Hard-magnetic soft materials exhibit significant shape morphing capabilities under non-contact magnetic actuation, yet their particulate composition tends to compromise material toughness. To quantify particle-matrix ...Hard-magnetic soft materials exhibit significant shape morphing capabilities under non-contact magnetic actuation, yet their particulate composition tends to compromise material toughness. To quantify particle-matrix interactions, we present a mechanics model describing the energy functional of planar magnetic composites. Through the Fourier series, the analytical solutions for stress distribution and interfacial peeling length of a single particle-polymer unit are derived with the Rayleigh-Ritz method under uniaxial tension. The calculated results of stress fields without the magnetic field agree well with those of the finite element method. The effects of external magnetic field strength and particle content on the stress distribution and peeling length are fully explored, and the enhanced analytical outcomes are obtained through numerical prediction.These insights can be used to validate the reliability of engineering designs, including adaptive structures, micro-electro-mechanical sensors, and soft robotic systems.展开更多
Ground response analysis and determination of site-specific ground motion parameters are necessary for evaluating seismic loads to enable sustainable design of aboveground and underground structures,particularly in de...Ground response analysis and determination of site-specific ground motion parameters are necessary for evaluating seismic loads to enable sustainable design of aboveground and underground structures,particularly in deep overburden sites.This study investigates the influence of bedrock interface conditions and depth of soil deposits on obtained site-specific ground motion parameters.Employing the one-dimensional seismic response analysis program SOILQUAKE,the ground responses of five representative soil profiles and 1050 case studies are calculated considering three different site models of seismic input interfaces.The analysis employs the actual bedrock interface with a shear wave velocity of 760 m/s as the reference input bedrock interface.The results illustrate that the selection of the bedrock interface condition significantly affects the seismic response on the ground surface of deep overburden sites.Specifically,the ground surface acceleration response spectra at longer periods are notably smaller compared to those at the actual bedrock site.This may present a challenge for designing long-period high-rise buildings situated in deep overburden sites.It is recommended to select a seismic input bedrock interface closely approximating the actual bedrock depth when conducting seismic response analyses for deep overburden sites.展开更多
In response to the complex characteristics of actual low-permeability tight reservoirs,this study develops a meshless-based numerical simulation method for oil-water two-phase flow in these reservoirs,considering comp...In response to the complex characteristics of actual low-permeability tight reservoirs,this study develops a meshless-based numerical simulation method for oil-water two-phase flow in these reservoirs,considering complex boundary shapes.Utilizing radial basis function point interpolation,the method approximates shape functions for unknown functions within the nodal influence domain.The shape functions constructed by the aforementioned meshless interpolation method haveδ-function properties,which facilitate the handling of essential aspects like the controlled bottom-hole flow pressure in horizontal wells.Moreover,the meshless method offers greater flexibility and freedom compared to grid cell discretization,making it simpler to discretize complex geometries.A variational principle for the flow control equation group is introduced using a weighted least squares meshless method,and the pressure distribution is solved implicitly.Example results demonstrate that the computational outcomes of the meshless point cloud model,which has a relatively small degree of freedom,are in close agreement with those of the Discrete Fracture Model(DFM)employing refined grid partitioning,with pressure calculation accuracy exceeding 98.2%.Compared to high-resolution grid-based computational methods,the meshless method can achieve a better balance between computational efficiency and accuracy.Additionally,the impact of fracture half-length on the productivity of horizontal wells is discussed.The results indicate that increasing the fracture half-length is an effective strategy for enhancing production from the perspective of cumulative oil production.展开更多
The Laguerre polynomial method has been successfully used to investigate the dynamic responses of a half-space.However,it fails to obtain the correct stress at the interfaces in a layered half-space,especially when th...The Laguerre polynomial method has been successfully used to investigate the dynamic responses of a half-space.However,it fails to obtain the correct stress at the interfaces in a layered half-space,especially when there are significant differences in material properties.Therefore,a coupled Legendre-Laguerre polynomial method with analytical integration is proposed.The Rayleigh waves in a one-dimensional(1D)hexagonal quasicrystal(QC)layered half-space with an imperfect interface are investigated.The correctness is validated by comparison with available results.Its computation efficiency is analyzed.The dispersion curves of the phase velocity,displacement distributions,and stress distributions are illustrated.The effects of the phonon-phason coupling and imperfect interface coefficients on the wave characteristics are investigated.Some novel findings reveal that the proposed method is highly efficient for addressing the Rayleigh waves in a QC layered half-space.It can save over 99%of the computation time.This method can be expanded to investigate waves in various layered half-spaces,including earth-layered media and surface acoustic wave(SAW)devices.展开更多
A novel simple two-dimensional square-lattice model of amphiphile at oil-water interface is developed,in which oil and water act as solvent and occupy empty sites and amphiphile occupies chains of sites. In this mode...A novel simple two-dimensional square-lattice model of amphiphile at oil-water interface is developed,in which oil and water act as solvent and occupy empty sites and amphiphile occupies chains of sites. In this model, the oil-water interface is fixed, And amphiphile molecules will be enriched at the oil-water interface. The interfacial concentration of amphiphile calculated by Monte Carlo method shows that it is easier for the hydrophilic-hydrophobic balanced amphiphile to stay at the interface. And the adsorption of amphiphile increases with the increase of amphiphile concentration and the decrease with temperature.展开更多
Amphiphile-oil-water system is complicated. The real behavior of amphiphile in the interface is still undnown despite that this behavior is very important in determining the stability of emulsion system. In this paper...Amphiphile-oil-water system is complicated. The real behavior of amphiphile in the interface is still undnown despite that this behavior is very important in determining the stability of emulsion system. In this paper, the interface properties of amphiphile at oil-water interface were investigated by a square-lattice model Monte Carlo simulation method. The synergistic effect was found for hydrophobic and hydrophilic amphiphile mixture systems; and the synergistic effect disappears or was weakened as the amphiphile at the interface region became dilute with the increasing of temperature.展开更多
Nowadays,the novel oil water interface method has attracted a considerable attention owing to the advantages of mild reaction conditions,simple operation,low cost,and high efficiency.In this paper,uniform oil-soluble ...Nowadays,the novel oil water interface method has attracted a considerable attention owing to the advantages of mild reaction conditions,simple operation,low cost,and high efficiency.In this paper,uniform oil-soluble Fe_3O_4 nanoparticles(NPs) were synthesized by oil-water interface method from mixing iron tristearate of 0.067mol/L in cyclohexane with ferrous sulfate in water.The as-prepared products were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),vibrating sample magnetometer(VSM),Fourier transform infrared spectroscopy(FT-IR) and thermogravimetric analyzer(TGA).TEM images and XRD profiles showed that the size of the oil-soluble products ranged in 1.7-6.9 nm.VSM indicated that the Fe_3O_4 NPs were superparamagetic.FT-IR and TGA proved that oleic acid was combined to the surface of Fe_3O_4 NPs closely.TEM images and XRD profiles revealed that the most suitable reaction concentration of NH_3·H_2O,oleic acid/water in volume,reaction temperature and reaction time were 4.5 mol/L,50:1 000,80℃ and 6 h,respectively.The formation mechanism of the nearly monodispersed Fe_3O_4 NPs was that the preformed Fe_3O_4 nuclei were capped by oleic acid as early as the nucleation occurred in oil-water interface and subsequently entered into oil phase to stop growing.展开更多
The growth interfaces of CdMnTe（CMT） crystals grown by traveling heater method（THM） were studied. Two types of polycrystalline CMT feed ingots synthesized in a traditional rocking furnace and vertical Bridgman（VB...The growth interfaces of CdMnTe（CMT） crystals grown by traveling heater method（THM） were studied. Two types of polycrystalline CMT feed ingots synthesized in a traditional rocking furnace and vertical Bridgman（VB） furnace were adopted in THM growth, and the effects of the polycrystalline feed on the growth interface were revealed. The morphology of the growth interface of CMT crystal（CMT2） grown from the feed by vertical Bridgman was smoother with lower curvature compared with that of CMT crystal（CMT1） from the feed by rocking furnace. The radial Mn composition and Te inclusion distribution of the CMT wafers were analyzed and correlated to the growth interface. The Mn segregation along the radial direction and Te inclusion density of CMT2 were lower than those of CMT1. The VB method synthesized polycrystalline feed could improve the growth interface morphology, which is beneficial for decreasing the Te inclusions and Mn segregation in CMT wafers.展开更多
Metal batteries have attracted considerable attention from researchers because of their low reduction voltage and high specific capacity.However,the reduction in the capacity and lifespan of batteries caused by the de...Metal batteries have attracted considerable attention from researchers because of their low reduction voltage and high specific capacity.However,the reduction in the capacity and lifespan of batteries caused by the dendrite growth of metal anode limits the development of metal batteries.Metal-organic frameworks (MOFs) can be used to protect metal anodes owing to their advantages of ideal specific surface area,tunable porosity,and physiochemical stability in electrolytes.Therefore,MOFs have been extensively investigated in metal batteries.The introduction of MOFs to the metal anode interface can greatly improve the performance of batteries.In this review,the synthesis methods of typical MOFs and their derivatives,their protective mechanism on the metal anode,including Li,Na,K,Zn,and Mg,and their effects on the performance of metal batteries were elucidated.This review would help to design and apply MOFs to the anode interface in metal batteries.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 paper,two-grid immersed finite element (IFE) algorithms are proposed and analyzed for semi-linear interface problems with discontinuous diffusion coefficients in two dimension.Because of the advantages of fini...In this paper,two-grid immersed finite element (IFE) algorithms are proposed and analyzed for semi-linear interface problems with discontinuous diffusion coefficients in two dimension.Because of the advantages of finite element (FE) formulation and the simple structure of Cartesian grids,the IFE discretization is used in this paper.Two-grid schemes are formulated to linearize the FE equations.It is theoretically and numerically illustrated that the coarse space can be selected as coarse as H =O(h^1/4)(or H =O(h^1/8)),and the asymptotically optimal approximation can be achieved as the nonlinear schemes.As a result,we can settle a great majority of nonlinear equations as easy as linearized problems.In order to estimate the present two-grid algorithms,we derive the optimal error estimates of the IFE solution in the L^p norm.Numerical experiments are given to verify the theorems and indicate that the present two-grid algorithms can greatly improve the computing efficiency.展开更多
It is important to quantify the effect of the root diameter, the embedment length of the root and load speed on the soil-root interface mechanical properties for studying the root anchorage. The soilroot interface mec...It is important to quantify the effect of the root diameter, the embedment length of the root and load speed on the soil-root interface mechanical properties for studying the root anchorage. The soilroot interface mechanical properties can be obtained through the pullout force and root slippage curve(F-S curve). About 120 Pinus tabulaeformis single roots whose diameters ranged from 1 mm to 10 mm divided into 6 groups based on different root embedment length(50 mm, 100 mm and 150 mm) and different load velocity(10 mm·min^(-1), 50 mm·min^(-1), 100 mm·min^(-1) and 300 mm·min^(-1)) were investigated using the pullout method. This study aims to explore the mechanical properties of the soil-root interface in the real conditions using the pullout test method. The results showed two kinds of pullout test failure modes during the experimental process: breakage failure and pullout failure. The results showed that the roots were easier to be broken when the root diameter was smaller or the loading speed was larger. The relationship between the maximum anchorage force and root diameter was linear and the linearly dependent coefficient(R^2) was larger than 0.85. The anchorage force increased with the root embedment length. An increase of 10%^(-1)5% for the maximumanchorage force was found when load speed increased from 10 to 300 mm.min^(-1). The mean peak slippage of the root was from 13.81 to 35.79 mm when the load velocity varied from 10 to 300 mm.min^(-1). The study will be helpful for the design of slopes reinforced by vegetation and in predicting risk of uprooting of trees, and will have practical benefits for understanding the mechanism of landslide.展开更多
This paper studies the interface curing stresses between polymethyl methacrylate (PMMA) and composite by means of digital speckle correlation method (DSCM).A new method by combining DSCM with the marker points is deve...This paper studies the interface curing stresses between polymethyl methacrylate (PMMA) and composite by means of digital speckle correlation method (DSCM).A new method by combining DSCM with the marker points is developed to measure the interface curing stresses,and the measurement principle is introduced.The interface curing stresses between PMMA and composite with different curing bonding conditions are measured and analyzed,this indicates that the residual stress for furnace heating and furnace cooling is the smallest.Finally,the measurement error is discussed by means of finite element method,the influences of glass microsphere between adhesive and PMMA can be ignored.展开更多
Two modeling methods of the root insert for wind turbine blade are presented,i.e.,the local mesh optimization method(LMOM)and the global modeling method(GMM).Based on the optimized mesh of the local model for the meta...Two modeling methods of the root insert for wind turbine blade are presented,i.e.,the local mesh optimization method(LMOM)and the global modeling method(GMM).Based on the optimized mesh of the local model for the metal contact interface,LMOM is proposed to analyze the load path and stress distribution characteristics,while GMM is used to calculate and analyze the stress distribution characteristics of the resin layer established between the bushing and composite layers of root insert.To validate the GMM,a tension test is carried out.The result successfully shows that the shear strain expresses a similar strain distribution tendency with the GMM′s results.展开更多
In this paper, we consider the mixed Navier-Stokes/Darcy model with BeaversJoseph interface conditions. Based on two-grid discretizations, a local and parallel finite element algorithm for this mixed model is proposed...In this paper, we consider the mixed Navier-Stokes/Darcy model with BeaversJoseph interface conditions. Based on two-grid discretizations, a local and parallel finite element algorithm for this mixed model is proposed and analyzed. Optimal errors are obtained and numerical experiments are presented to show the efficiency and effectiveness of the local and parallel finite element algorithm.展开更多
This paper presents the extension of the global description approach of a discontinuous function, which is proposed in the previous paper, to a spectral domain decomposition method. This multi-domain spectral immersed...This paper presents the extension of the global description approach of a discontinuous function, which is proposed in the previous paper, to a spectral domain decomposition method. This multi-domain spectral immersed interlace method（IIM） divides the whole computation domain into the smooth and discontinuous parts. Fewer points on the smooth domains are used via taking advantage of the high accuracy property of the spectral method, but more points on the discontinuous domains are employed to enhance the resolution of the calculation. Two that the domain decomposition technique can placed around the discontinuity. The present reached, in spite of the enlarged computational discontinuous problems are tested to verify the present method. The results show reduce the error of the spectral IIM, especially when more collocation points are method is t：avorable for the reason that the same level of the accuracy can be domain.展开更多
In this paper,a class of new immersed interface finite element methods (IIFEM) is developed to solve elasticity interface problems with homogeneous and non-homogeneous jump conditions in two dimensions.Simple non-body...In this paper,a class of new immersed interface finite element methods (IIFEM) is developed to solve elasticity interface problems with homogeneous and non-homogeneous jump conditions in two dimensions.Simple non-body-fitted meshes are used.For homogeneous jump conditions,both non-conforming and conforming basis functions are constructed in such a way that they satisfy the natural jump conditions. For non-homogeneous jump conditions,a pair of functions that satisfy the same non-homogeneous jump conditions are constructed using a level-set representation of the interface.With such a pair of functions,the discontinuities across the interface in the solution and flux are removed;and an equivalent elasticity interface problem with homogeneous jump conditions is formulated.Numerical examples are presented to demonstrate that such methods have second order convergence.展开更多
The lowest order Pl-nonconforming triangular finite element method （FEM） for elliptic and parabolic interface problems is investigated. Under some reasonable regularity assumptions on the exact solutions, the optima...The lowest order Pl-nonconforming triangular finite element method （FEM） for elliptic and parabolic interface problems is investigated. Under some reasonable regularity assumptions on the exact solutions, the optimal order error estimates are obtained in the broken energy norm. Finally, some numerical results are provided to verify the theoretical analysis.展开更多
A new treatment for interface of metal and dielectric in finite-difference time domain (FDTD) method was presented, further how and why this treatment should be as it is was explained. The FDTD method was developed to...A new treatment for interface of metal and dielectric in finite-difference time domain (FDTD) method was presented, further how and why this treatment should be as it is was explained. The FDTD method was developed to compute the low-frequency electromagnetic fields in the metal instead of the traditional high-frequency ones as it was originally proposed. The computational results agreed well with the experimental ones.展开更多
The embedded boundary method for solving elliptic and parabolic problems in geometrically complex domains using Cartesian meshes by Johansen and Colella （1998, J. Comput. Phys. 147, 60） has been extended for ellipti...The embedded boundary method for solving elliptic and parabolic problems in geometrically complex domains using Cartesian meshes by Johansen and Colella （1998, J. Comput. Phys. 147, 60） has been extended for elliptic and parabolic problems with interior boundaries or interfaces of discontinuities of material properties or solutions. Second order accuracy is achieved in space and time for both stationary and moving interface problems. The method is conservative for elliptic and parabolic problems with fixed interfaces. Based on this method, a front tracking algorithm for the Stefan problem has been developed. The accuracy of the method is measured through comparison with exact solution to a two-dimensional Stefan problem. The algorithm has been used for the study of melting and solidification problems.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 11972375 and12211530028)the Special Funds for the Basic Scientific Research Expenses of Central Government Universities of China (No. 2472022X03006A)
文摘Hard-magnetic soft materials exhibit significant shape morphing capabilities under non-contact magnetic actuation, yet their particulate composition tends to compromise material toughness. To quantify particle-matrix interactions, we present a mechanics model describing the energy functional of planar magnetic composites. Through the Fourier series, the analytical solutions for stress distribution and interfacial peeling length of a single particle-polymer unit are derived with the Rayleigh-Ritz method under uniaxial tension. The calculated results of stress fields without the magnetic field agree well with those of the finite element method. The effects of external magnetic field strength and particle content on the stress distribution and peeling length are fully explored, and the enhanced analytical outcomes are obtained through numerical prediction.These insights can be used to validate the reliability of engineering designs, including adaptive structures, micro-electro-mechanical sensors, and soft robotic systems.
基金supported by the National Natural Science Foundation of China(Nos.52408435,52278384)。
文摘Ground response analysis and determination of site-specific ground motion parameters are necessary for evaluating seismic loads to enable sustainable design of aboveground and underground structures,particularly in deep overburden sites.This study investigates the influence of bedrock interface conditions and depth of soil deposits on obtained site-specific ground motion parameters.Employing the one-dimensional seismic response analysis program SOILQUAKE,the ground responses of five representative soil profiles and 1050 case studies are calculated considering three different site models of seismic input interfaces.The analysis employs the actual bedrock interface with a shear wave velocity of 760 m/s as the reference input bedrock interface.The results illustrate that the selection of the bedrock interface condition significantly affects the seismic response on the ground surface of deep overburden sites.Specifically,the ground surface acceleration response spectra at longer periods are notably smaller compared to those at the actual bedrock site.This may present a challenge for designing long-period high-rise buildings situated in deep overburden sites.It is recommended to select a seismic input bedrock interface closely approximating the actual bedrock depth when conducting seismic response analyses for deep overburden sites.
文摘In response to the complex characteristics of actual low-permeability tight reservoirs,this study develops a meshless-based numerical simulation method for oil-water two-phase flow in these reservoirs,considering complex boundary shapes.Utilizing radial basis function point interpolation,the method approximates shape functions for unknown functions within the nodal influence domain.The shape functions constructed by the aforementioned meshless interpolation method haveδ-function properties,which facilitate the handling of essential aspects like the controlled bottom-hole flow pressure in horizontal wells.Moreover,the meshless method offers greater flexibility and freedom compared to grid cell discretization,making it simpler to discretize complex geometries.A variational principle for the flow control equation group is introduced using a weighted least squares meshless method,and the pressure distribution is solved implicitly.Example results demonstrate that the computational outcomes of the meshless point cloud model,which has a relatively small degree of freedom,are in close agreement with those of the Discrete Fracture Model(DFM)employing refined grid partitioning,with pressure calculation accuracy exceeding 98.2%.Compared to high-resolution grid-based computational methods,the meshless method can achieve a better balance between computational efficiency and accuracy.Additionally,the impact of fracture half-length on the productivity of horizontal wells is discussed.The results indicate that increasing the fracture half-length is an effective strategy for enhancing production from the perspective of cumulative oil production.
基金Project supported by the National Natural Science Foundation of China(No.12102131)the Natural Science Foundation of Henan Province of China(No.242300420248)the International Science and Technology Cooperation Project of Henan Province of China(No.242102521010)。
文摘The Laguerre polynomial method has been successfully used to investigate the dynamic responses of a half-space.However,it fails to obtain the correct stress at the interfaces in a layered half-space,especially when there are significant differences in material properties.Therefore,a coupled Legendre-Laguerre polynomial method with analytical integration is proposed.The Rayleigh waves in a one-dimensional(1D)hexagonal quasicrystal(QC)layered half-space with an imperfect interface are investigated.The correctness is validated by comparison with available results.Its computation efficiency is analyzed.The dispersion curves of the phase velocity,displacement distributions,and stress distributions are illustrated.The effects of the phonon-phason coupling and imperfect interface coefficients on the wave characteristics are investigated.Some novel findings reveal that the proposed method is highly efficient for addressing the Rayleigh waves in a QC layered half-space.It can save over 99%of the computation time.This method can be expanded to investigate waves in various layered half-spaces,including earth-layered media and surface acoustic wave(SAW)devices.
基金Supported by the National Natural Science Foundation of China (No. 29736170)and the Natural Science Foundation of Zhejiang Province(No. RC01051).
文摘A novel simple two-dimensional square-lattice model of amphiphile at oil-water interface is developed,in which oil and water act as solvent and occupy empty sites and amphiphile occupies chains of sites. In this model, the oil-water interface is fixed, And amphiphile molecules will be enriched at the oil-water interface. The interfacial concentration of amphiphile calculated by Monte Carlo method shows that it is easier for the hydrophilic-hydrophobic balanced amphiphile to stay at the interface. And the adsorption of amphiphile increases with the increase of amphiphile concentration and the decrease with temperature.
基金Supported by the National Natural Science Foundation of China (No. 29736170) the Natural Science Foundation of Zhejiang Province (No. RC01051).
文摘Amphiphile-oil-water system is complicated. The real behavior of amphiphile in the interface is still undnown despite that this behavior is very important in determining the stability of emulsion system. In this paper, the interface properties of amphiphile at oil-water interface were investigated by a square-lattice model Monte Carlo simulation method. The synergistic effect was found for hydrophobic and hydrophilic amphiphile mixture systems; and the synergistic effect disappears or was weakened as the amphiphile at the interface region became dilute with the increasing of temperature.
基金Nanometer Special Project of Shanghai,China(No.1052nm06400)
文摘Nowadays,the novel oil water interface method has attracted a considerable attention owing to the advantages of mild reaction conditions,simple operation,low cost,and high efficiency.In this paper,uniform oil-soluble Fe_3O_4 nanoparticles(NPs) were synthesized by oil-water interface method from mixing iron tristearate of 0.067mol/L in cyclohexane with ferrous sulfate in water.The as-prepared products were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),vibrating sample magnetometer(VSM),Fourier transform infrared spectroscopy(FT-IR) and thermogravimetric analyzer(TGA).TEM images and XRD profiles showed that the size of the oil-soluble products ranged in 1.7-6.9 nm.VSM indicated that the Fe_3O_4 NPs were superparamagetic.FT-IR and TGA proved that oleic acid was combined to the surface of Fe_3O_4 NPs closely.TEM images and XRD profiles revealed that the most suitable reaction concentration of NH_3·H_2O,oleic acid/water in volume,reaction temperature and reaction time were 4.5 mol/L,50:1 000,80℃ and 6 h,respectively.The formation mechanism of the nearly monodispersed Fe_3O_4 NPs was that the preformed Fe_3O_4 nuclei were capped by oleic acid as early as the nucleation occurred in oil-water interface and subsequently entered into oil phase to stop growing.
基金Projects(11375112,51472155,11275122)supported by the National Natural Science Foundation of China
文摘The growth interfaces of CdMnTe（CMT） crystals grown by traveling heater method（THM） were studied. Two types of polycrystalline CMT feed ingots synthesized in a traditional rocking furnace and vertical Bridgman（VB） furnace were adopted in THM growth, and the effects of the polycrystalline feed on the growth interface were revealed. The morphology of the growth interface of CMT crystal（CMT2） grown from the feed by vertical Bridgman was smoother with lower curvature compared with that of CMT crystal（CMT1） from the feed by rocking furnace. The radial Mn composition and Te inclusion distribution of the CMT wafers were analyzed and correlated to the growth interface. The Mn segregation along the radial direction and Te inclusion density of CMT2 were lower than those of CMT1. The VB method synthesized polycrystalline feed could improve the growth interface morphology, which is beneficial for decreasing the Te inclusions and Mn segregation in CMT wafers.
基金financial support from the National Natural Science Foundation of China (No.61904073)Spring City Plan-Special Program for Young Talents (No.K202005007)+2 种基金Yunnan Local Colleges Applied Basic Research Projects (Nos.202101BA070001-138,2018FH001-016)Yunnan Talents Support Plan for Yong Talents (No.XDYC-QNRC-2022-0482)Frontier Research Team of Kunming University 2023,and Yunnan Provincial Education Department (Nos.2022Y732,2022Y739)。
文摘Metal batteries have attracted considerable attention from researchers because of their low reduction voltage and high specific capacity.However,the reduction in the capacity and lifespan of batteries caused by the dendrite growth of metal anode limits the development of metal batteries.Metal-organic frameworks (MOFs) can be used to protect metal anodes owing to their advantages of ideal specific surface area,tunable porosity,and physiochemical stability in electrolytes.Therefore,MOFs have been extensively investigated in metal batteries.The introduction of MOFs to the metal anode interface can greatly improve the performance of batteries.In this review,the synthesis methods of typical MOFs and their derivatives,their protective mechanism on the metal anode,including Li,Na,K,Zn,and Mg,and their effects on the performance of metal batteries were elucidated.This review would help to design and apply MOFs to the anode interface in metal batteries.
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Project supported by the National Natural Science Foundation of China(Nos.11671157 and11826212)
文摘In this paper,two-grid immersed finite element (IFE) algorithms are proposed and analyzed for semi-linear interface problems with discontinuous diffusion coefficients in two dimension.Because of the advantages of finite element (FE) formulation and the simple structure of Cartesian grids,the IFE discretization is used in this paper.Two-grid schemes are formulated to linearize the FE equations.It is theoretically and numerically illustrated that the coarse space can be selected as coarse as H =O(h^1/4)(or H =O(h^1/8)),and the asymptotically optimal approximation can be achieved as the nonlinear schemes.As a result,we can settle a great majority of nonlinear equations as easy as linearized problems.In order to estimate the present two-grid algorithms,we derive the optimal error estimates of the IFE solution in the L^p norm.Numerical experiments are given to verify the theorems and indicate that the present two-grid algorithms can greatly improve the computing efficiency.
基金supported by the Fundamental Research Funds for the Central Universities(No.YX2010-20)the Open Projects Foundation of Key Laboratory of Soil and Water Conservation & Desertification Combat (Beijing ForestryUniversity), Ministry of Education of P.R. China (No.201002) the National Natural Science Foundation of China (No. 31570708, No.30901162)
文摘It is important to quantify the effect of the root diameter, the embedment length of the root and load speed on the soil-root interface mechanical properties for studying the root anchorage. The soilroot interface mechanical properties can be obtained through the pullout force and root slippage curve(F-S curve). About 120 Pinus tabulaeformis single roots whose diameters ranged from 1 mm to 10 mm divided into 6 groups based on different root embedment length(50 mm, 100 mm and 150 mm) and different load velocity(10 mm·min^(-1), 50 mm·min^(-1), 100 mm·min^(-1) and 300 mm·min^(-1)) were investigated using the pullout method. This study aims to explore the mechanical properties of the soil-root interface in the real conditions using the pullout test method. The results showed two kinds of pullout test failure modes during the experimental process: breakage failure and pullout failure. The results showed that the roots were easier to be broken when the root diameter was smaller or the loading speed was larger. The relationship between the maximum anchorage force and root diameter was linear and the linearly dependent coefficient(R^2) was larger than 0.85. The anchorage force increased with the root embedment length. An increase of 10%^(-1)5% for the maximumanchorage force was found when load speed increased from 10 to 300 mm.min^(-1). The mean peak slippage of the root was from 13.81 to 35.79 mm when the load velocity varied from 10 to 300 mm.min^(-1). The study will be helpful for the design of slopes reinforced by vegetation and in predicting risk of uprooting of trees, and will have practical benefits for understanding the mechanism of landslide.
基金supported by the National Basic Research Program (973 Program) of China (2011CB606105)
文摘This paper studies the interface curing stresses between polymethyl methacrylate (PMMA) and composite by means of digital speckle correlation method (DSCM).A new method by combining DSCM with the marker points is developed to measure the interface curing stresses,and the measurement principle is introduced.The interface curing stresses between PMMA and composite with different curing bonding conditions are measured and analyzed,this indicates that the residual stress for furnace heating and furnace cooling is the smallest.Finally,the measurement error is discussed by means of finite element method,the influences of glass microsphere between adhesive and PMMA can be ignored.
基金supported jointly by the National Basic Research Program of China("973"Program)(No2014CB046200)the National Science Foundation of Jiangsu Province(No.BK2014059)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe National Natural Science Foundation of China(No.11172135)
文摘Two modeling methods of the root insert for wind turbine blade are presented,i.e.,the local mesh optimization method(LMOM)and the global modeling method(GMM).Based on the optimized mesh of the local model for the metal contact interface,LMOM is proposed to analyze the load path and stress distribution characteristics,while GMM is used to calculate and analyze the stress distribution characteristics of the resin layer established between the bushing and composite layers of root insert.To validate the GMM,a tension test is carried out.The result successfully shows that the shear strain expresses a similar strain distribution tendency with the GMM′s results.
文摘In this paper, we consider the mixed Navier-Stokes/Darcy model with BeaversJoseph interface conditions. Based on two-grid discretizations, a local and parallel finite element algorithm for this mixed model is proposed and analyzed. Optimal errors are obtained and numerical experiments are presented to show the efficiency and effectiveness of the local and parallel finite element algorithm.
基金National Natural Science Foundation of China(51076006)
文摘This paper presents the extension of the global description approach of a discontinuous function, which is proposed in the previous paper, to a spectral domain decomposition method. This multi-domain spectral immersed interlace method（IIM） divides the whole computation domain into the smooth and discontinuous parts. Fewer points on the smooth domains are used via taking advantage of the high accuracy property of the spectral method, but more points on the discontinuous domains are employed to enhance the resolution of the calculation. Two that the domain decomposition technique can placed around the discontinuity. The present reached, in spite of the enlarged computational discontinuous problems are tested to verify the present method. The results show reduce the error of the spectral IIM, especially when more collocation points are method is t：avorable for the reason that the same level of the accuracy can be domain.
基金supported by the US ARO grants 49308-MA and 56349-MAthe US AFSOR grant FA9550-06-1-024+1 种基金he US NSF grant DMS-0911434the State Key Laboratory of Scientific and Engineering Computing of Chinese Academy of Sciences during a visit by Z.Li between July-August,2008.
文摘In this paper,a class of new immersed interface finite element methods (IIFEM) is developed to solve elasticity interface problems with homogeneous and non-homogeneous jump conditions in two dimensions.Simple non-body-fitted meshes are used.For homogeneous jump conditions,both non-conforming and conforming basis functions are constructed in such a way that they satisfy the natural jump conditions. For non-homogeneous jump conditions,a pair of functions that satisfy the same non-homogeneous jump conditions are constructed using a level-set representation of the interface.With such a pair of functions,the discontinuities across the interface in the solution and flux are removed;and an equivalent elasticity interface problem with homogeneous jump conditions is formulated.Numerical examples are presented to demonstrate that such methods have second order convergence.
基金Project supported by the National Natural Science Foundation of China(No.11271340)
文摘The lowest order Pl-nonconforming triangular finite element method （FEM） for elliptic and parabolic interface problems is investigated. Under some reasonable regularity assumptions on the exact solutions, the optimal order error estimates are obtained in the broken energy norm. Finally, some numerical results are provided to verify the theoretical analysis.
基金the National Natural Science Foundation (GrantNO.5973J080) and by the "973" Key FOundation (Grant No. G1998061510).
文摘A new treatment for interface of metal and dielectric in finite-difference time domain (FDTD) method was presented, further how and why this treatment should be as it is was explained. The FDTD method was developed to compute the low-frequency electromagnetic fields in the metal instead of the traditional high-frequency ones as it was originally proposed. The computational results agreed well with the experimental ones.
基金supported by the U.S.Department of Energy under Contract No.DE-AC02-98CH10886 and by the State of New York
文摘The embedded boundary method for solving elliptic and parabolic problems in geometrically complex domains using Cartesian meshes by Johansen and Colella （1998, J. Comput. Phys. 147, 60） has been extended for elliptic and parabolic problems with interior boundaries or interfaces of discontinuities of material properties or solutions. Second order accuracy is achieved in space and time for both stationary and moving interface problems. The method is conservative for elliptic and parabolic problems with fixed interfaces. Based on this method, a front tracking algorithm for the Stefan problem has been developed. The accuracy of the method is measured through comparison with exact solution to a two-dimensional Stefan problem. The algorithm has been used for the study of melting and solidification problems.
