The spherical Ti particle(Ti_(p))reinforced Mg-5Zn-0.5Ca(Ti_(p)/ZX50)composite was prepared via the semisolid stirring casting process and the effects of Ti_(p)on the hot deformation and hot processing behavior of mat...The spherical Ti particle(Ti_(p))reinforced Mg-5Zn-0.5Ca(Ti_(p)/ZX50)composite was prepared via the semisolid stirring casting process and the effects of Ti_(p)on the hot deformation and hot processing behavior of matrix alloy were investigated through uniaxial hot compression testing.The results indicate that a particle deformation zone(PDZ)forms around the Ti_(p)with the deformation of the Ti_(p)/ZX50 composite,which is propitious to the dynamic recrystallization(DRX)of the matrix alloy.The range of the PDZ and the promoting effect of the Ti_(p)on DRXed nucleation are inversely related to the deformation degree of the Ti_(p).Moreover,the deformation of Ti_(p)alleviates the high stress in the matrix alloy during deformation,expanding the processing range and reducing the average deformation activation energy of the matrix alloy.Notably,the minimum processing temperature(493 K)of the Ti_(p)/ZX50 composite is significantly lower than that of hardened particle reinforced magnesium matrix composites.The hot deformation mechanism of the Ti_(p)/ZX50 composite is dislocation climb controlled by both lattice diffusion and pipe diffusion.展开更多
Birds have developed near-perfect structures and functionality over millions of years of natural evolution.To improve the efficiency of fixed-wing vehicles in different environments,researchers have developed deformab...Birds have developed near-perfect structures and functionality over millions of years of natural evolution.To improve the efficiency of fixed-wing vehicles in different environments,researchers have developed deformable wings inspired by the wing structures of birds.Shape Memory Alloy(SMA)is applied as a smart material to the deformable wing.Compared with other drive methods,SMA actuators have the advantages of high drive capacity and a simple structure for driving wing deformation.According to the shape memory effect,SMA actuators are classified as single-range and dual-range actuators.The wing structure designed for each SMA drive is unique.By comparing and analyzing the structures of airfoils,airfoils with similar drive forms and deformation structures are put together for review and discussion.The deformable wings are categorized into out-of-face deformation,in-face deformation,airfoil curvature deformation,and combined deformation with multiple degrees of freedom based on the structure and location of the wing that produces the deformation.An overview of the deformed wing is introduced by telling the bionic theory of seagulls.The principles of deformation of the wing,the mechanics of the SMA actuator mechanism,and the aerodynamic characteristics of the deformable wing are presented.The structure and working principle of SMA actuators for each type of deformable wing are explained in detail.Methods and approaches to study the deformability of deformable wings are analyzed and summarized.This work provides comprehensive insights and perspectives for future studies of SMA-driven deformable airfoils.展开更多
Self-propulsion of a deformable ellipse immersed in an unbounded inviscid fluid is discussed in order to explore the effect of the deformation and controlled rotation of the body coupled with the shift of its internal...Self-propulsion of a deformable ellipse immersed in an unbounded inviscid fluid is discussed in order to explore the effect of the deformation and controlled rotation of the body coupled with the shift of its internal mass on the self-motion.The ellipse is capable of symmetric deformation along the two orthogonal axes and endowed with some self-regulation ability via the shift and rotation of its internal mass.From the model,the appropriate velocity potential induced by the motion of the ellipse with the deformation in an otherwise undisturbed fluid is derived,and then the equations of motion are obtained by means of integrals of the unsteady fluid pressure.The equations are utilized to explore self-translational behaviors of the ellipse through the cyclic shift of its internal mass and deformation coupled with its own controllable rotation.Analysis and numerical results show that the ellipse can break the kinematic time-reversal symmetry by properly adjusting its own rotation to coordinate with the deformation and the cyclic shift of the inner mass to meet a forward criterion,and push itself to move persistently forward without a regression at zero system momentum,exhibiting some basic serpentine movements according as the ellipse performs complete revolutions or oscillates between two extreme yaw angles during its self-motion.展开更多
The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from...The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from 0.001 s^(-1) to 1 s^(-1).The results show that the addition of Sn promotes dynamic recrystallization(DRX),and CaMgSn phases can act as nucleation sites during the compression deformation.Flow stress increases with increasing the strain rate and decreasing the temperature.Both the ZM61-0.5Ca and ZMT612-0.5Ca alloys exhibit obvious DRX characteristics.CaMgSn phases can effectively inhibit dislocation motion with the addition of Sn,thus increasing the peak fl ow stress of the alloy.The addition of Sn increases the hot deformation activation energy of the ZM61-0.5Ca alloy from 199.654 kJ/mol to 276.649 kJ/mol,thus improving the thermal stability of the alloy.For the ZMT612-0.5Ca alloy,the optimal hot deformation parameters are determined to be a deformation temperature range of 350–400℃and a strain rate range of 0.001–0.01 s^(-1).展开更多
The complex skin structure and insufficient intracellular entrapment limit the therapeutic effects of active substances,therefore appealing to a more effective transdermal drug delivery system design.Herein,a hyaluron...The complex skin structure and insufficient intracellular entrapment limit the therapeutic effects of active substances,therefore appealing to a more effective transdermal drug delivery system design.Herein,a hyaluronic acid(HA)modified steareth-2-based niosomes(HA-nio)with satisfactory deformability and targeting properties was designed for ergothioneine(EGT)(EGT@HA-nio)against ultraviolet(UV)-induced skin damage.The unique composition allows EGT@HA-nio to exhibit high mechanical softness,making it deformable to pass through the stratum corneum by the intercellular space without rupture.For further intracellular delivery,HA modification enables EGT to target human dermal cells(HDFs)with increased distribution in mitochondria without the restriction of specific EGT transporter-organic cation transporter1(OCTN-1).Benefiting from the above properties,an adequate amount of EGT in the active form was accumulated in the desired cellular sites,alleviating UV-radiation-induced reactive oxygen species(ROS)generation,inflammatory factor release,DNA damage,and mitochondrial dysfunction.The in vivo experimental results show that EGT@HA-nio could significantly decrease collagen degradation,restore epidermal thickness and morphology to healthy levels,and effectively prevent UV-induced skin damage.With the ability to penetrate biological barriers and deliver drugs,HA-nio may promote the development of inadequate drug penetration disease treatment including skin diseases,cancers,and bacterial infections.展开更多
Magnesium matrix composites(MMCs)combine exceptional low density,high specific strength,and stiffness,positioning them as critical materials for aerospace,automotive,and electronics industries.This review highlights r...Magnesium matrix composites(MMCs)combine exceptional low density,high specific strength,and stiffness,positioning them as critical materials for aerospace,automotive,and electronics industries.This review highlights recent progress in the fabrication of Ti-Mg composites and analyzes the mechanisms behind their enhanced mechanical properties.A key focus is the interfacial deformation incompatibility between Ti and Mg phases,which generates strain gradients and promotes the accumulation of geometrically necessary dislocations(GNDs)at the interface.This process not only improves strain hardening and ductility but also reveals the need for advanced micromechanical models to capture the plastic behavior of both phases.The review critically examines the impact of different Mg matrix types(AZ,AM,VW series)and the role of interfacial product morphology and size on bonding and overall performance.Furthermore,Ti reinforcement endows the composites with superior wear resistance and thermal conductivity,indicating broad application potential.展开更多
The early and precise identification of Alzheimer’s Disease(AD)continues to pose considerable clinical difficulty due to subtle structural alterations and overlapping symptoms across the disease phases.This study pre...The early and precise identification of Alzheimer’s Disease(AD)continues to pose considerable clinical difficulty due to subtle structural alterations and overlapping symptoms across the disease phases.This study presents a novel Deformable Attention Vision Transformer(DA-ViT)architecture that integrates deformable Multi-Head Self-Attention(MHSA)with a Multi-Layer Perceptron(MLP)block for efficient classification of Alzheimer’s disease(AD)using Magnetic resonance imaging(MRI)scans.In contrast to traditional vision transformers,our deformable MHSA module preferentially concentrates on spatially pertinent patches through learned offset predictions,markedly diminishing processing demands while improving localized feature representation.DA-ViT contains only 0.93 million parameters,making it exceptionally suitable for implementation in resource-limited settings.We evaluate the model using a class-imbalanced Alzheimer’s MRI dataset comprising 6400 images across four categories,achieving a test accuracy of 80.31%,a macro F1-score of 0.80,and an area under the receiver operating characteristic curve(AUC)of 1.00 for the Mild Demented category.Thorough ablation studies validate the ideal configuration of transformer depth,headcount,and embedding dimensions.Moreover,comparison research indicates that DA-ViT surpasses state-of-theart pre-trained Convolutional Neural Network(CNN)models in terms of accuracy and parameter efficiency.展开更多
This paper presents CW-HRNet,a high-resolution,lightweight crack segmentation network designed to address challenges in complex scenes with slender,deformable,and blurred crack structures.The model incorporates two ke...This paper presents CW-HRNet,a high-resolution,lightweight crack segmentation network designed to address challenges in complex scenes with slender,deformable,and blurred crack structures.The model incorporates two key modules:Constrained Deformable Convolution(CDC),which stabilizes geometric alignment by applying a tanh limiter and learnable scaling factor to the predicted offsets,and the Wavelet Frequency Enhancement Module(WFEM),which decomposes features using Haar wavelets to preserve low-frequency structures while enhancing high-frequency boundaries and textures.Evaluations on the CrackSeg9k benchmark demonstrate CW-HRNet’s superior performance,achieving 82.39%mIoU with only 7.49M parameters and 10.34 GFLOPs,outperforming HrSegNet-B48 by 1.83% in segmentation accuracy with minimal complexity overhead.The model also shows strong cross-dataset generalization,achieving 60.01%mIoU and 66.22%F1 on Asphalt3k without fine-tuning.These results highlight CW-HRNet’s favorable accuracyefficiency trade-off for real-world crack segmentation tasks.展开更多
Conventional deformable wheel systems in robots and other mechatronic systems face significant challenges in achieving miniaturization,intelligence,and integration.To address these issues,we propose a novel integrated...Conventional deformable wheel systems in robots and other mechatronic systems face significant challenges in achieving miniaturization,intelligence,and integration.To address these issues,we propose a novel integrated structural design method and four-dimensional printing strategy for deformable wheels capable of shaping among multiple programmable direct-driven deformation configurations.The load-bearing capacity of the printed wheel is strengthened by employing deformed components in various locations and actuated states.Additionally,a novel analytical design method is presented to determine the structure,actuation,and deformation parameters of each component under complex coupled deformation.Our findings reveal that the designed wheel can transform into three different configurations,exhibiting desired deformations of 12.5%in the radial direction and 19.6%in the axial direction.It also demonstrates robust deformation behavior and structural stability under multi-directional loads.By integrating a terrain sensing system,the designed wheel exhibits highly adaptive deformation capabilities on various terrains,showing great potential for exploring complex environments.展开更多
Shape prediction of deformable linear objects(DLO)plays critical roles in robotics,medical devices,aerospace,and manufacturing,especially in manipulating objects such as cables,wires,and fibers.Due to the inherent fle...Shape prediction of deformable linear objects(DLO)plays critical roles in robotics,medical devices,aerospace,and manufacturing,especially in manipulating objects such as cables,wires,and fibers.Due to the inherent flexibility of DLO and their complex deformation behaviors,such as bending and torsion,it is challenging to predict their dynamic characteristics accurately.Although the traditional physical modeling method can simulate the complex deformation behavior of DLO,the calculation cost is high and it is difficult to meet the demand of real-time prediction.In addition,the scarcity of data resources also limits the prediction accuracy of existing models.To solve these problems,a method of fiber shape prediction based on a physical information graph neural network(PIGNN)is proposed in this paper.This method cleverly combines the powerful expressive power of graph neural networks with the strict constraints of physical laws.Specifically,we learn the initial deformation model of the fiber through graph neural networks(GNN)to provide a good initial estimate for the model,which helps alleviate the problem of data resource scarcity.During the training process,we incorporate the physical prior knowledge of the dynamic deformation of the fiber optics into the loss function as a constraint,which is then fed back to the network model.This ensures that the shape of the fiber optics gradually approaches the true target shape,effectively solving the complex nonlinear behavior prediction problem of deformable linear objects.Experimental results demonstrate that,compared to traditional methods,the proposed method significantly reduces execution time and prediction error when handling the complex deformations of deformable fibers.This showcases its potential application value and superiority in fiber manipulation.展开更多
The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt%Nb addition after various plastic deformation and heat treatment processes were investigated.Through Vickers hardness tests,free resonance You...The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt%Nb addition after various plastic deformation and heat treatment processes were investigated.Through Vickers hardness tests,free resonance Young's modulus measurements,and microstructure analysis,the effects of dislocation density,vacancy formation,and recrystallization on the alloy performance were clarified.Results indicate that increasing the rolling reduction enhances damping property due to higher dislocation density,whereas aging below the recrystallization temperature reduces damping property via dislocation pinning by the Suzuki effect.Recrystallization heat treatment restores the original structure and damping level.This alloy possesses tensile strength of approximately 1500 MPa and logarithmic decrement valueδ^(-1) in the range of 2×10^(-4)–3×10^(-4),demonstrating superior mechanical properties compared with the Ti-based alloys,which makes it an excellent candidate material for ultrasonic tools and medical applications.展开更多
The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing t...The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing to this multi-principal element nature,high-entropy alloys exhibit complex deformation behavior dominated by alternating and coupled deformation mechanisms.Therefore,elucidating these intricate deformation mechanisms remains a key challenge in current research.Neutron diffraction(ND)techniques offer distinct advantages over traditional microscopic methods for characterizing such complex deformation behavior.The strong penetration capability of neutrons enables in-situ,real-time,and non-destructive detection of structural evolution in most centimeter-level bulk samples under complex environments,and ND allows precise characterization of lattice site occupations for light elements,such as C and O,and neighboring elements.This review discussed the principles of ND,experiment procedures,and data analysis.Combining with recent advances in the research about face-centered cubic high-entropy alloy,typical examples of using ND to investigate the deformation behavior were summarized,ultimately revealing deformation mechanisms dominated by dislocations,stacking faults,twinning,and phase transformations.展开更多
Quantitative assessment of microscale slip activities and plastic localizations is essential for understanding the complex deformation mechanisms in crystalline materials.However,few experimental studies have been abl...Quantitative assessment of microscale slip activities and plastic localizations is essential for understanding the complex deformation mechanisms in crystalline materials.However,few experimental studies have been able to dynamically measure the deformation fields of rapidly evolving slip activities at the microscale.In this study,we used the Sampling Moire?Method(SMM)to directly measure the dynamic deformation fields of slip activities in Nickel-Based Single-Crystal(NBSC)superalloy under in-situ tensile test,and the strain and displacement fields under the evolving microplastic events with intense slip activities around the notch of the NBSC superalloy specimen were obtained for the first time.The dynamic evolution of slip bands was quantitatively characterized through detailed statistical analysis of strains and displacements under different loads.The locations of the initial appearance of slip traces were successfully predicted by the regions of plasticity localization.The results show that the deformation fields exhibit both high spatial and temporal resolutions,enabling the capture of nanometer-scale displacement fields and visualization of the dynamic fluidity of slip accumulation.This method demonstrates the superiority of the dynamic characterization of the plastic deformation field at the microscale and the promise of its application for characterizing the slip activities of various crystalline metals.展开更多
The structures of even-even Gd and Dy isotopes around N=100 were investigated using a fully self-consistent microscopic model.The systematics of the exited 2_(1)^(+)and 4_(1)^(+)energies reveal a peak-like structure a...The structures of even-even Gd and Dy isotopes around N=100 were investigated using a fully self-consistent microscopic model.The systematics of the exited 2_(1)^(+)and 4_(1)^(+)energies reveal a peak-like structure at N=100 along the Gd(Z=64)and Dy(Z=66)isotopic chains.This supports the evidence for a subshell gap near N=100.The nuclear structure properties studied are important to understand the r-process elemental abundance peak at A~160.展开更多
A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.T...A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.The proposed method enables high-fidelity parameterized deformation for both flat and curved perforated surfaces while maintaining mesh quality with minimal geometric distortion.To evaluate its effectiveness,comparative studies between HFFD and conventional FFD methods are conducted,demonstrating superior performance in mesh quality and geometric fidelity.The HFFD-based framework is further applied to the Multidisciplinary Design Optimization(MDO)of a double-wall turbine blade leading edge.Results indicate an 11.6%increase in cooling efficiency and a 16.21%reduction in maximum stress.Additionally,compared to traditional geometry-based parameterization in MDO,the HFFD approach improves model processing efficiency by 84.15%and overall optimization efficiency by20.05%.These findings demonstrate HFFD's potential to significantly improve complex engineering design optimization by achieving precise shape preservation and improving computational efficiency.展开更多
The contact deformation and buckling of elastic rods against rigid surfaces represent a prevalent phenomenon in applications such as oil drilling,arterial stents,and energy harvesting.This has attracted widespread att...The contact deformation and buckling of elastic rods against rigid surfaces represent a prevalent phenomenon in applications such as oil drilling,arterial stents,and energy harvesting.This has attracted widespread attention from researchers.In this paper,the deformation and buckling behaviors of a circular arch subject to compression by a rigid plate are investigated with a planar elastic rod model that incorporates tension,shearing,and bending.In comparison with the existing models that solely consider the bending energy,the deflection curve,the internal force distribution,and the critical load of the present model show good agreement with the finite element results.Through the dimensional analysis and order-of-magnitude estimation,we examine the factors influencing the critical load.The study reveals that the semi-central angle of the arch has the most significant effect.The dimensionless geometric parameter describing arch slenderness becomes prominent when the semi-central angle is less than 30°,while Poisson's ratio and the cross-sectional shear correction factor exhibit negligible influence.Furthermore,the variation in the proportions of strain energy components during critical buckling is presented with respect to the semi-central angle and the geometric parameter,thereby delineating the applicable ranges of both the original model(OM)and the modified model(MM).展开更多
Central Sumatra,Indonesia,is historically known for its significant seismic activities,most notably the devastating 1883 earthquake.In this study,we measured the interseismic deformation using continuous GNSS observat...Central Sumatra,Indonesia,is historically known for its significant seismic activities,most notably the devastating 1883 earthquake.In this study,we measured the interseismic deformation using continuous GNSS observation data for three years from 2018 to 2021.5.The results show that the derived velocity fields indicate that the Central Sumatra deformation is primarily characterized by crustal strain shortening due to interaction between the India-Australian plate and the Sundaland plate.High strain values are observed along the Sumatran Fault Zone(SFZ),which is characterized by a history of significant seismic activity.Interseismic locking is divided into two segments.Segment A,located in the northern part of Siberut Island has an estimated moment magnitude of MW7.44 with a return period of200 years leading to a potential earthquake magnitude of MW8.98.Segment B in the southern part of Siberut Island has an estimated moment magnitude of MW7.26 with a return period of 200 years,resulting in a potential earthquake magnitude of MW8.79.The findings highlight critical seismic hazard implications,emphasizing the potential for a major earthquake in the Central Sumatra.展开更多
This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,Calcu...This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,CalculiX,and preCICE to simulate fluid-particle-structure interactions with large deformations.Mesh motion in the fluid field is handled using the radial basis function(RBF)method.The particle phase is modeled by MPPIC,where fluid-particle interaction is described through momentum exchange,and inter-particle collisions are characterized by collision stress.The structural field is solved by nonlinear FEM to capture large deformations induced by geometric nonlinearity.Coupling among fields is realized through a partitioned,parallel,and non-intrusive iterative strategy,ensuring stable transfer and convergence of interface forces and displacements.Notably,the influence of particles on the structure is not direct but mediated by the fluid,while structural motion directly affects particle dynamics.The results demonstrate that the proposed approach effectively captures multiphysics interaction processes and provides a valuable reference for numerical modeling of coupled fluid-particle-structure systems.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52271109 and 52401162)Natural Science Foundation of Shanxi(Nos.202403021211064 and 202403011212003)the Major Special Plan for Science and Technology in Shanxi Province(No.202201050201012).
文摘The spherical Ti particle(Ti_(p))reinforced Mg-5Zn-0.5Ca(Ti_(p)/ZX50)composite was prepared via the semisolid stirring casting process and the effects of Ti_(p)on the hot deformation and hot processing behavior of matrix alloy were investigated through uniaxial hot compression testing.The results indicate that a particle deformation zone(PDZ)forms around the Ti_(p)with the deformation of the Ti_(p)/ZX50 composite,which is propitious to the dynamic recrystallization(DRX)of the matrix alloy.The range of the PDZ and the promoting effect of the Ti_(p)on DRXed nucleation are inversely related to the deformation degree of the Ti_(p).Moreover,the deformation of Ti_(p)alleviates the high stress in the matrix alloy during deformation,expanding the processing range and reducing the average deformation activation energy of the matrix alloy.Notably,the minimum processing temperature(493 K)of the Ti_(p)/ZX50 composite is significantly lower than that of hardened particle reinforced magnesium matrix composites.The hot deformation mechanism of the Ti_(p)/ZX50 composite is dislocation climb controlled by both lattice diffusion and pipe diffusion.
基金supported by the National Science Fund for Distinguished Young Scholars(No.52025053)National Natural Science Foundation of China(No.52305302)+1 种基金the Natural Science Foundation of Jilin Province(No.20220101216JC)the asterisk indicates the corresponding authors.
文摘Birds have developed near-perfect structures and functionality over millions of years of natural evolution.To improve the efficiency of fixed-wing vehicles in different environments,researchers have developed deformable wings inspired by the wing structures of birds.Shape Memory Alloy(SMA)is applied as a smart material to the deformable wing.Compared with other drive methods,SMA actuators have the advantages of high drive capacity and a simple structure for driving wing deformation.According to the shape memory effect,SMA actuators are classified as single-range and dual-range actuators.The wing structure designed for each SMA drive is unique.By comparing and analyzing the structures of airfoils,airfoils with similar drive forms and deformation structures are put together for review and discussion.The deformable wings are categorized into out-of-face deformation,in-face deformation,airfoil curvature deformation,and combined deformation with multiple degrees of freedom based on the structure and location of the wing that produces the deformation.An overview of the deformed wing is introduced by telling the bionic theory of seagulls.The principles of deformation of the wing,the mechanics of the SMA actuator mechanism,and the aerodynamic characteristics of the deformable wing are presented.The structure and working principle of SMA actuators for each type of deformable wing are explained in detail.Methods and approaches to study the deformability of deformable wings are analyzed and summarized.This work provides comprehensive insights and perspectives for future studies of SMA-driven deformable airfoils.
基金supported by the National Natural Science Foundation of China(Grant No.11672182).
文摘Self-propulsion of a deformable ellipse immersed in an unbounded inviscid fluid is discussed in order to explore the effect of the deformation and controlled rotation of the body coupled with the shift of its internal mass on the self-motion.The ellipse is capable of symmetric deformation along the two orthogonal axes and endowed with some self-regulation ability via the shift and rotation of its internal mass.From the model,the appropriate velocity potential induced by the motion of the ellipse with the deformation in an otherwise undisturbed fluid is derived,and then the equations of motion are obtained by means of integrals of the unsteady fluid pressure.The equations are utilized to explore self-translational behaviors of the ellipse through the cyclic shift of its internal mass and deformation coupled with its own controllable rotation.Analysis and numerical results show that the ellipse can break the kinematic time-reversal symmetry by properly adjusting its own rotation to coordinate with the deformation and the cyclic shift of the inner mass to meet a forward criterion,and push itself to move persistently forward without a regression at zero system momentum,exhibiting some basic serpentine movements according as the ellipse performs complete revolutions or oscillates between two extreme yaw angles during its self-motion.
基金Sichuan Science and Technology Program(2025ZNSFSC1341)Fundamental Research Funds for the Central Universities(J2022-090,25CAFUC04087)。
文摘The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from 0.001 s^(-1) to 1 s^(-1).The results show that the addition of Sn promotes dynamic recrystallization(DRX),and CaMgSn phases can act as nucleation sites during the compression deformation.Flow stress increases with increasing the strain rate and decreasing the temperature.Both the ZM61-0.5Ca and ZMT612-0.5Ca alloys exhibit obvious DRX characteristics.CaMgSn phases can effectively inhibit dislocation motion with the addition of Sn,thus increasing the peak fl ow stress of the alloy.The addition of Sn increases the hot deformation activation energy of the ZM61-0.5Ca alloy from 199.654 kJ/mol to 276.649 kJ/mol,thus improving the thermal stability of the alloy.For the ZMT612-0.5Ca alloy,the optimal hot deformation parameters are determined to be a deformation temperature range of 350–400℃and a strain rate range of 0.001–0.01 s^(-1).
基金supported by the National Natural Science Foundation of China(No.82222066)the National Key Research and Development Program of China(No.2022YFC2304104)。
文摘The complex skin structure and insufficient intracellular entrapment limit the therapeutic effects of active substances,therefore appealing to a more effective transdermal drug delivery system design.Herein,a hyaluronic acid(HA)modified steareth-2-based niosomes(HA-nio)with satisfactory deformability and targeting properties was designed for ergothioneine(EGT)(EGT@HA-nio)against ultraviolet(UV)-induced skin damage.The unique composition allows EGT@HA-nio to exhibit high mechanical softness,making it deformable to pass through the stratum corneum by the intercellular space without rupture.For further intracellular delivery,HA modification enables EGT to target human dermal cells(HDFs)with increased distribution in mitochondria without the restriction of specific EGT transporter-organic cation transporter1(OCTN-1).Benefiting from the above properties,an adequate amount of EGT in the active form was accumulated in the desired cellular sites,alleviating UV-radiation-induced reactive oxygen species(ROS)generation,inflammatory factor release,DNA damage,and mitochondrial dysfunction.The in vivo experimental results show that EGT@HA-nio could significantly decrease collagen degradation,restore epidermal thickness and morphology to healthy levels,and effectively prevent UV-induced skin damage.With the ability to penetrate biological barriers and deliver drugs,HA-nio may promote the development of inadequate drug penetration disease treatment including skin diseases,cancers,and bacterial infections.
基金the financial support from the National Key R&D Program of China(No.2022YFB3708400)National Natural Science Foundation of China(No.52171133,52225101)Basic and Applied Basic Research Foundation of Guangdong(No.2020B0301030006)。
文摘Magnesium matrix composites(MMCs)combine exceptional low density,high specific strength,and stiffness,positioning them as critical materials for aerospace,automotive,and electronics industries.This review highlights recent progress in the fabrication of Ti-Mg composites and analyzes the mechanisms behind their enhanced mechanical properties.A key focus is the interfacial deformation incompatibility between Ti and Mg phases,which generates strain gradients and promotes the accumulation of geometrically necessary dislocations(GNDs)at the interface.This process not only improves strain hardening and ductility but also reveals the need for advanced micromechanical models to capture the plastic behavior of both phases.The review critically examines the impact of different Mg matrix types(AZ,AM,VW series)and the role of interfacial product morphology and size on bonding and overall performance.Furthermore,Ti reinforcement endows the composites with superior wear resistance and thermal conductivity,indicating broad application potential.
基金Prince Sattambin Abdulaziz University for funding this research work through the project number(PSAU/2025/R/1446).
文摘The early and precise identification of Alzheimer’s Disease(AD)continues to pose considerable clinical difficulty due to subtle structural alterations and overlapping symptoms across the disease phases.This study presents a novel Deformable Attention Vision Transformer(DA-ViT)architecture that integrates deformable Multi-Head Self-Attention(MHSA)with a Multi-Layer Perceptron(MLP)block for efficient classification of Alzheimer’s disease(AD)using Magnetic resonance imaging(MRI)scans.In contrast to traditional vision transformers,our deformable MHSA module preferentially concentrates on spatially pertinent patches through learned offset predictions,markedly diminishing processing demands while improving localized feature representation.DA-ViT contains only 0.93 million parameters,making it exceptionally suitable for implementation in resource-limited settings.We evaluate the model using a class-imbalanced Alzheimer’s MRI dataset comprising 6400 images across four categories,achieving a test accuracy of 80.31%,a macro F1-score of 0.80,and an area under the receiver operating characteristic curve(AUC)of 1.00 for the Mild Demented category.Thorough ablation studies validate the ideal configuration of transformer depth,headcount,and embedding dimensions.Moreover,comparison research indicates that DA-ViT surpasses state-of-theart pre-trained Convolutional Neural Network(CNN)models in terms of accuracy and parameter efficiency.
文摘This paper presents CW-HRNet,a high-resolution,lightweight crack segmentation network designed to address challenges in complex scenes with slender,deformable,and blurred crack structures.The model incorporates two key modules:Constrained Deformable Convolution(CDC),which stabilizes geometric alignment by applying a tanh limiter and learnable scaling factor to the predicted offsets,and the Wavelet Frequency Enhancement Module(WFEM),which decomposes features using Haar wavelets to preserve low-frequency structures while enhancing high-frequency boundaries and textures.Evaluations on the CrackSeg9k benchmark demonstrate CW-HRNet’s superior performance,achieving 82.39%mIoU with only 7.49M parameters and 10.34 GFLOPs,outperforming HrSegNet-B48 by 1.83% in segmentation accuracy with minimal complexity overhead.The model also shows strong cross-dataset generalization,achieving 60.01%mIoU and 66.22%F1 on Asphalt3k without fine-tuning.These results highlight CW-HRNet’s favorable accuracyefficiency trade-off for real-world crack segmentation tasks.
基金supported by the National Key Research and Development Program of China(Grant No 2022YFB4600102)the National Natural Science Foundation of China(Grant No.U23A20637 and Grant No 52275561)。
文摘Conventional deformable wheel systems in robots and other mechatronic systems face significant challenges in achieving miniaturization,intelligence,and integration.To address these issues,we propose a novel integrated structural design method and four-dimensional printing strategy for deformable wheels capable of shaping among multiple programmable direct-driven deformation configurations.The load-bearing capacity of the printed wheel is strengthened by employing deformed components in various locations and actuated states.Additionally,a novel analytical design method is presented to determine the structure,actuation,and deformation parameters of each component under complex coupled deformation.Our findings reveal that the designed wheel can transform into three different configurations,exhibiting desired deformations of 12.5%in the radial direction and 19.6%in the axial direction.It also demonstrates robust deformation behavior and structural stability under multi-directional loads.By integrating a terrain sensing system,the designed wheel exhibits highly adaptive deformation capabilities on various terrains,showing great potential for exploring complex environments.
基金Supported by the Fundamental Research Funds for the Central Universities(Grant Nos.2232024Y-01,LZB2023001)DHU Distinguished Young Professor Program+1 种基金National Natural Science Foundation of China(Grant No.52275478)AI-Enhanced Research Program of Shanghai Municipal Education Commission(Grant No.SMEC-AI-DHUY-05)。
文摘Shape prediction of deformable linear objects(DLO)plays critical roles in robotics,medical devices,aerospace,and manufacturing,especially in manipulating objects such as cables,wires,and fibers.Due to the inherent flexibility of DLO and their complex deformation behaviors,such as bending and torsion,it is challenging to predict their dynamic characteristics accurately.Although the traditional physical modeling method can simulate the complex deformation behavior of DLO,the calculation cost is high and it is difficult to meet the demand of real-time prediction.In addition,the scarcity of data resources also limits the prediction accuracy of existing models.To solve these problems,a method of fiber shape prediction based on a physical information graph neural network(PIGNN)is proposed in this paper.This method cleverly combines the powerful expressive power of graph neural networks with the strict constraints of physical laws.Specifically,we learn the initial deformation model of the fiber through graph neural networks(GNN)to provide a good initial estimate for the model,which helps alleviate the problem of data resource scarcity.During the training process,we incorporate the physical prior knowledge of the dynamic deformation of the fiber optics into the loss function as a constraint,which is then fed back to the network model.This ensures that the shape of the fiber optics gradually approaches the true target shape,effectively solving the complex nonlinear behavior prediction problem of deformable linear objects.Experimental results demonstrate that,compared to traditional methods,the proposed method significantly reduces execution time and prediction error when handling the complex deformations of deformable fibers.This showcases its potential application value and superiority in fiber manipulation.
文摘The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt%Nb addition after various plastic deformation and heat treatment processes were investigated.Through Vickers hardness tests,free resonance Young's modulus measurements,and microstructure analysis,the effects of dislocation density,vacancy formation,and recrystallization on the alloy performance were clarified.Results indicate that increasing the rolling reduction enhances damping property due to higher dislocation density,whereas aging below the recrystallization temperature reduces damping property via dislocation pinning by the Suzuki effect.Recrystallization heat treatment restores the original structure and damping level.This alloy possesses tensile strength of approximately 1500 MPa and logarithmic decrement valueδ^(-1) in the range of 2×10^(-4)–3×10^(-4),demonstrating superior mechanical properties compared with the Ti-based alloys,which makes it an excellent candidate material for ultrasonic tools and medical applications.
基金National Key R&D Program of China(2023YFB3711904,2022YFA1603801)National Natural Science Foundation of China(12404230,52471181,52301213,52130108,52471005)+2 种基金National Nature Science Foundation of Zhejiang Province(LY23E010002)Open Fund of the China Spallation Neutron Source,Songshan Lake Science City(KFKT2023B11)Guangdong Basic and Applied Basic Research Foundation(2022A1515110805,2024A1515010878)。
文摘The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing to this multi-principal element nature,high-entropy alloys exhibit complex deformation behavior dominated by alternating and coupled deformation mechanisms.Therefore,elucidating these intricate deformation mechanisms remains a key challenge in current research.Neutron diffraction(ND)techniques offer distinct advantages over traditional microscopic methods for characterizing such complex deformation behavior.The strong penetration capability of neutrons enables in-situ,real-time,and non-destructive detection of structural evolution in most centimeter-level bulk samples under complex environments,and ND allows precise characterization of lattice site occupations for light elements,such as C and O,and neighboring elements.This review discussed the principles of ND,experiment procedures,and data analysis.Combining with recent advances in the research about face-centered cubic high-entropy alloy,typical examples of using ND to investigate the deformation behavior were summarized,ultimately revealing deformation mechanisms dominated by dislocations,stacking faults,twinning,and phase transformations.
基金supported by the Natural Science Foundation of China(No.12372176)the National Science and Technology Major Project of China(No.J2019-IV-0007-0075)。
文摘Quantitative assessment of microscale slip activities and plastic localizations is essential for understanding the complex deformation mechanisms in crystalline materials.However,few experimental studies have been able to dynamically measure the deformation fields of rapidly evolving slip activities at the microscale.In this study,we used the Sampling Moire?Method(SMM)to directly measure the dynamic deformation fields of slip activities in Nickel-Based Single-Crystal(NBSC)superalloy under in-situ tensile test,and the strain and displacement fields under the evolving microplastic events with intense slip activities around the notch of the NBSC superalloy specimen were obtained for the first time.The dynamic evolution of slip bands was quantitatively characterized through detailed statistical analysis of strains and displacements under different loads.The locations of the initial appearance of slip traces were successfully predicted by the regions of plasticity localization.The results show that the deformation fields exhibit both high spatial and temporal resolutions,enabling the capture of nanometer-scale displacement fields and visualization of the dynamic fluidity of slip accumulation.This method demonstrates the superiority of the dynamic characterization of the plastic deformation field at the microscale and the promise of its application for characterizing the slip activities of various crystalline metals.
文摘The structures of even-even Gd and Dy isotopes around N=100 were investigated using a fully self-consistent microscopic model.The systematics of the exited 2_(1)^(+)and 4_(1)^(+)energies reveal a peak-like structure at N=100 along the Gd(Z=64)and Dy(Z=66)isotopic chains.This supports the evidence for a subshell gap near N=100.The nuclear structure properties studied are important to understand the r-process elemental abundance peak at A~160.
基金supported by the National Science and Technology Major Project,China(No.2017-II-0006-0019)the National Natural Science Foundation of China(No.52375266)the Shaanxi Science Foundation for Distinguished Young Scholars,China(No.2022JC-36)。
文摘A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.The proposed method enables high-fidelity parameterized deformation for both flat and curved perforated surfaces while maintaining mesh quality with minimal geometric distortion.To evaluate its effectiveness,comparative studies between HFFD and conventional FFD methods are conducted,demonstrating superior performance in mesh quality and geometric fidelity.The HFFD-based framework is further applied to the Multidisciplinary Design Optimization(MDO)of a double-wall turbine blade leading edge.Results indicate an 11.6%increase in cooling efficiency and a 16.21%reduction in maximum stress.Additionally,compared to traditional geometry-based parameterization in MDO,the HFFD approach improves model processing efficiency by 84.15%and overall optimization efficiency by20.05%.These findings demonstrate HFFD's potential to significantly improve complex engineering design optimization by achieving precise shape preservation and improving computational efficiency.
基金Project supported by the National Natural Science Foundation of China(Nos.124B2043,U2241267,12172155,and 12302278)the Science and Technology Leading Talent Project of Gansu Province of China(No.23ZDKA0009)the Natural Science Foundation of Gansu Province of China(Nos.24JRRA473 and 24JRRA489)。
文摘The contact deformation and buckling of elastic rods against rigid surfaces represent a prevalent phenomenon in applications such as oil drilling,arterial stents,and energy harvesting.This has attracted widespread attention from researchers.In this paper,the deformation and buckling behaviors of a circular arch subject to compression by a rigid plate are investigated with a planar elastic rod model that incorporates tension,shearing,and bending.In comparison with the existing models that solely consider the bending energy,the deflection curve,the internal force distribution,and the critical load of the present model show good agreement with the finite element results.Through the dimensional analysis and order-of-magnitude estimation,we examine the factors influencing the critical load.The study reveals that the semi-central angle of the arch has the most significant effect.The dimensionless geometric parameter describing arch slenderness becomes prominent when the semi-central angle is less than 30°,while Poisson's ratio and the cross-sectional shear correction factor exhibit negligible influence.Furthermore,the variation in the proportions of strain energy components during critical buckling is presented with respect to the semi-central angle and the geometric parameter,thereby delineating the applicable ranges of both the original model(OM)and the modified model(MM).
文摘Central Sumatra,Indonesia,is historically known for its significant seismic activities,most notably the devastating 1883 earthquake.In this study,we measured the interseismic deformation using continuous GNSS observation data for three years from 2018 to 2021.5.The results show that the derived velocity fields indicate that the Central Sumatra deformation is primarily characterized by crustal strain shortening due to interaction between the India-Australian plate and the Sundaland plate.High strain values are observed along the Sumatran Fault Zone(SFZ),which is characterized by a history of significant seismic activity.Interseismic locking is divided into two segments.Segment A,located in the northern part of Siberut Island has an estimated moment magnitude of MW7.44 with a return period of200 years leading to a potential earthquake magnitude of MW8.98.Segment B in the southern part of Siberut Island has an estimated moment magnitude of MW7.26 with a return period of 200 years,resulting in a potential earthquake magnitude of MW8.79.The findings highlight critical seismic hazard implications,emphasizing the potential for a major earthquake in the Central Sumatra.
基金supported in part by the Mining Hydraulic Technology and Equipment Engineering Research Center,Liaoning Technical University,Fuxin,China(Grant No.MHTE23-R04)the Fundamental Research Funds for the Central Universities(ID N25BSS068).
文摘This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,CalculiX,and preCICE to simulate fluid-particle-structure interactions with large deformations.Mesh motion in the fluid field is handled using the radial basis function(RBF)method.The particle phase is modeled by MPPIC,where fluid-particle interaction is described through momentum exchange,and inter-particle collisions are characterized by collision stress.The structural field is solved by nonlinear FEM to capture large deformations induced by geometric nonlinearity.Coupling among fields is realized through a partitioned,parallel,and non-intrusive iterative strategy,ensuring stable transfer and convergence of interface forces and displacements.Notably,the influence of particles on the structure is not direct but mediated by the fluid,while structural motion directly affects particle dynamics.The results demonstrate that the proposed approach effectively captures multiphysics interaction processes and provides a valuable reference for numerical modeling of coupled fluid-particle-structure systems.
