Phase change thermal interface materials(PC-TIMs)have emerged as a promising solution to address the increasing thermal management challenges in electronic devices.This is attributed to their dual mechanisms of latent...Phase change thermal interface materials(PC-TIMs)have emerged as a promising solution to address the increasing thermal management challenges in electronic devices.This is attributed to their dual mechanisms of latent heat absorption and phase change-induced interfacial wettability.This review explores the fundamental principles,material innovations,and diverse applications of PC-TIMs.The heat transfer enhancement mechanisms are first underlined with key factors such as thermal carrier mismatch at the microscale and contact geometry at the macroscale,emphasizing the importance of material selection and design for optimizing thermal performance.Section 2 focuses on corresponding experimental approaches provided,including intrinsic thermal conductivity improvements and interfacial heat transfer optimization.Section 3 discusses common methods such as physical adsorption via porous materials,chain-crosslinked network designs,and core-shell structures,and their effects on leakage prevention,heat transfer enhancement,and application flexibility.Furthermore,the extended applications of PC-TIMs in thermal energy storage are explored in Section 4,suggesting their potential in diverse technological fields.The current challenges in interfacial heat transfer research and the prospect of PC-TIMs are also discussed.The data-driven machine learning technologies will play an increasingly important role in addressing material development and performance prediction.展开更多
Organic-inorganic hybrid perovskite solar cells achieve remarkable efficiencies(>26%)yet face stability challenges.Quasi-2D alternating-cation-interlayer perovskites offer enhanced stability through hydrophobic spa...Organic-inorganic hybrid perovskite solar cells achieve remarkable efficiencies(>26%)yet face stability challenges.Quasi-2D alternating-cation-interlayer perovskites offer enhanced stability through hydrophobic spacer cations but suffer from vertical phase segregation and buried interface defects.Herein,we introduce dicyanodiamide(DCD)to simultaneously address these dual limitations in GA(MA)_(n)Pb_(n)I_(3n+1)perovskites.The guanidine group in DCD passivates undercoordinated Pb^(2+)and MA^(+)vacancies at the perovskite/TiO_(2)interface,while cyano groups eliminate oxygen vacancies in TiO_(2)via Ti^(4+)-CN coordination,reducing interfacial trap density by 73%with respect to the control sample.In addition,DCD regulates crystallization kinetics,suppressing low-n-phase aggregation and promoting vertical alignment of high-n phases,which benefit for carrier transport.This dual-functional modification enhances charge transport and stabilizes energy-level alignment.The optimized devices achieve a record power conversion efficiency of 21.54%(vs.19.05%control)and retain 94%initial efficiency after 1200 h,outperforming unmodified counterparts(84%retention).Combining defect passivation with phase homogenization,this work establishes a molecular bridge strategy to decouple stability-efficiency trade-offs in low-dimensional perovskites,providing a universal framework for interface engineering in high-performance optoelectronics.展开更多
We study the effects of gas adsorption on the dynamics and stability of nanobubbles at the solid–liquid interface. The phase diagram and dynamic evolution of surface nanobubbles were analyzed under varying equilibriu...We study the effects of gas adsorption on the dynamics and stability of nanobubbles at the solid–liquid interface. The phase diagram and dynamic evolution of surface nanobubbles were analyzed under varying equilibrium adsorption constant.Four distinct dynamic behaviors appear in the phase diagram: shrinking to dissolution, expanding to bursting, shrinking to stability, and expanding to stability. Special boundary states are identified in phase diagram, where the continuous growth of nanobubbles can take place even under very weak gas–surface interaction or with very small initial bubble size. Surface adsorption plays a critical role in the stability, lifetime, radius, and contact angle of nanobubbles, thereby demonstrating that pinning is not a prerequisite for stabilization. Furthermore, stable equilibrium nanobubbles exhibit a characteristic range of footprint radius, a limited height, and a small contact angle, consistent with experimental observations.展开更多
In order to maximize the advantages of high energy density in Li metal batteries,it is necessary to match cathode materials with high specific capacities.Ni-rich layered oxides have been shown to reversibly embed more...In order to maximize the advantages of high energy density in Li metal batteries,it is necessary to match cathode materials with high specific capacities.Ni-rich layered oxides have been shown to reversibly embed more Li+during charge and discharge processes due to the increased Ni content in their crystal structure,thereby providing higher energy density.However,a significant challenge associated with Ni-rich layered oxide cathodes is the crossover effect,which arises from the dissolution of Ni^(2+)from the cathode,leading to a rapid decline in battery capacity.Through the delocalization-induced effect of solvent molecules,Ni^(2+)is transformed into a fluorinated transition metal inorganic phase layer,thereby forming a corrosion-resistant Li metal interface.This prevents solvent molecules from being reduced and degraded by Li metal anode.The surface of the Li metal anode exhibits a smooth and flat deposition morphology after long-term cycling.Furthermore,the introduction of Ni^(2+)can enhance the concentration gradient of transition metal ions near the cathode,thereby suppressing the dissolution process of transition metal ions.Even the NCM955 cathode with a mass load of 22 mg cm^(−2)also has great capacity retention after cycling.The Ni^(2+)induced by high electronegative functional groups of solvent under the electron delocalization effect,preventing the Ni ions dissolution of cathode and constructing a corrosion-resistant Li metal interface layer.This work provides new insights into suppressing crossover effects in Li metal batteries with high nickel cathodes.展开更多
Magnesium alloys have gained extensive applications across various industries,including aerospace,transportation,and civil construction,owing to their excellent combinations of high specific strength and stiffness[1]....Magnesium alloys have gained extensive applications across various industries,including aerospace,transportation,and civil construction,owing to their excellent combinations of high specific strength and stiffness[1].However,their lim-ited strength due to the lack of effective strengthening phases has hindered their broader industrial applications[2].Never-theless,it has been challenging to achieve significant strength-ening due to the restricted solubility of alloying elements in magnesium[3].Thus,more and more efforts have been made to explore the concept of secondary phase-reinforced magne-sium alloys[2,4,5],where the secondary phase acts as re-inforcing agents within the magnesium matrix,resembling a composite material.展开更多
A novel approach based on the quantitative phase field model was proposed to calculate the interface mobility and applied to the α/β interface of a ternary Ti-6Al-4V alloy.Phase field simulations indicate that the h...A novel approach based on the quantitative phase field model was proposed to calculate the interface mobility and applied to the α/β interface of a ternary Ti-6Al-4V alloy.Phase field simulations indicate that the higher interface mobility leads to the faster transformation rate,but only a unique value of interface mobility matches the diffusion equation under the diffusion-controlled condition.By comparing the transformation kinetics from phase field simulations with that from classical diffusion equation,the interface mobility at different temperatures can be obtained.The results show that the calculated interface mobility increases with increasing temperature and accords with Arrhenius equation very well.展开更多
The infiltration casting method is widely employed for the preparation of ex-situ composite materials.However,the production of composite materials using this method must necessitates a comprehensive understanding of ...The infiltration casting method is widely employed for the preparation of ex-situ composite materials.However,the production of composite materials using this method must necessitates a comprehensive understanding of the wettability and interface characteristics between the reinforcing phase and the bulk metallic glasses(BMGs).This work optimized the composition of Zr-based BMGs through microalloying methods,resulting in a new set of Zr-based BMGs with excellent glass-forming ability.Wetting experiments between the Zr-based BMGs melts and W substrates were conducted using the traditional sessile drop method,and the interfaces were characterized utilizing a scanning electron microscope(SEM)equipped with energy dispersive X-ray spectroscopy(EDS).The work demonstrates that the microalloying method substantially enhances the wettability of the Zr-based BMGs melt.Additionally,the incorporation of Nb element impedes the formation of W-Zr phases,but the introduction of Nb element does not alter the extent of interdiffusion between the constituent elements of the amorphous matrix and W element,indicating that the influence of Nb element on the diffusion of individual elements is minute.展开更多
In this study, the phase field method was used to study the multi-controlling factors of dendrite growth in directional solidification. The effects of temperature gradient, propelling velocity, thermal disturbance and...In this study, the phase field method was used to study the multi-controlling factors of dendrite growth in directional solidification. The effects of temperature gradient, propelling velocity, thermal disturbance and growth orientation angle on the growth morphology of the dendritic growth in the solid/liquid interface were discussed. It is found that the redistribution of solute leads to multilevel cavity and multilevel fusion to form multistage solute segregation, and the increase of temperature gradient and propelling velocity can accelerate the dendrite growth of directional solidification, and also make the second dendrites more developed, which reduces the primary distance and the solute segregation. When the temperature gradient is large, the solid-liquid interface will move forward in a flat interface mode,and the thermal disturbance does not affect the steady state behavior of the directionally solidified dendrite tip. It only promotes the generation and growth of the second dendrites and forms the asymmetric dendrite. Meanwhile, it is found that the inclined dendrite is at a disadvantage in the competitive growth compared to the normal dendrite, and generally it will disappear. When the inclination angle is large, the initial primary dendrite may be eliminated by its secondary or third dendrite.展开更多
Laser cladding deposited Ti-6Al-4V titanium alloy universally shows more complex microstructures,each of which has significant effect on mechanical properties. Of particular α/β interface phase has been observed in ...Laser cladding deposited Ti-6Al-4V titanium alloy universally shows more complex microstructures,each of which has significant effect on mechanical properties. Of particular α/β interface phase has been observed in this paper under certain conditions. It demonstrates that the influence of the α/β interface phase on the tensile properties is closely associated with dislocations and twin substructure through comparison experiments. The results show that the α/β interface phase hinders dislocation motion and decreases effective slip length. In addition, the twin substructure has been activated in the α/β interface phase during tensile process and has acted somehow like grain boundaries. Therefore, the strength and the work-hardening rate of the laser cladding deposited Ti-6Al-4V titanium alloy have been significantly improved due to the dynamic Hall-Petch effect. Besides, the α/β interface phase leads to more uniform dislocations distribution, which implies that relative lower local concentrated stress will be produced along the α/β interface phase or colony boundary after the same amount of plastic deformation. Moreover,the twinning-induced plasticity effects in the α/β interface phase further increase the plastic deformation capacity. These results in higher elongation for the laser cladding deposited Ti-6Al-4V titanium alloy.It can be concluded that the current work suggests an effective method to simultaneously improve the strength and plasticity of laser cladding deposited Ti-6Al-4V titanium alloy based on the α/β interface phase.展开更多
The temperature gradients that arise in the paraelectric-ferroelectric interface dynamics induced by the latent heat transfer are studied from the point of view that a ferroelectric phase transition is a stationary, t...The temperature gradients that arise in the paraelectric-ferroelectric interface dynamics induced by the latent heat transfer are studied from the point of view that a ferroelectric phase transition is a stationary, thermal-electric coupled transport process. The local entropy production is derived for a ferroelectric phase transition system from the Gibbs equation. Three types of regions in the system are described well by using the Onsager relations and the principle of minimum entropy production. The theoretical results coincides with the experimental ones.展开更多
β-Nb is a typical second phase in Zr-Nb-based alloys used as fuel claddings in water-cooled nuclear reactors. The segregation of alloying element Fe may affect the corrosion resistance of Zr-Nb-based alloys. In this ...β-Nb is a typical second phase in Zr-Nb-based alloys used as fuel claddings in water-cooled nuclear reactors. The segregation of alloying element Fe may affect the corrosion resistance of Zr-Nb-based alloys. In this work, the Fe segregation at the interface between β-Nb phase and a-Zr matrix in Zr-2.5Nb alloy was studied using atom probe tomography and focused ion beam. The results suggested that the Fe concentration was much lower than Nb concentration in a-Zr matrix, while Fe selectively segregated at the β-Nb/a-Zr phase interface, leading to a Fe concentration peak at some interfaces. The peak Fe concentration varied from 0.4 to 1.2 at.% and appeared at the position where Zr concentration was approximately equal to Nb concentration. The selective segregation of Fe should be affected by the heat treatment and structure defects induced by cold rolling.展开更多
Over the past decades, topological interface states have attracted significant attention in classical wave systems. Generally, research on the topological interface states of elastic waves is conducted in the lattices...Over the past decades, topological interface states have attracted significant attention in classical wave systems. Generally, research on the topological interface states of elastic waves is conducted in the lattices with symmetric elements. This paper proposes composite lattices with/without symmetric elements, and demonstrates the realization of tunable topological interface states of elastic waves via parametric systems.To quantize the topological characteristics of the bands, a modified Zak phase is defined to calculate the topological invariant by the eigenstates for the lattices with/without symmetric elements. The numerical results show that the tunable frequencies of topological interface states can be realized in composite lattices with/without symmetric elements through the modulation of the parametric excitation frequency. The tunable topological interface states can be introduced into the vibration energy harvesting to design efficient and steady energy harvesting systems.展开更多
Based on the microscopic phase-field model, the structure and migration characteristic of ordered domain interfaces formed between DO22 and L12 phase are investigated, and the atomistic mechanism of phase transformati...Based on the microscopic phase-field model, the structure and migration characteristic of ordered domain interfaces formed between DO22 and L12 phase are investigated, and the atomistic mechanism of phase transformation from L12 （Ni3Al） to DO22 （Ni3V） in Ni75AlxV25-x alloys are explored, using the simulated microstructure evolution pictures and the occupation probability evolution of alloy elements at the interface. The results show that five kinds of heterointerfaces are formed between DO22 and L12 phase and four of them can migrate during the phase transformation from L12 to DO22 except the interface （002）D//（001）L. The structure of interface （100）D//（200）L and interface （100）D//（200）L·^1/2[001] remain the same before and after migration, while the interface （002）D//（002）L is formed after the migration of interface （002）D//（002）L·^1/2[100] and vice versa. These two kinds of interface appear alternatively. The jump and substitute of atoms selects the optimization way to induce the migration of interface during the phase transformation, and the number of atoms needing to jump during the migration is the least among all of the possible atom jump modes.展开更多
Interface and scale effects are the two most important factors which strongly affect the structure and the properties of nano-/micro-crystals under pressure.We conduct an experiment under high pressure in situ alterna...Interface and scale effects are the two most important factors which strongly affect the structure and the properties of nano-/micro-crystals under pressure.We conduct an experiment under high pressure in situ alternating current impedance to elucidate the effects of interface on the structure and electrical transport behavior of two Zn Se samples with different sizes obtained by physical grinding.The results show that（i） two different-sized Zn Se samples undergo the same phase transitions from zinc blend to cinnabar-type phase and then to rock salt phase;（ii） the structural transition pressure of the859-nm Zn Se sample is higher than that of the sample of 478 nm,which indicates the strong scale effect.The pressure induced boundary resistance change is obtained by fitting the impedance spectrum,which shows that the boundary conduction dominates the electrical transport behavior of Zn Se in the whole experimental pressure range.By comparing the impedance spectra of two different-sized Zn Se samples at high pressure,we find that the resistance of the 478-nm Zn Se sample is lower than that of the 859-nm sample,which illustrates that the sample with smaller particle size has more defects which are due to physical grinding.展开更多
The influences of additives on the phase transformation, occurrence state, and the interface of the Ti component in Ti-bearing blast furnace slag were investigated. After oxidation, most of the Ti component in the sla...The influences of additives on the phase transformation, occurrence state, and the interface of the Ti component in Ti-bearing blast furnace slag were investigated. After oxidation, most of the Ti component in the slag was enriched into the perovskite phase, which served as the Ti-rich phase during the crystallization process. The phase transformation, occurrence state, and the interface of the Ti component were observed to be affected by the addition of different types of agents. During the oxidation process, titanaugite and Ti-rich diopside phases gradually transformed into non-Ti phases（anorthite： CaMgSi2O6 and CaAl2Si2O8） in the form of dendrites or columns, which were observed to be distributed at the surface of the perovskite phase. Several more cracks appeared along the grain boundaries of the perovskite phase after the addition of P2O5, facilitating the liberation of the perovskite phase. Composite additives combining both an acid and a base, such as CaO ＋ CaF2 or P2O5 ＋ CaF2, were used. We observed that the disadvantages of using single additives were successfully overcome.展开更多
The interface of ceramic particles and metal matrixes extremely impacts the mechanical properties of particle-reinforced metal matrix composites,especially at elevated temperatures.We provide a strategy for constructi...The interface of ceramic particles and metal matrixes extremely impacts the mechanical properties of particle-reinforced metal matrix composites,especially at elevated temperatures.We provide a strategy for constructing extremely fine,in situ-formed coherent nanolamellar solute-twining architectures in a supersaturated MAX/Ni composite to modify the interface,aiming for higher strengths.Through this unique architecture,a coherent interface of ceramic particles and a metal matrix is formed,with an enormous coherent interface known as a ladder interface.The tensile strength at 1023 K is approximately 1 GPa by forming a thermally stable Schwarz crystal structure(<3 nm).Developing heat-tolerant composites using this architecture may enhance the materials’available properties for high-temperature applications.展开更多
Niobium pentoxide(Nb2O5)has attracted much attention in lithium batteries due to its advantages of high operating voltage,large theoretical capacity,environmental friendliness and cost-effectiveness.However,the intrin...Niobium pentoxide(Nb2O5)has attracted much attention in lithium batteries due to its advantages of high operating voltage,large theoretical capacity,environmental friendliness and cost-effectiveness.However,the intrinsic poor electrical conductivity,sluggish kinetics,and large volume changes hinder its electrochemical performance at high power density,making it away from the requirements for practical applications.In this research work,we regulate the electron transport of niobium-nickel oxide(NiNbO)anode material with enhanced structural stability at high power density by constructing the two-phase boundaries between niobium pentoxide(Nb2O5)and nickel niobate(NiNb2O6)through simple solid phase reaction.In addition,the presence of lattice defects in NiNbO-F further speeds up the transport of Li+and promotes the electrochemical reaction kinetics more effectively.The two-phase boundaries and defect modulated anode material displays high Li+diffusion coefficient of 1.63×10^(−10) cm^(2) s^(−1),pretty high initial discharge capacity of 222.8 mAh g^(−1) at 1 C,extraordinary high rate performance(66.7 mAh g^(−1))at an ultrahigh rate(100 C)and ultra-long cycling stability under high rate of 25 C(83.4 mAh g^(−1) after 2000 cycles)with only 0.016%attenuation per cycle.These results demonstrate an effective approach for developing electrode materials that greatly improve rate performance and durability.展开更多
TiAl/Ti_(2)AlNb intermetallic-intermetallic laminated(IIL)composites featuring brittle/ductile heterogeneous interfaces were fabricated through vacuum hot-pack rolling.The microstructures and the phase transfor-mation...TiAl/Ti_(2)AlNb intermetallic-intermetallic laminated(IIL)composites featuring brittle/ductile heterogeneous interfaces were fabricated through vacuum hot-pack rolling.The microstructures and the phase transfor-mation behaviors of the interfaces of the IIL composites before and after annealing at 900°C/6 h were in-vestigated.The heterogeneous interfaces are composed of four distinct regions,individually I(β_(o)+γ+α_(2)),II(β_(o)/B_(2)+ω)(brittle part),III(O lath),and IV(equiaxed O)(ductile part)regions from TiAl to Ti_(2)AlNb side.Notably,after annealing,an equiaxed O band approximately 50μm wide was observed in region IV of the interface.In addition,a significant microhardness variation was observed between regions II and IV of the interface,where region II exhibited higher hardness compared to the TiAl alloy,and region IV displayed lower hardness than the Ti_(2)AlNb alloy.The enhanced fracture toughness of the IIL composites,three times that of the TiAl base alloy,is attributed to the formation of the brittle/ductile heterogeneous interfaces and the layered design incorporating the Ti_(2)AlNb alloy.The corresponding toughening mech-anism was further discussed.The brittle II region plays a role in increasing crack branching,while the ductile IV region inhibits the propagation of microcracks and prevents the formation of main cracks.This work highlights the crucial role of the brittle/ductile heterogeneous interface in the toughening of lam-inated composites.Furthermore,the discovery of the O band provides novel insights into the design of TiAl/Ti_(2)AlNb heterostructures.展开更多
In the welding process of SiCp/Al composites,Al reacts with SiC particles in the molten pool to form Al_(4)C_(3),a brittle phase,damaging the reinforcement and causing a sharp decline in the mechanical properties of w...In the welding process of SiCp/Al composites,Al reacts with SiC particles in the molten pool to form Al_(4)C_(3),a brittle phase,damaging the reinforcement and causing a sharp decline in the mechanical properties of weld joints.To mitigate this,a method of welding SiCp/Al composites by pulsed laser welding with powder-filling is proposed,inhibiting the interface reaction between Al and SiC particles in the molten pool.This study investigates the effect of pulse frequency on the temperature field of the molten pool,and combines thermal-fluid numerical simulation to analyze the peak temperature at different pulse frequencies,optimizing the Si content to ultimately inhibit the interface reaction in the molten pool.Results indicate that an appropriate pulse frequency achieves good welding formation and effectively regulates the peak temperature of the molten pool.Only a small amount of brittle phase is present in the weld joint,creating favorable conditions for the addition of alloying elements.The interface reaction is slowed down by adjusting the pulse frequency,though it is not completely inhibited.When the addition of Si content reaches 8%,the occurrence of the interface reaction is effectively inhibited.In weld joints with the addition of 8wt%Si powder,no Al_(4)C_(3)brittle phase is present,and the tensile strength of the weld joint is 266 MPa,up to 70%of the base material.展开更多
A hierarchically structured MnO_(x)-NiCo_(2)O_(4) monolithic catalyst with rich phase interfaces was designed by a simple,eco-friendly and time-saving in-situ electro-deposition method.The abundance of active oxygen s...A hierarchically structured MnO_(x)-NiCo_(2)O_(4) monolithic catalyst with rich phase interfaces was designed by a simple,eco-friendly and time-saving in-situ electro-deposition method.The abundance of active oxygen species due to this rich phase interfaces contributed to the excellent benzene combustion performance of MnO_(x)-NiCo_(2)O_(4)-2:2 sample,oxidizing about 90% of benzene(T_(90)) at 198℃ under 12000 h^(-1) gaseous hourly space velocity.This work shed new light on the design of excellent monolithic catalysts,which might pave the way for the industrialization of benzene combustion.展开更多
基金funding from the National Natural Science Foundation of China(Grant Nos.52306214,52425601,and 52276074)the Shanghai Chenguang Plan Program(Grant No.22CGA78)the National Key Research and the Development Program of China(Grant No.2023YFB4404104)。
文摘Phase change thermal interface materials(PC-TIMs)have emerged as a promising solution to address the increasing thermal management challenges in electronic devices.This is attributed to their dual mechanisms of latent heat absorption and phase change-induced interfacial wettability.This review explores the fundamental principles,material innovations,and diverse applications of PC-TIMs.The heat transfer enhancement mechanisms are first underlined with key factors such as thermal carrier mismatch at the microscale and contact geometry at the macroscale,emphasizing the importance of material selection and design for optimizing thermal performance.Section 2 focuses on corresponding experimental approaches provided,including intrinsic thermal conductivity improvements and interfacial heat transfer optimization.Section 3 discusses common methods such as physical adsorption via porous materials,chain-crosslinked network designs,and core-shell structures,and their effects on leakage prevention,heat transfer enhancement,and application flexibility.Furthermore,the extended applications of PC-TIMs in thermal energy storage are explored in Section 4,suggesting their potential in diverse technological fields.The current challenges in interfacial heat transfer research and the prospect of PC-TIMs are also discussed.The data-driven machine learning technologies will play an increasingly important role in addressing material development and performance prediction.
基金support from the National Key R&D Program of China(Grant No.2023YFE0111500)the National Natural Science Foundation of China(Grant No.52321006,T2394480,T2394484,22109143,22479131)+8 种基金Beijing National Laboratory for Molecular Sciences(BNLMS-CXXM-202005)the China Postdoctoral Innovative Talent Support Program(Grant No.BX2021271)the China Postdoctoral Science Foundation(2022M712851)the Opening Project of State Key Laboratory of Advanced Technology for Float Glass(Grant No.2022KF04)Graduate Education Reform Project of Henan Province(Grant No.2023SJGLX136Y)Key R&D Special Program of Henan Province(Grant No.241111242000)Program for Science and Technology Innovation Talents in Universities of Henan Province(Grant No.25HASTIT005)Training Plan for Young Backbone Teachers of Zhengzhou University(Grant No.2023ZDGGJS017)the Joint Research Project of Puyang Shengtong Juyuan New Materials Co.,Ltd.(Grant No.20230128A).
文摘Organic-inorganic hybrid perovskite solar cells achieve remarkable efficiencies(>26%)yet face stability challenges.Quasi-2D alternating-cation-interlayer perovskites offer enhanced stability through hydrophobic spacer cations but suffer from vertical phase segregation and buried interface defects.Herein,we introduce dicyanodiamide(DCD)to simultaneously address these dual limitations in GA(MA)_(n)Pb_(n)I_(3n+1)perovskites.The guanidine group in DCD passivates undercoordinated Pb^(2+)and MA^(+)vacancies at the perovskite/TiO_(2)interface,while cyano groups eliminate oxygen vacancies in TiO_(2)via Ti^(4+)-CN coordination,reducing interfacial trap density by 73%with respect to the control sample.In addition,DCD regulates crystallization kinetics,suppressing low-n-phase aggregation and promoting vertical alignment of high-n phases,which benefit for carrier transport.This dual-functional modification enhances charge transport and stabilizes energy-level alignment.The optimized devices achieve a record power conversion efficiency of 21.54%(vs.19.05%control)and retain 94%initial efficiency after 1200 h,outperforming unmodified counterparts(84%retention).Combining defect passivation with phase homogenization,this work establishes a molecular bridge strategy to decouple stability-efficiency trade-offs in low-dimensional perovskites,providing a universal framework for interface engineering in high-performance optoelectronics.
基金Project supported by the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant No. 2022GXNSFAA035487)the National Natural Science Foundation of China (Grant Nos. 12272100, 11474285, and 12074382)+2 种基金the Graduate Education Innovation Project of Guangxi Zhuang Autonomous Region, China (Grant No. XJCY2022012)the Guangxi Normal University Ideological and Political Demonstration Course Construction Project (Grant Nos. 2022kcsz15 and 2023kcsz29)the Innovation Project of Graduate Education of Guangxi Zhuang Autonomous Region, China (Grant No. YCBZ2024087)。
文摘We study the effects of gas adsorption on the dynamics and stability of nanobubbles at the solid–liquid interface. The phase diagram and dynamic evolution of surface nanobubbles were analyzed under varying equilibrium adsorption constant.Four distinct dynamic behaviors appear in the phase diagram: shrinking to dissolution, expanding to bursting, shrinking to stability, and expanding to stability. Special boundary states are identified in phase diagram, where the continuous growth of nanobubbles can take place even under very weak gas–surface interaction or with very small initial bubble size. Surface adsorption plays a critical role in the stability, lifetime, radius, and contact angle of nanobubbles, thereby demonstrating that pinning is not a prerequisite for stabilization. Furthermore, stable equilibrium nanobubbles exhibit a characteristic range of footprint radius, a limited height, and a small contact angle, consistent with experimental observations.
基金the support from Yunnan Fundamental Research Projects(202301BE070001-029,202401CF070129,202501CF070181)National Natural Science Foundation of China(22209012,22479067)Kunming University of Science and Technology Analysis and Testing Fund Support Project(2023T20220172)。
文摘In order to maximize the advantages of high energy density in Li metal batteries,it is necessary to match cathode materials with high specific capacities.Ni-rich layered oxides have been shown to reversibly embed more Li+during charge and discharge processes due to the increased Ni content in their crystal structure,thereby providing higher energy density.However,a significant challenge associated with Ni-rich layered oxide cathodes is the crossover effect,which arises from the dissolution of Ni^(2+)from the cathode,leading to a rapid decline in battery capacity.Through the delocalization-induced effect of solvent molecules,Ni^(2+)is transformed into a fluorinated transition metal inorganic phase layer,thereby forming a corrosion-resistant Li metal interface.This prevents solvent molecules from being reduced and degraded by Li metal anode.The surface of the Li metal anode exhibits a smooth and flat deposition morphology after long-term cycling.Furthermore,the introduction of Ni^(2+)can enhance the concentration gradient of transition metal ions near the cathode,thereby suppressing the dissolution process of transition metal ions.Even the NCM955 cathode with a mass load of 22 mg cm^(−2)also has great capacity retention after cycling.The Ni^(2+)induced by high electronegative functional groups of solvent under the electron delocalization effect,preventing the Ni ions dissolution of cathode and constructing a corrosion-resistant Li metal interface layer.This work provides new insights into suppressing crossover effects in Li metal batteries with high nickel cathodes.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030006)the Guangdong Basic and Applied Basic Research Foundation[Grant No.2021B1515120071]+1 种基金R.Shi would like to thank the financial support from the open research fund of Songshan Lake Materials Laboratory(2021SLABFK06)start-up funding from Harbin Institute of Technology(Shenzhen).
文摘Magnesium alloys have gained extensive applications across various industries,including aerospace,transportation,and civil construction,owing to their excellent combinations of high specific strength and stiffness[1].However,their lim-ited strength due to the lack of effective strengthening phases has hindered their broader industrial applications[2].Never-theless,it has been challenging to achieve significant strength-ening due to the restricted solubility of alloying elements in magnesium[3].Thus,more and more efforts have been made to explore the concept of secondary phase-reinforced magne-sium alloys[2,4,5],where the secondary phase acts as re-inforcing agents within the magnesium matrix,resembling a composite material.
基金Project (51101059) supported by the National Natural Science Foundation of ChinaProject (20110490874) supported by the China Postdoctoral Science Foundation
文摘A novel approach based on the quantitative phase field model was proposed to calculate the interface mobility and applied to the α/β interface of a ternary Ti-6Al-4V alloy.Phase field simulations indicate that the higher interface mobility leads to the faster transformation rate,but only a unique value of interface mobility matches the diffusion equation under the diffusion-controlled condition.By comparing the transformation kinetics from phase field simulations with that from classical diffusion equation,the interface mobility at different temperatures can be obtained.The results show that the calculated interface mobility increases with increasing temperature and accords with Arrhenius equation very well.
基金the support of the China Manned Space Engineering(YYMT1201-EXP08)。
文摘The infiltration casting method is widely employed for the preparation of ex-situ composite materials.However,the production of composite materials using this method must necessitates a comprehensive understanding of the wettability and interface characteristics between the reinforcing phase and the bulk metallic glasses(BMGs).This work optimized the composition of Zr-based BMGs through microalloying methods,resulting in a new set of Zr-based BMGs with excellent glass-forming ability.Wetting experiments between the Zr-based BMGs melts and W substrates were conducted using the traditional sessile drop method,and the interfaces were characterized utilizing a scanning electron microscope(SEM)equipped with energy dispersive X-ray spectroscopy(EDS).The work demonstrates that the microalloying method substantially enhances the wettability of the Zr-based BMGs melt.Additionally,the incorporation of Nb element impedes the formation of W-Zr phases,but the introduction of Nb element does not alter the extent of interdiffusion between the constituent elements of the amorphous matrix and W element,indicating that the influence of Nb element on the diffusion of individual elements is minute.
基金financially supported by the National Natural Science Foundation of China(NSFC)under grant Nos.51774254,51774253,U1610123,51574207,51574206the Science and Technology Major Project of Shanxi Province under grant No.MC2016-06
文摘In this study, the phase field method was used to study the multi-controlling factors of dendrite growth in directional solidification. The effects of temperature gradient, propelling velocity, thermal disturbance and growth orientation angle on the growth morphology of the dendritic growth in the solid/liquid interface were discussed. It is found that the redistribution of solute leads to multilevel cavity and multilevel fusion to form multistage solute segregation, and the increase of temperature gradient and propelling velocity can accelerate the dendrite growth of directional solidification, and also make the second dendrites more developed, which reduces the primary distance and the solute segregation. When the temperature gradient is large, the solid-liquid interface will move forward in a flat interface mode,and the thermal disturbance does not affect the steady state behavior of the directionally solidified dendrite tip. It only promotes the generation and growth of the second dendrites and forms the asymmetric dendrite. Meanwhile, it is found that the inclined dendrite is at a disadvantage in the competitive growth compared to the normal dendrite, and generally it will disappear. When the inclination angle is large, the initial primary dendrite may be eliminated by its secondary or third dendrite.
基金supported by the National Key Research And Development Plan, China (No. 2016YFB1100100)the Research Fund of the State Key Laboratory of Solidification Processing (NWPU), China (No. KP201611)the National Natural Science Foundation of China (No. 51475380)
文摘Laser cladding deposited Ti-6Al-4V titanium alloy universally shows more complex microstructures,each of which has significant effect on mechanical properties. Of particular α/β interface phase has been observed in this paper under certain conditions. It demonstrates that the influence of the α/β interface phase on the tensile properties is closely associated with dislocations and twin substructure through comparison experiments. The results show that the α/β interface phase hinders dislocation motion and decreases effective slip length. In addition, the twin substructure has been activated in the α/β interface phase during tensile process and has acted somehow like grain boundaries. Therefore, the strength and the work-hardening rate of the laser cladding deposited Ti-6Al-4V titanium alloy have been significantly improved due to the dynamic Hall-Petch effect. Besides, the α/β interface phase leads to more uniform dislocations distribution, which implies that relative lower local concentrated stress will be produced along the α/β interface phase or colony boundary after the same amount of plastic deformation. Moreover,the twinning-induced plasticity effects in the α/β interface phase further increase the plastic deformation capacity. These results in higher elongation for the laser cladding deposited Ti-6Al-4V titanium alloy.It can be concluded that the current work suggests an effective method to simultaneously improve the strength and plasticity of laser cladding deposited Ti-6Al-4V titanium alloy based on the α/β interface phase.
文摘The temperature gradients that arise in the paraelectric-ferroelectric interface dynamics induced by the latent heat transfer are studied from the point of view that a ferroelectric phase transition is a stationary, thermal-electric coupled transport process. The local entropy production is derived for a ferroelectric phase transition system from the Gibbs equation. Three types of regions in the system are described well by using the Onsager relations and the principle of minimum entropy production. The theoretical results coincides with the experimental ones.
基金supported by the National Natural Science Foundation of China (No. 51171102)
文摘β-Nb is a typical second phase in Zr-Nb-based alloys used as fuel claddings in water-cooled nuclear reactors. The segregation of alloying element Fe may affect the corrosion resistance of Zr-Nb-based alloys. In this work, the Fe segregation at the interface between β-Nb phase and a-Zr matrix in Zr-2.5Nb alloy was studied using atom probe tomography and focused ion beam. The results suggested that the Fe concentration was much lower than Nb concentration in a-Zr matrix, while Fe selectively segregated at the β-Nb/a-Zr phase interface, leading to a Fe concentration peak at some interfaces. The peak Fe concentration varied from 0.4 to 1.2 at.% and appeared at the position where Zr concentration was approximately equal to Nb concentration. The selective segregation of Fe should be affected by the heat treatment and structure defects induced by cold rolling.
基金Project supported by the National Natural Science Foundation of China (Nos. 62188101 and 11902097)。
文摘Over the past decades, topological interface states have attracted significant attention in classical wave systems. Generally, research on the topological interface states of elastic waves is conducted in the lattices with symmetric elements. This paper proposes composite lattices with/without symmetric elements, and demonstrates the realization of tunable topological interface states of elastic waves via parametric systems.To quantize the topological characteristics of the bands, a modified Zak phase is defined to calculate the topological invariant by the eigenstates for the lattices with/without symmetric elements. The numerical results show that the tunable frequencies of topological interface states can be realized in composite lattices with/without symmetric elements through the modulation of the parametric excitation frequency. The tunable topological interface states can be introduced into the vibration energy harvesting to design efficient and steady energy harvesting systems.
基金Funded by the National Natural Science Foundation of China (Nos.50941020, 10902086, 50875217, and 20903075)Natural Science Foundation of Shaanxi Province (Nos. SJ08-ZT05 and SJ08-B14)Doctorate Foundation of Northwest Polytechnical University (No. CX200905)
文摘Based on the microscopic phase-field model, the structure and migration characteristic of ordered domain interfaces formed between DO22 and L12 phase are investigated, and the atomistic mechanism of phase transformation from L12 （Ni3Al） to DO22 （Ni3V） in Ni75AlxV25-x alloys are explored, using the simulated microstructure evolution pictures and the occupation probability evolution of alloy elements at the interface. The results show that five kinds of heterointerfaces are formed between DO22 and L12 phase and four of them can migrate during the phase transformation from L12 to DO22 except the interface （002）D//（001）L. The structure of interface （100）D//（200）L and interface （100）D//（200）L·^1/2[001] remain the same before and after migration, while the interface （002）D//（002）L is formed after the migration of interface （002）D//（002）L·^1/2[100] and vice versa. These two kinds of interface appear alternatively. The jump and substitute of atoms selects the optimization way to induce the migration of interface during the phase transformation, and the number of atoms needing to jump during the migration is the least among all of the possible atom jump modes.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11404133 and 11374121)the Program of Science and Technology Development Plan of Jilin Province,China(Grant No.20140520105JH)
文摘Interface and scale effects are the two most important factors which strongly affect the structure and the properties of nano-/micro-crystals under pressure.We conduct an experiment under high pressure in situ alternating current impedance to elucidate the effects of interface on the structure and electrical transport behavior of two Zn Se samples with different sizes obtained by physical grinding.The results show that（i） two different-sized Zn Se samples undergo the same phase transitions from zinc blend to cinnabar-type phase and then to rock salt phase;（ii） the structural transition pressure of the859-nm Zn Se sample is higher than that of the sample of 478 nm,which indicates the strong scale effect.The pressure induced boundary resistance change is obtained by fitting the impedance spectrum,which shows that the boundary conduction dominates the electrical transport behavior of Zn Se in the whole experimental pressure range.By comparing the impedance spectra of two different-sized Zn Se samples at high pressure,we find that the resistance of the 478-nm Zn Se sample is lower than that of the 859-nm sample,which illustrates that the sample with smaller particle size has more defects which are due to physical grinding.
基金supported by the Open Research Fund of the Key Laboratory for Ferrous Metallurgy and Resources Utilization of the Ministry of EducationWuhan University of Science and Technology (FMRU2007K10)
文摘The influences of additives on the phase transformation, occurrence state, and the interface of the Ti component in Ti-bearing blast furnace slag were investigated. After oxidation, most of the Ti component in the slag was enriched into the perovskite phase, which served as the Ti-rich phase during the crystallization process. The phase transformation, occurrence state, and the interface of the Ti component were observed to be affected by the addition of different types of agents. During the oxidation process, titanaugite and Ti-rich diopside phases gradually transformed into non-Ti phases（anorthite： CaMgSi2O6 and CaAl2Si2O8） in the form of dendrites or columns, which were observed to be distributed at the surface of the perovskite phase. Several more cracks appeared along the grain boundaries of the perovskite phase after the addition of P2O5, facilitating the liberation of the perovskite phase. Composite additives combining both an acid and a base, such as CaO ＋ CaF2 or P2O5 ＋ CaF2, were used. We observed that the disadvantages of using single additives were successfully overcome.
基金supported financially by the Beijing Natural Science Foundation(No.2212046)the National Natural Science Foundation of China(Nos.51871011 and 51572017)+2 种基金the Research Fund for Commercialization of Major Scientific and Technological Achievements of Hebei Province(No.22281006Z)the Beijing Government Funds for the Constructive Project of Central UniversitiesThe financial supports by them are greatly appreciated.
文摘The interface of ceramic particles and metal matrixes extremely impacts the mechanical properties of particle-reinforced metal matrix composites,especially at elevated temperatures.We provide a strategy for constructing extremely fine,in situ-formed coherent nanolamellar solute-twining architectures in a supersaturated MAX/Ni composite to modify the interface,aiming for higher strengths.Through this unique architecture,a coherent interface of ceramic particles and a metal matrix is formed,with an enormous coherent interface known as a ladder interface.The tensile strength at 1023 K is approximately 1 GPa by forming a thermally stable Schwarz crystal structure(<3 nm).Developing heat-tolerant composites using this architecture may enhance the materials’available properties for high-temperature applications.
基金supported by the National Natural Science Foundation of China(Nos.52002119 and 52102346)the National Key R&D Program of China(No.2021YFB3400800)the Startup Funds from the Henan University of Science and Technology(Nos.13480095,13480096,13554031 and 13554032).
文摘Niobium pentoxide(Nb2O5)has attracted much attention in lithium batteries due to its advantages of high operating voltage,large theoretical capacity,environmental friendliness and cost-effectiveness.However,the intrinsic poor electrical conductivity,sluggish kinetics,and large volume changes hinder its electrochemical performance at high power density,making it away from the requirements for practical applications.In this research work,we regulate the electron transport of niobium-nickel oxide(NiNbO)anode material with enhanced structural stability at high power density by constructing the two-phase boundaries between niobium pentoxide(Nb2O5)and nickel niobate(NiNb2O6)through simple solid phase reaction.In addition,the presence of lattice defects in NiNbO-F further speeds up the transport of Li+and promotes the electrochemical reaction kinetics more effectively.The two-phase boundaries and defect modulated anode material displays high Li+diffusion coefficient of 1.63×10^(−10) cm^(2) s^(−1),pretty high initial discharge capacity of 222.8 mAh g^(−1) at 1 C,extraordinary high rate performance(66.7 mAh g^(−1))at an ultrahigh rate(100 C)and ultra-long cycling stability under high rate of 25 C(83.4 mAh g^(−1) after 2000 cycles)with only 0.016%attenuation per cycle.These results demonstrate an effective approach for developing electrode materials that greatly improve rate performance and durability.
基金supported by the National Key Re-search and Development Program of China(No.2021YFB3702603)the Innovation Foundation for Doctor Dissertation of Northwest-ern Polytechnical University(No.CX2023045)+2 种基金the National Nat-ural Science Foundation of China(No.52174377)Chongqing Technology Innovation and Application Development Project(No.CSTB2022TIAD-KPX0032)the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(No.2022-TS-06).
文摘TiAl/Ti_(2)AlNb intermetallic-intermetallic laminated(IIL)composites featuring brittle/ductile heterogeneous interfaces were fabricated through vacuum hot-pack rolling.The microstructures and the phase transfor-mation behaviors of the interfaces of the IIL composites before and after annealing at 900°C/6 h were in-vestigated.The heterogeneous interfaces are composed of four distinct regions,individually I(β_(o)+γ+α_(2)),II(β_(o)/B_(2)+ω)(brittle part),III(O lath),and IV(equiaxed O)(ductile part)regions from TiAl to Ti_(2)AlNb side.Notably,after annealing,an equiaxed O band approximately 50μm wide was observed in region IV of the interface.In addition,a significant microhardness variation was observed between regions II and IV of the interface,where region II exhibited higher hardness compared to the TiAl alloy,and region IV displayed lower hardness than the Ti_(2)AlNb alloy.The enhanced fracture toughness of the IIL composites,three times that of the TiAl base alloy,is attributed to the formation of the brittle/ductile heterogeneous interfaces and the layered design incorporating the Ti_(2)AlNb alloy.The corresponding toughening mech-anism was further discussed.The brittle II region plays a role in increasing crack branching,while the ductile IV region inhibits the propagation of microcracks and prevents the formation of main cracks.This work highlights the crucial role of the brittle/ductile heterogeneous interface in the toughening of lam-inated composites.Furthermore,the discovery of the O band provides novel insights into the design of TiAl/Ti_(2)AlNb heterostructures.
基金Supported by Equipment Pre-Research Foundation of China(Grant No.50923030512)。
文摘In the welding process of SiCp/Al composites,Al reacts with SiC particles in the molten pool to form Al_(4)C_(3),a brittle phase,damaging the reinforcement and causing a sharp decline in the mechanical properties of weld joints.To mitigate this,a method of welding SiCp/Al composites by pulsed laser welding with powder-filling is proposed,inhibiting the interface reaction between Al and SiC particles in the molten pool.This study investigates the effect of pulse frequency on the temperature field of the molten pool,and combines thermal-fluid numerical simulation to analyze the peak temperature at different pulse frequencies,optimizing the Si content to ultimately inhibit the interface reaction in the molten pool.Results indicate that an appropriate pulse frequency achieves good welding formation and effectively regulates the peak temperature of the molten pool.Only a small amount of brittle phase is present in the weld joint,creating favorable conditions for the addition of alloying elements.The interface reaction is slowed down by adjusting the pulse frequency,though it is not completely inhibited.When the addition of Si content reaches 8%,the occurrence of the interface reaction is effectively inhibited.In weld joints with the addition of 8wt%Si powder,no Al_(4)C_(3)brittle phase is present,and the tensile strength of the weld joint is 266 MPa,up to 70%of the base material.
基金financially supported by National Key R&D Program of China(Nos.2017YFC0211503,2016YFC0207100)the National Natural Science Foundation of China(Nos.21401200,51672273)the Open Research Fund of State Key Laboratory of Multi-phase Complex Systems(No.MPCS-2017-D-06)。
文摘A hierarchically structured MnO_(x)-NiCo_(2)O_(4) monolithic catalyst with rich phase interfaces was designed by a simple,eco-friendly and time-saving in-situ electro-deposition method.The abundance of active oxygen species due to this rich phase interfaces contributed to the excellent benzene combustion performance of MnO_(x)-NiCo_(2)O_(4)-2:2 sample,oxidizing about 90% of benzene(T_(90)) at 198℃ under 12000 h^(-1) gaseous hourly space velocity.This work shed new light on the design of excellent monolithic catalysts,which might pave the way for the industrialization of benzene combustion.
