Peridynamics(PD)demonstrates unique advantages in addressing fracture problems,however,its nonlocality and meshfree discretization result in high computational and storage costs.Moreover,in its engineering application...Peridynamics(PD)demonstrates unique advantages in addressing fracture problems,however,its nonlocality and meshfree discretization result in high computational and storage costs.Moreover,in its engineering applications,the computational scale of classical GPU parallel schemes is often limited by the finite graphics memory of GPU devices.In the present study,we develop an efficient particle information management strategy based on the cell-linked list method and on this basis propose a subdomain-based GPU parallel scheme,which exhibits outstanding acceleration performance in specific compute kernels while significantly reducing graphics memory usage.Compared to the classical parallel scheme,the cell-linked list method facilitates efficient management of particle information within subdomains,enabling the proposed parallel scheme to effectively reduce graphics memory usage by optimizing the size and number of subdomains while significantly improving the speed of neighbor search.As demonstrated in PD examples,the proposed parallel scheme enhances the neighbor search efficiency dramatically and achieves a significant speedup relative to serial programs.For instance,without considering the time of data transmission,the proposed scheme achieves a remarkable speedup of nearly 1076.8×in one test case,due to its excellent computational efficiency in the neighbor search.Additionally,for 2D and 3D PD models with tens of millions of particles,the graphics memory usage can be reduced up to 83.6%and 85.9%,respectively.Therefore,this subdomain-based GPU parallel scheme effectively avoids graphics memory shortages while significantly improving the computational efficiency,providing new insights into studying more complex large-scale problems.展开更多
Spiral bevel gears are critical transmission components,and are widely used in the aerospace field.This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears.Firstly,the multi-DOF ...Spiral bevel gears are critical transmission components,and are widely used in the aerospace field.This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears.Firstly,the multi-DOF envelope forming principle of spiral bevel gears is proposed.Secondly,the design methods for the envelope tool geometry and movement are proposed based on the envelope geometry and movement relationships.Thirdly,the metal flow and tooth filling laws are revealed through 3D FE simulation of the multi-DOF envelope forming process of a typical spiral bevel gear.Fourthly,a new method for separating the envelope tool and the formed spiral bevel gear with back taper tooth is proposed to avoid their interference.Finally,experiments on multi-DOF envelope forming of this typical spiral bevel gear are conducted using new heavy load multi-DOF envelope forming equipment.The simulation and experimental results show the feasibility of the proposed multi-DOF envelope forming process for fabricating spiral bevel gears with back taper tooth and the corresponding process design methods.展开更多
Battery technology plays a crucial role across various sectors,powering devices from smartphones to electric vehicles and supporting grid-scale energy storage.To ensure their safety and efficiency,batteries must be ev...Battery technology plays a crucial role across various sectors,powering devices from smartphones to electric vehicles and supporting grid-scale energy storage.To ensure their safety and efficiency,batteries must be evaluated under diverse operating conditions.Traditional modeling techniques,which often rely on first principles and atomic-level calculations,struggle with practical applications due to incomplete or noisy data.Furthermore,the complexity of battery dynamics,shaped by physical,chemical,and electrochemical interactions,presents substantial challenges for precise and efficient modeling.The Transformer model,originally designed for natural language processing,has proven effective in time-series analysis and forecasting.It adeptly handles the extensive,complex datasets produced during battery cycles,efficiently filtering out noise and identifying critical features without extensive preprocessing.This capability positions Transformers as potent tools for tackling the intricacies of battery data.This review explores the application of customized Transformers in battery state estimation,emphasizing crucial aspects such as charging,health assessment,lifetime prediction,and safety monitoring.It highlights the distinct advantages of Transformer-based models and addresses ongoing challenges and future opportunities in the field.By combining data-driven AI techniques with empirical insights from battery analysis,these pre-trained models can deliver precise diagnostics and comprehensive monitoring,enhancing performance metrics like health monitoring,anomaly detection,and early-warning systems.This integrated approach promises significant improvements in battery technology management and application.展开更多
Biomineralization of natural composites are usually highly finely adjusted to achieve extremely precise control over the shape,size and distribution of inorganic crystals,giving them unique structures and properties o...Biomineralization of natural composites are usually highly finely adjusted to achieve extremely precise control over the shape,size and distribution of inorganic crystals,giving them unique structures and properties of biomaterials.These underlying mechanisms and pathways provide inspiration for the design and construction of materials for repairing hard tissues.Due to good biocompatibility of hydrogels,materials using gel-like systems as media are inextricably linked to biological macrocomponents and mineralization.Inspired by those bioprocesses,polyacrylamide hydrogel with enzymes was 3D printed to form controlled shapes and structures,then was used as templates for mineralization.Effect of polyacrylamide hydrogel pore size on the mineralization was studied via incorporating NaF and CaCl2 and controlling the mineralization degree.The mineralization processes of 3D printed hydrogels with different pore sizes were also explored to find out the confinement influence of pores.Mineralization in hydrogels with smaller pores is developed in a columnar stacked pattern,which is similar to the vesicular mineralization stage of bone mineralization.展开更多
Magnesium alloy thin-walled cylindrical components with the advantages of high specific stiffness and strength present broad prospect for the lightweight of aerospace components.However,poor formability resulting from...Magnesium alloy thin-walled cylindrical components with the advantages of high specific stiffness and strength present broad prospect for the lightweight of aerospace components.However,poor formability resulting from the hexagonal close-packed crystal structure in magnesium alloy puts forwards a great challenge for thin-walled cylindrical components fabrication,especially for extreme structure with the thicknesschanging web and the high thin-wall.In this research,an ZK61 magnesium alloy thin-walled cylindrical component was successfully fabricated by two-step forging,i.e.,the pre-forging and final-forging is mainly used for wed and thin-wall formation,respectively.Microstructure and mechanical properties at the core,middle and margin of the web and the thin-wall of the pre-forged and final-forged components are studied in detail.Due to the large strain-effectiveness and metal flow along the radial direction(RD),the grains of the web are all elongated along RD for the pre-forged component,where an increasingly elongated trend is found from the core to the margin of the wed.A relatively low recrystallized degree occurs during pre-forging,and the web at different positions are all with prismatic and pyramid textures.During finalforging,the microstructures of the web and the thin-wall are almost equiaxed due to the remarkable occurrence of dynamic recrystallization.Similarity,except for few basal texture of the thin-wall,only prismatic and pyramid textures are found for the final-forged component.Compared with the initial billet,an obviously improved mechanical isotropy is achieved during pre-forging,which is well-maintained during final-forging.展开更多
The synergistic cooling of thermoelectromagnetic materials promises a breakthrough in the efficiency of single refrigeration and has attracted extensive research.The study of heterogeneous interface is crucial for ach...The synergistic cooling of thermoelectromagnetic materials promises a breakthrough in the efficiency of single refrigeration and has attracted extensive research.The study of heterogeneous interface is crucial for achieving the synergistic performance of both materials.In this work,a composite material comprising Bi_(2)Te_(3)-based thermoelectric material and MnCoGe-based magnetocaloric material is synthesized,which is a material exhibiting both thermoelectric and magnetocaloric properties.During the plasma-activated sintering process of the composite material,elemental interdiffusion of Mn,Co,Sb,and Te occurs,forming a diffusion layer of MnTe and CoSbTe.Reaction of heterogeneous interface leads to point defects within the material,significantly increasing the carrier concentration.Optimization of the sintering temperature results in a thermoelectric figure of merit(ZT)of 0.69 at 300 K and−ΔS_(max) of 0.97 J kg^(−1) K^(−1) at room temperature under a 5 T magnetic field for the Bi_(0.5)Sb_(1.5)Te_(3)/10 wt%Mn_(0.9)Cu_(0.1)CoGe composite sintered at 623 K and under 50 MPa.This study demonstrates that Bi_(0.5)Sb_(1.5)Te_(3)/Mn_(0.9)Cu_(0.1)CoGe is a potential candidate for efficient thermoelectromagnetic cooling applications.展开更多
To improve braking performance and achieve lightweight in transport equipment,it is necessary to implement overall plastic forming manufacturing of the brake pad baseboard(BPB),which is the core safety component of th...To improve braking performance and achieve lightweight in transport equipment,it is necessary to implement overall plastic forming manufacturing of the brake pad baseboard(BPB),which is the core safety component of the brake system.This study presents an innovative multi-DOF envelope forming(MDFEF)process to realize the plastic forming of BPB with thin skin and high reinforcing ribs.The MDFEF principle for BPB,and the design methods for the envelope mold are first presented.Through FE simulations,the behavior of metal flow,uneven growth pattern of reinforcing ribs,evolution of equivalent strain and evolution of forming force in MDFEF of BPB are investigated.To realize MDFEF,an innovative MDFEF equipment driven by parallel linkages is exploited.The force states of linkages in MDFEF are calculated,and the reasonable mold position is determined to reduce the maximum force on the linkages and improve the service performance of MDFEF equipment.The MDFEF experiments of BPB are conducted and qualified BPB is obtained,which demonstrates that the presented MDFEF process and equipment are applicable to manufacture BPB with thin skin and high reinforcing ribs.展开更多
To achieve the manufacturing of Thin-Wall and High-Rib Components(TWHRC)with high precision,a novel heavy load Multi-DOF Envelope Forming Press(MEFP)with Parallel Kinematic Mechanism(PKM),driven by six Permanent Magne...To achieve the manufacturing of Thin-Wall and High-Rib Components(TWHRC)with high precision,a novel heavy load Multi-DOF Envelope Forming Press(MEFP)with Parallel Kinematic Mechanism(PKM),driven by six Permanent Magnet Synchronous Motors(PMSMs),is developed.However,on account of the heavy forming load,the PMSM parameters are in great variation.Meanwhile,the PMSM is always in a transient state caused by fast time-varying forming load,resulting in low identification precision of varied PMSM parameters and control precision of PMSM under traditional parameter identification methods.To solve this problem,a novel Sliding Mode Control Method with Enhanced PMSM Parameter Identification(SMCMEPPI)for heavy load MEFP is proposed.Firstly,the kinematic model of MEFP is established.Secondly,the variation law of PMSM parameters under heavy load is revealed.Thirdly,an enhanced PMSM parameter identification method is proposed,in which the q axis current of PMSM is used to represent the changing rate of forming load and the adjustment factor is first proposed to remove improper input of PMSM parameter identification online.Fourthly,the Electromechanical Coupling Dynamic Model(ECDM)of MEFP,which includes identified PMSM parameters,is developed.Finally,based on the developed ECDM,a novel SMCMEPPI is proposed to realize the high-precision control of heavy load MEFP.The experimental results indicate that the proposed SMCMEPPI can significantly improve the control precision of heavy load MEFP.展开更多
BiCuSeO thermoelectric ceramics were fabricated using self-propagating high-temperature synthesis(SHS)combined with spark plasma sintering(SPS),and their phase compositions,microstructure,electrical properties,and the...BiCuSeO thermoelectric ceramics were fabricated using self-propagating high-temperature synthesis(SHS)combined with spark plasma sintering(SPS),and their phase compositions,microstructure,electrical properties,and thermal properties were systematically characterized and analyzed.The experimental results demonstrate that applying high-pressure condition during the sintering process will effectively restrict grain growth,reduce porosity,and lead to an increase in electrical conductivity.Simultaneously,high pressure sintering conditions reduce grain size and introduce additional grain boundaries and defects,which strengthens phonon scattering,thereby further decreasing both lattice thermal conductivity and total thermal conductivity.As a result,the high-pressure conditions significantly improve the thermoelectric figure of merit(ZT)of BiCuSeO.In brief,the samples sintered at 600℃under 200 MPa achieve a maximum ZT value of 0.64 at approximately 792 K.展开更多
We investigated the adsorption mechanisms including physical and chemical adsorption for heavy metals(Cd,Pb,Zn,Co,Cu)on C-lignin using density functional theory(DFT)simulations.Physical adsorption,involving metal atom...We investigated the adsorption mechanisms including physical and chemical adsorption for heavy metals(Cd,Pb,Zn,Co,Cu)on C-lignin using density functional theory(DFT)simulations.Physical adsorption,involving metal atoms near carbon atoms,is found to be endothermic;meanwhile,chemical adsorption,where hydroxyl groups replace metal ions,is exothermic and spontaneous.Pb exhibits the highest physical adsorption potential,while Cu and Co demonstrate the strongest chemical adsorption due to their highly negative adsorption energies.These findings provide valuable insights into the design of eco-friendly nano lignocellulosic composite films for effective heavy metal removal from contaminated water sources.Key words:C-lignin;adsorption;We investigated the adsorption mechanisms including physical and chemical adsorption for heavy metals(Cd,Pb,Zn,Co,Cu)on C-lignin using density functional theory(DFT)simulations.Physical adsorption,involving metal atoms near carbon atoms,is found to be endothermic;meanwhile,chemical adsorption,where hydroxyl groups replace metal ions,is exothermic and spontaneous.Pb exhibits the highest physical adsorption potential,while Cu and Co demonstrate the strongest chemical adsorption due to their highly negative adsorption energies.These findings provide valuable insights into the design of eco-friendly nano lignocellulosic composite films for effective heavy metal removal from contaminated water sources.展开更多
Zinc perchlorate(Zn(ClO_(4))_(2))electrolytes have demonstrated favorable low-temperature performance in aqueous zinc-ion batteries(AZIBs).However,the Zn anode encounters serious dendrite formation and parasitic react...Zinc perchlorate(Zn(ClO_(4))_(2))electrolytes have demonstrated favorable low-temperature performance in aqueous zinc-ion batteries(AZIBs).However,the Zn anode encounters serious dendrite formation and parasitic reactions in zinc perchlorate electrolytes,which is caused by the fast corrosive kinetics at room temperature.Herein,a concentrated perchlorate-based electrolyte consisting of 4.0 M Zn(ClO_(4))_(2)and saturated NaClO_(4)solution is developed to achieve dendrite-free and stable AZIBs at room temperature.The ClO_(4)−participates in the primary solvation sheath of Zn^(2+),facilitating the in situ formation of Zn_(5)(OH)_(8)Cl_(2)·H_(2)O-rich solid electrolyte interphase(SEI)to suppress the corrosion effect of ClO_(4)^(−).The Zn anode protected by the SEI achieves stable Zn plating/stripping over 3000 h.Furthermore,the MnO_(2)||Zn full cells manifest a stable specific capacity of 200 mAh·g^(−1)at 28℃and 101 mAh·g^(−1)at−20℃.This work introduces a promising approach for boosting the room-temperature performance of perchlorate-based electrolytes for AZIBs.展开更多
Multifunctional carbon fibers(C_(f))/ZrB_(2) based composites were synthesized through a series of processes termed as IVI including sequential slurry injection,vacuum impregnation,pyrolysis and reimpregnation cycles,...Multifunctional carbon fibers(C_(f))/ZrB_(2) based composites were synthesized through a series of processes termed as IVI including sequential slurry injection,vacuum impregnation,pyrolysis and reimpregnation cycles,which facilitated the effective incorporation of ZrB_(2) powder into the carbon fiber preform.A single IVI cycle reduced the porosity of the preform from∼77%to∼40%.Microstructural analysis revealed a preferential distribution of ZrB_(2) powders within random layers and pyrolytic carbon effectively bridging the ceramic particles and fibers.Due to the hierarchical 0°/90°carbon fiber architecture,as fabricated Cf/ZrB_(2) composites exhibited anisotropy in mechanical and physical properties.Vertically oriented com-posites demonstrated higher compressive strain and low thermal conductivity(1.00-2.59 W m^(−1) K^(−1) from 298 to 1173 K).In contrast,horizontally oriented specimens exhibited higher compressive strength(60.77±20.30 MPa)and thermal conductivity(1.6-4.5 W m^(−1) K^(−1) from 298 to 1173 K).Furthermore,the continuous Cf endowed the composites with a positive temperature-dependent electrical conductiv-ity characteristic,not only contributed to their higher electrical conductivity values,but also was helpful for maintaining the excellent EMI shielding effectiveness(19.80-22.51 dB)of Cf/ZrB_(2) up to 800℃without obvious degradation.Considering the low-density characteristics of as-prepared composites,their specific performance metrics demonstrate good competitiveness compared to those fabricated via alternative processes.展开更多
Previous studies on SnTe have indicated that its low ZT value is associated with a high carrier concentration of up to 10^(20)–10^(21)cm^(−3)and an excessively high lattice thermal conductivity.However,the high carri...Previous studies on SnTe have indicated that its low ZT value is associated with a high carrier concentration of up to 10^(20)–10^(21)cm^(−3)and an excessively high lattice thermal conductivity.However,the high carrier concentration and lattice thermal conductivity observed in SnTe are not solely attributable to the presence of numerous intrinsic tin vacancies and a simple crystal structure.Additionally,the oxides formed through the oxidation of Sn and SnTe exert a partial influence on these properties.In this study,by pretreating the raw Sn material and isolating it from oxygen during preparation,we achieve a significant improvement in the thermoelectric performance of binary SnTe at high temperatures,with a peak ZT of approximately 0.83 at 800 K.This approach effectively reduces the content of SnO_(2)in the matrix,enhancing the electrical and thermal transport properties of the samples.Specifically,the high-thermal conductivity of SnO_(2)facilitates the formation of channels at grain boundaries that are more conducive to heat transfer,while its poor electrical conductivity and Seebeck coefficient diminish the intrinsic electrical transport behavior of SnTe.The removal of SnO_(2)reflects the true thermoelectric performance of SnTe,making the samples prepared by this method stand out compared to other reported binary SnTe materials.展开更多
In the process of spraying coating perovskite films,the"coffee ring"effect(CRE)leads to the problem of excessive organic ammonium salt accumulation in local areas that cannot be completely eliminated.We intr...In the process of spraying coating perovskite films,the"coffee ring"effect(CRE)leads to the problem of excessive organic ammonium salt accumulation in local areas that cannot be completely eliminated.We introduce an in-situ targeted defect-healing strategy by incorporating butylamine formate(BAFa)ionic liquid into the spray ink.Ionic liquids,due to their long carbon chain structure,tend to target flow towards the CRE region during the droplet evaporation process.The coordination between the lone pair electrons in the C=O group of BAFa and Pb^(2+)effectively reduces defects in perovskite and suppresses non-radiative recombination losses.Simultaneously,amine ligands,which are repelled to the film surface and grain boundaries,form a thin insulating monolayer in the CRE areas,forcing charge carriers to transport through areas of the perovskite with fewer defects.This approach enables the crystallization control and defect-heal over the Cs_(0.19)FA_(0.81)PbI_(3-x-y)Br_(x)Cl_(y)perovskite films.Consequently,the champion perovskite solar cell achieved a power conversion efficiency of 22.04%,while mini-modules with an effective area of 64.8 cm^(2)reached a peak power conversion efficiency of 18.35%,demonstrating the significant potential for commercializing large-area perovskite solar cells.展开更多
Electrochemical water splitting(EWS),a sustainable pathway for green hydrogen production,faces critical industrial chal-lenges:insuffi cient activity and stability at high current densities,reliance on scarce noble me...Electrochemical water splitting(EWS),a sustainable pathway for green hydrogen production,faces critical industrial chal-lenges:insuffi cient activity and stability at high current densities,reliance on scarce noble metals,and unresolved kinetic bottlenecks in proton-coupled electron transfer(PCET)dynamics.Natural metalloenzymes drive water splitting at excep-tionally low overpotentials via precisely coordinated proton-coupled electron transfer(PCET)pathways within their active sites,achieving effi ciencies approaching the theoretical thermodynamic potential of the reaction(1.23 V vs.RHE),thereby off ering transformative design principles for synthetic catalysts.This review begins by analyzing the structural motifs and catalytic mechanisms of natural metalloenzymes involved in the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),with a particular focus on their PCET-driven reaction dynamics.Subsequently,we summarize the inspir-ing strategies derived from the design of the natural enzyme active sites and their ligand environments,highlighting their relevance to HER and OER catalyst development.In conclusion,we advocate for a multiscale,nature-inspired catalyst design paradigm that integrates deep learning,high-throughput computation,and cutting-edge in situ characterization to systematically understand and optimize intrinsic activity(overpotential),stability,and reaction pathway(selectivity),thereby achieving synergistic design from atomic-scale active sites to macroscopic system architectures.These nature-inspired strategies could bridge the gap between enzymatic precision and industrial scalability,unlocking EWS technologies with enzyme-like effi ciency and durability.展开更多
Compared with sintered silicon carbides(SiC),highly-orientated 3C-SiC by CVD methods boast out-of-plane orientation uniformity,which ensures that such materials produce lower surface damage.Through the electrolytic in...Compared with sintered silicon carbides(SiC),highly-orientated 3C-SiC by CVD methods boast out-of-plane orientation uniformity,which ensures that such materials produce lower surface damage.Through the electrolytic in-process dressing(ELID)grinding technique,the differences in grinding behaviors between<110>and<111>-orientated 3C-SiC were investigated.Both highly-orientated 3C-SiC exhibited a grinding surface where brittle and ductile removal coexisted.Specifically,brittle removal regions were observed at grain boundaries,while ductile removal regions were observed within the grains.Further indentation experiments between the two 3C-SiC show that<111>-oriented 3C-SiC displays a larger critical cut depth of 28.99 nm,with 1.5 times higher than that of<110>-oriented 3C-SiC.The larger critical depth of cut contributes to more ductile removal regions with only a few brittle pits in the<111>-oriented 3C-SiC grinding surface.In addition,the subsurface deformation of<110>-oriented 3C-SiC was characterized by the presence of amorphous zones,dislocations and stacking faults.In contrast to the<111>-oriented,the<110>-oriented 3C-SiC tends to exhibit a brittle removal mode dominated by pits and cracks at the twin boundaries,as its pre-existing twins hinder the dislocation glide,resulting in stress concentration and thus forming cracks.展开更多
As a natural biopolymer material,silk fibroin with unique mechanical properties can be used in the preparation of biocomposite hydrogels for strain sensors.But,the electromechanical properties of bio-composite hydroge...As a natural biopolymer material,silk fibroin with unique mechanical properties can be used in the preparation of biocomposite hydrogels for strain sensors.But,the electromechanical properties of bio-composite hydrogel strain sensors are still insufficient,such as the deterioration of electrical signals and low sensitivity,which need to develop a hydrogel with a stable transmission network for electric con-duction.Herein,a silk fibroin biocomposite hydrogel is prepared by incorporating tannic acid and MXene nanosheets into a polyacrylamide and silk fibroin double network.The electromechanical properties of hydrogels are improved by optimizing the proportion of material components.As a result,the double network structure and supramolecular interaction enhance the stretchability of hydrogels(692% fracture strain).The hydrogel also exhibits good biocompatibility and conductivity(0.85 S/m),which shows the application prospect in wearable sensors.The wireless strain sensor assembled by this biocomposite hy-drogel presents good portability and sensing performance,such as high sensitivity(gauge factor=6.04),wide working range(500% strain),and outstanding stability(1000 cycles at 100%strain).The results in-dicate that the hydrogel strain sensor can be used to monitor human body movement.The biocomposite hydrogel is expected to be applied in the field of wearable strain sensors,and this study can provide a new way for the design of flexible electronic materials.展开更多
The commercial ZK 60 magnesium alloy with extruded state experienced aging heat treatment(T 6)was dynamically loaded at strain rate of 3000 s−1 by means of the split Hopkinson pressure bar(SHPB)in this paper.Transmiss...The commercial ZK 60 magnesium alloy with extruded state experienced aging heat treatment(T 6)was dynamically loaded at strain rate of 3000 s−1 by means of the split Hopkinson pressure bar(SHPB)in this paper.Transmission electron microscopy(TEM)observations showed that the precipitatedβ′_(1) phases partially dissolved(spheroidized)with blurred interfaces within 160μs at 3000 s^(−1).The average length and diameter of the rod-shapedβ′_(1) phase particles were 48.5 and 9.8 nm after the T 6 heat treatment;while the average diameter of the sphericalβ′_(1) phases changed to 8.8 nm after loading.The deformedβ′_(1) phase generated larger lattice distortion energy than Mg matrix under high strain rate loading.Therefore,the difference of free energy(the driving force of dissolution)between theβ′_(1) phase and the matrix increased,making the instantaneous dissolution of theβ′_(1) phase thermodynamically feasible.The dissolution(spheroidization)of theβ′_(1) phase particles was kinetically promoted because the diffusion rate of the solute Zn atoms was accelerated by combined actions of adiabatic temperature rise,high density of dislocations(vacancies)and high deviatoric stresses during high strain rate loading.The increase in hardness of ZK 60-T 6 alloy could be attributed to solid solution strengthening,dislocation strengthening and second phase particle strengthening.展开更多
Electroshocking treatment(EST),an efficient and rapid material treatment method,promotes microstructure evolution and improves mechanical properties.This study incorporates EST into the conventional cold rolling-quenc...Electroshocking treatment(EST),an efficient and rapid material treatment method,promotes microstructure evolution and improves mechanical properties.This study incorporates EST into the conventional cold rolling-quenching tempering process of M50 steel and investigates the influence and mechanism of applying EST at different stages of the process on the microstructure and mechanical properties.Scanning electron microscope(SEM),transmission electron microscope(TEM),and X-ray diffraction(XRD)were used to characterize the effect of EST on microstructure.The results show that EST can refine the grains of M50(average reduction of 10.1%in grain size),homogenize the grain size distribution,reduce the dislocation density(20.9%in average),promote the dissolution of carbides in the matrix and distribute them more uniformly along the grain boundaries,resulting in the improvement of mechanical properties.The mechanical properties of the specimen with the process flow of rolling-quenching-tempering-electroshocking showed excellent performance,with an increase in hardness of 1.4%,tensile strength of 17.7%,and elongation at break of 24.3%as compared to the specimen without EST.The tensile properties of the specimen with the process flow of rolling electroshocking-quenching-tempering showed the best performance,with an increase in tensile strength of 30.0%and elongation at break of 30.7%as compared to the specimen without EST.展开更多
Intrinsic two-dimensional(2D)ferromagnetic(FM)semiconductors have attracted extensive attentions for their potential applications in next-generation spintronics devices.In recent years,the van der Waals material VI_(3...Intrinsic two-dimensional(2D)ferromagnetic(FM)semiconductors have attracted extensive attentions for their potential applications in next-generation spintronics devices.In recent years,the van der Waals material VI_(3) has been experimentally found to be an intrinsic FM semiconductor.However,the electronic structure of the VI_(3) is not fully understood.To reveal why the VI_(3)is a ferromagnetic semiconductor with strong out-of-plane anisotropy,we systematically studied the electronic structure of the monolayer VI_(3).Our results confirm that the monolayer VI_(3) is a Mott insulator,and d^(2) electrons occupy a_(g) and e_(g)^(π+) orbitals.The half-metallic state is a metastable state with a total energy 0.7 e V higher than the ferromagnetic Mott insulating state.Furthermore,our study confirmed that the VI_(3)exhibits the out-of-plane magnetic anisotropy,which originates from d^(2) electrons occupying low-lying agand egπ+orbitals.Since the orbital angular momentum of the e_(g)^(π+) state is not completely quenched,the VI_(3) has the out-of-plane anisotropy under interplay between the spin-orbit coupling and crystal field.Our study provides valuable guidance for the design of 2D magnetic materials with pronounced out-of-plane anisotropy.展开更多
基金Jun Li was supported by National Natural Science Foundation of China(No.:U2441215)Lisheng Liu and Xin Lai were supported by National Natural Science Foundation of China(No.:52494933).
文摘Peridynamics(PD)demonstrates unique advantages in addressing fracture problems,however,its nonlocality and meshfree discretization result in high computational and storage costs.Moreover,in its engineering applications,the computational scale of classical GPU parallel schemes is often limited by the finite graphics memory of GPU devices.In the present study,we develop an efficient particle information management strategy based on the cell-linked list method and on this basis propose a subdomain-based GPU parallel scheme,which exhibits outstanding acceleration performance in specific compute kernels while significantly reducing graphics memory usage.Compared to the classical parallel scheme,the cell-linked list method facilitates efficient management of particle information within subdomains,enabling the proposed parallel scheme to effectively reduce graphics memory usage by optimizing the size and number of subdomains while significantly improving the speed of neighbor search.As demonstrated in PD examples,the proposed parallel scheme enhances the neighbor search efficiency dramatically and achieves a significant speedup relative to serial programs.For instance,without considering the time of data transmission,the proposed scheme achieves a remarkable speedup of nearly 1076.8×in one test case,due to its excellent computational efficiency in the neighbor search.Additionally,for 2D and 3D PD models with tens of millions of particles,the graphics memory usage can be reduced up to 83.6%and 85.9%,respectively.Therefore,this subdomain-based GPU parallel scheme effectively avoids graphics memory shortages while significantly improving the computational efficiency,providing new insights into studying more complex large-scale problems.
基金the National Science and Technology Major Project of China(No.2019-VII0017e0158)the National Natural Science Foundation of China(No.U21A20131)+1 种基金the Industry-University Research Cooperation Project,China(No.HFZL2020CXY025)the National Key Laboratory of Science and Technology on Helicopter Transmission,China(No.HTL-O-21G05).
文摘Spiral bevel gears are critical transmission components,and are widely used in the aerospace field.This paper proposes a new multi-DOF envelope forming process for fabricating spiral bevel gears.Firstly,the multi-DOF envelope forming principle of spiral bevel gears is proposed.Secondly,the design methods for the envelope tool geometry and movement are proposed based on the envelope geometry and movement relationships.Thirdly,the metal flow and tooth filling laws are revealed through 3D FE simulation of the multi-DOF envelope forming process of a typical spiral bevel gear.Fourthly,a new method for separating the envelope tool and the formed spiral bevel gear with back taper tooth is proposed to avoid their interference.Finally,experiments on multi-DOF envelope forming of this typical spiral bevel gear are conducted using new heavy load multi-DOF envelope forming equipment.The simulation and experimental results show the feasibility of the proposed multi-DOF envelope forming process for fabricating spiral bevel gears with back taper tooth and the corresponding process design methods.
基金the support provided by the California Department of Transportation(Caltrans)through the Fiscal Year 2023-24 grant(65A0686)for the research project titled‘Revolutions in Battery technologies and Future Electric Vehicles’。
文摘Battery technology plays a crucial role across various sectors,powering devices from smartphones to electric vehicles and supporting grid-scale energy storage.To ensure their safety and efficiency,batteries must be evaluated under diverse operating conditions.Traditional modeling techniques,which often rely on first principles and atomic-level calculations,struggle with practical applications due to incomplete or noisy data.Furthermore,the complexity of battery dynamics,shaped by physical,chemical,and electrochemical interactions,presents substantial challenges for precise and efficient modeling.The Transformer model,originally designed for natural language processing,has proven effective in time-series analysis and forecasting.It adeptly handles the extensive,complex datasets produced during battery cycles,efficiently filtering out noise and identifying critical features without extensive preprocessing.This capability positions Transformers as potent tools for tackling the intricacies of battery data.This review explores the application of customized Transformers in battery state estimation,emphasizing crucial aspects such as charging,health assessment,lifetime prediction,and safety monitoring.It highlights the distinct advantages of Transformer-based models and addresses ongoing challenges and future opportunities in the field.By combining data-driven AI techniques with empirical insights from battery analysis,these pre-trained models can deliver precise diagnostics and comprehensive monitoring,enhancing performance metrics like health monitoring,anomaly detection,and early-warning systems.This integrated approach promises significant improvements in battery technology management and application.
基金Funded by the Joint Fund of Natural Science Foundation of Hubei Province(No.2024AFD033)the Open Fund of Hubei Longzhong Laboratory。
文摘Biomineralization of natural composites are usually highly finely adjusted to achieve extremely precise control over the shape,size and distribution of inorganic crystals,giving them unique structures and properties of biomaterials.These underlying mechanisms and pathways provide inspiration for the design and construction of materials for repairing hard tissues.Due to good biocompatibility of hydrogels,materials using gel-like systems as media are inextricably linked to biological macrocomponents and mineralization.Inspired by those bioprocesses,polyacrylamide hydrogel with enzymes was 3D printed to form controlled shapes and structures,then was used as templates for mineralization.Effect of polyacrylamide hydrogel pore size on the mineralization was studied via incorporating NaF and CaCl2 and controlling the mineralization degree.The mineralization processes of 3D printed hydrogels with different pore sizes were also explored to find out the confinement influence of pores.Mineralization in hydrogels with smaller pores is developed in a columnar stacked pattern,which is similar to the vesicular mineralization stage of bone mineralization.
基金supported by the National Natural Science Foundation of China(No.52405408,No.U21A20131,No.U2037204,No.52422510)the Natural Science Foundation of Hubei Province(No.2023AFB116)+1 种基金the State Key Laboratory of Materials Processing and Die&Mould TechnologyHuazhong University of Science and Technology(No.P2022-005)。
文摘Magnesium alloy thin-walled cylindrical components with the advantages of high specific stiffness and strength present broad prospect for the lightweight of aerospace components.However,poor formability resulting from the hexagonal close-packed crystal structure in magnesium alloy puts forwards a great challenge for thin-walled cylindrical components fabrication,especially for extreme structure with the thicknesschanging web and the high thin-wall.In this research,an ZK61 magnesium alloy thin-walled cylindrical component was successfully fabricated by two-step forging,i.e.,the pre-forging and final-forging is mainly used for wed and thin-wall formation,respectively.Microstructure and mechanical properties at the core,middle and margin of the web and the thin-wall of the pre-forged and final-forged components are studied in detail.Due to the large strain-effectiveness and metal flow along the radial direction(RD),the grains of the web are all elongated along RD for the pre-forged component,where an increasingly elongated trend is found from the core to the margin of the wed.A relatively low recrystallized degree occurs during pre-forging,and the web at different positions are all with prismatic and pyramid textures.During finalforging,the microstructures of the web and the thin-wall are almost equiaxed due to the remarkable occurrence of dynamic recrystallization.Similarity,except for few basal texture of the thin-wall,only prismatic and pyramid textures are found for the final-forged component.Compared with the initial billet,an obviously improved mechanical isotropy is achieved during pre-forging,which is well-maintained during final-forging.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFA0704900)the National Natural Science Foundation of China(Grant No.52171221).
文摘The synergistic cooling of thermoelectromagnetic materials promises a breakthrough in the efficiency of single refrigeration and has attracted extensive research.The study of heterogeneous interface is crucial for achieving the synergistic performance of both materials.In this work,a composite material comprising Bi_(2)Te_(3)-based thermoelectric material and MnCoGe-based magnetocaloric material is synthesized,which is a material exhibiting both thermoelectric and magnetocaloric properties.During the plasma-activated sintering process of the composite material,elemental interdiffusion of Mn,Co,Sb,and Te occurs,forming a diffusion layer of MnTe and CoSbTe.Reaction of heterogeneous interface leads to point defects within the material,significantly increasing the carrier concentration.Optimization of the sintering temperature results in a thermoelectric figure of merit(ZT)of 0.69 at 300 K and−ΔS_(max) of 0.97 J kg^(−1) K^(−1) at room temperature under a 5 T magnetic field for the Bi_(0.5)Sb_(1.5)Te_(3)/10 wt%Mn_(0.9)Cu_(0.1)CoGe composite sintered at 623 K and under 50 MPa.This study demonstrates that Bi_(0.5)Sb_(1.5)Te_(3)/Mn_(0.9)Cu_(0.1)CoGe is a potential candidate for efficient thermoelectromagnetic cooling applications.
基金Supported by National Natural Science Foundation of China(Grant No.U21A20131)Innovative Research Team Development Program of Ministry of Education of China(Grant No.IRT17R83)111 Project(Grant No.B17034)。
文摘To improve braking performance and achieve lightweight in transport equipment,it is necessary to implement overall plastic forming manufacturing of the brake pad baseboard(BPB),which is the core safety component of the brake system.This study presents an innovative multi-DOF envelope forming(MDFEF)process to realize the plastic forming of BPB with thin skin and high reinforcing ribs.The MDFEF principle for BPB,and the design methods for the envelope mold are first presented.Through FE simulations,the behavior of metal flow,uneven growth pattern of reinforcing ribs,evolution of equivalent strain and evolution of forming force in MDFEF of BPB are investigated.To realize MDFEF,an innovative MDFEF equipment driven by parallel linkages is exploited.The force states of linkages in MDFEF are calculated,and the reasonable mold position is determined to reduce the maximum force on the linkages and improve the service performance of MDFEF equipment.The MDFEF experiments of BPB are conducted and qualified BPB is obtained,which demonstrates that the presented MDFEF process and equipment are applicable to manufacture BPB with thin skin and high reinforcing ribs.
基金the National Science and Technology Major Project of China(No.2019-Ⅶ-0017-0158)the National Natural Science Foundation of China(Nos.U2037204,U21A20131)the Innovative Research Team Development Program of Ministry of Education of China(No.IRT17R83)for the support given to this research。
文摘To achieve the manufacturing of Thin-Wall and High-Rib Components(TWHRC)with high precision,a novel heavy load Multi-DOF Envelope Forming Press(MEFP)with Parallel Kinematic Mechanism(PKM),driven by six Permanent Magnet Synchronous Motors(PMSMs),is developed.However,on account of the heavy forming load,the PMSM parameters are in great variation.Meanwhile,the PMSM is always in a transient state caused by fast time-varying forming load,resulting in low identification precision of varied PMSM parameters and control precision of PMSM under traditional parameter identification methods.To solve this problem,a novel Sliding Mode Control Method with Enhanced PMSM Parameter Identification(SMCMEPPI)for heavy load MEFP is proposed.Firstly,the kinematic model of MEFP is established.Secondly,the variation law of PMSM parameters under heavy load is revealed.Thirdly,an enhanced PMSM parameter identification method is proposed,in which the q axis current of PMSM is used to represent the changing rate of forming load and the adjustment factor is first proposed to remove improper input of PMSM parameter identification online.Fourthly,the Electromechanical Coupling Dynamic Model(ECDM)of MEFP,which includes identified PMSM parameters,is developed.Finally,based on the developed ECDM,a novel SMCMEPPI is proposed to realize the high-precision control of heavy load MEFP.The experimental results indicate that the proposed SMCMEPPI can significantly improve the control precision of heavy load MEFP.
基金Funded by the National Natural Science Foundation of China(Nos.52322207 and 52202289)the National Key Research and Development Plan of China(No.2021YFB3701400)+2 种基金the Independent Innovation Projects of the Hubei Longzhong Laboratory(No.2022ZZ-11)Funded by the National Natural Science Foundation of China(Nos.52322207 and 52202289)the National Key Research and Development Plan of China(No.2021YFB3701400)the Independent Innovation Projects of the Hubei Longzhong Laboratory(No.2022ZZ-11)。
文摘BiCuSeO thermoelectric ceramics were fabricated using self-propagating high-temperature synthesis(SHS)combined with spark plasma sintering(SPS),and their phase compositions,microstructure,electrical properties,and thermal properties were systematically characterized and analyzed.The experimental results demonstrate that applying high-pressure condition during the sintering process will effectively restrict grain growth,reduce porosity,and lead to an increase in electrical conductivity.Simultaneously,high pressure sintering conditions reduce grain size and introduce additional grain boundaries and defects,which strengthens phonon scattering,thereby further decreasing both lattice thermal conductivity and total thermal conductivity.As a result,the high-pressure conditions significantly improve the thermoelectric figure of merit(ZT)of BiCuSeO.In brief,the samples sintered at 600℃under 200 MPa achieve a maximum ZT value of 0.64 at approximately 792 K.
基金Funded by the Hubei Province Key Research Foundation for Water Resources,China(No.HBSLKY2023035)the National College Students’Innovation and Entrepreneurship Training Program,China(No.202310500012)the Wuhan Talents Outstanding Young Talents Program。
文摘We investigated the adsorption mechanisms including physical and chemical adsorption for heavy metals(Cd,Pb,Zn,Co,Cu)on C-lignin using density functional theory(DFT)simulations.Physical adsorption,involving metal atoms near carbon atoms,is found to be endothermic;meanwhile,chemical adsorption,where hydroxyl groups replace metal ions,is exothermic and spontaneous.Pb exhibits the highest physical adsorption potential,while Cu and Co demonstrate the strongest chemical adsorption due to their highly negative adsorption energies.These findings provide valuable insights into the design of eco-friendly nano lignocellulosic composite films for effective heavy metal removal from contaminated water sources.Key words:C-lignin;adsorption;We investigated the adsorption mechanisms including physical and chemical adsorption for heavy metals(Cd,Pb,Zn,Co,Cu)on C-lignin using density functional theory(DFT)simulations.Physical adsorption,involving metal atoms near carbon atoms,is found to be endothermic;meanwhile,chemical adsorption,where hydroxyl groups replace metal ions,is exothermic and spontaneous.Pb exhibits the highest physical adsorption potential,while Cu and Co demonstrate the strongest chemical adsorption due to their highly negative adsorption energies.These findings provide valuable insights into the design of eco-friendly nano lignocellulosic composite films for effective heavy metal removal from contaminated water sources.
基金supported by Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(No.2021JJLH0069)the Project of Sanya Yazhou Bay Science and Technology City(No.SCKJ-JYRC-2023-55)Hainan Provincial Natural Science Foundation of China(No.522CXTD516).
文摘Zinc perchlorate(Zn(ClO_(4))_(2))electrolytes have demonstrated favorable low-temperature performance in aqueous zinc-ion batteries(AZIBs).However,the Zn anode encounters serious dendrite formation and parasitic reactions in zinc perchlorate electrolytes,which is caused by the fast corrosive kinetics at room temperature.Herein,a concentrated perchlorate-based electrolyte consisting of 4.0 M Zn(ClO_(4))_(2)and saturated NaClO_(4)solution is developed to achieve dendrite-free and stable AZIBs at room temperature.The ClO_(4)−participates in the primary solvation sheath of Zn^(2+),facilitating the in situ formation of Zn_(5)(OH)_(8)Cl_(2)·H_(2)O-rich solid electrolyte interphase(SEI)to suppress the corrosion effect of ClO_(4)^(−).The Zn anode protected by the SEI achieves stable Zn plating/stripping over 3000 h.Furthermore,the MnO_(2)||Zn full cells manifest a stable specific capacity of 200 mAh·g^(−1)at 28℃and 101 mAh·g^(−1)at−20℃.This work introduces a promising approach for boosting the room-temperature performance of perchlorate-based electrolytes for AZIBs.
基金financially supported by the National Natural Science Foundation of China(Nos.52332003,52293373,52022072 and 52202067)the Hubei Provincial Natural Science Foundation of China(Distinguished Young Scholars No.2022CFA042)Independent Innovation Projects of Hubei Longzhong Laboratory(No.2022ZZ-10).
文摘Multifunctional carbon fibers(C_(f))/ZrB_(2) based composites were synthesized through a series of processes termed as IVI including sequential slurry injection,vacuum impregnation,pyrolysis and reimpregnation cycles,which facilitated the effective incorporation of ZrB_(2) powder into the carbon fiber preform.A single IVI cycle reduced the porosity of the preform from∼77%to∼40%.Microstructural analysis revealed a preferential distribution of ZrB_(2) powders within random layers and pyrolytic carbon effectively bridging the ceramic particles and fibers.Due to the hierarchical 0°/90°carbon fiber architecture,as fabricated Cf/ZrB_(2) composites exhibited anisotropy in mechanical and physical properties.Vertically oriented com-posites demonstrated higher compressive strain and low thermal conductivity(1.00-2.59 W m^(−1) K^(−1) from 298 to 1173 K).In contrast,horizontally oriented specimens exhibited higher compressive strength(60.77±20.30 MPa)and thermal conductivity(1.6-4.5 W m^(−1) K^(−1) from 298 to 1173 K).Furthermore,the continuous Cf endowed the composites with a positive temperature-dependent electrical conductiv-ity characteristic,not only contributed to their higher electrical conductivity values,but also was helpful for maintaining the excellent EMI shielding effectiveness(19.80-22.51 dB)of Cf/ZrB_(2) up to 800℃without obvious degradation.Considering the low-density characteristics of as-prepared composites,their specific performance metrics demonstrate good competitiveness compared to those fabricated via alternative processes.
基金supported by the National Natural Science Foundation of China(Grant No.52371235)the National Natural Science Foundation of China(Grant No.52171221).
文摘Previous studies on SnTe have indicated that its low ZT value is associated with a high carrier concentration of up to 10^(20)–10^(21)cm^(−3)and an excessively high lattice thermal conductivity.However,the high carrier concentration and lattice thermal conductivity observed in SnTe are not solely attributable to the presence of numerous intrinsic tin vacancies and a simple crystal structure.Additionally,the oxides formed through the oxidation of Sn and SnTe exert a partial influence on these properties.In this study,by pretreating the raw Sn material and isolating it from oxygen during preparation,we achieve a significant improvement in the thermoelectric performance of binary SnTe at high temperatures,with a peak ZT of approximately 0.83 at 800 K.This approach effectively reduces the content of SnO_(2)in the matrix,enhancing the electrical and thermal transport properties of the samples.Specifically,the high-thermal conductivity of SnO_(2)facilitates the formation of channels at grain boundaries that are more conducive to heat transfer,while its poor electrical conductivity and Seebeck coefficient diminish the intrinsic electrical transport behavior of SnTe.The removal of SnO_(2)reflects the true thermoelectric performance of SnTe,making the samples prepared by this method stand out compared to other reported binary SnTe materials.
基金supported by the National Natural Science Foundation of China(U21A20171,U20A20245)Natural Scienceof Hubei Province(2023AFA010)Independent Innovation Projects of the Hubei Longzhong Laboratory。
文摘In the process of spraying coating perovskite films,the"coffee ring"effect(CRE)leads to the problem of excessive organic ammonium salt accumulation in local areas that cannot be completely eliminated.We introduce an in-situ targeted defect-healing strategy by incorporating butylamine formate(BAFa)ionic liquid into the spray ink.Ionic liquids,due to their long carbon chain structure,tend to target flow towards the CRE region during the droplet evaporation process.The coordination between the lone pair electrons in the C=O group of BAFa and Pb^(2+)effectively reduces defects in perovskite and suppresses non-radiative recombination losses.Simultaneously,amine ligands,which are repelled to the film surface and grain boundaries,form a thin insulating monolayer in the CRE areas,forcing charge carriers to transport through areas of the perovskite with fewer defects.This approach enables the crystallization control and defect-heal over the Cs_(0.19)FA_(0.81)PbI_(3-x-y)Br_(x)Cl_(y)perovskite films.Consequently,the champion perovskite solar cell achieved a power conversion efficiency of 22.04%,while mini-modules with an effective area of 64.8 cm^(2)reached a peak power conversion efficiency of 18.35%,demonstrating the significant potential for commercializing large-area perovskite solar cells.
基金supported by the National Natural Science Foundation of China(No.51832003)the National Key Research and Development Program of China(No.2021YFA0715700).
文摘Electrochemical water splitting(EWS),a sustainable pathway for green hydrogen production,faces critical industrial chal-lenges:insuffi cient activity and stability at high current densities,reliance on scarce noble metals,and unresolved kinetic bottlenecks in proton-coupled electron transfer(PCET)dynamics.Natural metalloenzymes drive water splitting at excep-tionally low overpotentials via precisely coordinated proton-coupled electron transfer(PCET)pathways within their active sites,achieving effi ciencies approaching the theoretical thermodynamic potential of the reaction(1.23 V vs.RHE),thereby off ering transformative design principles for synthetic catalysts.This review begins by analyzing the structural motifs and catalytic mechanisms of natural metalloenzymes involved in the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),with a particular focus on their PCET-driven reaction dynamics.Subsequently,we summarize the inspir-ing strategies derived from the design of the natural enzyme active sites and their ligand environments,highlighting their relevance to HER and OER catalyst development.In conclusion,we advocate for a multiscale,nature-inspired catalyst design paradigm that integrates deep learning,high-throughput computation,and cutting-edge in situ characterization to systematically understand and optimize intrinsic activity(overpotential),stability,and reaction pathway(selectivity),thereby achieving synergistic design from atomic-scale active sites to macroscopic system architectures.These nature-inspired strategies could bridge the gap between enzymatic precision and industrial scalability,unlocking EWS technologies with enzyme-like effi ciency and durability.
基金the Central Guidance on Local Science and Technology Development Fund of Hubei Province(No.2022BFE002)the Independent Innovation Projects of the Hubei Longzhong Laboratory(No.2022ZZ-06)the National Natural Science Foundation of China(Nos.52002075 and 62204179)。
文摘Compared with sintered silicon carbides(SiC),highly-orientated 3C-SiC by CVD methods boast out-of-plane orientation uniformity,which ensures that such materials produce lower surface damage.Through the electrolytic in-process dressing(ELID)grinding technique,the differences in grinding behaviors between<110>and<111>-orientated 3C-SiC were investigated.Both highly-orientated 3C-SiC exhibited a grinding surface where brittle and ductile removal coexisted.Specifically,brittle removal regions were observed at grain boundaries,while ductile removal regions were observed within the grains.Further indentation experiments between the two 3C-SiC show that<111>-oriented 3C-SiC displays a larger critical cut depth of 28.99 nm,with 1.5 times higher than that of<110>-oriented 3C-SiC.The larger critical depth of cut contributes to more ductile removal regions with only a few brittle pits in the<111>-oriented 3C-SiC grinding surface.In addition,the subsurface deformation of<110>-oriented 3C-SiC was characterized by the presence of amorphous zones,dislocations and stacking faults.In contrast to the<111>-oriented,the<110>-oriented 3C-SiC tends to exhibit a brittle removal mode dominated by pits and cracks at the twin boundaries,as its pre-existing twins hinder the dislocation glide,resulting in stress concentration and thus forming cracks.
基金supported by the National Key Re-search and Development Program of China(No.2021YFA0715700)the National Natural Science Foundation of China(No.52003212).
文摘As a natural biopolymer material,silk fibroin with unique mechanical properties can be used in the preparation of biocomposite hydrogels for strain sensors.But,the electromechanical properties of bio-composite hydrogel strain sensors are still insufficient,such as the deterioration of electrical signals and low sensitivity,which need to develop a hydrogel with a stable transmission network for electric con-duction.Herein,a silk fibroin biocomposite hydrogel is prepared by incorporating tannic acid and MXene nanosheets into a polyacrylamide and silk fibroin double network.The electromechanical properties of hydrogels are improved by optimizing the proportion of material components.As a result,the double network structure and supramolecular interaction enhance the stretchability of hydrogels(692% fracture strain).The hydrogel also exhibits good biocompatibility and conductivity(0.85 S/m),which shows the application prospect in wearable sensors.The wireless strain sensor assembled by this biocomposite hy-drogel presents good portability and sensing performance,such as high sensitivity(gauge factor=6.04),wide working range(500% strain),and outstanding stability(1000 cycles at 100%strain).The results in-dicate that the hydrogel strain sensor can be used to monitor human body movement.The biocomposite hydrogel is expected to be applied in the field of wearable strain sensors,and this study can provide a new way for the design of flexible electronic materials.
基金Projects(51871243,51574290)supported by the National Natural Science Foundation of ChinaProject(ASSIKFJJ202304001)supported by the Open Fund of the National Key Laboratory of Strength and Structural Integrity,China+3 种基金Project(HT-CSNS-DG-CD-0092/2021)supported by the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology,ChinaProject(2022KF-08)supported by the Hubei Longzhong Laboratory,ChinaProject(22kfgk06)supported by the Shock and Vibration of Engineering Materials and Structures Key Laboratory of Sichuan Province,ChinaProject(PBSKL2022C01)supported by the State Key Laboratory of Precision Blasting and Hubei Key Laboratory of Blasting Engineering,China。
文摘The commercial ZK 60 magnesium alloy with extruded state experienced aging heat treatment(T 6)was dynamically loaded at strain rate of 3000 s−1 by means of the split Hopkinson pressure bar(SHPB)in this paper.Transmission electron microscopy(TEM)observations showed that the precipitatedβ′_(1) phases partially dissolved(spheroidized)with blurred interfaces within 160μs at 3000 s^(−1).The average length and diameter of the rod-shapedβ′_(1) phase particles were 48.5 and 9.8 nm after the T 6 heat treatment;while the average diameter of the sphericalβ′_(1) phases changed to 8.8 nm after loading.The deformedβ′_(1) phase generated larger lattice distortion energy than Mg matrix under high strain rate loading.Therefore,the difference of free energy(the driving force of dissolution)between theβ′_(1) phase and the matrix increased,making the instantaneous dissolution of theβ′_(1) phase thermodynamically feasible.The dissolution(spheroidization)of theβ′_(1) phase particles was kinetically promoted because the diffusion rate of the solute Zn atoms was accelerated by combined actions of adiabatic temperature rise,high density of dislocations(vacancies)and high deviatoric stresses during high strain rate loading.The increase in hardness of ZK 60-T 6 alloy could be attributed to solid solution strengthening,dislocation strengthening and second phase particle strengthening.
基金Project(G202403)supported by the Open Foundation of The State Key Laboratory of Refractories and Metallurgy,ChinaProject(2022CFB378)supported by the Natural Science Foundation of Hubei Province,China+2 种基金Project(B 17034)supported by 111 Project,ChinaProject(IRT_17R83)supported by the Innovative Research Team Development Program of Ministry of Education of ChinaProject(P2024-026)supported by the Open Foundation of The State Key Laboratory of Materials Processing and Die&Mould Technology,China。
文摘Electroshocking treatment(EST),an efficient and rapid material treatment method,promotes microstructure evolution and improves mechanical properties.This study incorporates EST into the conventional cold rolling-quenching tempering process of M50 steel and investigates the influence and mechanism of applying EST at different stages of the process on the microstructure and mechanical properties.Scanning electron microscope(SEM),transmission electron microscope(TEM),and X-ray diffraction(XRD)were used to characterize the effect of EST on microstructure.The results show that EST can refine the grains of M50(average reduction of 10.1%in grain size),homogenize the grain size distribution,reduce the dislocation density(20.9%in average),promote the dissolution of carbides in the matrix and distribute them more uniformly along the grain boundaries,resulting in the improvement of mechanical properties.The mechanical properties of the specimen with the process flow of rolling-quenching-tempering-electroshocking showed excellent performance,with an increase in hardness of 1.4%,tensile strength of 17.7%,and elongation at break of 24.3%as compared to the specimen without EST.The tensile properties of the specimen with the process flow of rolling electroshocking-quenching-tempering showed the best performance,with an increase in tensile strength of 30.0%and elongation at break of 30.7%as compared to the specimen without EST.
基金partially supported by the Natural Science Foundation of Hubei Province(No.2022CFC030)the Science and Technology Research Project of Hubei Provincial Department of Education(No.D20212603)+2 种基金Hubei University of Arts and Science(No.2020kypytd002)the support from National Natural Science Foundation of China(No.22303098)the support from Anhui Provincial Natural Science Foundation(No.1908085MA10)。
文摘Intrinsic two-dimensional(2D)ferromagnetic(FM)semiconductors have attracted extensive attentions for their potential applications in next-generation spintronics devices.In recent years,the van der Waals material VI_(3) has been experimentally found to be an intrinsic FM semiconductor.However,the electronic structure of the VI_(3) is not fully understood.To reveal why the VI_(3)is a ferromagnetic semiconductor with strong out-of-plane anisotropy,we systematically studied the electronic structure of the monolayer VI_(3).Our results confirm that the monolayer VI_(3) is a Mott insulator,and d^(2) electrons occupy a_(g) and e_(g)^(π+) orbitals.The half-metallic state is a metastable state with a total energy 0.7 e V higher than the ferromagnetic Mott insulating state.Furthermore,our study confirmed that the VI_(3)exhibits the out-of-plane magnetic anisotropy,which originates from d^(2) electrons occupying low-lying agand egπ+orbitals.Since the orbital angular momentum of the e_(g)^(π+) state is not completely quenched,the VI_(3) has the out-of-plane anisotropy under interplay between the spin-orbit coupling and crystal field.Our study provides valuable guidance for the design of 2D magnetic materials with pronounced out-of-plane anisotropy.
