All-solid-state batteries(ASSBs)assembled with sulfide solid electrolytes(SSEs)and nickel(Ni)-rich oxide cathode materials are expected to achieve high energy density and safety,representing potential candidates for t...All-solid-state batteries(ASSBs)assembled with sulfide solid electrolytes(SSEs)and nickel(Ni)-rich oxide cathode materials are expected to achieve high energy density and safety,representing potential candidates for the next-generation energy storage systems.However,interfacial issues between SSEs and Nirich oxide cathode materials,attributed to space charge layer,interfacial side reactions,and mechanical contact failure,significantly restrict the performances of ASSBs.The interface degradation is closely related to the components of the composite cathode and the process of electrode fabrication.Focusing on the influencing factors of interface compatibility between SSEs and Ni-rich oxide cathode,this article systematically discusses how cathode active materials(CAMs),electrolytes,conductive additives,binders,and electrode fabrication impact the interface compatibility.In addition,the strategies for the compatibility modification are reviewed.Furthermore,the challenges and prospects of intensive research on the degradation and modification of the SSE/Ni-rich cathode material interface are discussed.This review is intended to inspire the development of high-energy-density and high-safety all-solid-state batteries.展开更多
In this study, a water/silicone oil interface was used to simulate the steel/slag interface in a converter. A high-speed camera was used to record the entrainment process of droplets when air bubbles were passed throu...In this study, a water/silicone oil interface was used to simulate the steel/slag interface in a converter. A high-speed camera was used to record the entrainment process of droplets when air bubbles were passed through the water/silicone oil interface. Motion parameters of the bubbles and droplets were obtained using particle kinematic analysis software, and the entrainment rate of the droplets was calculated. It was found that the entrainment rate decreased from 29.5% to 0 when the viscosity of the silicone oil was increased from 60 mPa.s to 820 mPa.s in the case of bubbles with a 5 mm equivalent diameter passing through the water/silicone oil interface. The results indicate that in- creasing the viscosity of the silicone oil is conducive to reducing the entrainment rate. The entrainment rate increased from 0 to 136.3% in the case of silicone oil with a viscosity of 60 mPa.s when the equivalent diameter of the bubbles was increased from 3 mm to 7 ram. We there- fore conclude that small bubbles are also conductive to reducing the entrainment rate. The force analysis results for the water colmnn indicate that the entrainment rate of droplets is affected by the velocity of the bubble passing through the water/silicone oil interface and that the en- trainment rate decreases with the bubble velocity.展开更多
Theempiricalelectrontheory of solidsand molecules( EET) and theimproved TFDtheory wereapplied tocalculatethe phasestructurefactorsand interfaceconjunction factorsofcom mon alloying elementsincastiron. Akind of Si- M...Theempiricalelectrontheory of solidsand molecules( EET) and theimproved TFDtheory wereapplied tocalculatethe phasestructurefactorsand interfaceconjunction factorsofcom mon alloying elementsincastiron. Akind of Si- Mo- Cu ductileiron with rareearth Mg asnodularizer was designed accordingtothese valenceelectron structure parameters. Actual applicationtestsshow thatthelongevity of thisiron is 1.5 timesof thatof high manganesesteel. This accordance of theoretical results and actual effectsshows the composition design methodcan beused in othercastiron research.展开更多
The aim of the present work is to investigate the numerical modeling of interfacial cracks that may appear at the interface between two isotropic elastic materials. The extended finite element method is employed to an...The aim of the present work is to investigate the numerical modeling of interfacial cracks that may appear at the interface between two isotropic elastic materials. The extended finite element method is employed to analyze brittle and bi-material interfacial fatigue crack growth by computing the mixed mode stress intensity factors(SIF). Three different approaches are introduced to compute the SIFs. In the first one, mixed mode SIF is deduced from the computation of the contour integral as per the classical J-integral method,whereas a displacement method is used to evaluate the SIF by using either one or two displacement jumps located along the crack path in the second and third approaches. The displacement jump method is rather classical for mono-materials,but has to our knowledge not been used up to now for a bimaterial. Hence, use of displacement jump for characterizing bi-material cracks constitutes the main contribution of the present study. Several benchmark tests including parametric studies are performed to show the effectiveness of these computational methodologies for SIF considering static and fatigue problems of bi-material structures. It is found that results based on the displacement jump methods are in a very good agreement with those of exact solutions, such as for the J-integral method, but with a larger domain of applicability and a better numerical efficiency(less time consuming and less spurious boundary effect).展开更多
Adopting the complex function approach, the paper studies the stress intensity factor in orthotropic bi-material interface cracks under mixed loads. With con- sideration of the boundary conditions, a new stress functi...Adopting the complex function approach, the paper studies the stress intensity factor in orthotropic bi-material interface cracks under mixed loads. With con- sideration of the boundary conditions, a new stress function is introduced to transform the problem of bi-material interface crack into a boundary value problem of partial dif- ferential equations. Two sets of non-homogeneous linear equations with 16 unknowns are constructed. By solving the equations, the expressions for the real bi-material elastic constant εt and the real stress singularity exponents λt are obtained with the bi-material engineering parameters satisfying certain conditions. By the uniqueness theorem of limit, undetermined coefficients are determined, and thus the bi-material stress intensity factor in mixed cracks is obtained. The bi-material stress intensity factor characterizes features of mixed cracks. When orthotropic bi-materials are of the same material, the degenerate solution to the stress intensity factor in mixed bi-material interface cracks is in complete agreement with the present classic conclusion. The relationship between the bi-material stress intensity factor and the ratio of bi-material shear modulus and the relationship be- tween the bi-material stress intensity factor and the ratio of bi-material Young＇s modulus are given in the numerical analysis.展开更多
Incubation experiments are carried out to study the exchange rates of dissolved inorganic nutrients including silicate, phosphate, ammonium, nitrite, and nitrate (vSiO3-Si, vPO4-P, vNH4-N, vNO2-N and vNO3-N) at the se...Incubation experiments are carried out to study the exchange rates of dissolved inorganic nutrients including silicate, phosphate, ammonium, nitrite, and nitrate (vSiO3-Si, vPO4-P, vNH4-N, vNO2-N and vNO3-N) at the sediment-water interface in the Jiaozhou Bay. Major factors influencing the exchange rates are discussed in detail, which include the dissolved inorganic nutrient concentrations in porewater (Cpw), water and clay contents, and grain size of the sediments (CH2O, Cclay and GSsed). The results may provide insight into the dynamics of nutrient transport and the environmental capacity of nutrients in Jiaozhou Bay, and should be beneficial to solving the problems caused by excessive nutrient input this area.展开更多
This paper studies the dynamic stress intensity factor （DSIF） at the interface in an adhesive joint under shear loading. Material damage is considered. By introducing the dislocation density function and using the i...This paper studies the dynamic stress intensity factor （DSIF） at the interface in an adhesive joint under shear loading. Material damage is considered. By introducing the dislocation density function and using the integral transform, the problem is reduced to algebraic equations and can be solved with the collocation dots method in the Laplace domain. Time response of DSIF is calculated with the inverse Laplace integral transform. The results show that the mode Ⅱ DSIF increases with the shear relaxation parameter, shear module and Poisson ratio, while decreases with the swell relaxation parameter. Damage shielding only occurs at the initial stage of crack propagation. The singular index of crack tip is -0.5 and independent on the material parameters, damage conditions of materials, and time. The oscillatory index is controlled by viscoelastic material parameters.展开更多
The direct conversion of atmospheric CO_(2) into fuel via photocatalysis exhibits significant practical application value in advancing the carbon cycle.In this study,we established an electro-assisted photocatalytic s...The direct conversion of atmospheric CO_(2) into fuel via photocatalysis exhibits significant practical application value in advancing the carbon cycle.In this study,we established an electro-assisted photocatalytic system with dual compartments and interfaces,and coated Ag nanoparticles on the titanium nanotube arrays(TNTAs)by polydopamine modification.In the absence of sacrificial agent and alkali absorption liquid conditions,the stable,efficient and highly selective conversion of CO_(2) to CO at the gas-solid interface in ambient air was realized by photoelectric synergy.Specifically,with the assistance of potential,the CO formation rates reached 194.9μmol h^(−1) m^(−2) and 103.9μmol h^(−1) m^(−2) under ultraviolet and visible light irradiation,respectively;the corresponding CO_(2) conversion rates in ambient air were 30%and 16%,respectively.The excellent catalytic effect is mainly attributed to the formation of P–N heterojunction during the catalytic process and the surface plasmon resonance effect.Additionally,the introduction of solid agar electrolytes effectively inhibits the hydrogen evolution reaction and improves the electron utilization rate.This system promotes the development of photocatalytic technology for practical applications and provides new insights and support for the carbon cycle.展开更多
The recently proposed interface propagation-based method has shown its advantages in obtaining the thermal conductivity of phase change materials during solid-liquid transition over conventional techniques. However, i...The recently proposed interface propagation-based method has shown its advantages in obtaining the thermal conductivity of phase change materials during solid-liquid transition over conventional techniques. However, in previous investigation, the analysis on the measurement error was qualitative and only focused on the total effects on the measurement without decoupling the influencing factors. This paper discusses the effects of influencing factors on the measurement results for the interface propagation-based method. Numerical simulations were performed to explore the influencing factors, namely model simplification, subcooling and natural convection, along with their impact on the measurement process and corresponding measurement results. The numerical solutions were provided in terms of moving curves of the solid-liquid interface and the predicted values of thermal conductivity. Results indicated that the impact of simplified model was strongly dependent on Stefan number of the melting process. The degree of subcooling would lead to underestimated values for thermal conductivity prediction. The natural convection would intensify the heat transfer rate in the liquid region, thereby overestimating the obtained results of thermal conductivity. Correlations and experimental guidelines are provided. The relative errors are limited in ±1.5%,±3%and ±2% corresponding to the impact of simplified model, subcooling and natural convection, respectively.展开更多
The problems of finite bimaterial plates, hearing uniform tension, compact: tension and three point bending, are studied by using the eigenfunction expansion variation method (EEVM). And interfacial stress intensity f...The problems of finite bimaterial plates, hearing uniform tension, compact: tension and three point bending, are studied by using the eigenfunction expansion variation method (EEVM). And interfacial stress intensity factors (SIFs) are determined. The SIFs varying with shear modulus mu and Poisson's ratios nu of both materials are discussed.展开更多
Organic-inorganic hybrid metal halide perovskite solar cells(PSCs)have attracted much attention due to their high photoelectric conversion efficiency(PCE)and low cost.The certificated PCE of small active area(below 0....Organic-inorganic hybrid metal halide perovskite solar cells(PSCs)have attracted much attention due to their high photoelectric conversion efficiency(PCE)and low cost.The certificated PCE of small active area(below 0.1 cm^(2))device has reached 26.7%[1].However,when considering the scaled-up commercialization of PSCs,an obvious efficiency drop exists for the translation to large-area perovskite submodules(PSMs)with areas more than 200 cm^(2),thus limiting the practical commercialization[2].The major PCE gap between small area cells and large area modules arises the drop of open-circuit voltage(VOC)and fill factor(FF).Formamidinium lead iodide(FAPbI_(3))is now the mostly widely used and highly efficient perovskite composition.However,the photo-active black α-FAPbI_(3) phase will spontaneously transform into photo-inactive yellowδ-FAPbI_(3) phase at room temperature[3].展开更多
The accelerating factor （AF） method is a simple and appropriate way to investigate the atomic long-time deep diffusion at solid-solid interface. In the framework of AF hyperdynamics （HD） simulation, the relationsh...The accelerating factor （AF） method is a simple and appropriate way to investigate the atomic long-time deep diffusion at solid-solid interface. In the framework of AF hyperdynamics （HD） simulation, the relationship between the diffusion coefficient along the direction of z-axis which is normal to the Mg/Zn interface and temperature was investigated, and the AF＇s impact on the diffusion constant （D0） and activation energy （Q^＊） was studied. Then, two steps were taken to simulate the atomic diffusion process and the formation of new phases： one for acceleration and the other for equilibration. The results show that： the Arrhenius equation works well for the description of Dz with different accelerating factors; the AF has no effect on the diffusion constant Do in the case of no phase transition; and the relationship between Q＊ and Q conforms to Q^＊=Q/A. Then, the new Arrhenius equation for AFHD is successfully constructed as Dz=Doexp[-Q/（ART）]. Meanwhile, the authentic equilibrium conformations at any dynamic moment can only be reproduced by the equilibration simulation of the HD-simulated configurations. Key words： accelerating factor method; Arrhenius equation; two-steps scheme; Mg/Zn interface; hyperdynamic simulation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
OBJECTIVE:To assess the effects of Bushenantai(BSAT)granule(补肾安胎颗粒)on angiogenesis-related factors[E2,P,and vascular endothelial growth factor(VEGF)]at the maternal-fetal interface of recurrent spontaneous abort...OBJECTIVE:To assess the effects of Bushenantai(BSAT)granule(补肾安胎颗粒)on angiogenesis-related factors[E2,P,and vascular endothelial growth factor(VEGF)]at the maternal-fetal interface of recurrent spontaneous abortion(RSA)mice,and to evaluate the role of BSAT in promoting angiogenesis at the maternal-fetal interface by influencing the expression of sex hormones,and VEGF.METHODS:A mouse model with normal pregnancy and another with Clark’s classic RSA were established.The RSA mice were randomly assigned to six groups:normal,model,progesterone,high-doseBSAT granule(BSAT-H),medium-dose-BSAT granule(BSAT-M),and low-dose-BSAT granule(BSAT-L)(n=10 for each group).The embryo loss rate and the histopathological changes in the decidual tissues were measured.Serum levels of estrogen(E2),progesterone(P),and VEGF were detected by enzyme-linked immunosorbent assay.The m RNA and protein expressions of estradiol receptor(ER),progesterone receptor(PR),VEGF,and vascular endothelial growth factor receptor 2(VEGFR2)in the decidual tissues were identified by immunohistochemistry,Western blotting,and quantitative reverse transcription polymerase chain reaction.RESULTS:The embryo loss rate in all groups that received BSAT treatment was reduced,while the number of blood vessels at decidual tissues was increased.The serum levels of E2,P and VEGF were elevated,and the m RNA and protein expressions of ER,PR,VEGF,and VEGFR2 in the decidual tissues were enhanced.CONCLUSION:BSAT can improve angiogenesis at the maternal-fetal interface and reduce the embryo loss rate,which may be associated with its ability to increase the serum levels of estrogen,progesterone,and VEGF,in addition to up-regulation of m RNA and protein expression of ER,PR,VEGF,and VEGFR2 in the decidual tissues.展开更多
Due to the incompatibility of the interlaminar deformations,the interface debonding or cracking usually happens in a layered magnetoelectric(ME)structure under an applied load.In this paper,the transient responses of ...Due to the incompatibility of the interlaminar deformations,the interface debonding or cracking usually happens in a layered magnetoelectric(ME)structure under an applied load.In this paper,the transient responses of the anti-plane interface cracks in piezoelectric(PE)-piezomagnetic(PM)sandwich structures are studied by the standard methods of the integral transform and singular integral equation.Discussion on the numerical examples indicates that the PE-PM-PE structure under electric impact is more likely to fracture than the PM-PE-PM structure under a magnetic impact.The dynamic stress intensity factors(DSIFs)are more sensitive to the variation of the active layer thickness.The effects of the material constants on the DSIFs are dependent on the roles played by PE and PM media during the deformation process.展开更多
The dynamic behavior of two unequal parallel permeable interface cracks in a piezoelectric layer bonded to two half-piezoelectric material planes subjected to harmonic anti-plane shear waves is investigated. By using ...The dynamic behavior of two unequal parallel permeable interface cracks in a piezoelectric layer bonded to two half-piezoelectric material planes subjected to harmonic anti-plane shear waves is investigated. By using the Fourier transform, the problem can be solved with the help of two pairs of dual integral equations in which the unknown variables were the jumps of the displacements across the crack surfaces. Numerical results are presented graphically to show the effects of the geometric parameters, the frequency of the incident wave on the dynamic stress intensity factors and the electric displacement intensity factors. Especially, the present problem can be returned to static problem of two parallel permeable interface cracks. Compared with the solutions of impermeable crack surface condition, it is found that the electric displacement intensity factors for the permeable crack surface conditions are much smaller.展开更多
The behavior of a Mode-Ⅰ interface crack in piezoelectric materials was investigated under the assumptions that the effect of the crack surface overlapping very near the crack tips was negligible. By use of the Fouri...The behavior of a Mode-Ⅰ interface crack in piezoelectric materials was investigated under the assumptions that the effect of the crack surface overlapping very near the crack tips was negligible. By use of the Fourier transform, the problem can be solved with the help of two pairs of dual integral equations. To solve the dual integral equations, the jumps of the displacements across the crack surfaces were expanded in a series of Jacobi polynomials. It is found that the stress and the electric displacement singularities of the present interface crack solution are the same as ones of the ordinary crack in homogenous materials. The solution of the present paper can be returned to the exact solution when the upper half plane material is the same as the lower half plane material.展开更多
The fracture problems near the similar orthotropic composite materials are interface crack tip for mode Ⅱ of double disstudied. The mechanical models of interface crack for mode Ⅱ are given. By translating the gover...The fracture problems near the similar orthotropic composite materials are interface crack tip for mode Ⅱ of double disstudied. The mechanical models of interface crack for mode Ⅱ are given. By translating the governing equations into the generalized hi-harmonic equations, the stress functions containing two stress singularity exponents are derived with the help of a complex function method. Based on the boundary conditions, a system of non-homogeneous linear equations is found. Two real stress singularity exponents are determined be solving this system under appropriate conditions about bimaterial engineering parameters. According to the uniqueness theorem of limit, both the formulae of stress intensity factors and theoretical solutions of stress field near the interface crack tip are derived. When the two orthotropic materials are the same, the stress singularity exponents, stress intensity factors and stresses for mode II crack of the orthotropic single material are obtained.展开更多
The complex stress intensity factor K governing the stress field of an interface crack tip may be split into two parts, i.e.,■ and s^（-iε）, so that K = ■ s^（-iε）, s is a characteristic length and ε is the osc...The complex stress intensity factor K governing the stress field of an interface crack tip may be split into two parts, i.e.,■ and s^（-iε）, so that K = ■ s^（-iε）, s is a characteristic length and ε is the oscillatory index. ■ has the same dimension as the classical stress intensity factor and characterizes the interface crack tip field. That means a criterion for interface cracks may be formulated directly with■, as Irwin（ASME J. Appl. Mech. 24：361–364, 1957） did in 1957 for the classical fracture mechanics. Then, for an interface crack,it is demonstrated that the quasi Mode I and Mode II tip fields can be defined and distinguished from the coupled mode tip fields. Built upon SIF-based fracture criteria for quasi Mode I and Mode II, the stress intensity factor（SIF）-based fracture criterion for mixed mode interface cracks is proposed and validated against existing experimental results.展开更多
Using dislocation simulation approach, the basic equation for a finite crack perpendicular to and terminating at a bimaterial interface is formulated. A novel expansion method is proposed for solving the problem. The ...Using dislocation simulation approach, the basic equation for a finite crack perpendicular to and terminating at a bimaterial interface is formulated. A novel expansion method is proposed for solving the problem. The complete solution to the problem, including the explicit formulae for theT stresses ahead of the crack tip and the stress intensity factors are presented. The stress field characteristics are analysed in detail. It is found that normal stresses {ie27-1} and {ie27-2} ahead of the crack tip, are characterised byQ fields if the crack is within a stiff material and the parameters |p T | and |q T | are very small, whereQ is a generalised stress intensity factor for a crack normal to and terminating at the interface. If the crack is within a weak material, the normal stresses {ie27-3} and {ie27-4} are dominated by theQ field plusT stress.展开更多
基金financially supported by the National Natural Science Foundation of China(52072036,52272187)the China Petroleum&Chemical Corporation(SINOPEC)project(223128).
文摘All-solid-state batteries(ASSBs)assembled with sulfide solid electrolytes(SSEs)and nickel(Ni)-rich oxide cathode materials are expected to achieve high energy density and safety,representing potential candidates for the next-generation energy storage systems.However,interfacial issues between SSEs and Nirich oxide cathode materials,attributed to space charge layer,interfacial side reactions,and mechanical contact failure,significantly restrict the performances of ASSBs.The interface degradation is closely related to the components of the composite cathode and the process of electrode fabrication.Focusing on the influencing factors of interface compatibility between SSEs and Ni-rich oxide cathode,this article systematically discusses how cathode active materials(CAMs),electrolytes,conductive additives,binders,and electrode fabrication impact the interface compatibility.In addition,the strategies for the compatibility modification are reviewed.Furthermore,the challenges and prospects of intensive research on the degradation and modification of the SSE/Ni-rich cathode material interface are discussed.This review is intended to inspire the development of high-energy-density and high-safety all-solid-state batteries.
基金financially supported by the China Postdoctoral Science Foundation (Nos. 2015T80039 and 2014M560890)
文摘In this study, a water/silicone oil interface was used to simulate the steel/slag interface in a converter. A high-speed camera was used to record the entrainment process of droplets when air bubbles were passed through the water/silicone oil interface. Motion parameters of the bubbles and droplets were obtained using particle kinematic analysis software, and the entrainment rate of the droplets was calculated. It was found that the entrainment rate decreased from 29.5% to 0 when the viscosity of the silicone oil was increased from 60 mPa.s to 820 mPa.s in the case of bubbles with a 5 mm equivalent diameter passing through the water/silicone oil interface. The results indicate that in- creasing the viscosity of the silicone oil is conducive to reducing the entrainment rate. The entrainment rate increased from 0 to 136.3% in the case of silicone oil with a viscosity of 60 mPa.s when the equivalent diameter of the bubbles was increased from 3 mm to 7 ram. We there- fore conclude that small bubbles are also conductive to reducing the entrainment rate. The force analysis results for the water colmnn indicate that the entrainment rate of droplets is affected by the velocity of the bubble passing through the water/silicone oil interface and that the en- trainment rate decreases with the bubble velocity.
文摘Theempiricalelectrontheory of solidsand molecules( EET) and theimproved TFDtheory wereapplied tocalculatethe phasestructurefactorsand interfaceconjunction factorsofcom mon alloying elementsincastiron. Akind of Si- Mo- Cu ductileiron with rareearth Mg asnodularizer was designed accordingtothese valenceelectron structure parameters. Actual applicationtestsshow thatthelongevity of thisiron is 1.5 timesof thatof high manganesesteel. This accordance of theoretical results and actual effectsshows the composition design methodcan beused in othercastiron research.
文摘The aim of the present work is to investigate the numerical modeling of interfacial cracks that may appear at the interface between two isotropic elastic materials. The extended finite element method is employed to analyze brittle and bi-material interfacial fatigue crack growth by computing the mixed mode stress intensity factors(SIF). Three different approaches are introduced to compute the SIFs. In the first one, mixed mode SIF is deduced from the computation of the contour integral as per the classical J-integral method,whereas a displacement method is used to evaluate the SIF by using either one or two displacement jumps located along the crack path in the second and third approaches. The displacement jump method is rather classical for mono-materials,but has to our knowledge not been used up to now for a bimaterial. Hence, use of displacement jump for characterizing bi-material cracks constitutes the main contribution of the present study. Several benchmark tests including parametric studies are performed to show the effectiveness of these computational methodologies for SIF considering static and fatigue problems of bi-material structures. It is found that results based on the displacement jump methods are in a very good agreement with those of exact solutions, such as for the J-integral method, but with a larger domain of applicability and a better numerical efficiency(less time consuming and less spurious boundary effect).
基金supported by the National Key Basic Research Program of China(973 Program)(No.2009CB724201)the Science and Technology Major Project of the Ministry of Education of China(No.208022)+1 种基金the Postgraduate Scientific and Technological Innovation Project of Taiyuan University of Science and Technology(No.20125027)the Scientific Research Funds for Doctoral Students of Taiyuan University of Science and Technology(No.20122005)
文摘Adopting the complex function approach, the paper studies the stress intensity factor in orthotropic bi-material interface cracks under mixed loads. With con- sideration of the boundary conditions, a new stress function is introduced to transform the problem of bi-material interface crack into a boundary value problem of partial dif- ferential equations. Two sets of non-homogeneous linear equations with 16 unknowns are constructed. By solving the equations, the expressions for the real bi-material elastic constant εt and the real stress singularity exponents λt are obtained with the bi-material engineering parameters satisfying certain conditions. By the uniqueness theorem of limit, undetermined coefficients are determined, and thus the bi-material stress intensity factor in mixed cracks is obtained. The bi-material stress intensity factor characterizes features of mixed cracks. When orthotropic bi-materials are of the same material, the degenerate solution to the stress intensity factor in mixed bi-material interface cracks is in complete agreement with the present classic conclusion. The relationship between the bi-material stress intensity factor and the ratio of bi-material shear modulus and the relationship be- tween the bi-material stress intensity factor and the ratio of bi-material Young＇s modulus are given in the numerical analysis.
基金This research was partially supported by the National Natural Science Foundation of China (Nos 40136020 and 49976027)the Key Project of Chinese Ministry of Education (No.01110).
文摘Incubation experiments are carried out to study the exchange rates of dissolved inorganic nutrients including silicate, phosphate, ammonium, nitrite, and nitrate (vSiO3-Si, vPO4-P, vNH4-N, vNO2-N and vNO3-N) at the sediment-water interface in the Jiaozhou Bay. Major factors influencing the exchange rates are discussed in detail, which include the dissolved inorganic nutrient concentrations in porewater (Cpw), water and clay contents, and grain size of the sediments (CH2O, Cclay and GSsed). The results may provide insight into the dynamics of nutrient transport and the environmental capacity of nutrients in Jiaozhou Bay, and should be beneficial to solving the problems caused by excessive nutrient input this area.
基金the National Natural Science Foundation of China(No.10672027)the National Basic Research Program of China(No.2006CB601205)the National Science Fund for Distin-guished Young Scholars of China(No.50625414)
文摘This paper studies the dynamic stress intensity factor （DSIF） at the interface in an adhesive joint under shear loading. Material damage is considered. By introducing the dislocation density function and using the integral transform, the problem is reduced to algebraic equations and can be solved with the collocation dots method in the Laplace domain. Time response of DSIF is calculated with the inverse Laplace integral transform. The results show that the mode Ⅱ DSIF increases with the shear relaxation parameter, shear module and Poisson ratio, while decreases with the swell relaxation parameter. Damage shielding only occurs at the initial stage of crack propagation. The singular index of crack tip is -0.5 and independent on the material parameters, damage conditions of materials, and time. The oscillatory index is controlled by viscoelastic material parameters.
文摘The direct conversion of atmospheric CO_(2) into fuel via photocatalysis exhibits significant practical application value in advancing the carbon cycle.In this study,we established an electro-assisted photocatalytic system with dual compartments and interfaces,and coated Ag nanoparticles on the titanium nanotube arrays(TNTAs)by polydopamine modification.In the absence of sacrificial agent and alkali absorption liquid conditions,the stable,efficient and highly selective conversion of CO_(2) to CO at the gas-solid interface in ambient air was realized by photoelectric synergy.Specifically,with the assistance of potential,the CO formation rates reached 194.9μmol h^(−1) m^(−2) and 103.9μmol h^(−1) m^(−2) under ultraviolet and visible light irradiation,respectively;the corresponding CO_(2) conversion rates in ambient air were 30%and 16%,respectively.The excellent catalytic effect is mainly attributed to the formation of P–N heterojunction during the catalytic process and the surface plasmon resonance effect.Additionally,the introduction of solid agar electrolytes effectively inhibits the hydrogen evolution reaction and improves the electron utilization rate.This system promotes the development of photocatalytic technology for practical applications and provides new insights and support for the carbon cycle.
基金Project(51606224) supported by the National Natural Science Foundation of China
文摘The recently proposed interface propagation-based method has shown its advantages in obtaining the thermal conductivity of phase change materials during solid-liquid transition over conventional techniques. However, in previous investigation, the analysis on the measurement error was qualitative and only focused on the total effects on the measurement without decoupling the influencing factors. This paper discusses the effects of influencing factors on the measurement results for the interface propagation-based method. Numerical simulations were performed to explore the influencing factors, namely model simplification, subcooling and natural convection, along with their impact on the measurement process and corresponding measurement results. The numerical solutions were provided in terms of moving curves of the solid-liquid interface and the predicted values of thermal conductivity. Results indicated that the impact of simplified model was strongly dependent on Stefan number of the melting process. The degree of subcooling would lead to underestimated values for thermal conductivity prediction. The natural convection would intensify the heat transfer rate in the liquid region, thereby overestimating the obtained results of thermal conductivity. Correlations and experimental guidelines are provided. The relative errors are limited in ±1.5%,±3%and ±2% corresponding to the impact of simplified model, subcooling and natural convection, respectively.
文摘The problems of finite bimaterial plates, hearing uniform tension, compact: tension and three point bending, are studied by using the eigenfunction expansion variation method (EEVM). And interfacial stress intensity factors (SIFs) are determined. The SIFs varying with shear modulus mu and Poisson's ratios nu of both materials are discussed.
基金support from open fund of Fujian Provincial Key Laboratory of Functional Materials and Applications(Xiamen University of Technology,fma2024003)the National Key R&D Program of China(No.2021YFB3500400)the National Natural Science Foundation of China(Nos.52073286 and 22275185).
文摘Organic-inorganic hybrid metal halide perovskite solar cells(PSCs)have attracted much attention due to their high photoelectric conversion efficiency(PCE)and low cost.The certificated PCE of small active area(below 0.1 cm^(2))device has reached 26.7%[1].However,when considering the scaled-up commercialization of PSCs,an obvious efficiency drop exists for the translation to large-area perovskite submodules(PSMs)with areas more than 200 cm^(2),thus limiting the practical commercialization[2].The major PCE gap between small area cells and large area modules arises the drop of open-circuit voltage(VOC)and fill factor(FF).Formamidinium lead iodide(FAPbI_(3))is now the mostly widely used and highly efficient perovskite composition.However,the photo-active black α-FAPbI_(3) phase will spontaneously transform into photo-inactive yellowδ-FAPbI_(3) phase at room temperature[3].
基金Project (2012CB722805) supported by the National Basic Research Program of ChinaProjects (50974083, 51174131) supported by the National Natural Science Foundation of China+1 种基金Project (50774112) supported by the Joint Fund of NSFC and Baosteel, ChinaProject(07QA4021) supported by the Shanghai "Phosphor" Science Foundation, China
文摘The accelerating factor （AF） method is a simple and appropriate way to investigate the atomic long-time deep diffusion at solid-solid interface. In the framework of AF hyperdynamics （HD） simulation, the relationship between the diffusion coefficient along the direction of z-axis which is normal to the Mg/Zn interface and temperature was investigated, and the AF＇s impact on the diffusion constant （D0） and activation energy （Q^＊） was studied. Then, two steps were taken to simulate the atomic diffusion process and the formation of new phases： one for acceleration and the other for equilibration. The results show that： the Arrhenius equation works well for the description of Dz with different accelerating factors; the AF has no effect on the diffusion constant Do in the case of no phase transition; and the relationship between Q＊ and Q conforms to Q^＊=Q/A. Then, the new Arrhenius equation for AFHD is successfully constructed as Dz=Doexp[-Q/（ART）]. Meanwhile, the authentic equilibrium conformations at any dynamic moment can only be reproduced by the equilibration simulation of the HD-simulated configurations. Key words： accelerating factor method; Arrhenius equation; two-steps scheme; Mg/Zn interface; hyperdynamic simulation
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 Natural Science Foundation of China(No.81574017)Special Fund Project of 2015 Provincial Traditional Chinese Medicine Development of Health and Family Planning Commission of Anhui Province(Wei Ban Mi[2015]No.404)Scientific Research Project of Traditional Chinese Medicine of Health and Family Planning Commission of Anhui Province(No.2016zy19)。
文摘OBJECTIVE:To assess the effects of Bushenantai(BSAT)granule(补肾安胎颗粒)on angiogenesis-related factors[E2,P,and vascular endothelial growth factor(VEGF)]at the maternal-fetal interface of recurrent spontaneous abortion(RSA)mice,and to evaluate the role of BSAT in promoting angiogenesis at the maternal-fetal interface by influencing the expression of sex hormones,and VEGF.METHODS:A mouse model with normal pregnancy and another with Clark’s classic RSA were established.The RSA mice were randomly assigned to six groups:normal,model,progesterone,high-doseBSAT granule(BSAT-H),medium-dose-BSAT granule(BSAT-M),and low-dose-BSAT granule(BSAT-L)(n=10 for each group).The embryo loss rate and the histopathological changes in the decidual tissues were measured.Serum levels of estrogen(E2),progesterone(P),and VEGF were detected by enzyme-linked immunosorbent assay.The m RNA and protein expressions of estradiol receptor(ER),progesterone receptor(PR),VEGF,and vascular endothelial growth factor receptor 2(VEGFR2)in the decidual tissues were identified by immunohistochemistry,Western blotting,and quantitative reverse transcription polymerase chain reaction.RESULTS:The embryo loss rate in all groups that received BSAT treatment was reduced,while the number of blood vessels at decidual tissues was increased.The serum levels of E2,P and VEGF were elevated,and the m RNA and protein expressions of ER,PR,VEGF,and VEGFR2 in the decidual tissues were enhanced.CONCLUSION:BSAT can improve angiogenesis at the maternal-fetal interface and reduce the embryo loss rate,which may be associated with its ability to increase the serum levels of estrogen,progesterone,and VEGF,in addition to up-regulation of m RNA and protein expression of ER,PR,VEGF,and VEGFR2 in the decidual tissues.
基金Project supported by the National Natural Science Foundation of China(Nos.11272222,11502108,and 11611530686)the Natural Science Foundation for Distinguished Young Scholars of Jiangsu Province of China(No.BK20140037)
文摘Due to the incompatibility of the interlaminar deformations,the interface debonding or cracking usually happens in a layered magnetoelectric(ME)structure under an applied load.In this paper,the transient responses of the anti-plane interface cracks in piezoelectric(PE)-piezomagnetic(PM)sandwich structures are studied by the standard methods of the integral transform and singular integral equation.Discussion on the numerical examples indicates that the PE-PM-PE structure under electric impact is more likely to fracture than the PM-PE-PM structure under a magnetic impact.The dynamic stress intensity factors(DSIFs)are more sensitive to the variation of the active layer thickness.The effects of the material constants on the DSIFs are dependent on the roles played by PE and PM media during the deformation process.
文摘The dynamic behavior of two unequal parallel permeable interface cracks in a piezoelectric layer bonded to two half-piezoelectric material planes subjected to harmonic anti-plane shear waves is investigated. By using the Fourier transform, the problem can be solved with the help of two pairs of dual integral equations in which the unknown variables were the jumps of the displacements across the crack surfaces. Numerical results are presented graphically to show the effects of the geometric parameters, the frequency of the incident wave on the dynamic stress intensity factors and the electric displacement intensity factors. Especially, the present problem can be returned to static problem of two parallel permeable interface cracks. Compared with the solutions of impermeable crack surface condition, it is found that the electric displacement intensity factors for the permeable crack surface conditions are much smaller.
基金Project supported by the National Natural Science Foundation of China (Nos.10572155, 10572043) the Natural Science Foundation for Distinguished Young Scholars of Heilongjiang Province of China (No.JC04-08)
文摘The behavior of a Mode-Ⅰ interface crack in piezoelectric materials was investigated under the assumptions that the effect of the crack surface overlapping very near the crack tips was negligible. By use of the Fourier transform, the problem can be solved with the help of two pairs of dual integral equations. To solve the dual integral equations, the jumps of the displacements across the crack surfaces were expanded in a series of Jacobi polynomials. It is found that the stress and the electric displacement singularities of the present interface crack solution are the same as ones of the ordinary crack in homogenous materials. The solution of the present paper can be returned to the exact solution when the upper half plane material is the same as the lower half plane material.
基金supported by the Natural Science Foundation of Shaanxi Province (No.2007011008)
文摘The fracture problems near the similar orthotropic composite materials are interface crack tip for mode Ⅱ of double disstudied. The mechanical models of interface crack for mode Ⅱ are given. By translating the governing equations into the generalized hi-harmonic equations, the stress functions containing two stress singularity exponents are derived with the help of a complex function method. Based on the boundary conditions, a system of non-homogeneous linear equations is found. Two real stress singularity exponents are determined be solving this system under appropriate conditions about bimaterial engineering parameters. According to the uniqueness theorem of limit, both the formulae of stress intensity factors and theoretical solutions of stress field near the interface crack tip are derived. When the two orthotropic materials are the same, the stress singularity exponents, stress intensity factors and stresses for mode II crack of the orthotropic single material are obtained.
文摘The complex stress intensity factor K governing the stress field of an interface crack tip may be split into two parts, i.e.,■ and s^（-iε）, so that K = ■ s^（-iε）, s is a characteristic length and ε is the oscillatory index. ■ has the same dimension as the classical stress intensity factor and characterizes the interface crack tip field. That means a criterion for interface cracks may be formulated directly with■, as Irwin（ASME J. Appl. Mech. 24：361–364, 1957） did in 1957 for the classical fracture mechanics. Then, for an interface crack,it is demonstrated that the quasi Mode I and Mode II tip fields can be defined and distinguished from the coupled mode tip fields. Built upon SIF-based fracture criteria for quasi Mode I and Mode II, the stress intensity factor（SIF）-based fracture criterion for mixed mode interface cracks is proposed and validated against existing experimental results.
基金This work was supported by the Swedish Research Council for Engineering Sciences.
文摘Using dislocation simulation approach, the basic equation for a finite crack perpendicular to and terminating at a bimaterial interface is formulated. A novel expansion method is proposed for solving the problem. The complete solution to the problem, including the explicit formulae for theT stresses ahead of the crack tip and the stress intensity factors are presented. The stress field characteristics are analysed in detail. It is found that normal stresses {ie27-1} and {ie27-2} ahead of the crack tip, are characterised byQ fields if the crack is within a stiff material and the parameters |p T | and |q T | are very small, whereQ is a generalised stress intensity factor for a crack normal to and terminating at the interface. If the crack is within a weak material, the normal stresses {ie27-3} and {ie27-4} are dominated by theQ field plusT stress.
