding failure of Al substrate to peeled-off shallow fiber or delamination failure of CFRP panel.The combined treatments could be utilized to manufacture high-performance Al-CFRP composites for aviation industry application.展开更多
Layered rare-earth metal oxides,harnessing the dual properties of oxides and two-dimensional layered materials,exhibit remarkable thermal stability and quantum confinement effects.Therefore,this work adopts the first-...Layered rare-earth metal oxides,harnessing the dual properties of oxides and two-dimensional layered materials,exhibit remarkable thermal stability and quantum confinement effects.Therefore,this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound.The coexistence of weak interlayer van der Waals interactions,robust intralayer ionic bonding,and partial covalent bonding leads to remarkable bonding heterogeneity,which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction.The weakened chemical bonds induced by the antibonding states,together with the rattling-like behavior of the Zn atom,culminate in the profound anharmonicity in the layered NdZnSbO compound.The weakening bond and heavy element contribute to the softness of phonon modes,which significantly diminishes the phonon group velocity.The redistribution-dominated four-phonon scattering process spans a large optical gap,which effectively reduces the lattice thermal conductivity.The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-Ernzerhof(HSE06)functional in combination with spin–orbit coupling(SOC)effect.The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy,thus amplifying the power factor.Consequently,an optimal figure-of-merit(ZT)of 3.40 at 900 K is achieved for the n-type NdZnSbO compound.The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.展开更多
Dye-based color films are increasingly considered as viable alternatives to pigment-based color films in complementary metal-oxide-semiconductor(CMOS) image sensors.Herein,a series of azo dyes utilizing 5-methyl-2-phe...Dye-based color films are increasingly considered as viable alternatives to pigment-based color films in complementary metal-oxide-semiconductor(CMOS) image sensors.Herein,a series of azo dyes utilizing 5-methyl-2-phenyl-4-(2-phenylhydrazono)-2,4-dihydro-3H-pyrazol-3-one as the coupling component and aromatic amines with various electron-withdrawing groups(NO_(2),CN,Br) as diazo components were designed and synthesized.The presence of intermolecular hydrogen bonding between the hydrogen atom on the N-H group and the oxygen atom of the C=O group of the hydrazo structure facilitates the formation of a stable six-membered ring.Additionally,the electron-withdrawing groups in the diazo component further stabilize this hydrogen-bonded structure.As a result,these azo dyes(P-2,P-3,P-4,P-5)exhibit not only excellent light stability but also ultra-highly thermal stability(T_(d)> 260℃).Therein,the synthesized dyes P-2 and P-3 with great bright yellow color(~400 nm),proper solubility(~6.00g/100 g)were selected to make for color films.And their dye-based color films displayed ultra-highly thermal and light stability(color difference ΔE<3).Notably,the increased planarity of the molecular structure by hydrogen bonding for the novel dyes ensures a balance between high transmittance(>90%) in the 550-780 nm wavelength range and the solvent resistance of the dye-based color films.This work contributes to the advancement of next-generation smart CMOS devices and offers valuable insights into the design of azo dyes for applications in the field of organic electronics.展开更多
In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,...In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,especially at the interface between the semiconductor and cocatalyst,has received insufficient attention.In this study,we report a Co,Ni and Mn trimetallic fluoride-modified BVO photoanode featuring a unique interfacial chemical bond(V-F).Under AM 1.5 G illumination,an exciting photocurrent density of 6.05 mA cm^(-2)was achieved at 1.23 V vs.RHE by the integrated BVO/CoNi_(0.18)Mn_(0.12)(OH)_(x)F photoanode and over 98%of the initial photocurrent was maintained after 10 h of photoelectrolysis.Control experiments and theoretical calculations demonstrate that the V-F interfacial bond stabilizes the Co^(2+)active sites.It serves as a transmission gear,interlinking the migration of interfacial charge and the regeneration of cocatalyst,endowing the photoanode with significant activity and stability.Furthermore,we have systematically elucidated the role of the individual Co,Ni,and Mn components in the synergistic cocatalyst layer.The interfacial modification provides novel insights into developing advanced photoanodes towards PEC water splitting.展开更多
Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtai...Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtained in high yields(up to 95%)and excellent enantioselectivities(up to 99%).In terms of synthetic utility,the reaction can be performed on a gram scale,and the product can be converted into potential biological nucleoside analog.展开更多
Effect of flip chip bonding parameters on microstructure at the interconnect interface and shear properties of 64.8Sn35.2Pb microbumps were investigated in this work.Results show that the main intermetallic compound(I...Effect of flip chip bonding parameters on microstructure at the interconnect interface and shear properties of 64.8Sn35.2Pb microbumps were investigated in this work.Results show that the main intermetallic compound(IMC)at the interconnect interface is(Ni,Cu)_(3)Sn_(4)phase,and meanwhile a small amount of(Cu,Ni)_(6)Sn_(5)phase with a size of 50−100 nm is formed around(Ni,Cu)_(3)Sn_(4)phase.The orientation relationship of[-1-56](Ni,Cu)_(3)Sn_(4)//[152](Cu,Ni)_(6)Sn_(5)and(601)(Ni,Cu)_(3)Sn_(4)//(-201)(Cu,Ni)_(6)Sn_(5)is found between these two phases,and the atomic matching at the interface of the two phases is low.The highest shear force of 77.3 gf is achieved in the 64.8Sn35.2Pb microbump at the peak temperature of 250℃and parameter V1 because dense IMCs and no cracks form at the interconnect interface.Two typical fracture modes of microbumps are determined as solder fracture and mixed fracture.The high thermal stress presenting in the thick IMCs layer induces crack initiation,and cracks propagate along theα/βphase boundaries in the Sn-Pb solder under shear force,leading to a mixed fracture mode in the microbumps.展开更多
基金support from National Natural Science Foundation of China(NSFC,Grant numbers U22A20185,U21A20128,52175302 and 52305353)Aeronautical Science Foundation(ASFC-20230036077001)Fundamental Research Funds for the Central Universities(2022FRFK060009,HIT.DZI1.2023012).
文摘The excellent irradiation resistance,high strength and plasticity exhibited by high-entropy alloys(HEAs)make it candidate for engin-eering applications.Diffusion bonding of Al_(0.3)CoCrFeNi single-phase HEAs was carried out using electric-assisted diffusion bonding(EADB),and the effect of bonding temperature on the evolution of the interfacial microstructure and the mechanical properties was investigated.The results indicate that as the bonding temperature increases,the pores at the interface gradually decrease in size and undergo closure.The electric current significantly promotes the pore closure mechanism dominated by plastic deformation at the diffusion interface and promotes the recrystallisation behavior at the interface,and the fracture mode changes from intergranular fracture at the interface to jagged fracture along the grains spanning the weld parent material.Due to the activation effect of EADB,higher-strength diffusion bonding of high-entropy alloys can be achieved at the same temperature compared with the conventional hot-pressure diffusion bonding(HPDB)process.
基金supported by grants from the Natural Science Foundation of Fujian Province(2021J011062)Minjiang Scholars Funding(GY-633Z21067).
文摘This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ratio and thickness of steel tube influence the bond strength characteristics.The results show that as the enhancement of the steel tube wall thickness,the ultimate bond strength at the interface improves significantly,whereas the initial bond strength exhibits only slight variations.The influence of steel fiber volumetric ratio presents a nonlinear trend,with initial bond strength decreasing at low fiber content and increasing significantly as fiber content rises.Additionally,finite element(FE)simulations were applied to replicate the experimental conditions,and the outcomes showed strong correlation with the experimental data,confirming the exactitude of the FE model in predicting the bond behavior at the UHPC-Steel interface.These findings provide valuable insights for optimizing the design of UHPC-Filled steel tubes in high-performance structure.
基金sponsored by the National Natural Science Foundation of China (Nos. 22308145, 22208140, 22178159, 22078145)Natural Science Foundation of Jiangsu Province (BK20230791)Postgraduate Research Innovation Program of Jiangsu Province (KYCX24_0165)。
文摘Removing H_(2)S and CO_(2)is of great significance for natural gas purification.With excellent gas affinity and tunable structure,ionic liquids(ILs) have been regarded as nontrivial candidates for fabricating polymer-based membranes.Herein,we firstly reported the incorporation of protic ILs (PILs) having ether-rich and carboxylate sites (ECPILs) into poly(ether-block-amide)(Pebax) matrix for efficient separation H_(2)S and CO_(2)from CH_(4).Notably,the optimal permeability of H_(2)S reaches up to 4310 Barrer (40C,0.50 bar) in Pebax/ECPIL membranes,along with H_(2)S/CH_(4)and (H_(2)StCO_(2))/CH_(4)selectivity of 97.7 and 112.3,respectively.These values are increased by 1125%,160.8%and 145.9%compared to those in neat Pebax membrane.Additionally,the solubility and diffusion coefficients of the gases were measured,demonstrating that ECPIL can simultaneously strengthen the dissolution and diffusion of H_(2)S and CO_(2),thus elevating the permeability and permselectivity.By using quantum chemical calculations and FT-IR spectroscopy,the highly reversible multi-site hydrogen bonding interaction between ECPILs and H_(2)S was revealed,which is responsible for the fast permeation of H_(2)S and good selectivity.Furthermore,H_(2)S/CO_(2)/CH_(4)(3/3/94 mol/mol) ternary mixed gas can be efficiently and stably separated by Pebax/ECPIL membrane for at least 100 h.Overall,this work not only illustrates that PILs with ether-rich and carboxylate hydrogen bonding sites are outstanding materials for simultaneous removal of H_(2)S and CO_(2),but may also provide a novel insight into the design of membrane materials for natural gas upgrading.
基金Project supported by the National Natural Science Foundation of China (Grant No. 72174121)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, and the Soft Science Research Project of Shanghai (Grant No. 22692112600)。
文摘Information plays a crucial role in guiding behavioral decisions during public health emergencies. Individuals communicate to acquire relevant knowledge about an epidemic, which influences their decisions to adopt protective measures.However, whether to disseminate specific information is also a behavioral decision. In light of this understanding, we develop a coupled information–vaccination–epidemic model to depict these co-evolutionary dynamics in a three-layer network. Negative information dissemination and vaccination are treated as separate decision-making processes. We then examine the combined effects of herd and risk motives on information dissemination and vaccination decisions through the lens of game theory. The microscopic Markov chain approach(MMCA) is used to describe the dynamic process and to derive the epidemic threshold. Simulation results indicate that increasing the cost of negative information dissemination and providing timely clarification can effectively control the epidemic. Furthermore, a phenomenon of diminishing marginal utility is observed as the cost of dissemination increases, suggesting that authorities do not need to overinvest in suppressing negative information. Conversely, reducing the cost of vaccination and increasing vaccine efficacy emerge as more effective strategies for outbreak control. In addition, we find that the scale of the epidemic is greater when the herd motive dominates behavioral decision-making. In conclusion, this study provides a new perspective for understanding the complexity of epidemic spreading by starting with the construction of different behavioral decisions.
基金supported by the National Natural Science Foundation of China(Nos.52305612 and U20A6004)Open Fund of Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration(Wuhan University)(NO.EMPI2023015).
文摘Surface tension-induced shrinkage of heterogeneously bonded interfaces is a key factor in limiting the performance of nanostructures.Herein,we demonstrate a laser-induced thermo-compression bonding technology to suppress surface tension-induced shrinkage of Cu-Au bonded interface.A focused laser beam is used to apply localized heating and scattering force to the exposed Cu nanowire.The laser-induced scattering force and the heating can be adjusted by regulating the exposure intensity.When the ratio of scattering forces to the gravity of the exposed nanowire reaches 3.6×10^(3),the molten Cu nanowire is compressed into flattened shape rather than shrinking into nanosphere by the surface tension.As a result,the Cu-Au bonding interface is broadened fourfold by the scattering force,leading to a reduction in contact resistance of approximately 56%.This noncontact thermo-compression bonding technology provides significant possibilities for the interconnect packaging and integration of nanodevices.
基金supported by the National Natural Science Foundation of China(Grant Nos.92164105 and 51975151)the Heilongjiang Provincial Natural Science Foundation of China under grant LH2019E041+1 种基金the Heilongjiang Touyan Innovation Team Program(HITTY-20190013)State Key Laboratory of Precision Welding&Joining of Materials and Structures(No.24-T-04)。
文摘Due to its superior nanoscale properties,cobalt(Co)is highly desirable for ultrahigh-density 3D integration into materials through metal/dielectric hybrid bonding.However,this process is very challenging through Co/SiO_(2)hybrid bonding,as very hydrophilic SiO_(2)surfaces are needed for bonding during dehydration reactions and oxidation of the Co surfaces must be avoided.Additionally,the substantial coefficient of thermal expansion mismatch between the robust capping layers(Co and SiO_(2)layers)necessitates hybrid bonding with minimal thermal input and compression.In this study,we introduce a ternary plasma activation strategy employing an Ar/NH_(3)/H_(2)O gas mixture to facilitate Co/SiO_(2)hybrid bonding at temperatures as low as~200℃,which is markedly lower than the melting point of Co(~1500℃).Intriguingly,non-oxide metallization at the Co-Co interface can be realized without the hindrance of a bonding barrier,thereby reducing the electrical resistance by over 40%and compression force requirements.Moreover,the enhancement in the SiO_(2)surface energy through active group terminations fosters extensive interfacial hydration and strengthens the mechanical properties.This research paves the way for fine-tuning bonding surfaces using a material-selective strategy which should advance metal/dielectric hybrid bonding for future integration applications.
基金funding support from the National Natural Science Foundation of China (Nos. 42477208 and 52079134)the Natural Science Foundation of Hubei Province, China (No. 2024AFA072)+2 种基金the Youth Innovation Promotion Association CAS (No. 2022332)the National Key R&D Program of China (No. 2024YFF0508203)the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering Safety (Nos. SKLGME-JBGS2402 and SKLGME022022)。
文摘Accurate acquisition of the rock stress is crucial for various rock engineering applications.The hollow inclusion (HI) technique is widely used for measuring in-situ rock stress.This technique calculates the stress tensor by measuring strain using an HI strain cell.However,existing analytical solutions for stress calculation based on an HI strain cell in a double-layer medium are not applicable when an HI strain cell is used in a three-layer medium,leading to erroneous stress calculations.To address this issue,this paper presents a method for calculating stress tensors in a three-layer medium using numerical simulations,specifically by obtaining a constitutive matrix that relates strain measurements to stress tensors in a three-layer medium.Furthermore,using Latin hypercube sampling (LHS) and orthogonal experimental design strategies,764 groups of numerical models encompassing various stress measurement scenarios have been established and calculated using FLAC^(3D)software.Finally,a surrogate model based on artificial neural network (ANN) was developed to predict constitutive matrices,achieving a goodness of fit (R^(2)) of 0.999 and a mean squared error (MSE) of 1.254.A software program has been developed from this surrogate model for ease of use in practical engineering applications.The method’s accuracy was verified through numerical simulations,analytical solution and laboratory experiment,demonstrating its effectiveness in calculating stress in a three-layer medium.The surrogate model was applied to calculate mining-induced stress in the roadway roof rock of a coal mine,a typical case for stress measurement in a three-layer medium.Errors in stress calculations arising from the use of existing analytical solutions were corrected.The study also highlights the significant errors associated with using double-layer analytical solutions in a three-layer medium,which could lead to inappropriate engineering design.
文摘Surface chemistry plays a critical role in the fields of electrochemistry,heterogeneous catalysis,adsorption,etc.[1–4].The representative D-band center theory reported through Hammer and Nørskov in surface chemistry has been widely used in early studies to predict adsorption strength[5,6].Generally,the adsorption strength of active sites correlates inversely with the downward shift of the D-band center(εd)relative to the Fermi level,as lower-energy positioning increases anti-bonding orbital occupancy,weakening surface interactions(Fig.1(a)).
基金The authors are grateful to the National Natural Science Foundation of China(Grant Nos.52034004 and 52271111)the National Key R&D Program of China(2022YFB3705300)for grant and financial support.
文摘Interfacial evolution and bonding mechanism of reduced activation ferritic/martensitic(RAFM)steel were systematically investigated through a series of hot compression tests conducted at various strains(0.15-0.8),strain rates(0.001-1 s^(-1)),and temperatures(950-1050℃).Interfacial microstructural analysis revealed that plastic deformation of surface asperities effectively removes interfacial voids,and the evolution of dynamic recrystallization(DRX)aids in achieving a joint characterized by homogeneously refined microstructure and adequate interfacial grain boundary(IGB)migration.Electron backscattered diffraction analysis demonstrated that the continuous dynamic recrystallization,characterized by progressive subgrain rotation,is the prevailing DRX nucleation mechanism in RAFM steel during hot compression bonding.During DRX evolution,emerging DRX grains in the interfacial region expand into adjacent areas,transforming T-type triple junction grain boundaries into equal form,and resulting in a serrated and intricate interface.Elevated temperatures and strains,coupled with reduced strain rates,augment DRX grain nucleation and IGB migration,thus enhancing RAFM joint quality with regard to the interface bonding ratio and the interface migration ratio.
基金Project(52276068)supported by the National Natural Science Foundation of China。
文摘This study examines the intricate occurrences of thermal and solutal Marangoni convection in three-layered flows of viscous fluids,with a particular emphasis on their relevance to renewable energy systems.This research examines the flow of a three-layered viscous fluid,considering the combined influence of heat and solutal buoyancy driven Rayleigh-Bénard convection,as well as thermal and solutal Marangoni convection.The homotopy perturbation method is used to examine and simulate complex fluid flow and transport phenomena,providing important understanding of the fundamental physics and assisting in the optimization of various battery configurations.The inquiry examines the primary elements that influence Marangoni convection and its impact on battery performance,providing insights on possible enhancements in energy storage devices.The findings indicate that the velocity profiles shown graphically exhibit a prominent core zone characterized by the maximum speed,which progressively decreases as it approaches the walls of the channel.This study enhances our comprehension of fluid dynamics and the transmission of heat and mass in intricate systems,which has substantial ramifications for the advancement of sustainable energy solutions.
基金supported in part by the Equipment Development Pre-research Project funded by Equipment Development Department,PRC under Grant No.50923010501Fundamental Research Program of Shenyang Institute of Automation(SIA),Chinese Academy of Sciencess under Grant No.355060201。
文摘Bonding quality at the interface of solid propellant grains is crucial for the reliability and safety of solid rocket motors.Although bonding reliability is influenced by numerous factors,the lack of quantitative characterization of interface debonding mechanisms and the challenge of identifying key factors have made precise control of process variables difficult,resulting in unpredictable failure risks.This paper presents an improved fuzzy failure probability evaluation method that combines fuzzy fault tree analysis with expert knowledge,transforming process data into fuzzy failure probability to accurately assess debonding probabilities.The predictive model is constructed through a general regression neural network and optimized using the particle swarm optimization algorithm.Sensitivity analysis is conducted to identify key decision variables,including normal force,grain rotation speed,and adhesive weight,which are verified experimentally.Compared with classical models,the maximum error margin of the constructed reliability prediction model is only 0.02%,and it has high stability.The experimental results indicate that the main factors affecting debonding are processing roughness and coating uniformity.Controlling the key decision variable as the median resulted in a maximum increase of 200.7%in bonding strength.The feasibility of the improved method has been verified,confirming that identifying key decision variables has the ability to improve bonding reliability.The proposed method simplifies the evaluation of propellant interface bonding reliability under complex conditions by quantifying the relationship between process parameters and failure risk,enabling targeted management of key decision variables.
文摘This paper examines the role of traumatic bonding in Anita Brookner’s novel Providence.Through the perspective of traumatic bonding theory,this paper explores the true nature of the relationship between Kitty Maule and Maurice Bishop.The paper analyzes the intermittent cycles of affection and neglect that characterize their interactions,highlighting how Bishop’s emotional detachment and sporadic gestures of warmth create a power imbalance that traps Kitty in a cycle of idealization and disillusionment.Drawing on the work of Dutton and Painter(1981)on traumatic bonding,the paper explores how Kitty’s emotional dependence on Maurice mirrors the patterns found in emotionally abusive relationships,revealing how the traumatic bond between Kitty and Bishop shapes her journey toward self-growth.
基金supported by the National Natural Science Foundation of China(Nos.T2222013 and 52073203)Tianjin Natural Science Foundation(No.22JCQNJC01040)the State Key Laboratory of Molecular Engineering of Polymers(Fudan University)(No.K2024-19).
文摘Flexible strain sensors have received tremendous attention because of their potential applications as wearable sensing devices.However, the integration of key functions into a single sensor, such as high stretchability, low hysteresis, self-adhesion, andexcellent antifreezing performance, remains an unmet challenge. In this respect, zwitterionic hydrogels have emerged asideal material candidates for breaking through the above dilemma. The mechanical properties of most reported zwitterionichydrogels, however, are relatively poor, significantly restricting their use under load-bearing conditions. Traditional improve-ment approaches often involve complex preparation processes, making large-scale production challenging. Additionally,zwitterionic hydrogels prepared with chemical crosslinkers are typically fragile and prone to irreversible deformation underlarge strains, resulting in the slow recovery of structure and function. To fundamentally enhance the mechanical properties ofpure zwitterionic hydrogels, the most effective approach is the regulation of the chemical structure of zwitterionic monomersthrough a targeted design strategy. This study employed a novel zwitterionic monomer carboxybetaine urethane acrylate(CBUTA), which contained one urethane group and one carboxybetaine group on its side chain. Through the direct polym-erization of ultrahigh concentration monomer solutions without adding any chemical crosslinker, we successfully developedpure zwitterionic supramolecular hydrogels with significantly enhanced mechanical properties, self-adhesive behavior, andantifreezing performance. Most importantly, the resultant zwitterionic hydrogels exhibited high tensile strength and tough-ness and displayed ultralow hysteresis under strain conditions up to 1100%. This outstanding performance was attributedto the unique liquid–liquid phase separation phenomenon induced by the ultrahigh concentration of CBUTA monomers inan aqueous solution, as well as the enhanced polymer chain entanglement and the strong hydrogen bonds between urethanegroups on the side chains. The potential application of hydrogels in strain sensors and high-performance triboelectric nano-generators was further explored. Overall, this work provides a promising strategy for developing pure zwitterionic hydrogelsfor flexible strain sensors and self-powered electronic devices.
基金supported financially by the National Natural Science Foundations of China(No.52102115)the Natural Science Foundation of Sichuan Province,China(No.2025HJRC0019)+1 种基金the Basalt Fiber and Composite Key Laboratory of Sichuan Province,China(No.XXKFJJ202308)Shock and Vibration of Engineering Materials and Structures Key Lab of Sichuan Province,China(No.23kfgk06)。
文摘This study focused on the various surface treatments of grinding,Na OH etching,HCl pickling,micro-arc oxidation and anodic oxidation to strengthen adhesive bonding joint of Aluminum(Al)substrate and Carbon Fiber Reinforced Plastics(CFRP).Different surface conditions were created by these treatments and simple Resin Pre-Coating(RPC)technique was further used to reduce the potential void defects at the root of those micro-cavities.Carbon Nanotubes(CNTs)were guided into the etched micro-cavities to construct quasi-Z-directional fiber bridging and form the“CNT-reinforced epoxy-pins”.The surface performance testing results imply that anodic oxidation of Al substrate created relatively even and continuous channels with higher hardness and better wettability among these treatments,which could provide quasi-vertical spaces for containing epoxy adhesive or CNTs.The single lap shear test results show combined treatments of anodic oxidation and upgraded RPC with CNTs technique on Al substrate yielded the highest bonding strength of 21.8 MPa(up to 243.3% greater than base strength).The constructed through-the-thickness“epoxy-pins”or“CNT-reinforced epoxy-pins”contributed to failure modes changing from complete debonding failure of Al substrate to peeled-off shallow fiber or delamination failure of CFRP panel.The combined treatments could be utilized to manufacture high-performance Al-CFRP composites for aviation industry application.
基金Financial supports from the National Natural Science Foundation of China(21503039)Department of Science and Technology of Liaoning Province(2019MS164)+1 种基金Department of Education of Liaoning Province(LJ2020JCL034)Discipline Innovation Team of Liaoning Technical University(LNTU20TD-16)are greatly acknowledged。
文摘Layered rare-earth metal oxides,harnessing the dual properties of oxides and two-dimensional layered materials,exhibit remarkable thermal stability and quantum confinement effects.Therefore,this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound.The coexistence of weak interlayer van der Waals interactions,robust intralayer ionic bonding,and partial covalent bonding leads to remarkable bonding heterogeneity,which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction.The weakened chemical bonds induced by the antibonding states,together with the rattling-like behavior of the Zn atom,culminate in the profound anharmonicity in the layered NdZnSbO compound.The weakening bond and heavy element contribute to the softness of phonon modes,which significantly diminishes the phonon group velocity.The redistribution-dominated four-phonon scattering process spans a large optical gap,which effectively reduces the lattice thermal conductivity.The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-Ernzerhof(HSE06)functional in combination with spin–orbit coupling(SOC)effect.The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy,thus amplifying the power factor.Consequently,an optimal figure-of-merit(ZT)of 3.40 at 900 K is achieved for the n-type NdZnSbO compound.The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.
基金supported by the Program of the National Natural Science Foundation of China(No.22238002)the Fundamental Research Funds for the Central Universities(No.DUT22LAB610)+1 种基金Research and Innovation Team Project of Dalian University of Technology(No.DUT2022TB10)China Postdoctoral Science Foundation(No.2022M720639)。
文摘Dye-based color films are increasingly considered as viable alternatives to pigment-based color films in complementary metal-oxide-semiconductor(CMOS) image sensors.Herein,a series of azo dyes utilizing 5-methyl-2-phenyl-4-(2-phenylhydrazono)-2,4-dihydro-3H-pyrazol-3-one as the coupling component and aromatic amines with various electron-withdrawing groups(NO_(2),CN,Br) as diazo components were designed and synthesized.The presence of intermolecular hydrogen bonding between the hydrogen atom on the N-H group and the oxygen atom of the C=O group of the hydrazo structure facilitates the formation of a stable six-membered ring.Additionally,the electron-withdrawing groups in the diazo component further stabilize this hydrogen-bonded structure.As a result,these azo dyes(P-2,P-3,P-4,P-5)exhibit not only excellent light stability but also ultra-highly thermal stability(T_(d)> 260℃).Therein,the synthesized dyes P-2 and P-3 with great bright yellow color(~400 nm),proper solubility(~6.00g/100 g)were selected to make for color films.And their dye-based color films displayed ultra-highly thermal and light stability(color difference ΔE<3).Notably,the increased planarity of the molecular structure by hydrogen bonding for the novel dyes ensures a balance between high transmittance(>90%) in the 550-780 nm wavelength range and the solvent resistance of the dye-based color films.This work contributes to the advancement of next-generation smart CMOS devices and offers valuable insights into the design of azo dyes for applications in the field of organic electronics.
文摘In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,especially at the interface between the semiconductor and cocatalyst,has received insufficient attention.In this study,we report a Co,Ni and Mn trimetallic fluoride-modified BVO photoanode featuring a unique interfacial chemical bond(V-F).Under AM 1.5 G illumination,an exciting photocurrent density of 6.05 mA cm^(-2)was achieved at 1.23 V vs.RHE by the integrated BVO/CoNi_(0.18)Mn_(0.12)(OH)_(x)F photoanode and over 98%of the initial photocurrent was maintained after 10 h of photoelectrolysis.Control experiments and theoretical calculations demonstrate that the V-F interfacial bond stabilizes the Co^(2+)active sites.It serves as a transmission gear,interlinking the migration of interfacial charge and the regeneration of cocatalyst,endowing the photoanode with significant activity and stability.Furthermore,we have systematically elucidated the role of the individual Co,Ni,and Mn components in the synergistic cocatalyst layer.The interfacial modification provides novel insights into developing advanced photoanodes towards PEC water splitting.
基金supported by the National Natural Science Foundation of China(Nos.82130103,82151525 and 81903465)the Central Plains Scholars and Scientists Studio Fund(2018002)+1 种基金the Natural Science Foundation of Henan Province(No.212300410051)the Science and Technology Major Project of Henan Province(No.221100310300)。
文摘Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtained in high yields(up to 95%)and excellent enantioselectivities(up to 99%).In terms of synthetic utility,the reaction can be performed on a gram scale,and the product can be converted into potential biological nucleoside analog.
基金Project(U2341254)supported by Ye Qisun Science Foundation of National Natural Science Foundation of ChinaProject(52475406)supported by the National Nature Science Foundation of ChinaProject(2024CY2-GJHX-32)supported by the Key R&D Program of Shaanxi Province,China。
文摘Effect of flip chip bonding parameters on microstructure at the interconnect interface and shear properties of 64.8Sn35.2Pb microbumps were investigated in this work.Results show that the main intermetallic compound(IMC)at the interconnect interface is(Ni,Cu)_(3)Sn_(4)phase,and meanwhile a small amount of(Cu,Ni)_(6)Sn_(5)phase with a size of 50−100 nm is formed around(Ni,Cu)_(3)Sn_(4)phase.The orientation relationship of[-1-56](Ni,Cu)_(3)Sn_(4)//[152](Cu,Ni)_(6)Sn_(5)and(601)(Ni,Cu)_(3)Sn_(4)//(-201)(Cu,Ni)_(6)Sn_(5)is found between these two phases,and the atomic matching at the interface of the two phases is low.The highest shear force of 77.3 gf is achieved in the 64.8Sn35.2Pb microbump at the peak temperature of 250℃and parameter V1 because dense IMCs and no cracks form at the interconnect interface.Two typical fracture modes of microbumps are determined as solder fracture and mixed fracture.The high thermal stress presenting in the thick IMCs layer induces crack initiation,and cracks propagate along theα/βphase boundaries in the Sn-Pb solder under shear force,leading to a mixed fracture mode in the microbumps.
