It is discussed that a tangential force T induces a self-excited vibration in the motion ofspindle blades of a ring spinning frame.Depending on the relative magnitude of the tangentialforce compared with the tangentia...It is discussed that a tangential force T induces a self-excited vibration in the motion ofspindle blades of a ring spinning frame.Depending on the relative magnitude of the tangentialforce compared with the tangential damping force the motion of blade is either stable orunstable.The chief factors causing the self-excited vibration can also be traced from the charac-ter of the experimental locus.展开更多
To exploit the combined strengthening effects of nanotwins and carbon nanotubes(CNTs)in Cu matrix composites,the nanotwins with a width ranging from 3 to 30 nm were incorporated into the CNTs-reinforced Cu matrix comp...To exploit the combined strengthening effects of nanotwins and carbon nanotubes(CNTs)in Cu matrix composites,the nanotwins with a width ranging from 3 to 30 nm were incorporated into the CNTs-reinforced Cu matrix composites using cryogenic rolling and optimizing the initial particle size of the raw Cu powders.The formation of nanotwins in the Cu matrix composite reinforced by only 0.2 wt.%CNTs is accompanied by the increased dislocation density and refined Cu grain size,resulting in much better strength−ductility synergy than the referenced composite without significant nanotwins formation.The analysis of strengthening and toughening mechanisms demonstrates that the strength increment mainly derives from grain refinement strengthening,dislocation strengthening,and nanotwin strengthening.The strength increment from the contribution of the nanotwins accounts for 19.9%of the overall strength increment for the composite.Meanwhile,the retention of good tensile ductility can be reasonably explained by the increased dislocation accommodation ability due to the formed nanotwins and the decreased induced dislocation proliferation.展开更多
The high hydrophilicity of pineapple leaf fibres(PALF)limits their use in cement-and gypsum-based composites exposed to moisture.This study evaluates,for the first time,the combined effect of palm kernel oil and beesw...The high hydrophilicity of pineapple leaf fibres(PALF)limits their use in cement-and gypsum-based composites exposed to moisture.This study evaluates,for the first time,the combined effect of palm kernel oil and beeswax on the hygroscopic resistance and mechanical stability of PALF.The fibres were functionalised with three formulations(oil,wax,and a 1:2 oil/wax blend)applied at different mass ratios(CR=0.5-2).Treatments increased the average bundle diameter by up to+46%(238μm)and reduced density down to 1.06 g/cm^(3).Hygroscopically,water absorption decreased from 202.4%(raw fibres)to 76.3%(CR=2),representing a maximum reduction of 59.4%in saline medium,while moisture regain dropped from 27.9%to 14.6%(−47.7%).The oil/wax blend proved most effective,simultaneously reducing water absorption(−51.2%)and moisture regain(−46.8%)at CR=1.Mechanically,the fibres retained tensile strength(415.2 vs.460.8 MPa,+11%at CR=1)and exhibited enhanced ductility(+62.5%,with elongation at break increasing from 1.6%to 2.6%),without significantly altering Young’s modulus(12.3 to 10 GPa).Water absorption kinetics were accurately described by the Czel and Mohsenin models(R^(2)>0.98).These findings clearly demonstrate that bio-based lipid coatings can provide an eco-friendly alternative to conventional chemical treatments.They improve hygroscopic resistance and preserve mechanical integrity of PALF,providing original quantitative data for their integration into durable cement-and gypsum-based composites subjected to humid or cyclic wet-dry conditions.展开更多
Two-dimensional(2D)materials have attracted extensive attention from aerospace,integrated circuits,precision sensors,and flexible electronics due to their unique layered structure and excellent physicochemical propert...Two-dimensional(2D)materials have attracted extensive attention from aerospace,integrated circuits,precision sensors,and flexible electronics due to their unique layered structure and excellent physicochemical properties.In practice applications,the components of functional nanodevices are subjected to mechanical stress,which can affect the robust performance and structural reliability of these devices.Therefore,it is imperative to explore the mechanical properties and underlying mechanisms of 2D materials.However,researchers have an inadequate understanding of the accuracy of various in situ microscopy techniques and neglect the significance of high-quality,clean transfer techniques,resulting in deviated measurement results.There is now an urgent need to develop guidelines that allow researchers to select appropriate material transfer techniques and mechanical testing strategies based on the specific properties of 2D materials.Furthermore,the mechanical mechanism of 2D materials lacks systematic and comprehensive studies,which hinders researchers from deeply understanding the relationship between the material structure and the device performance.This work reviews the latest progress in the mechanics of 2D materials,focusing on the challenges of various transfer techniques and in situ microscopy techniques in mechanical testing,and provides effective guidance for the formulation of experimental schemes for mechanical testing.In addition,we offer detailed mechanistic insights into the fracture behavior,geometric dimension effects,edge defects,and interlayer bonding effects of 2D materials.This work is expected to advance the field development of 2D material mechanics.展开更多
Laser additively manufactured microscale metallic lattices show great potential for high-performance applications,yet trade-offs among geometric precision,structural integrity,and computational efficiency still persis...Laser additively manufactured microscale metallic lattices show great potential for high-performance applications,yet trade-offs among geometric precision,structural integrity,and computational efficiency still persist.Here,we introduce a stereolithography file format-free(STL-free)hybrid toolpath generation method for laser-based powder bed fusion(PBF-LB)that synergizes implicit geometric modeling with optimized laser scanning strategy,overcoming these limitations.By circumventing traditional mesh-based workflows,our method directly translates implicit lattice geometries into laser toolpaths while precisely regulating energy deposition trajectories.This mesh-free process enables the fabrication of complex shell lattices with ultra-thin walls and enhanced surface quality.In addition to reducing memory usage and processing time by up to 90%,the method yields a synergistic enhancement in mechanical performance,notably improving both strength and toughness.By bridging computational design and fabrication,this framework enables the scalable production of high-performance microscale lattices and unlocks their potential for industrial applications.展开更多
Producing steel requires large amounts of energy to convert iron ores into steel,which often comes from fossil fuels,leading to carbon emissions and other pollutants.Increasing scrap usage emerges as one of the most e...Producing steel requires large amounts of energy to convert iron ores into steel,which often comes from fossil fuels,leading to carbon emissions and other pollutants.Increasing scrap usage emerges as one of the most effective strategies for addressing these issues.However,typical residual elements(Cu,As,Sn,Sb,Bi,etc.)inherited from scrap could significantly influence the mechanical properties of steel.In this work,we investigate the effects of residual elements on the microstructure evolution and mechanical properties of a quenching and partitioning(Q&P)steel by comparing a commercial QP1180 steel(referred to as QP)to the one containing typical residual elements(Cu+As+Sn+Sb+Bi<0.3wt%)(referred to as QP-R).The results demonstrate that in comparison with the QP steel,the residual elements significantly refine the prior austenite grain(9.7μm vs.14.6μm)due to their strong solute drag effect,leading to a higher volume fraction(13.0%vs.11.8%),a smaller size(473 nm vs.790 nm)and a higher average carbon content(1.26 wt%vs.0.99 wt%)of retained austenite in the QP-R steel.As a result,the QP-R steel exhibits a sustained transformation-induced plasticity(TRIP)effect,leading to an enhanced strain hardening effect and a simultaneous improvement of strength and ductility.Grain boundary segregation of residual elements was not observed at prior austenite grain boundaries in the QP-R steel,primarily due to continuous interface migration during austenitization.This study demonstrates that the residual elements with concentrations comparable to that in scrap result in significant microstructural refinement,causing retained austenite with relatively higher stability and thus offering promising mechanical properties and potential applications.展开更多
Titanium(Ti)and its alloys are frequently utilized as critical components in a variety of engineering ap-plications because of their high specific strength and excellent corrosion resistance.Compared to conven-tional ...Titanium(Ti)and its alloys are frequently utilized as critical components in a variety of engineering ap-plications because of their high specific strength and excellent corrosion resistance.Compared to conven-tional surface strengthening technologies,laser shock peening(LSP)has increasingly attracted attention from researchers and industries,since it significantly improves the surface strength,biocompatibility,fa-tigue resistance,and anti-corrosion ability of Ti and its alloys.Despite numerous studies that have been carried out to elucidate the effects of LSP on microstructural evolution and mechanical properties of Ti and its alloys in recent years,a comprehensive review of recent advancements in the field of Ti and its alloys subjected to LSP is still lacking.In this review,the standard LSP and the novel process designs of LSP assisted by thermal,cryogenic,electropulsing and magnetic fields are discussed and compared.Microstructural evolution,with focuses on the dislocation dynamics,deformation twinning,grain refine-ment and surface amorphization,during LSP processing of Ti alloys is reviewed.Furthermore,the en-hanced engineering performance of the L SP-processed(L SPed)Ti alloys,including surface hardness,wear resistance,fatigue life and corrosion resistance are summarized.Finally,this review concludes by present-ing an overview of the current challenges encountered in this field and offering insights into anticipated future trends.展开更多
This study investigates the mechanical properties and microstructure of SS304L stainless steel(SS)fabricated via laser powder bed fusion(LPBF)under controlled oxygen levels(0.2%)at both room and cryogenic temperatures...This study investigates the mechanical properties and microstructure of SS304L stainless steel(SS)fabricated via laser powder bed fusion(LPBF)under controlled oxygen levels(0.2%)at both room and cryogenic temperatures(77 K and 4 K).Experimental results show that the LPBF SS304L exhibits significant improvements in yield strength(YS),with an increase of∼336 MPa at room temperature and up to∼398 MPa at 4 K compared to wrought SS304L.Additionally,the current LPBF SS304L demonstrates an extra∼64 MPa YS strengthening over previous LPBF SS304L data at room temperature.These strength enhancements are primarily attributed to oxide dispersion hardening,promoted by the controlled oxygen level,alongside grain boundary strengthening and dislocation hardening,without significant ductility loss.Furthermore,strain-induced martensitic transformation(SIMT)was absent at room temperature and reduced at cryogenic temperatures compared to wrought SS304L,likely due to high dislocation density and nitrogen-stabilized austenite.A jerk flow observed at 4 K is attributed to adiabatic heating from plastic deformation,consistent with the low thermal conductivity.Finite element simulations reveal a short residence time(0.0137 s)for molten material during the LPBF process,with oxide particles forming predominantly through heterogeneous nucleation at the melt pool surface,and uniformly distributed by Marangoni convection.These findings provide key insights into developing LPBF parameters for enhanced mechanical performance of SS304L for cryogenic and ambient temperature applications.展开更多
Control of the columnar to equiaxed transition(CET)is a major challenge in additively manufacturedβtitanium alloys.In this work,the promotion of CET was successfully achieved through in-situ fabrication of Ti-5Cu(wt....Control of the columnar to equiaxed transition(CET)is a major challenge in additively manufacturedβtitanium alloys.In this work,the promotion of CET was successfully achieved through in-situ fabrication of Ti-5Cu(wt.%)alloys with additions of 5,15,and 25 wt.%Nb using elemental Ti,Cu,and Nb powders by employing laser powder bed fusion(LPBF).The alloy containing 5 wt.%Nb consisted ofαlamellae,Ti2 Cu precipitates,and unmeltedβ-Nb inclusions,whereas the 25 wt.%Nb alloy consisted of equiaxedβgrains,ωprecipitates,and Ti2 Cu precipitates at the grain boundaries.In terms of mechanical proper-ties,despite the presence of Nb inclusions and liquation cracks in the 5 wt.%Nb alloy,it showed a yield strength of 1051±40 MPa and an elongation of 5.2%±1.3%.Both the strength and ductility decreased with increasing Nb content,e.g.,the 25 wt.%Nb alloy exhibited a yield strength of 808±53 MPa and an elongation of 1.6%±0.2%.As the Nb content increased from 5 to 25 wt.%,the Young’s modulus decreased from 110 to 65 GPa.The 25 wt.%Nb alloy showed a high ratio of hardness to Young’s mod-ulus(H/E)and yield pressure(H3/E2).However,due to its brittle nature,the material manifested high wear rates.These findings provide a basis for the future development of novel low-modulus isotropicβ-titanium alloys using LPBF.展开更多
The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engin...The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engineering of conductive/dielectric genes.Electron migration modes within HEAs as manipulated by the electronegativity,valence electron configurations and molar proportions of constituent elements determine the steady state and efficiency of equivalent dipoles.Herein,enlightened by skin-like effect,a reformative carbothermal shock method using carbonized cellulose paper(CCP)as carbon supporter is used to preserve the oxygencontaining functional groups(O·)of carbonized cellulose fibers(CCF).Nucleation of HEAs and construction of emblematic shell-core CCF/HEAs heterointerfaces are inextricably linked to carbon metabolism induced by O·.Meanwhile,the electron migration mode of switchable electronrich sites promotes the orientation polarization of anisotropic equivalent dipoles.By virtue of the reinforcement strategy,CCP/HEAs composite prepared by 35%molar ratio of Mn element(CCP/HEAs-Mn_(2.15))achieves efficient electromagnetic wave(EMW)absorption of−51.35 dB at an ultra-thin thickness of 1.03 mm.The mechanisms of the resulting dielectric properties of HEAs-based EMW absorbing materials are elucidated by combining theoretical calculations with experimental characterizations,which provide theoretical bases and feasible strategies for the simulation and practical application of electromagnetic functional devices(e.g.,ultra-wideband bandpass filter).展开更多
The functionally graded materials(FGMs)are obtained by various processes.Although a few FGMs are obtained naturally,such as oyster,pearl,and bamboo,additive manufacturing(AM),known as 3D printing,is a net-shaped manuf...The functionally graded materials(FGMs)are obtained by various processes.Although a few FGMs are obtained naturally,such as oyster,pearl,and bamboo,additive manufacturing(AM),known as 3D printing,is a net-shaped manufacturing process employed to manufacture complex 3D objects without tools,molds,assembly,and joining.Currently,commercial AM techniques mostly use homogeneous composition with simplified geometric descriptions,employing a single material across the entire component to achieve functional graded additive manufacturing(FGAM),in contrast to multi-material FGAM with heterogeneous structures.FGMs are widely used in various fields due to their mechanical property advantages.Because FGM plays a significant role in the industrial production,the characteristics and mechanical behaviour of FGMs prepared by AM were reviewed.In this review,the research on FGMs and AM over the past 30 years was reviewed,suggesting that future researchers should focus on the application of artificial intelligence and machine learning technologies in industry to optimize the process parameters of different gradient systems.展开更多
Fatigue failure continues to be a significant challenge in designing structural and mechanical components subjected to repeated and complex loading.While earlier studies mainly examined material properties and how str...Fatigue failure continues to be a significant challenge in designing structural and mechanical components subjected to repeated and complex loading.While earlier studies mainly examined material properties and how stress affects lifespan,this review offers the first comprehensive,multiscale comparison of strategies that optimize geometry to improve fatigue performance.This includes everything from microscopic features like the shape of graphite nodules to large-scale design elements such as fillets,notches,and overall structural layouts.We analyze and combine various methods,including topology and shape optimization,the ability of additive manufacturing to finetune internal geometries,and reliability-based design approaches.A key new contribution is our proposal of a standard way to evaluate geometry-focused fatigue design,allowing for consistent comparison and encouraging validation across different fields.Furthermore,we highlight important areas for future research,such as incorporating manufacturing flaws,using multiscale models,and integrating machine learning techniques.This work is the first to provide a broad geometric viewpoint in fatigue engineering,laying the groundwork for future design methods that are driven by data and centered on reliability.展开更多
This study investigates the impact of welding heat input on weldments of modified 9Cr-1Mo(P91)steel,a high-strength material that requires high-energy welding processes like submerged arc welding.In the as-welded cond...This study investigates the impact of welding heat input on weldments of modified 9Cr-1Mo(P91)steel,a high-strength material that requires high-energy welding processes like submerged arc welding.In the as-welded condition,P91 steel welds primarily consist of untempered martensite,which transforms into tempered martensite during post-weld heat treatment(PWHT).Electron spectro-scopy analysis reveals the presence of M_(23)C_(6) and MX carbonitride precipitates at grain boundaries.Increasing the heat input leads to greater quantities of precipitates in the prior austenite grain boundaries,which can affect material properties.Weldment hardness profiles exhibit modest improvements,while ultimate tensile strength and toughness decrease with higher welding heat input,poten-tially due to the formation of a ferritic phase.Residual stress distributions are noticeably influenced by the welding heat input level.展开更多
The precise computation of nanoelectromechanical switches’(NEMS)multi-physical interactions requires advanced numerical models and is a crucial part of the development of micro-and nano-systems.This paper presents a ...The precise computation of nanoelectromechanical switches’(NEMS)multi-physical interactions requires advanced numerical models and is a crucial part of the development of micro-and nano-systems.This paper presents a novel compound numerical method to study the instability of a functionally graded(FG)beam-type NEMS,considering surface elasticity effects as stated by Gurtin-Murdoch theory in an Euler-Bernoulli beam.The presented method is based on a combination of the Method of Adjoints(MoA)together with the Bézier-based multistep technique.By utilizing the MoA,a boundary value problem(BVP)is turned into an initial value problem(IVP).The resulting IVP is then solved by employing a cost-efficient multi-step process.It is demonstrated that the mentioned method can arrive at a high level of accuracy.Furthermore,it is revealed that the stability of the presented methodology is far better than that of other common multi-step methods,such as Adams-Bashforth,particularly at higher step sizes.Finally,the effects of axially functionally graded(FG)properties on the pull-in phenomenon and the main design parameters of NEMS,including the detachment length,are inspected.It was shown that the main parameter of design is the modulus of elasticity of the material,as Silver(Ag),which had better mechanical properties,showed almost a 6%improvement compared to aluminum(Al).However,by applying the correct amount of material with sturdier surface parameters,such as Aluminum(Al),at certain points,the nanobeams’functionality can be improved even further by around 1.5%.展开更多
The mechanical behaviour of Titanium-based Fiber Metal Laminates(FMLs)reinforced with Kevlar,Jute and the novel woven(Kevlar+Jute)fiber mat were evaluated through tensile,flexural,Charpy impact,and drop-weight tests.T...The mechanical behaviour of Titanium-based Fiber Metal Laminates(FMLs)reinforced with Kevlar,Jute and the novel woven(Kevlar+Jute)fiber mat were evaluated through tensile,flexural,Charpy impact,and drop-weight tests.The FMLs were fabricated with various stacking configurations(2/1,3/2,4/3,and 5/4)to examine their influence on mechanical properties.Kevlar-reinforced laminates consistently demonstrated superior tensile and flexural strengths,with the highest tensile strength of 772 MPa observed in the 3/2 configuration,attributed to Kevlar's excellent load-bearing capacity.Jute-reinforced laminates exhibited lower performance due to poor bonding and early delamination,while the FMLs reinforced with woven(Kevlar+Jute)fiber mat achieved a balance between mechanical strength and cost-effectiveness by attaining a tensile strength of 718 MPa in the 3/2 configuration.Impact energy absorption results revealed that Kevlar-reinforced FMLs provided the highest energy absorption under Charpy tests,reaching 13.5 J in the 3/2 configuration.The 4/3 configu ration exhibited superior resistance under drop-weight impacts,absorbing 104.7 J of energy.Failure analysis using SEM revealed key mechanisms such as fiber debonding,delamination,and fiber pull-out,with increased severity observed in laminates with a higher number of fiber-epoxy layers,especially in the 5/4 configuration.This study highlights the potential of Kevlar-Jute hybrid fiber-reinforced FMLs for applications requiring high mechanical performance and impact resistance.Future research should explore advanced surface treatments and the environmental durability of these laminates for aerospace and automotive applications.展开更多
This paper introduces a novel optimization approach called Recuperated Seed Search Optimization(RSSO),designed to address challenges in solving mechanical engineering design problems.Many optimization techniques strug...This paper introduces a novel optimization approach called Recuperated Seed Search Optimization(RSSO),designed to address challenges in solving mechanical engineering design problems.Many optimization techniques struggle with slow convergence and suboptimal solutions due to complex,nonlinear natures.The Sperm Swarm Optimization(SSO)algorithm,which mimics the sperm’s movement to reach an egg,is one such technique.To improve SSO,researchers combined it with three strategies:opposition-based learning(OBL),Cauchy mutation(CM),and position clamping.OBL introduces diversity to SSO by exploring opposite solutions,speeding up convergence.CM enhances both exploration and exploitation capabilities throughout the optimization process.This combined approach,RSSO,has been rigorously tested on standard benchmark functions,real-world engineering problems,and through statistical analysis(Wilcoxon test).The results demonstrate that RSSO significantly outperforms other optimization algorithms,achieving faster convergence and better solutions.The paper details the RSSO algorithm,discusses its implementation,and presents comparative results that validate its effectiveness in solving complex engineering design challenges.展开更多
In this study,the effect of Tin(Sn)addition on the microstructure,mechanical properties,and wear resistance of pure magnesium(Mg)was examined.Mg-Sn alloys were synthesized using stir casting technique with Sn concentr...In this study,the effect of Tin(Sn)addition on the microstructure,mechanical properties,and wear resistance of pure magnesium(Mg)was examined.Mg-Sn alloys were synthesized using stir casting technique with Sn concentrations of 2.5%,5%,and 7.5% by weight.The specimens were prepared as per ASTM standards for their evaluation.Higher Sn concentrations result in a reduced volume fraction of the eutectic phase,while Mg_(2)Sn precipitates are observed in alloys with 5% or more Sn.Scanning electron microscopy(SEM)analysis of the Mg-7.5wt.%Sn alloy reveals the presence of Mg(OH)_(2),with X-ray diffraction(XRD)confirming an oxygen content of 18% by weight.The addition of Sn minimizes casting porosity,enhancing the quality of the alloys.The findings demonstrate a positive correlation between increasing Sn content and enhanced strength and wear resistance.The Mg-7.5wt.%Sn alloy exhibits significantly enhanced tensile properties attributed to grain refinement and the formation of well-defined grain boundaries compared to alloys with lower Sn additions(2.5% and 5%),although a slight reduction in microhardness is observed.Tribological evaluation indicates reduced wear and friction,suggesting better surface performance.This research underscores the complex interplay between Sn content,microstructural evolution,and the resulting mechanical and tribological performance of Mg-Sn alloys.展开更多
Nuclear DNA, which is essential for the transmission of genetic information, is constantly damaged by external stresses and is subsequently repaired by the removal of the damaged region, followed by resynthesis of the...Nuclear DNA, which is essential for the transmission of genetic information, is constantly damaged by external stresses and is subsequently repaired by the removal of the damaged region, followed by resynthesis of the excised region. Accumulation of DNA damage with failure of repair processes leads to fatal diseases such as cancer. Recent studies have suggested that intra- and extra-nuclear environments play essential roles in DNA damage. However, numerous questions regarding the role of the nuclear mechanical environment in DNA damage remain unanswered. In this study, we investigated the effects of cell confluency (cell crowding) on the morphology of cell nuclei, and cytoskeletal structures, and DNA damage in NIH3T3 skin fibroblasts and HeLa cervical cancer cells. Although nuclear downsizing was observed in both NIH3T3 and HeLa cells with cell crowding, intracellular mechanical changes in the two cell types displayed opposite tendencies. Cell crowding in NIH3T3 cells induced reinforcement of actin filament structures, cell stiffening, and nuclear downsizing, resulting in a significant decrease in endogenous DNA damage, whereas cell crowding in HeLa cells caused partial depolymerization of actin filaments and cell softening, inducing endogenous DNA damage. Ultraviolet (UV) radiation significantly increased DNA damage in NIH3T3;however, this response did not change with cell crowding. In contrast, UV radiation did not cause DNA damage in HeLa cells under either sparse or confluent conditions. These results suggested that cell crowding significantly influenced endogenous DNA damage in cells and was quite different in NIH3T3 and HeLa cells. However, cell crowding did not affect the UV-induced DNA damage in either cell type.展开更多
With the growing importance of wearable and portable electronics in modern society and industry,researchers from all over the world have reported on advances in energy harvesting and self-powered sensing technologies....With the growing importance of wearable and portable electronics in modern society and industry,researchers from all over the world have reported on advances in energy harvesting and self-powered sensing technologies.The current review discusses recent developments in triboelectric platforms from a manufacturing perspective,including material,design,application,and industrialization.Manufacturing is an essential component of both industry and technology.The use of a proper manufacturing process enables cutting-edge technology in a lab-scale stage to progress to commercialization and popularization with scalability,availability,commercial advantage,and consistent quality.Furthermore,much literature has emphasized that the most powerful advantage of the triboelectric platform is its wide range of available materials and simple working mechanism,both of which are important characteristics in manufacturing engineering.As a result,different manufacturing processes can be implemented as needed.Because the practical process can have a synergetic effect on the fundamental development,resulting in the growth of both,the development of the triboelectric platform from the standpoint of manufacturing engineering can be further advanced.However,research into the development of a productive manufacturing process is still in its early stages in the field of triboelectric platforms.This review looks at the various manufacturing technologies used in previous studies and discusses the potential benefits of the appropriate process for triboelectric platforms.Given its unique strength,which includes a diverse material selection and a simple working mechanism,the triboelectric platform can use a variety of manufacturing technologies and the process can be optimized as needed.Numerous research groups have clearly demonstrated the triboelectric platform's advantages.As a result,using appropriate manufacturing processes can accelerate the technological advancement of triboelectric platforms in a variety of research and industrial fields by allowing them to move beyond the lab-scale fabrication stage.展开更多
Although the existence of glass–glass interfaces(GGIs)enables improved ductility of metallic nanoglasses(NGs),the excess free volumes at GGIs would cause the NGs to have a much-reduced mechanical strength.Herein,entr...Although the existence of glass–glass interfaces(GGIs)enables improved ductility of metallic nanoglasses(NGs),the excess free volumes at GGIs would cause the NGs to have a much-reduced mechanical strength.Herein,entropy-stabilized GGIs have been in-vestigated in Co–Fe–Ni–Zn–P NGs,which have a large entropy of mixing(1.32R,where R is the gas constant)and could be in a new glass phase,different from that of glassy grain interiors.Through quantitatively determining the activation energy of glass transition sep-arately for the GGIs and glassy grain interiors,the excess free volumes at GGIs are found to be reduced in comparison with those in the glassy grain interiors.The thermodynamically stable GGIs could be associated with increasing entropy of mixing in the GGI regions,which stabilizes the atomic structures of GGIs and enhances the glass forming ability of Co–Fe–Ni–Zn–P NGs.The influences of entropy-stabilized GGIs on the mechanical properties of Co–Fe–Ni–Zn–P NGs are further investigated by nanoindentation and creep tests under tensile deformation,demonstrating that there are notable enhancements in the ductility and mechanical strength for Co–Fe–Ni–Zn–P NGs.This work contributes to an in-depth understanding on the GGI phase in NGs and offers an alternative method for strengthening NGs through GGI engineering.展开更多
文摘It is discussed that a tangential force T induces a self-excited vibration in the motion ofspindle blades of a ring spinning frame.Depending on the relative magnitude of the tangentialforce compared with the tangential damping force the motion of blade is either stable orunstable.The chief factors causing the self-excited vibration can also be traced from the charac-ter of the experimental locus.
基金financially supported by the Fundamental Research Funds for the Central Universities,China(No.21624408)the Guangdong Basic and Applied Basic Research Foundation,China(Nos.2023A1515012850,2024A1515010416)+2 种基金Guangzhou Science and Technology Planning Project,China(No.2024A04J9966)the National Natural Science Foundation of China(Nos.52271132,52004101)the Key Laboratory of Advanced Materials of Yunnan Province,China(No.2024KF02)。
文摘To exploit the combined strengthening effects of nanotwins and carbon nanotubes(CNTs)in Cu matrix composites,the nanotwins with a width ranging from 3 to 30 nm were incorporated into the CNTs-reinforced Cu matrix composites using cryogenic rolling and optimizing the initial particle size of the raw Cu powders.The formation of nanotwins in the Cu matrix composite reinforced by only 0.2 wt.%CNTs is accompanied by the increased dislocation density and refined Cu grain size,resulting in much better strength−ductility synergy than the referenced composite without significant nanotwins formation.The analysis of strengthening and toughening mechanisms demonstrates that the strength increment mainly derives from grain refinement strengthening,dislocation strengthening,and nanotwin strengthening.The strength increment from the contribution of the nanotwins accounts for 19.9%of the overall strength increment for the composite.Meanwhile,the retention of good tensile ductility can be reasonably explained by the increased dislocation accommodation ability due to the formed nanotwins and the decreased induced dislocation proliferation.
文摘The high hydrophilicity of pineapple leaf fibres(PALF)limits their use in cement-and gypsum-based composites exposed to moisture.This study evaluates,for the first time,the combined effect of palm kernel oil and beeswax on the hygroscopic resistance and mechanical stability of PALF.The fibres were functionalised with three formulations(oil,wax,and a 1:2 oil/wax blend)applied at different mass ratios(CR=0.5-2).Treatments increased the average bundle diameter by up to+46%(238μm)and reduced density down to 1.06 g/cm^(3).Hygroscopically,water absorption decreased from 202.4%(raw fibres)to 76.3%(CR=2),representing a maximum reduction of 59.4%in saline medium,while moisture regain dropped from 27.9%to 14.6%(−47.7%).The oil/wax blend proved most effective,simultaneously reducing water absorption(−51.2%)and moisture regain(−46.8%)at CR=1.Mechanically,the fibres retained tensile strength(415.2 vs.460.8 MPa,+11%at CR=1)and exhibited enhanced ductility(+62.5%,with elongation at break increasing from 1.6%to 2.6%),without significantly altering Young’s modulus(12.3 to 10 GPa).Water absorption kinetics were accurately described by the Czel and Mohsenin models(R^(2)>0.98).These findings clearly demonstrate that bio-based lipid coatings can provide an eco-friendly alternative to conventional chemical treatments.They improve hygroscopic resistance and preserve mechanical integrity of PALF,providing original quantitative data for their integration into durable cement-and gypsum-based composites subjected to humid or cyclic wet-dry conditions.
基金National Natural Science Foundation of China(Grant.Nos.52422505,12274124)the Shanghai Pilot Program for Basic Research(Grant.No.22TQ14001006)+2 种基金National Natural Science Foundation of China(Grant No.52275149)the Scientific Research Innovation Capability Support Project for Young Faculty(Grant No.ZYGXQNJSKYCXNLZCXM-D5)Innovative Research Group Project of the National Natural Science Foundation of China(Grant.No.52321002)。
文摘Two-dimensional(2D)materials have attracted extensive attention from aerospace,integrated circuits,precision sensors,and flexible electronics due to their unique layered structure and excellent physicochemical properties.In practice applications,the components of functional nanodevices are subjected to mechanical stress,which can affect the robust performance and structural reliability of these devices.Therefore,it is imperative to explore the mechanical properties and underlying mechanisms of 2D materials.However,researchers have an inadequate understanding of the accuracy of various in situ microscopy techniques and neglect the significance of high-quality,clean transfer techniques,resulting in deviated measurement results.There is now an urgent need to develop guidelines that allow researchers to select appropriate material transfer techniques and mechanical testing strategies based on the specific properties of 2D materials.Furthermore,the mechanical mechanism of 2D materials lacks systematic and comprehensive studies,which hinders researchers from deeply understanding the relationship between the material structure and the device performance.This work reviews the latest progress in the mechanics of 2D materials,focusing on the challenges of various transfer techniques and in situ microscopy techniques in mechanical testing,and provides effective guidance for the formulation of experimental schemes for mechanical testing.In addition,we offer detailed mechanistic insights into the fracture behavior,geometric dimension effects,edge defects,and interlayer bonding effects of 2D materials.This work is expected to advance the field development of 2D material mechanics.
基金financial support of the Hong Kong Special Administrative Region University Grants Committee—General Research Fund CUHK14209523Collaborative Research Fund C4074-22G,C4002-22Y and C7074-23Gsupport by the University of Massachusetts Amherst。
文摘Laser additively manufactured microscale metallic lattices show great potential for high-performance applications,yet trade-offs among geometric precision,structural integrity,and computational efficiency still persist.Here,we introduce a stereolithography file format-free(STL-free)hybrid toolpath generation method for laser-based powder bed fusion(PBF-LB)that synergizes implicit geometric modeling with optimized laser scanning strategy,overcoming these limitations.By circumventing traditional mesh-based workflows,our method directly translates implicit lattice geometries into laser toolpaths while precisely regulating energy deposition trajectories.This mesh-free process enables the fabrication of complex shell lattices with ultra-thin walls and enhanced surface quality.In addition to reducing memory usage and processing time by up to 90%,the method yields a synergistic enhancement in mechanical performance,notably improving both strength and toughness.By bridging computational design and fabrication,this framework enables the scalable production of high-performance microscale lattices and unlocks their potential for industrial applications.
基金financially supported by the National Natural Science Foundation of China(Nos.52293395 and 52293393)the Xiongan Science and Technology Innovation Talent Project of MOST,China(No.2022XACX0500).
文摘Producing steel requires large amounts of energy to convert iron ores into steel,which often comes from fossil fuels,leading to carbon emissions and other pollutants.Increasing scrap usage emerges as one of the most effective strategies for addressing these issues.However,typical residual elements(Cu,As,Sn,Sb,Bi,etc.)inherited from scrap could significantly influence the mechanical properties of steel.In this work,we investigate the effects of residual elements on the microstructure evolution and mechanical properties of a quenching and partitioning(Q&P)steel by comparing a commercial QP1180 steel(referred to as QP)to the one containing typical residual elements(Cu+As+Sn+Sb+Bi<0.3wt%)(referred to as QP-R).The results demonstrate that in comparison with the QP steel,the residual elements significantly refine the prior austenite grain(9.7μm vs.14.6μm)due to their strong solute drag effect,leading to a higher volume fraction(13.0%vs.11.8%),a smaller size(473 nm vs.790 nm)and a higher average carbon content(1.26 wt%vs.0.99 wt%)of retained austenite in the QP-R steel.As a result,the QP-R steel exhibits a sustained transformation-induced plasticity(TRIP)effect,leading to an enhanced strain hardening effect and a simultaneous improvement of strength and ductility.Grain boundary segregation of residual elements was not observed at prior austenite grain boundaries in the QP-R steel,primarily due to continuous interface migration during austenitization.This study demonstrates that the residual elements with concentrations comparable to that in scrap result in significant microstructural refinement,causing retained austenite with relatively higher stability and thus offering promising mechanical properties and potential applications.
基金supported by the National Key R&D Plan of China(No.2022YFB3705603)the National Natural Science Foundation of China(No.52101046)+1 种基金the Excellent Youth Overseas Project of National Science and Natural Foundation of China,the Baowu Special Metallurgy Cooperation Limited(No.22H010101336)the Medicine-Engineering Interdisciplinary Project of Shanghai Jiao Tong University(No.YG2022QN076).
文摘Titanium(Ti)and its alloys are frequently utilized as critical components in a variety of engineering ap-plications because of their high specific strength and excellent corrosion resistance.Compared to conven-tional surface strengthening technologies,laser shock peening(LSP)has increasingly attracted attention from researchers and industries,since it significantly improves the surface strength,biocompatibility,fa-tigue resistance,and anti-corrosion ability of Ti and its alloys.Despite numerous studies that have been carried out to elucidate the effects of LSP on microstructural evolution and mechanical properties of Ti and its alloys in recent years,a comprehensive review of recent advancements in the field of Ti and its alloys subjected to LSP is still lacking.In this review,the standard LSP and the novel process designs of LSP assisted by thermal,cryogenic,electropulsing and magnetic fields are discussed and compared.Microstructural evolution,with focuses on the dislocation dynamics,deformation twinning,grain refine-ment and surface amorphization,during LSP processing of Ti alloys is reviewed.Furthermore,the en-hanced engineering performance of the L SP-processed(L SPed)Ti alloys,including surface hardness,wear resistance,fatigue life and corrosion resistance are summarized.Finally,this review concludes by present-ing an overview of the current challenges encountered in this field and offering insights into anticipated future trends.
基金supported financially by Fundamental Research Program of the Korea Institute of Materials Science(No.PNKA320)the Korea Institute of Energy Technology Evaluation and Planning(KETEP)and the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(RS-2024-00435433).
文摘This study investigates the mechanical properties and microstructure of SS304L stainless steel(SS)fabricated via laser powder bed fusion(LPBF)under controlled oxygen levels(0.2%)at both room and cryogenic temperatures(77 K and 4 K).Experimental results show that the LPBF SS304L exhibits significant improvements in yield strength(YS),with an increase of∼336 MPa at room temperature and up to∼398 MPa at 4 K compared to wrought SS304L.Additionally,the current LPBF SS304L demonstrates an extra∼64 MPa YS strengthening over previous LPBF SS304L data at room temperature.These strength enhancements are primarily attributed to oxide dispersion hardening,promoted by the controlled oxygen level,alongside grain boundary strengthening and dislocation hardening,without significant ductility loss.Furthermore,strain-induced martensitic transformation(SIMT)was absent at room temperature and reduced at cryogenic temperatures compared to wrought SS304L,likely due to high dislocation density and nitrogen-stabilized austenite.A jerk flow observed at 4 K is attributed to adiabatic heating from plastic deformation,consistent with the low thermal conductivity.Finite element simulations reveal a short residence time(0.0137 s)for molten material during the LPBF process,with oxide particles forming predominantly through heterogeneous nucleation at the melt pool surface,and uniformly distributed by Marangoni convection.These findings provide key insights into developing LPBF parameters for enhanced mechanical performance of SS304L for cryogenic and ambient temperature applications.
基金the National Natural Science Foun-dation of China(Grant Nos.12374022,U23A20540)the Natu-ral Science Foundation of Hunan Province for Distinguished Young Scholars(Grant No.2023JJ10075)+3 种基金the China Postdoctoral Science Foundation(Grant Nos.GZC20241335,2024MD753962)the YueLuShan Center Industrial Innovation(Grant No.2024YCII0106)the Scientific and Technological Project of Yunnan Precious Met-als Laboratory(Grant No.YPML-2023050247)the Central South University Research Programme of Advanced Interdisci-plinary Studies(Grant No.2023QYJC039).
文摘Control of the columnar to equiaxed transition(CET)is a major challenge in additively manufacturedβtitanium alloys.In this work,the promotion of CET was successfully achieved through in-situ fabrication of Ti-5Cu(wt.%)alloys with additions of 5,15,and 25 wt.%Nb using elemental Ti,Cu,and Nb powders by employing laser powder bed fusion(LPBF).The alloy containing 5 wt.%Nb consisted ofαlamellae,Ti2 Cu precipitates,and unmeltedβ-Nb inclusions,whereas the 25 wt.%Nb alloy consisted of equiaxedβgrains,ωprecipitates,and Ti2 Cu precipitates at the grain boundaries.In terms of mechanical proper-ties,despite the presence of Nb inclusions and liquation cracks in the 5 wt.%Nb alloy,it showed a yield strength of 1051±40 MPa and an elongation of 5.2%±1.3%.Both the strength and ductility decreased with increasing Nb content,e.g.,the 25 wt.%Nb alloy exhibited a yield strength of 808±53 MPa and an elongation of 1.6%±0.2%.As the Nb content increased from 5 to 25 wt.%,the Young’s modulus decreased from 110 to 65 GPa.The 25 wt.%Nb alloy showed a high ratio of hardness to Young’s mod-ulus(H/E)and yield pressure(H3/E2).However,due to its brittle nature,the material manifested high wear rates.These findings provide a basis for the future development of novel low-modulus isotropicβ-titanium alloys using LPBF.
基金Financial support from the National Natural Science Foundation of China(52372289,52102368,52231007,12327804,T2321003,22088101,22178037 and U22A20424)Regional Joint Fund for Basic Research and Applied Basic Research of Guangdong Province(No.2020A1515110905)+1 种基金Guangdong Special Fund for key Areas(20237DZX3042)Shenzhen Stable Support Project,Liaoning Revitalization Talents Program(XLYC2002114)are highly appreciated.
文摘The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engineering of conductive/dielectric genes.Electron migration modes within HEAs as manipulated by the electronegativity,valence electron configurations and molar proportions of constituent elements determine the steady state and efficiency of equivalent dipoles.Herein,enlightened by skin-like effect,a reformative carbothermal shock method using carbonized cellulose paper(CCP)as carbon supporter is used to preserve the oxygencontaining functional groups(O·)of carbonized cellulose fibers(CCF).Nucleation of HEAs and construction of emblematic shell-core CCF/HEAs heterointerfaces are inextricably linked to carbon metabolism induced by O·.Meanwhile,the electron migration mode of switchable electronrich sites promotes the orientation polarization of anisotropic equivalent dipoles.By virtue of the reinforcement strategy,CCP/HEAs composite prepared by 35%molar ratio of Mn element(CCP/HEAs-Mn_(2.15))achieves efficient electromagnetic wave(EMW)absorption of−51.35 dB at an ultra-thin thickness of 1.03 mm.The mechanisms of the resulting dielectric properties of HEAs-based EMW absorbing materials are elucidated by combining theoretical calculations with experimental characterizations,which provide theoretical bases and feasible strategies for the simulation and practical application of electromagnetic functional devices(e.g.,ultra-wideband bandpass filter).
文摘The functionally graded materials(FGMs)are obtained by various processes.Although a few FGMs are obtained naturally,such as oyster,pearl,and bamboo,additive manufacturing(AM),known as 3D printing,is a net-shaped manufacturing process employed to manufacture complex 3D objects without tools,molds,assembly,and joining.Currently,commercial AM techniques mostly use homogeneous composition with simplified geometric descriptions,employing a single material across the entire component to achieve functional graded additive manufacturing(FGAM),in contrast to multi-material FGAM with heterogeneous structures.FGMs are widely used in various fields due to their mechanical property advantages.Because FGM plays a significant role in the industrial production,the characteristics and mechanical behaviour of FGMs prepared by AM were reviewed.In this review,the research on FGMs and AM over the past 30 years was reviewed,suggesting that future researchers should focus on the application of artificial intelligence and machine learning technologies in industry to optimize the process parameters of different gradient systems.
文摘Fatigue failure continues to be a significant challenge in designing structural and mechanical components subjected to repeated and complex loading.While earlier studies mainly examined material properties and how stress affects lifespan,this review offers the first comprehensive,multiscale comparison of strategies that optimize geometry to improve fatigue performance.This includes everything from microscopic features like the shape of graphite nodules to large-scale design elements such as fillets,notches,and overall structural layouts.We analyze and combine various methods,including topology and shape optimization,the ability of additive manufacturing to finetune internal geometries,and reliability-based design approaches.A key new contribution is our proposal of a standard way to evaluate geometry-focused fatigue design,allowing for consistent comparison and encouraging validation across different fields.Furthermore,we highlight important areas for future research,such as incorporating manufacturing flaws,using multiscale models,and integrating machine learning techniques.This work is the first to provide a broad geometric viewpoint in fatigue engineering,laying the groundwork for future design methods that are driven by data and centered on reliability.
文摘This study investigates the impact of welding heat input on weldments of modified 9Cr-1Mo(P91)steel,a high-strength material that requires high-energy welding processes like submerged arc welding.In the as-welded condition,P91 steel welds primarily consist of untempered martensite,which transforms into tempered martensite during post-weld heat treatment(PWHT).Electron spectro-scopy analysis reveals the presence of M_(23)C_(6) and MX carbonitride precipitates at grain boundaries.Increasing the heat input leads to greater quantities of precipitates in the prior austenite grain boundaries,which can affect material properties.Weldment hardness profiles exhibit modest improvements,while ultimate tensile strength and toughness decrease with higher welding heat input,poten-tially due to the formation of a ferritic phase.Residual stress distributions are noticeably influenced by the welding heat input level.
文摘The precise computation of nanoelectromechanical switches’(NEMS)multi-physical interactions requires advanced numerical models and is a crucial part of the development of micro-and nano-systems.This paper presents a novel compound numerical method to study the instability of a functionally graded(FG)beam-type NEMS,considering surface elasticity effects as stated by Gurtin-Murdoch theory in an Euler-Bernoulli beam.The presented method is based on a combination of the Method of Adjoints(MoA)together with the Bézier-based multistep technique.By utilizing the MoA,a boundary value problem(BVP)is turned into an initial value problem(IVP).The resulting IVP is then solved by employing a cost-efficient multi-step process.It is demonstrated that the mentioned method can arrive at a high level of accuracy.Furthermore,it is revealed that the stability of the presented methodology is far better than that of other common multi-step methods,such as Adams-Bashforth,particularly at higher step sizes.Finally,the effects of axially functionally graded(FG)properties on the pull-in phenomenon and the main design parameters of NEMS,including the detachment length,are inspected.It was shown that the main parameter of design is the modulus of elasticity of the material,as Silver(Ag),which had better mechanical properties,showed almost a 6%improvement compared to aluminum(Al).However,by applying the correct amount of material with sturdier surface parameters,such as Aluminum(Al),at certain points,the nanobeams’functionality can be improved even further by around 1.5%.
基金the aid of Research and Development Fund-Seed Money provided by Vel Tech Rangarajan Dr.Sagunthala R&D Institute of Science and Technology。
文摘The mechanical behaviour of Titanium-based Fiber Metal Laminates(FMLs)reinforced with Kevlar,Jute and the novel woven(Kevlar+Jute)fiber mat were evaluated through tensile,flexural,Charpy impact,and drop-weight tests.The FMLs were fabricated with various stacking configurations(2/1,3/2,4/3,and 5/4)to examine their influence on mechanical properties.Kevlar-reinforced laminates consistently demonstrated superior tensile and flexural strengths,with the highest tensile strength of 772 MPa observed in the 3/2 configuration,attributed to Kevlar's excellent load-bearing capacity.Jute-reinforced laminates exhibited lower performance due to poor bonding and early delamination,while the FMLs reinforced with woven(Kevlar+Jute)fiber mat achieved a balance between mechanical strength and cost-effectiveness by attaining a tensile strength of 718 MPa in the 3/2 configuration.Impact energy absorption results revealed that Kevlar-reinforced FMLs provided the highest energy absorption under Charpy tests,reaching 13.5 J in the 3/2 configuration.The 4/3 configu ration exhibited superior resistance under drop-weight impacts,absorbing 104.7 J of energy.Failure analysis using SEM revealed key mechanisms such as fiber debonding,delamination,and fiber pull-out,with increased severity observed in laminates with a higher number of fiber-epoxy layers,especially in the 5/4 configuration.This study highlights the potential of Kevlar-Jute hybrid fiber-reinforced FMLs for applications requiring high mechanical performance and impact resistance.Future research should explore advanced surface treatments and the environmental durability of these laminates for aerospace and automotive applications.
文摘This paper introduces a novel optimization approach called Recuperated Seed Search Optimization(RSSO),designed to address challenges in solving mechanical engineering design problems.Many optimization techniques struggle with slow convergence and suboptimal solutions due to complex,nonlinear natures.The Sperm Swarm Optimization(SSO)algorithm,which mimics the sperm’s movement to reach an egg,is one such technique.To improve SSO,researchers combined it with three strategies:opposition-based learning(OBL),Cauchy mutation(CM),and position clamping.OBL introduces diversity to SSO by exploring opposite solutions,speeding up convergence.CM enhances both exploration and exploitation capabilities throughout the optimization process.This combined approach,RSSO,has been rigorously tested on standard benchmark functions,real-world engineering problems,and through statistical analysis(Wilcoxon test).The results demonstrate that RSSO significantly outperforms other optimization algorithms,achieving faster convergence and better solutions.The paper details the RSSO algorithm,discusses its implementation,and presents comparative results that validate its effectiveness in solving complex engineering design challenges.
文摘In this study,the effect of Tin(Sn)addition on the microstructure,mechanical properties,and wear resistance of pure magnesium(Mg)was examined.Mg-Sn alloys were synthesized using stir casting technique with Sn concentrations of 2.5%,5%,and 7.5% by weight.The specimens were prepared as per ASTM standards for their evaluation.Higher Sn concentrations result in a reduced volume fraction of the eutectic phase,while Mg_(2)Sn precipitates are observed in alloys with 5% or more Sn.Scanning electron microscopy(SEM)analysis of the Mg-7.5wt.%Sn alloy reveals the presence of Mg(OH)_(2),with X-ray diffraction(XRD)confirming an oxygen content of 18% by weight.The addition of Sn minimizes casting porosity,enhancing the quality of the alloys.The findings demonstrate a positive correlation between increasing Sn content and enhanced strength and wear resistance.The Mg-7.5wt.%Sn alloy exhibits significantly enhanced tensile properties attributed to grain refinement and the formation of well-defined grain boundaries compared to alloys with lower Sn additions(2.5% and 5%),although a slight reduction in microhardness is observed.Tribological evaluation indicates reduced wear and friction,suggesting better surface performance.This research underscores the complex interplay between Sn content,microstructural evolution,and the resulting mechanical and tribological performance of Mg-Sn alloys.
文摘Nuclear DNA, which is essential for the transmission of genetic information, is constantly damaged by external stresses and is subsequently repaired by the removal of the damaged region, followed by resynthesis of the excised region. Accumulation of DNA damage with failure of repair processes leads to fatal diseases such as cancer. Recent studies have suggested that intra- and extra-nuclear environments play essential roles in DNA damage. However, numerous questions regarding the role of the nuclear mechanical environment in DNA damage remain unanswered. In this study, we investigated the effects of cell confluency (cell crowding) on the morphology of cell nuclei, and cytoskeletal structures, and DNA damage in NIH3T3 skin fibroblasts and HeLa cervical cancer cells. Although nuclear downsizing was observed in both NIH3T3 and HeLa cells with cell crowding, intracellular mechanical changes in the two cell types displayed opposite tendencies. Cell crowding in NIH3T3 cells induced reinforcement of actin filament structures, cell stiffening, and nuclear downsizing, resulting in a significant decrease in endogenous DNA damage, whereas cell crowding in HeLa cells caused partial depolymerization of actin filaments and cell softening, inducing endogenous DNA damage. Ultraviolet (UV) radiation significantly increased DNA damage in NIH3T3;however, this response did not change with cell crowding. In contrast, UV radiation did not cause DNA damage in HeLa cells under either sparse or confluent conditions. These results suggested that cell crowding significantly influenced endogenous DNA damage in cells and was quite different in NIH3T3 and HeLa cells. However, cell crowding did not affect the UV-induced DNA damage in either cell type.
基金supported by the National Research Foundation of Korea(NRF)(No.2021R1C1C2009703)supported by the National Research Foundation of Korea(NRF)Grant funded by the Korea government(MSIT)(RS-2024-00344920)supported by the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)Grant funded by the Ministry of Trade,Industry and Energy of Korea(No.RS2023-00244330)。
文摘With the growing importance of wearable and portable electronics in modern society and industry,researchers from all over the world have reported on advances in energy harvesting and self-powered sensing technologies.The current review discusses recent developments in triboelectric platforms from a manufacturing perspective,including material,design,application,and industrialization.Manufacturing is an essential component of both industry and technology.The use of a proper manufacturing process enables cutting-edge technology in a lab-scale stage to progress to commercialization and popularization with scalability,availability,commercial advantage,and consistent quality.Furthermore,much literature has emphasized that the most powerful advantage of the triboelectric platform is its wide range of available materials and simple working mechanism,both of which are important characteristics in manufacturing engineering.As a result,different manufacturing processes can be implemented as needed.Because the practical process can have a synergetic effect on the fundamental development,resulting in the growth of both,the development of the triboelectric platform from the standpoint of manufacturing engineering can be further advanced.However,research into the development of a productive manufacturing process is still in its early stages in the field of triboelectric platforms.This review looks at the various manufacturing technologies used in previous studies and discusses the potential benefits of the appropriate process for triboelectric platforms.Given its unique strength,which includes a diverse material selection and a simple working mechanism,the triboelectric platform can use a variety of manufacturing technologies and the process can be optimized as needed.Numerous research groups have clearly demonstrated the triboelectric platform's advantages.As a result,using appropriate manufacturing processes can accelerate the technological advancement of triboelectric platforms in a variety of research and industrial fields by allowing them to move beyond the lab-scale fabrication stage.
基金This work has been endorsed by the Chengdu Guangming Paite Precious Metal Co.,Ltd.,the CDGM Glass Co.,Ltd.,China,and the Research Grants Council of Hong Kong Special Administrative Region,China(No.15233823).
文摘Although the existence of glass–glass interfaces(GGIs)enables improved ductility of metallic nanoglasses(NGs),the excess free volumes at GGIs would cause the NGs to have a much-reduced mechanical strength.Herein,entropy-stabilized GGIs have been in-vestigated in Co–Fe–Ni–Zn–P NGs,which have a large entropy of mixing(1.32R,where R is the gas constant)and could be in a new glass phase,different from that of glassy grain interiors.Through quantitatively determining the activation energy of glass transition sep-arately for the GGIs and glassy grain interiors,the excess free volumes at GGIs are found to be reduced in comparison with those in the glassy grain interiors.The thermodynamically stable GGIs could be associated with increasing entropy of mixing in the GGI regions,which stabilizes the atomic structures of GGIs and enhances the glass forming ability of Co–Fe–Ni–Zn–P NGs.The influences of entropy-stabilized GGIs on the mechanical properties of Co–Fe–Ni–Zn–P NGs are further investigated by nanoindentation and creep tests under tensile deformation,demonstrating that there are notable enhancements in the ductility and mechanical strength for Co–Fe–Ni–Zn–P NGs.This work contributes to an in-depth understanding on the GGI phase in NGs and offers an alternative method for strengthening NGs through GGI engineering.
