[Tb4oFe6o（x nm）/Fe49Co49V2（y nm）]N multilayers were prepared by multitarget magnetron sputtering using a rotary turn-table technique in a stop-and-go mode. The mulfilayers were investigated using X-ray diffraction...[Tb4oFe6o（x nm）/Fe49Co49V2（y nm）]N multilayers were prepared by multitarget magnetron sputtering using a rotary turn-table technique in a stop-and-go mode. The mulfilayers were investigated using X-ray diffraction, field emission scan electron microscopy and vibrating sample magnetometry. The result shows that the coercive field drops abruptly with increasing number of bilayers, and it remains generally stable when the number of bilayers is 10 or higher. An excellent magnetic softness with a coercivity of 1.0 mT is obtained for x = 5 and y = 5 after annealing at 250℃. A crystalline state is observed in FeCoV layers before and after annealing by X-ray diffraction.展开更多
The inverse relationship between the saturation magnetic flux density(Bs)and coercivity(Hc)of Febased amorphous alloys is a very active research topic that has been extensively debated.In this work,we conducted a deta...The inverse relationship between the saturation magnetic flux density(Bs)and coercivity(Hc)of Febased amorphous alloys is a very active research topic that has been extensively debated.In this work,we conducted a detailed investigation on the magnetic softness of Fe_(83.2-x)Co_(x)B_(10)C_(6)Cu_(0.8)(x=0 and 6 at.%)amorphous alloys based on analysis of the surface morphology,microstructure,magnetic anisotropy,and magnetic domain structure.Enhanced magnetic softness-magnetization synergy was realized in the present alloys by magnetic field annealing(MFA)during the de-stressing process.A dramatic 84%reduction of Hc to 2.2 A/m was achieved for the Co-doped alloy under MFA,exhibiting excellent magnetic performance with a superb Bs of 1.86 T.The consistency between the experimental results and theoretical analysis revealed that the MFA process can mitigate the trade-off between stress-induced anisotropy and induced uniaxial anisotropy owing to the homogenized structure formed by field annealing.Thus,the process favored a low Hc due to the significant continuous decline in the total magnetic anisotropy,which coincided well with the results of Magneto-optical Kerr microscopy.The study elucidates a mechanism for tuning Hc in Co-doped alloy systems and affords a possible pathway for softening amorphous alloys with high Bs.展开更多
Compared to the commercial soft-magnetic alloys,the high saturation magnetic flux density(Bs)and low coercivity(Hc)of post-developed novel nanocrystalline alloys tend to realize the miniaturization and lightweight of ...Compared to the commercial soft-magnetic alloys,the high saturation magnetic flux density(Bs)and low coercivity(Hc)of post-developed novel nanocrystalline alloys tend to realize the miniaturization and lightweight of electronic products,thus attracting great attention.In this work,we designed a new FeNiBCuSi formulation with a novel atomic ratio,and the microstructure evolution and magnetic softness were investigated.Microstructure analysis revealed that the amount of Si prompted the differential chemical fluctuations of Cu element,favoring the different nucleation and growth processes ofα-Fe nanocrystals.Furthermore,microstructural defects associated with chemical heterogeneities were unveiled using the Maxwell-Voigt model with two Kelvin units and one Maxwell unit based on creeping analysis by nanoindentation.The defect,with a long relaxation time in relaxation spectra,was more likely to induce the formation of crystal nuclei that ultimately evolved into theα-Fe nanocrystals.As a result,Fe_(84)Ni_(2)B_(12.5)Cu_(1)Si_(0.5)alloy with refined uniform nanocrystalline microstructure exhibited excellent magnetic softness,including a high B_(s)of 1.79 T and very low H_(c)of 2.8 A/m.Our finding offers new insight into the influence of activated defects associated with chemical heterogeneities on the microstructures of nanocrystalline alloy with excellent magnetic softness.展开更多
Chemical reactivity towards electron transfer is captured by the Fukui function.However,this is not well defined when the system or its ions have degenerate or pseudo-degenerate ground states.In such a case,the first-...Chemical reactivity towards electron transfer is captured by the Fukui function.However,this is not well defined when the system or its ions have degenerate or pseudo-degenerate ground states.In such a case,the first-order chemical response is not independent of the perturbation and the correct response has to be computed using the mathematical formalism of perturbation theory for degenerate states.Spatialpseudo-degeneracy is ubiquitous in nanostructures with high symmetry and totally extended systems.Given the size of these systems,using degenerate-state perturbation theory is impractical because it requires the calculation of many excited states.Here we present an alternative to compute the chemical response of extended systems using models of local softness in terms of the local density of states.The local softness is approximately equal to the density of states at the Fermi level.However,such approximation leaves out the contribution of inner states.In order to include and weight the contribution of the states around the Fermi level,a model inspired by the long-range behavior of the local softness is presented.Single wall capped carbon nanotubes(SWCCNT)illustrate the limitation of the frontier orbital theory in extended systems.Thus,we have used a C360 SWCCNT to test the proposed model and how it compares with available models based on the local density of states.Interestingly,a simple Hückel approximation captures the main features of chemical response of these systems.Our results suggest that density-of-states models of the softness along simple tight binding Hamiltonians could be used to explore the chemical reactivity of more complex system,such a surfaces and nanoparticles.展开更多
The metallic softness parameterαr 0 determines the structure of the cluster and governs the rule of magic numbers. Using molecular dynamic method, the stable structures and magic numbers are determined for the cluste...The metallic softness parameterαr 0 determines the structure of the cluster and governs the rule of magic numbers. Using molecular dynamic method, the stable structures and magic numbers are determined for the clusters consisting of 13 up to 147 atoms in medium range Morse potentials, which is suitable for most of metals. As the number of atoms constituting the cluster increases, the stable structures undergo transition from face-centered (FC) to edge-centered (EC) structures. The magic number take ones of FC series before transition and take ones of EC series after that. The transition point from FC to EC structures depends on the value of softness parameter.展开更多
The term ＂softness＂ is loosely used to describe the physical as well as sensory attributes of fabric and other textiles, and several psychophysicai evaluation methods as well as its predicting equations exist. Howev...The term ＂softness＂ is loosely used to describe the physical as well as sensory attributes of fabric and other textiles, and several psychophysicai evaluation methods as well as its predicting equations exist. However, the information for physiological mechanism of fabric softness is lack. To explain the blomechauical and the potential neurophysiologicai phecnomenon for exploring fabric softness, accompanying to the procedures in manual exploration for softness and the anatomical multllayor structures of human finer, a contact finite dement （FE） model between finger and fabric is made to conduct an active contact analysis. In present FE model, the effect of surface friction index, compression modulus, Poisson＇s ratio of fabric on softness dlscrimination is Investigated. The interests are in the contributlons of these fabric property variables to contact area, Interracial friction shear stress and contact pressure distributions, which arc significant cognitive variables or stimulus parameters in peripheral neural levels. The mechanistic data for fabric specimens indicates that the basis for the perception of softness of flexible and bulk fabric is likely on the spatial variation of pressure on the skin （or, equivalently the skin displacement and its derivatives） resulting from surface friction phenomenon and compression property of fabric. In present model, however, the effect of Poisson＇s ratio on the total force exerted by fingertip is not significant statistically. Therefore, compression modulus of fabric is, not the only underlying physical variable accounting for peripheral neural response, and also the surface friction phenomenon plays an important role in feeltouch softness of fabric, i.e. the compressibility and surface properties of fabric arc the necessary physical variables involved for the haptic rendering of its softness.展开更多
Simulating the softness property of object is quite a challenge in virtual reality system. A novel softness display system was developed based on the principle of deformable length of elastic element control （DLEEC）...Simulating the softness property of object is quite a challenge in virtual reality system. A novel softness display system was developed based on the principle of deformable length of elastic element control （DLEEC）. In the system, the equivalent stiffness of the device is adjustable, and is inversely proportional to the third power of the deformable length of elastic beam. PD position control is employed to guarantee the accurate softness display. The softness of the virtual objects in large scale can be felt with the softness display device. Compared with other haptic devices, the device is passive and exert the react force only when the operator ＂actively touch＂ the virtual objects. The stability of the softness display system was analyzed. It was theoretical proved that the system satisfied the criteria of wide impedance range ＂Z-width＂, and the performance was superior to an active system. The experimental results were presented.展开更多
Fe-based amorphous alloys with high saturation magnetic flux density(B_(s))are increasingly attractive from both scientific and technological points of view,however,they usually suffer from the trade-off between magne...Fe-based amorphous alloys with high saturation magnetic flux density(B_(s))are increasingly attractive from both scientific and technological points of view,however,they usually suffer from the trade-off between magnetization and softness.In this work,we explore the soft magnetic properties(SMPs),magnetic and atomic structures,and defect activation during creep deformation of as-quenched and annealed Fe_(82.65-x)Co_(x)Si_(2)B_(14)Cu_(1.35)(x=0-20)amorphous alloys(AAs).Improved magnetic softness-magnetization synergy has been realized in all these alloys by field annealing.Particularly,superb SMPs with superhigh B_(s) of 1.86 T,low coercivity of 1.2 A/m and high effective permeability of 16300 are obtained in the Fe_(66.65)Co_(16)Si_(2)B_(14)Cu_(1.35) AA.The locally regularized arrangement of domains,homogenized structure with less structural/magnetic defects and suppressed crystal-like ordering by field annealing contribute synergistically to the superb SMPs.Besides,the relaxation time spectra obtained from creep deformation indicate less liquid-like and solid-like defects activated in the field-annealed AA,which is correlated with the structural homogenization and superb SMPs.This work provides new and comprehensive insight into the interplay among external field,heterogeneous structure,SMPs and defect activation of Fe-based AAs,and offers a promising pathway for softening amorphous alloys with high Bs.展开更多
Haloacetamides（HAMs） are cytotoxic, genotoxic, and mutagenic byproducts of drinking water disinfection. They are soft electrophilic compounds that form covalent bonds with the free thiol/thiolate in cysteine residue...Haloacetamides（HAMs） are cytotoxic, genotoxic, and mutagenic byproducts of drinking water disinfection. They are soft electrophilic compounds that form covalent bonds with the free thiol/thiolate in cysteine residues through an S_N2 reaction mechanism.Toxicity of the monohalogenated HAMs（iodoacetamide, IAM; bromoacetamide, BAM;or chloroacetamide, CAM） varied depending on the halogen substituent. The aim of this research was to investigate how the halogen atom affects the reactivity and toxicological properties of HAMs, measured as induction of oxidative/electrophilic stress response and genotoxicity. Additionally, we wanted to determine how well in silico estimates of electrophilic softness matched thiol/thiolate reactivity and in vitro toxicological endpoints.Each of the HAMs significantly induced nuclear Rad51 accumulation and ARE signaling activity compared to a negative control. The rank order of effect was IAM 〉 BAM 〉 CAM for Rad51, and BAM ≈ IAM 〉 CAM for ARE. In general, electrophilic softness and in chemico thiol/thiolate reactivity provided a qualitative indicator of toxicity, as the softer electrophiles IAM and BAM were more thiol/thiolate reactive and were more toxic than CAM.展开更多
The contact line pinning and supersaturation theory for the nanobubble stability has attracted extensive concerns from experimental investigators,and some experimenters argue that the contact line pinning is unnecessa...The contact line pinning and supersaturation theory for the nanobubble stability has attracted extensive concerns from experimental investigators,and some experimenters argue that the contact line pinning is unnecessary.To interpret the experimental observations,we have proposed previously through molecular dynamics simulations that the deformation of soft substrates caused by surface nanobubbles may play an important role in stabilizing surface nanobubbles,while yet no quantitative theory is available for explanation of this mechanism.Here,the detailed mechanism of self-pinning-induced stability of surface nanobubbles is investigated through theoretical analysis.By manipulating substrate softness,we find that the formation of surface nanobubbles may create a deformation ridge nearby their contact lines which leads to the self-pinning effect.Theoretical analysis shows that the formation of nanobubbles on sufficiently rigid substrates or on liquid-liquid interfaces corresponds to a local free energy maximum,while that on the substrates with intermediate softness corresponds to a local minimum.Thus,the substrate softness could regulate the surface nanobubble stability.The critical condition for the self-pinning effect is determined based on contact line depinning,and the effect of gas supersaturation is explored.Finally,the approximate stability range for the surface nanobubbles is also predicted.展开更多
Aiming at the problem of difficult contact finishing for mini structural surface in course of mould manufacturing,a new no-tool precision machining method based on soft abrasive flow machining(SAFM)was proposed.It all...Aiming at the problem of difficult contact finishing for mini structural surface in course of mould manufacturing,a new no-tool precision machining method based on soft abrasive flow machining(SAFM)was proposed.It allocated restrained component near surface machined,constituted restrained abrasive flow passage,and made the surface become a segment of passage wall.It could control turbulence abrasive flow in restrained passage,realize micro cutting for passage wall,and utilize the irregular motion of abrasive flow to eliminate the mono-directional marks on machined surfaces,and the precision could reach the specular level.A two-phase dynamic model of abrasive flow oriented to SAFM combined with discrete phase model(DPM)was established,the law of two-phase flow motion and the related physical parameters was obtained by corresponding numerical simulation method,and the mechanism of precision machining in SAFM was discussed.Simulation results show that the abrasive flow machining process mainly appears as translation of ablating location with the influence by granular pressure,and as the variation of machining efficiency with the influence by near-wall particle velocity.Thus via control of the inlet velocity and its corresponding machining time,it is supposed to work out the machining process according to the machining requirements by using the Preston equation to seek the relationship among velocity,pressure and material removing rate.By tracking near-wall particles,it can be confirmed that the movement of near-wall abrasive particles is similar to stream-wise vortices.The cutting traces on workpiece surfaces assume disorderly arrangement,so the feasibility of the SAFM method can be reaffirmed.展开更多
Indium selenide(InSe)crystals are reported to show exceptional plasticity,a new property to twodimensional van der Waals(2D vdW)semiconductors.However,the correlation between plasticity and specific prototypes is uncl...Indium selenide(InSe)crystals are reported to show exceptional plasticity,a new property to twodimensional van der Waals(2D vdW)semiconductors.However,the correlation between plasticity and specific prototypes is unclear,and the understanding of detailed plastic deformation mechanisms is inadequate.Here three prototypes of InSe are predicted to be plastically deformable by calculation,and the plasticity of polymorphic crystals is verified by experiment.Moreover,distinct nanoindentation behaviors are seen on the cleavage and cross-section surfaces.The modulus and hardness of InSe are the lowest ones among a large variety of materials.The plastic deformation is further perceived from chemical interactions during the slip process.Particularly for the cross-layer slip,the initial In-Se bonds break while new In-In and Se-Se bonds are newly formed,maintaining a decent interaction strength.The remarkable plasticity and softness alongside the novel physical properties,endow InSe great promise for application in deformable and flexible electronics.展开更多
Soft magnetic alloys are extensively used in various power electronic devices due to their advantageous properties,including high saturation magnetic induction,low coercivity,and high permeability.In certain applicati...Soft magnetic alloys are extensively used in various power electronic devices due to their advantageous properties,including high saturation magnetic induction,low coercivity,and high permeability.In certain applications,complex-shaped components are increasingly required for performance enhancement.Additive manufacturing technique,particularly selective laser melting(SLM),has emerged as an effective method for fabricating such complex-shaped soft magnetic components.SLM,a laserbased additive manufacturing technique,employs high-power-density lasers to melt and fuse metal powders within a powder bed selectively.This approach enables rapid prototyping,precise geometrical control,and the integration of multi-material designs.This review highlights recent advancements in the application of SLM technique for the production of soft magnetic alloys,focusing on Fe-Si,Fe-Ni,Fe-Co,and amorphous alloy systems.Moreover,it explores the implementation of SLM in manufacturing processes and evaluates both the opportunities and challenges associated with SLM-based production of soft magnetic alloys.展开更多
The properties of γ instability in rapidly rotating even-even132-138 Nd isotopes have been investigated using the pairing-deformation self-consistent total-Routhian-surface calculations in a deformation space of（β...The properties of γ instability in rapidly rotating even-even132-138 Nd isotopes have been investigated using the pairing-deformation self-consistent total-Routhian-surface calculations in a deformation space of（β2, γ,β4）. It is found that even-even134-138 Nd nuclei exhibit triaxiality in both ground and excited states, even up to high-spin states. The lightest isotope possesses a well-deformed prolate shape without a γ deformation component.The current numerical results are compared with previous calculations and available observables such as quadrupole deformation β2 and the feature of γ-band levels, showing basically a general agreement with the observed trend ofγ correlations（e.g. the pattern of the odd-even energy staggering of the γ band）. The existing differences between theory and experiment are analyzed and discussed briefly.展开更多
Soft-tissue motion introduces significant challenges in robotic teleoperation,especially in medical scenarios where precise target tracking is critical.Latency across sensing,computation,and actuation chains leads to ...Soft-tissue motion introduces significant challenges in robotic teleoperation,especially in medical scenarios where precise target tracking is critical.Latency across sensing,computation,and actuation chains leads to degraded tracking performance,particularly around high-acceleration segments and trajectory inflection points.This study investigates machine learning-based predictive compensation for latency mitigation in soft-tissue tracking.Three models—autoregressive(AR),long short-term memory(LSTM),and temporal convolutional network(TCN)—were implemented and evaluated on both synthetic and real datasets.By aligning the prediction horizon with the end-to-end system delay,we demonstrate that prediction-based compensation significantly reduces tracking errors.Among the models,TCN achieved superior robustness and accuracy on complex motion patterns,particularly in multi-step prediction tasks,and exhibited better latency–horizon compatibility.The results suggest that TCN is a promising candidate for real-time latency compensation in teleoperated robotic systems involving dynamic soft-tissue interaction.展开更多
This paper develops a semi-analytical solution for pile penetration in natural soft clays using the strain path method(SPM).The stress-strain behavior of soils is characterized by the S-CLAY1S model,which can capture ...This paper develops a semi-analytical solution for pile penetration in natural soft clays using the strain path method(SPM).The stress-strain behavior of soils is characterized by the S-CLAY1S model,which can capture the anisotropic evolution and destructuring nature of soft clays.By integrating the S-CLAY1S model into the theoretical framework of the SPM,a set of ordinary differential equations is formulated with respect to the vertical coordinate of soil particles.The distribution of excess pore water pressure(EPWP)following pile installation is approximated through one-dimensional(1D)radial integration around the pile shaft.The distribution of stresses and EPWP,along with the evolution of fabric anisotropy within the soil surrounding the pile,is presented to illustrate the response of pile penetration in natural soft clays.The proposed solution is validated against existing theoretical solutions using the SPM and cavity expansion method(CEM),along with experimental data.The findings demonstrate that the SPM reveals lower radial effective stresses and EPWP at the pile shaft than that of CEM.Pile penetration alters the soil's anisotropic properties,inducing rotational hardening and affecting post-installation stress distribution.Soil destructuration eliminates bonding among particles near the pile,resulting in a complete disruption of soil structure at the pile surface,which is particularly pronounced for higher initial soil structure ratios.Minimal variation was observed in the three principal stresses and shear stress on the cone side surface as the angle increased from 18°to 60°,except for a slight reduction in EPWP.展开更多
Polyurethane elastomers exhibit high dielectric constants owing to their polar groups,and can be used as energy storage capacitors.Energy storage depends not only on the dielectric constant but also on the dielectric ...Polyurethane elastomers exhibit high dielectric constants owing to their polar groups,and can be used as energy storage capacitors.Energy storage depends not only on the dielectric constant but also on the dielectric loss.However,the relationship between chain structure and dielectric properties is not yet clear.Ketal-containing crosslinked polyurethane elastomers were prepared using cyclic ketal diol as a chain extender.The effect of the soft segment length on the dielectric properties and energy storage was investigated.The cause of the change in the dipolar polarization with the soft segment length was analyzed.As the soft segment length increased,the hard-soft hydrogen bonding decreased,whereas the hard-hard hydrogen bonding increased.Under the action of an electric field,the polar bonds in the ketal-containing polyurethane elastomer overcome the hydrogen bonding between hard-soft segments to produce polarization;meanwhile,they also experience crankshaft motions to generate polarization.The former has a relatively high relaxation activation energy of approximately 10-20 k J·mol^(-1),resulting in a large dielectric loss.The latter has a relatively low relaxation activation energy,approximately 0.7-1.7 kJ·mol^(-1),leading to low dielectric loss.As a result,the dielectric constant showed a decreasing trend,and the dielectric loss gradually decreased.This study provides a theoretical foundation for improving the dielectric properties of polyurethane elastomers.展开更多
A Tibetan art form bridges the past and present and connects cultures around the world.THANGKA,a unique form of Tibetan sacred painting,is gaining prominence globally due to its vibrant colors,exquisite craftsmanship,...A Tibetan art form bridges the past and present and connects cultures around the world.THANGKA,a unique form of Tibetan sacred painting,is gaining prominence globally due to its vibrant colors,exquisite craftsmanship,and profound religious and cultural significance.With the acceleration of globalization,this symbol of Tibetan culture that combines artistic expression with spirituality has become a bridge for cultural exchange between the East and the West.Recently,China Today spoke to Yixi Puncog,art collector and council member of the China Association for Preservation and Development of Tibetan Culture,to learn more about Thangka art,its role in international exchange,and how it is enhancing China’s cultural soft power.展开更多
Conductive elastomers combining micromechanical sensitivity,lightweight adaptability,and environmental sustainability are critically needed for advanced flexible electronics requiring precise responsiveness and long-t...Conductive elastomers combining micromechanical sensitivity,lightweight adaptability,and environmental sustainability are critically needed for advanced flexible electronics requiring precise responsiveness and long-term wearability;however,the integration of these properties remains a significant challenge.Here,we present a biomass-derived conductive elastomer featuring a rationally engineered dynamic crosslinked network integrated with a tunable microporous architecture.This structural design imparts pronounced micromechanical sensitivity,an ultralow density(~0.25 g cm^(−3)),and superior mechanical compliance for adaptive deformation.Moreover,the unique micro-spring effect derived from the porous architecture ensures exceptional stretchability(>500%elongation at break)and superior resilience,delivering immediate and stable electrical response under both subtle(<1%)and large(>200%)mechanical stimuli.Intrinsic dynamic interactions endow the elastomer with efficient room temperature self-healing and complete recyclability without compromising performance.First-principles simulations clarify the mechanisms behind micropore formation and the resulting functionality.Beyond its facile and mild fabrication process,this work establishes a scalable route toward high-performance,sustainable conductive elastomers tailored for next-generation soft electronics.展开更多
基金supported by the National Natural Science Foundation of China (No. 50871007)the Research Fund for the Doctoral Program of Higher Education of China
文摘[Tb4oFe6o（x nm）/Fe49Co49V2（y nm）]N multilayers were prepared by multitarget magnetron sputtering using a rotary turn-table technique in a stop-and-go mode. The mulfilayers were investigated using X-ray diffraction, field emission scan electron microscopy and vibrating sample magnetometry. The result shows that the coercive field drops abruptly with increasing number of bilayers, and it remains generally stable when the number of bilayers is 10 or higher. An excellent magnetic softness with a coercivity of 1.0 mT is obtained for x = 5 and y = 5 after annealing at 250℃. A crystalline state is observed in FeCoV layers before and after annealing by X-ray diffraction.
基金supported by the Anhui Provincial Natural Science Foundation(No.2208085QE121)the Key Research&Development plan of Anhui Province(No.2022a05020016)+2 种基金the University Natural Science Research Project of Anhui Province(No.2023AH051084)the National Natural Science Foundation of China(No.52071078)the“Zhishan”Scholars Programs of Southeast University(No.2242021R41158).
文摘The inverse relationship between the saturation magnetic flux density(Bs)and coercivity(Hc)of Febased amorphous alloys is a very active research topic that has been extensively debated.In this work,we conducted a detailed investigation on the magnetic softness of Fe_(83.2-x)Co_(x)B_(10)C_(6)Cu_(0.8)(x=0 and 6 at.%)amorphous alloys based on analysis of the surface morphology,microstructure,magnetic anisotropy,and magnetic domain structure.Enhanced magnetic softness-magnetization synergy was realized in the present alloys by magnetic field annealing(MFA)during the de-stressing process.A dramatic 84%reduction of Hc to 2.2 A/m was achieved for the Co-doped alloy under MFA,exhibiting excellent magnetic performance with a superb Bs of 1.86 T.The consistency between the experimental results and theoretical analysis revealed that the MFA process can mitigate the trade-off between stress-induced anisotropy and induced uniaxial anisotropy owing to the homogenized structure formed by field annealing.Thus,the process favored a low Hc due to the significant continuous decline in the total magnetic anisotropy,which coincided well with the results of Magneto-optical Kerr microscopy.The study elucidates a mechanism for tuning Hc in Co-doped alloy systems and affords a possible pathway for softening amorphous alloys with high Bs.
基金Project supported by the Anhui Provincial Natural Science Foundation(Grant No.2208085QE121)the Key Research&Development Plan of Anhui Province(Grant No.2022a05020016)+1 种基金the University Natural Science Research Project of Anhui Province(Grant No.2023AH051084)the National Natural Science Foundation of China(Grant No.52071078)。
文摘Compared to the commercial soft-magnetic alloys,the high saturation magnetic flux density(Bs)and low coercivity(Hc)of post-developed novel nanocrystalline alloys tend to realize the miniaturization and lightweight of electronic products,thus attracting great attention.In this work,we designed a new FeNiBCuSi formulation with a novel atomic ratio,and the microstructure evolution and magnetic softness were investigated.Microstructure analysis revealed that the amount of Si prompted the differential chemical fluctuations of Cu element,favoring the different nucleation and growth processes ofα-Fe nanocrystals.Furthermore,microstructural defects associated with chemical heterogeneities were unveiled using the Maxwell-Voigt model with two Kelvin units and one Maxwell unit based on creeping analysis by nanoindentation.The defect,with a long relaxation time in relaxation spectra,was more likely to induce the formation of crystal nuclei that ultimately evolved into theα-Fe nanocrystals.As a result,Fe_(84)Ni_(2)B_(12.5)Cu_(1)Si_(0.5)alloy with refined uniform nanocrystalline microstructure exhibited excellent magnetic softness,including a high B_(s)of 1.79 T and very low H_(c)of 2.8 A/m.Our finding offers new insight into the influence of activated defects associated with chemical heterogeneities on the microstructures of nanocrystalline alloy with excellent magnetic softness.
基金FONDECYT grants 1140313 and 11150164.CC and PFFinanciamiento Basal para CentrosCientíficos y Tecnológicos de Excelencia-FB0807+2 种基金project RC-130006 CILISthe Fondo de Innovación para la Competitividad del Ministeriode Economía,Fomento y Turismo de Chile.MMCONICYT through grant 21130691.
文摘Chemical reactivity towards electron transfer is captured by the Fukui function.However,this is not well defined when the system or its ions have degenerate or pseudo-degenerate ground states.In such a case,the first-order chemical response is not independent of the perturbation and the correct response has to be computed using the mathematical formalism of perturbation theory for degenerate states.Spatialpseudo-degeneracy is ubiquitous in nanostructures with high symmetry and totally extended systems.Given the size of these systems,using degenerate-state perturbation theory is impractical because it requires the calculation of many excited states.Here we present an alternative to compute the chemical response of extended systems using models of local softness in terms of the local density of states.The local softness is approximately equal to the density of states at the Fermi level.However,such approximation leaves out the contribution of inner states.In order to include and weight the contribution of the states around the Fermi level,a model inspired by the long-range behavior of the local softness is presented.Single wall capped carbon nanotubes(SWCCNT)illustrate the limitation of the frontier orbital theory in extended systems.Thus,we have used a C360 SWCCNT to test the proposed model and how it compares with available models based on the local density of states.Interestingly,a simple Hückel approximation captures the main features of chemical response of these systems.Our results suggest that density-of-states models of the softness along simple tight binding Hamiltonians could be used to explore the chemical reactivity of more complex system,such a surfaces and nanoparticles.
基金Supported by the National Natural Science Foundation of China(196 740 42 198340 70 ) Science and Technology Program of Natio
文摘The metallic softness parameterαr 0 determines the structure of the cluster and governs the rule of magic numbers. Using molecular dynamic method, the stable structures and magic numbers are determined for the clusters consisting of 13 up to 147 atoms in medium range Morse potentials, which is suitable for most of metals. As the number of atoms constituting the cluster increases, the stable structures undergo transition from face-centered (FC) to edge-centered (EC) structures. The magic number take ones of FC series before transition and take ones of EC series after that. The transition point from FC to EC structures depends on the value of softness parameter.
基金Supported by The National Natural Science Foundation (No.30270339)
文摘The term ＂softness＂ is loosely used to describe the physical as well as sensory attributes of fabric and other textiles, and several psychophysicai evaluation methods as well as its predicting equations exist. However, the information for physiological mechanism of fabric softness is lack. To explain the blomechauical and the potential neurophysiologicai phecnomenon for exploring fabric softness, accompanying to the procedures in manual exploration for softness and the anatomical multllayor structures of human finer, a contact finite dement （FE） model between finger and fabric is made to conduct an active contact analysis. In present FE model, the effect of surface friction index, compression modulus, Poisson＇s ratio of fabric on softness dlscrimination is Investigated. The interests are in the contributlons of these fabric property variables to contact area, Interracial friction shear stress and contact pressure distributions, which arc significant cognitive variables or stimulus parameters in peripheral neural levels. The mechanistic data for fabric specimens indicates that the basis for the perception of softness of flexible and bulk fabric is likely on the spatial variation of pressure on the skin （or, equivalently the skin displacement and its derivatives） resulting from surface friction phenomenon and compression property of fabric. In present model, however, the effect of Poisson＇s ratio on the total force exerted by fingertip is not significant statistically. Therefore, compression modulus of fabric is, not the only underlying physical variable accounting for peripheral neural response, and also the surface friction phenomenon plays an important role in feeltouch softness of fabric, i.e. the compressibility and surface properties of fabric arc the necessary physical variables involved for the haptic rendering of its softness.
基金Supported by the National Basic Research and Development Program （No. 2002CB312102） and the National Natural Science Foundation of China （No. 60643007, 60475034）.
文摘Simulating the softness property of object is quite a challenge in virtual reality system. A novel softness display system was developed based on the principle of deformable length of elastic element control （DLEEC）. In the system, the equivalent stiffness of the device is adjustable, and is inversely proportional to the third power of the deformable length of elastic beam. PD position control is employed to guarantee the accurate softness display. The softness of the virtual objects in large scale can be felt with the softness display device. Compared with other haptic devices, the device is passive and exert the react force only when the operator ＂actively touch＂ the virtual objects. The stability of the softness display system was analyzed. It was theoretical proved that the system satisfied the criteria of wide impedance range ＂Z-width＂, and the performance was superior to an active system. The experimental results were presented.
基金financially supported by the National Natural Science Foundation of China(Nos.51631003 and 51971061)。
文摘Fe-based amorphous alloys with high saturation magnetic flux density(B_(s))are increasingly attractive from both scientific and technological points of view,however,they usually suffer from the trade-off between magnetization and softness.In this work,we explore the soft magnetic properties(SMPs),magnetic and atomic structures,and defect activation during creep deformation of as-quenched and annealed Fe_(82.65-x)Co_(x)Si_(2)B_(14)Cu_(1.35)(x=0-20)amorphous alloys(AAs).Improved magnetic softness-magnetization synergy has been realized in all these alloys by field annealing.Particularly,superb SMPs with superhigh B_(s) of 1.86 T,low coercivity of 1.2 A/m and high effective permeability of 16300 are obtained in the Fe_(66.65)Co_(16)Si_(2)B_(14)Cu_(1.35) AA.The locally regularized arrangement of domains,homogenized structure with less structural/magnetic defects and suppressed crystal-like ordering by field annealing contribute synergistically to the superb SMPs.Besides,the relaxation time spectra obtained from creep deformation indicate less liquid-like and solid-like defects activated in the field-annealed AA,which is correlated with the structural homogenization and superb SMPs.This work provides new and comprehensive insight into the interplay among external field,heterogeneous structure,SMPs and defect activation of Fe-based AAs,and offers a promising pathway for softening amorphous alloys with high Bs.
基金partial support from the U.S.Army Engineer Research and Development Center and the Army Environmental Quality Technology program, CESU W9132T-16-2-0005 (MJP)partly supported by the interagency agreement IAG #NTR 12003 from the National Institute of Environmental Health Sciences/Division of the National Toxicology Program to the National Center for Advancing Translational Sciences, National Institutes of Health
文摘Haloacetamides（HAMs） are cytotoxic, genotoxic, and mutagenic byproducts of drinking water disinfection. They are soft electrophilic compounds that form covalent bonds with the free thiol/thiolate in cysteine residues through an S_N2 reaction mechanism.Toxicity of the monohalogenated HAMs（iodoacetamide, IAM; bromoacetamide, BAM;or chloroacetamide, CAM） varied depending on the halogen substituent. The aim of this research was to investigate how the halogen atom affects the reactivity and toxicological properties of HAMs, measured as induction of oxidative/electrophilic stress response and genotoxicity. Additionally, we wanted to determine how well in silico estimates of electrophilic softness matched thiol/thiolate reactivity and in vitro toxicological endpoints.Each of the HAMs significantly induced nuclear Rad51 accumulation and ARE signaling activity compared to a negative control. The rank order of effect was IAM 〉 BAM 〉 CAM for Rad51, and BAM ≈ IAM 〉 CAM for ARE. In general, electrophilic softness and in chemico thiol/thiolate reactivity provided a qualitative indicator of toxicity, as the softer electrophiles IAM and BAM were more thiol/thiolate reactive and were more toxic than CAM.
基金supported by the National Natural Science Foundation of China(No.21978007)。
文摘The contact line pinning and supersaturation theory for the nanobubble stability has attracted extensive concerns from experimental investigators,and some experimenters argue that the contact line pinning is unnecessary.To interpret the experimental observations,we have proposed previously through molecular dynamics simulations that the deformation of soft substrates caused by surface nanobubbles may play an important role in stabilizing surface nanobubbles,while yet no quantitative theory is available for explanation of this mechanism.Here,the detailed mechanism of self-pinning-induced stability of surface nanobubbles is investigated through theoretical analysis.By manipulating substrate softness,we find that the formation of surface nanobubbles may create a deformation ridge nearby their contact lines which leads to the self-pinning effect.Theoretical analysis shows that the formation of nanobubbles on sufficiently rigid substrates or on liquid-liquid interfaces corresponds to a local free energy maximum,while that on the substrates with intermediate softness corresponds to a local minimum.Thus,the substrate softness could regulate the surface nanobubble stability.The critical condition for the self-pinning effect is determined based on contact line depinning,and the effect of gas supersaturation is explored.Finally,the approximate stability range for the surface nanobubbles is also predicted.
基金supported by the National Natural Science Foundation of China(Grant Nos.50875242,50905163)Key Project of Natural Science Foundation of Zhejiang Province(Grant Nos.Z107517,Y1090836)
文摘Aiming at the problem of difficult contact finishing for mini structural surface in course of mould manufacturing,a new no-tool precision machining method based on soft abrasive flow machining(SAFM)was proposed.It allocated restrained component near surface machined,constituted restrained abrasive flow passage,and made the surface become a segment of passage wall.It could control turbulence abrasive flow in restrained passage,realize micro cutting for passage wall,and utilize the irregular motion of abrasive flow to eliminate the mono-directional marks on machined surfaces,and the precision could reach the specular level.A two-phase dynamic model of abrasive flow oriented to SAFM combined with discrete phase model(DPM)was established,the law of two-phase flow motion and the related physical parameters was obtained by corresponding numerical simulation method,and the mechanism of precision machining in SAFM was discussed.Simulation results show that the abrasive flow machining process mainly appears as translation of ablating location with the influence by granular pressure,and as the variation of machining efficiency with the influence by near-wall particle velocity.Thus via control of the inlet velocity and its corresponding machining time,it is supposed to work out the machining process according to the machining requirements by using the Preston equation to seek the relationship among velocity,pressure and material removing rate.By tracking near-wall particles,it can be confirmed that the movement of near-wall abrasive particles is similar to stream-wise vortices.The cutting traces on workpiece surfaces assume disorderly arrangement,so the feasibility of the SAFM method can be reaffirmed.
基金the National Natural Science Foundation of China(T2122013,52232010)the Basic Research Project of the Shanghai Science and Technology Committee(20JC1415100)。
文摘Indium selenide(InSe)crystals are reported to show exceptional plasticity,a new property to twodimensional van der Waals(2D vdW)semiconductors.However,the correlation between plasticity and specific prototypes is unclear,and the understanding of detailed plastic deformation mechanisms is inadequate.Here three prototypes of InSe are predicted to be plastically deformable by calculation,and the plasticity of polymorphic crystals is verified by experiment.Moreover,distinct nanoindentation behaviors are seen on the cleavage and cross-section surfaces.The modulus and hardness of InSe are the lowest ones among a large variety of materials.The plastic deformation is further perceived from chemical interactions during the slip process.Particularly for the cross-layer slip,the initial In-Se bonds break while new In-In and Se-Se bonds are newly formed,maintaining a decent interaction strength.The remarkable plasticity and softness alongside the novel physical properties,endow InSe great promise for application in deformable and flexible electronics.
基金National Natural Science Foundation of China(52171191,52371198)Project of Constructing National Independent Innovation Demonstration Zones(XM2024XTGXQ05)。
文摘Soft magnetic alloys are extensively used in various power electronic devices due to their advantageous properties,including high saturation magnetic induction,low coercivity,and high permeability.In certain applications,complex-shaped components are increasingly required for performance enhancement.Additive manufacturing technique,particularly selective laser melting(SLM),has emerged as an effective method for fabricating such complex-shaped soft magnetic components.SLM,a laserbased additive manufacturing technique,employs high-power-density lasers to melt and fuse metal powders within a powder bed selectively.This approach enables rapid prototyping,precise geometrical control,and the integration of multi-material designs.This review highlights recent advancements in the application of SLM technique for the production of soft magnetic alloys,focusing on Fe-Si,Fe-Ni,Fe-Co,and amorphous alloy systems.Moreover,it explores the implementation of SLM in manufacturing processes and evaluates both the opportunities and challenges associated with SLM-based production of soft magnetic alloys.
基金Supported by National Natural Science Foundation of China(10805040,11175217)Foundation and Advanced Technology Research Program of Henan Province(132300410125)S&T Research Key Program of Henan Province Education Department(13A140667)
文摘The properties of γ instability in rapidly rotating even-even132-138 Nd isotopes have been investigated using the pairing-deformation self-consistent total-Routhian-surface calculations in a deformation space of（β2, γ,β4）. It is found that even-even134-138 Nd nuclei exhibit triaxiality in both ground and excited states, even up to high-spin states. The lightest isotope possesses a well-deformed prolate shape without a γ deformation component.The current numerical results are compared with previous calculations and available observables such as quadrupole deformation β2 and the feature of γ-band levels, showing basically a general agreement with the observed trend ofγ correlations（e.g. the pattern of the odd-even energy staggering of the γ band）. The existing differences between theory and experiment are analyzed and discussed briefly.
基金Support by Sichuan Science and Technology Program[2023YFSY0026,2023YFH0004]Guangzhou Huashang University[2024HSZD01,HS2023JYSZH01].
文摘Soft-tissue motion introduces significant challenges in robotic teleoperation,especially in medical scenarios where precise target tracking is critical.Latency across sensing,computation,and actuation chains leads to degraded tracking performance,particularly around high-acceleration segments and trajectory inflection points.This study investigates machine learning-based predictive compensation for latency mitigation in soft-tissue tracking.Three models—autoregressive(AR),long short-term memory(LSTM),and temporal convolutional network(TCN)—were implemented and evaluated on both synthetic and real datasets.By aligning the prediction horizon with the end-to-end system delay,we demonstrate that prediction-based compensation significantly reduces tracking errors.Among the models,TCN achieved superior robustness and accuracy on complex motion patterns,particularly in multi-step prediction tasks,and exhibited better latency–horizon compatibility.The results suggest that TCN is a promising candidate for real-time latency compensation in teleoperated robotic systems involving dynamic soft-tissue interaction.
基金support from the National Natural Science Foundation of China(Grant No.42407256)the State Key Laboratory of Hydraulics and Mountain River Engineering,China(Grant No.SKHL2113)the Sichuan Science and Technology Program(Grant No.2024YFHZ0341).
文摘This paper develops a semi-analytical solution for pile penetration in natural soft clays using the strain path method(SPM).The stress-strain behavior of soils is characterized by the S-CLAY1S model,which can capture the anisotropic evolution and destructuring nature of soft clays.By integrating the S-CLAY1S model into the theoretical framework of the SPM,a set of ordinary differential equations is formulated with respect to the vertical coordinate of soil particles.The distribution of excess pore water pressure(EPWP)following pile installation is approximated through one-dimensional(1D)radial integration around the pile shaft.The distribution of stresses and EPWP,along with the evolution of fabric anisotropy within the soil surrounding the pile,is presented to illustrate the response of pile penetration in natural soft clays.The proposed solution is validated against existing theoretical solutions using the SPM and cavity expansion method(CEM),along with experimental data.The findings demonstrate that the SPM reveals lower radial effective stresses and EPWP at the pile shaft than that of CEM.Pile penetration alters the soil's anisotropic properties,inducing rotational hardening and affecting post-installation stress distribution.Soil destructuration eliminates bonding among particles near the pile,resulting in a complete disruption of soil structure at the pile surface,which is particularly pronounced for higher initial soil structure ratios.Minimal variation was observed in the three principal stresses and shear stress on the cone side surface as the angle increased from 18°to 60°,except for a slight reduction in EPWP.
基金financially supported by the Hubei Key Laboratory of Pollutant Analysis&Reuse Technology(No.PA230102)。
文摘Polyurethane elastomers exhibit high dielectric constants owing to their polar groups,and can be used as energy storage capacitors.Energy storage depends not only on the dielectric constant but also on the dielectric loss.However,the relationship between chain structure and dielectric properties is not yet clear.Ketal-containing crosslinked polyurethane elastomers were prepared using cyclic ketal diol as a chain extender.The effect of the soft segment length on the dielectric properties and energy storage was investigated.The cause of the change in the dipolar polarization with the soft segment length was analyzed.As the soft segment length increased,the hard-soft hydrogen bonding decreased,whereas the hard-hard hydrogen bonding increased.Under the action of an electric field,the polar bonds in the ketal-containing polyurethane elastomer overcome the hydrogen bonding between hard-soft segments to produce polarization;meanwhile,they also experience crankshaft motions to generate polarization.The former has a relatively high relaxation activation energy of approximately 10-20 k J·mol^(-1),resulting in a large dielectric loss.The latter has a relatively low relaxation activation energy,approximately 0.7-1.7 kJ·mol^(-1),leading to low dielectric loss.As a result,the dielectric constant showed a decreasing trend,and the dielectric loss gradually decreased.This study provides a theoretical foundation for improving the dielectric properties of polyurethane elastomers.
文摘A Tibetan art form bridges the past and present and connects cultures around the world.THANGKA,a unique form of Tibetan sacred painting,is gaining prominence globally due to its vibrant colors,exquisite craftsmanship,and profound religious and cultural significance.With the acceleration of globalization,this symbol of Tibetan culture that combines artistic expression with spirituality has become a bridge for cultural exchange between the East and the West.Recently,China Today spoke to Yixi Puncog,art collector and council member of the China Association for Preservation and Development of Tibetan Culture,to learn more about Thangka art,its role in international exchange,and how it is enhancing China’s cultural soft power.
基金supported by National Natural Science Foundation of China(No.52103044)Double First-Class Initiative University of Science and Technology of China(KY2400000037)the Young Talent Programme(GG2400007009).
文摘Conductive elastomers combining micromechanical sensitivity,lightweight adaptability,and environmental sustainability are critically needed for advanced flexible electronics requiring precise responsiveness and long-term wearability;however,the integration of these properties remains a significant challenge.Here,we present a biomass-derived conductive elastomer featuring a rationally engineered dynamic crosslinked network integrated with a tunable microporous architecture.This structural design imparts pronounced micromechanical sensitivity,an ultralow density(~0.25 g cm^(−3)),and superior mechanical compliance for adaptive deformation.Moreover,the unique micro-spring effect derived from the porous architecture ensures exceptional stretchability(>500%elongation at break)and superior resilience,delivering immediate and stable electrical response under both subtle(<1%)and large(>200%)mechanical stimuli.Intrinsic dynamic interactions endow the elastomer with efficient room temperature self-healing and complete recyclability without compromising performance.First-principles simulations clarify the mechanisms behind micropore formation and the resulting functionality.Beyond its facile and mild fabrication process,this work establishes a scalable route toward high-performance,sustainable conductive elastomers tailored for next-generation soft electronics.
