A 5M Synchronization Mechanism for Digital Twin Shop-Floor

In recent years,as a promising way to realize digital transformation,digital twin shop-floor(DTS)plays an impor-tant role in smart manufacturing.The core feature of DTS is the synchronization.How to implement and maintain the synchronization is critical for DTS.However,there is still a lack of a common definition for synchronization in DTS.Besides,a systematic synchronization mechanism for DTS is strongly needed.This paper first summarizes the defi-nition and requirements of synchronization in DTS,to clarify the understanding of synchronization in DTS.Then,a 5M synchronization mechanism for DTS is proposed,where 5M refers to multi-system data,multi-fidelity model,multi-resource state,multi-level state,and multi-stage operation.As a bottom-up synchronization mechanism,5M synchronization mechanism for DTS has the potential to support DTS to achieve and maintain physical-virtual state synchronization,and to realize operation synchronization of DTS.The implementation methods of 5M synchronization mechanism for DTS are also introduced.Finally,the proposed synchronization mechanism is validated in a digital twin satellite assembly shop-floor,which proves the effectiveness and feasibility of the mechanism.

Recent progress on the planar Hall effect in quantum materials

The planar Hall effect(PHE),which originates from anisotropic magnetoresistance,presents a qualitative and simple approach to characterize electronic structures of quantum materials by applying an in-plane rotating magnetic field to induce identical oscillations in both longitudinal and transverse resistances.In this review,we focus on the recent research on the PHE in various quantum materials,including ferromagnetic materials,topological insulators,Weyl semimetals,and orbital anisotropic matters.Firstly,we briefly introduce the family of Hall effect and give a basic deduction of PHE formula with the second-order resistance tensor,showing the mechanism of the characteristicπ-period oscillation in trigonometric function form with aπ/4 phase delay between the longitudinal and transverse resistances.Then,we will introduce the four main mechanisms to realize PHE in quantum materials.After that,the origin of the anomalous planar Hall effect(APHE)results,of which the curve shapes deviate from that of PHE,will be reviewed and discussed.Finally,the challenges and prospects for this field of study are discussed.

makeTwin:A reference architecture for digital twin software platform

Digital twin is currently undergoing a significant transformation from the conceptual and theoretical research phase to the implementation and application phase.However,a universally adaptable research and development platform for digital twin is critically needed to meet the development requirements.Specifically,a publicly accessible simulation,testing,and validation platform which can support digital twin model building,data processing,algorithm design,configuration,etc.,is urgently required for researchers.Furthermore,for developers from the industry,a lowcode development platform that can offer a customizable suite of functions such as model creation,data management,protocol configuration,and visualization is urgently needed.Meanwhile,for enterprise users,there is a lack of an application management platform that can be configured and migrated for various application scenarios,functions,and modes.Therefore,based on the system research of digital twin theories and key technologies by the authors(such as the five-dimension digital twin model,digital twin modeling and digital twin data theory,digital twin standards,and so on),a digital twin software platform reference architecture,namely make Twin,is proposed and designed,as well as its ten core functions.The workflow of the make Twin and the interaction mechanisms among its core functions are described.Finally,a digital twin application system for a chemical fiber textile shop floor(CFTS)which was developed according to make Twin,is introduced,which validates the proposed reference architecture.

MBenes-supported single-atom catalysts for oxygen reduction and oxygen evolution reactions by first-principles study and machine learning

Oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)are key catalytic processes in various renewable energy conversion and energy storage technologies.Herein,we systematically investigated the ORR and OER catalytic activity of the single-atom catalysts(SACs)composed of 4d/5d period transition metal(TM)atoms embedded on MBene substrates(TM-M_(2)B_(2)O_(2),M=Ti,Mo,and W).We found that TM dominates the catalytic activity compared to the MBene substrates.The SACs embedded with Rh,Pd,Au,and Ir exhibit excellent ORR or OER catalytic activity.Specifically,Rh-Mo2B2O2and Rh-W2B2O2are promising bifunctional catalysts with ultra-low ORR/OER overpotentials of 0.39/0.21 V and0.19/0.32 V,respectively,lower than that of Pt/RuO_(2)(0.45/0.42 V).Importantly,through machine learning,the models containing 10 element features of SACs were developed to quickly and accurately identify the superior ORR and OER electrocatalysts.Our findings provide several promising SACs for ORR and OER,and offer effective models for catalyst design.

Nanoscale Wire Bonding of Individual Ag Nanowires on Au Substrate at Room Temperature

The controllable wire bonding of individual Ag nanowires onto a Au electrode was achieved at room temperature. The plastic deformation induced by pressure using nanoindentation could break the protective organic shell on the surface of the Ag nanowires and cause atomic contact to promote the diffusion and nanojoining at the Ag and Au interface. Severe slip bands were observed in the Ag nanowires after the deformation. A metallic bond was formed at the interface, with the Ag diffusing into the Au more than the Au diffused into the Ag. This nanoscale wire bonding might present opportunities for nanoscale packaging and nanodevice design.

A Laser Scanner-Stage Synchronized System Supporting the Large-Area Precision Polishing of Additive-Manufactured Metallic Surfaces

This paper proposes a scanner–stage synchronized approach emphasizing a novel control structure for the laser polishing of Inconel 718 components manufactured by selective laser melting in order to address increasing demands for high surface quality in metal additive manufacturing.The proposed synchronized control system is composed of a motion decomposition module and an error synthesis module.The experimental results show that stitching errors can be avoided thanks to continuous motion during laser processing.Moreover,in comparison with the existing step-scan method,the processing efficiency of the proposed method is improved by 38.22%and the surface quality of the laser-polished area is significantly enhanced due to a more homogeneous distribution of the laser energy during the material phase change.The proposed synchronized system paves the way for high-speed,high-precision,and large-area laser material processing without stitching errors.

Revealing the Pressure-Induced Softening/Weakening Mechanism in Representative Covalent Materials

Diamond, cubic boron nitride(c-BN), silicon(Si), and germanium(Ge), as examples of typical strong covalent materials, have been extensively investigated in recent decades, owing to their fundamental importance in material science and industry. However, an in-depth analysis of the character of these materials' mechanical behaviors under harsh service environments, such as high pressure, has yet to be conducted. Based on several mechanical criteria, the effect of pressure on the mechanical properties of these materials is comprehensively investigated.It is demonstrated that, with respect to their intrinsic brittleness/ductile nature, all these materials exhibit ubiquitous pressure-enhanced ductility. By analyzing the strength variation under uniform deformation, together with the corresponding electronic structures, we reveal for the first time that the pressure-induced mechanical softening/weakening exhibits distinct characteristics between diamond and c-BN, owing to the differences in their abnormal charge-depletion evolution under applied strain, whereas a monotonous weakening phenomenon is observed in Si and Ge. Further investigation into dislocation-mediated plastic resistance indicates that the pressure-induced shuffle-set plane softening in diamond(c-BN), and weakening in Si(Ge), can be attributed to the reduction of antibonding states below the Fermi level, and an enhanced metallization, corresponding to the weakening of the bonds around the slipped plane with increasing pressure, respectively. These findings not only reveal the physical mechanism of pressure-induced softening/weakening in covalent materials, but also highlights the necessity of exploring strain-tunable electronic structures to emphasize the mechanical response in such covalent materials.

Large-area ultrastrong and stiff aramid nanofiber based layered nanocomposite films

One-dimensional(1D)aramid nanofiber(ANF)based nanocomposite films have drawn increasing attentions in various applications due to their excellent mechanical properties and impressive chemical and thermal stabilities.However,the large-area fabrication of aramid nanocomposite films with ultrastrong mechanical properties under mild conditions remains a great challenge.Here we present a facile superspreading-assisted strategy to produce aramid nanofiber based oriented layered nanocomposites using phase inversion process that occurs at the fully swollen hydrogel surfaces.The nanocomposite films based on ANF,carboxylation carbon tube(CNT–COOH),poly(vinyl alcohol)(PVA),and MXene nanosheet exhibit a tensile strength of up to 870.8±85 MPa,a Young’s modulus of 21.8±2.2 GPa,and outstanding toughness(up to 43.2±4.6 MJ/m^(3)),which are much better than those conventional aramid nanofiber based materials.Electrical conductivity of our nanocomposite films reaches the maximum of about 1100 S/m.The fabulous mechanical properties combination and continuous production capability render our strategy representing a promising direction for the development of high-performance nanocomposites.

Continuous preparation of strong and tough PVA nanocomposite fibers by mechanical stretching-assisted salting-out treatment

Polymer composite fibers with superior properties such as excellent combined strength and toughness and biocompatibility can be used in high-tech applications of braided protective devices and smart wearable,however the research of high-performance polymer composite fiber remains in the infant stage.Here we present a strategy to produce strong and tough anisotropic polymer nanocomposite fibers with orientedly aligned salt rods using mechanical stretching-assisted salting-out treatment.The prepared nanocomposite fibers have a tensile strength of up to 786±2.7 MPa and an elongation at break of 81%,and the anisotropic fibers exhibit good transmission of mechanical vibration in the longitudinal direction with high resolution.During the fabrication process,the salt builds up into oriented rods during the directional salting process,and the polymer is confined to the 150 nm domain between the rods after the solvent is completely evaporated,giving the nanocomposite fibers superior mechanical properties.The presented strategy can be applied to the continuous mass production of nanocomposite fibers and is also generalizable to other polymer nanocomposites,which could extend the applicability of nanocomposite fibers to conditions involving more demanding mechanical loading and mechanical vibration transmission.

Investigation on the Lateral Line Systems of Two Cavefish： Sinocyclocheilus Macrophthalmus and S. Microphthalmus （Cypriniformes： Cyprinidae）

Cavefish, with sensitive lateral lines, can swim freely and locate preys in invisible and complex cave environments, though their eyes are greatly degenerated. Investigations on the morphology and distribution characteristics of their lateral line systems would benefit our understanding of the high-sensitivity mechanism of the fish. In this study, the arrangement and morphology of the lateral lines are described for two species ofSinocyclocheilus： S. macrophthalmus and S. microphthalmus, which live in the karst caves in Guangxi, China. The behavior experiments indicate that the lateral line system of the S. macrophthalmus is more sensitive at a low vibration frequency range from 20 Hz to 70 Hz. The cephalic and trunk lateral line systems both contribute to the efficient object-locating capability. For both of the two species of cavefish, the diameter of the lateral canal nearby the neuromasts is narrower than that nearby the canal pores. This variation can increase the normal pressure to the surface of the cupula, and increase the sensitivity of the canal lateral line system.

Prediction of thermoelectric performance for layered IV-V-VI semiconductors by high-throughput ab initio calculations and machine learning

Layered IV-V-VI semiconductors have immense potential for thermoelectric(TE)applications due to their intrinsically ultralow lattice thermal conductivity.However,it is extremely difficult to assess their TE performance via experimental trial-and-error methods.Here,we present a machine-learning-based approach to accelerate the discovery of promising thermoelectric candidates in this chalcogenide family.Based on a dataset generated from high-throughput ab initio calculations,we develop two highly accurateand-efficient neural network models to predict the maximum ZT(ZT_(max))and corresponding doping type,respectively.The top candidate,n-type Pb_(2)Sb_(2)S_(5),is successfully identified,with the ZT_(max) over 1.0 at 650 K,owing to its ultralow thermal conductivity and decent power factor.Besides,we find that n-type Te-based compounds exhibit a combination of high Seebeck coefficient and electrical conductivity,thereby leading to better TE performance under electron doping than hole doping.Whereas p-type TE performance of Se-based semiconductors is superior to n-type,resulting from large Seebeck coefficient induced by high density-ofstates near valence band edges.

Magnetic-programmable organohydrogels with reconfigurable network for mechanical homeostasis

Synthetic materials with tunable mechanical properties have great potential in soft robotics and biomedical engineering.However,current materials are limited to the mechanical duality altering their mechanical properties only between soft and hard states and lack of consecutively programmable mechanics.Herein,the magnetic-programmable organohydrogels with heterogeneous dynamic architecture are designed by encasing oleophilic ferrofluid droplets into hydrogel matrix.As magnetic field increases,the mechanical properties of organohydrogels can be consecutively modulated owing to the gradual formation of chain-like assembly structures of nanoparticles.The storage modulus G'increases by 2.5 times when magnetic field goes up to 0.35 T.Small-Angle X-ray Scattering(SAXS)confirms the reconfigurable orientation of nanoparticles and the organohydrogels show reversible modulus switching.Besides,the materials also exhibit high stretchability,magnetic actuation behavior and effective self-healing capability.Furthermore,the organohydrogels are applied into the design of effectors with mechanical adaptivity.When subjected to serious external perturbations,the effector can maintain mechanical homeostasis by regulating modulus of organohydrogel under applied magnetic field.Such materials are applicable to homeostatic systems with mechanically adaptive behaviors and programmed responses to external force stimuli.

Direct-Writing Large-Area Cross-Aligned Ag Nanowires Network:Toward High-Performance Transparent Quantum Dot Light-Emitting Diodes

Flexible transparent electrodes(FTEs)made of silver nanowires(AgNWs)have been widely used in wearable and foldable electronics devices.For obtaining FTEs with both high transparency and low resistance,the AgNWs network should be highly cross-aligned with a low density.Various solution processes have been developed,but most suffer from poor control of the distribution of the AgNWs.

基于天然多孔材料的双梯度结构设计负泊松比超材料

负泊松比超材料由于其优异的力学性能,包括优异的抗剪切性能、抗冲击性能、抗断裂性能、吸能隔振等,在个体防护和抗冲击、减振吸能等领域有着重要的应用价值,从而引起了科学家和工程师们极大的研究兴趣.大多数传统的负泊松比超材料通常基于单元胞体的拓扑结构设计,这类超材料通常不可避免地面临着由其复杂拓扑结构,特别是内凹多边形结构,所带来的设计、制备难题.迄今为止,尽管许多研究人员致力于开发新的负泊松比超结构和材料,但很少有研究能明确指出负泊松比超材料的设计指南或工作流程,更多的研究是基于研究人员的设计灵感和对特定胞元结构的计算机辅助优化.基于此,我们提出了一种受自然启发的负泊松比超材料设计策略,利用天然多孔材料所具有的独特双梯度结构,例如以松质骨和向日葵茎髓心作为生物模型,通过在多孔结构中引入双梯度变化即可得到负泊松比效应,从而制备负泊松比超材料.这种受自然启发的负泊松比超材料设计思路具有一定的普适性,可以扩展到具有常见凸多边形胞元的多孔结构中,基本胞元结构并不局限于特定的内凹多边形等常见的用来构造负泊松比超材料的结构和形状.

Constructing unextendible product bases from multiqubit ones

The construction of multipartite unextendible product bases(UPBs)is a basic problem in quantum information.We respectively construct two families of 2×2×4 and 2×2×2×4 UPBs of size eight by using the existing four-qubit and five-qubit UPBs.As an application,we construct novel families of multipartite positive-partial-transpose entangled states,as well as their entanglement properties in terms of the geometric measure of entanglement.

Structural and Mechanical Characterization ofAtrina Pectinata and Freshwater Mussel Shells

The microstructures ofAtrina pectinata and freshwater mussel shells are investigated by optical microscopy and scanning electron microscopy. The mechanical properties of these shells are characterized by nanoindentation and three-point bending tests. Results show that both shells possess a prismatic microstructure mainly composed of columnar crystals and an organic matrix. The fracture toughness of the prismatic structure of Atrina pectinata and freshwater mussel are approximately 1.15 MPa.m1/2 and 0.87 MPa.m1/2, respectively, while the fracture toughness of natural calcite is approximately 0.2 MPa.m1/2. Calculated results from indentations agree with those obtained from the three-point bending tests. The columnar crystal material shows excellent fracture toughness due to grain refinement. In addition, the organic matrix of the prismatic layer can arrest cracks, and thereby improves the fracture toughness.

热响应性自恢复、形状记忆半结晶水凝胶（英文）

热响应性水凝胶在组织工程、药物运输和柔性器件等领域有着广泛应用.但传统的热响应性水凝胶在大形变下回复性能差,而且一般需要复杂的化学合成.亲疏水二元协同作用可以使水凝胶网络具备优异的响应性和力学性能.基于此,我们制备了具有异质梳状网络的半结晶水凝胶.这种半结晶水凝胶以亲水的DMA和MEA作为网络框架,疏水的PCL聚集形成结晶微区作为热响应单元,表现出优异的力学性质、自恢复特性、热响应性机械性能和形状记忆的能力.

水凝胶表面沟槽内液流诱导制备具有取向碳纳米管的超韧高强纳米复合纤维（英文）

纳米复合纤维由于其广泛的应用前景受到科学家的关注.但是在温和条件下制备具有优异断裂韧性与高强度的纳米复合纤维仍然面临很大的挑战.本文中,我们展示了一种简单的基于液流组装的策略用于制备具有超高断裂韧性与强度的纳米复合纤维.在准液态的水凝胶表面和重力的双重作用下,含有碳纳米管的水溶液可以沿水凝胶沟槽极快速地流动,从而诱导碳纳米管取向排列.我们制备出的纳米复合纤维拉伸强度和断裂韧性分别高达643±27 MPa和77.3±3.4 MJ m-3,极限断裂伸长率14.8±1.5%.这种具有较强普适性和高效率的液流诱导取向策略为高性能纳米复合纤维的实际应用提供了新的可行的发展方向.

Development of a Tactile and Slip Sensor with a Biomimetic Structure-enhanced Sensing Mechanism

Tactile and slip sensors have gained tremendous attention for their promising applications in the fields of smart robotics,implantable medical devices and minimally invasive surgery.Inspired by the structure-enhanced sensing mechanisms of human fingertips and tree frog toes,we developed a tactile and slip sensor by combining biomimetic surface microstructures with highly sensitive P(VDF-TrFE)nanofiber sensors on a flexible polyimide substrate.As the surface microstructures could mediate the micro-vibration induced by slip motion,the frequencies of output signals revealed a strong correlation with the periods of microstructures.In addition,we proposed a method to discriminate touch force from slip motion using the criterion of standard deviation of time delay from the output signals of neighboring sensor elements.

材料科学中的自然辩证法:二元协同材料（英文）

"二元协同材料"这一新概念,不同于传统的单一体相材料,是在材料的宏观表面或体相内建造二元协同纳米界面结构.该材料设计原理是,在介观尺度引入不同甚至完全相反理化性质的纳米微区,在某种条件下具有协同的相互作用,以致在宏观上呈现出超常规物性的材料.这一新原理的关键是找出这两种组分间的协同距离,该协同距离应该与物理或化学中的某一特征常数相关.这一设计原理可以拓展到材料科学的多个领域,用于指导制备各种新型功能材料.