Recent Advances in Aqueous Zn||MnO_(2)Batteries

Recently,rechargeable aqueous zinc-based batteries using manganese oxide as the cathode(e.g.,MnO_(2))have gained attention due to their inherent safety,environmental friendliness,and low cost.Despite their potential,achieving high energy density in Zn||MnO_(2)batteries remains challenging,highlighting the need to understand the electrochemical reaction mechanisms underlying these batteries more deeply and optimize battery components,including electrodes and electrolytes.This review comprehensively summarizes the latest advancements for understanding the electrochemistry reaction mechanisms and designing electrodes and electrolytes for Zn||MnO_(2)batteries in mildly and strongly acidic environments.Furthermore,we highlight the key challenges hindering the extensive application of Zn||MnO_(2)batteries,including high-voltage requirements and areal capacity,and propose innovative solutions to overcome these challenges.We suggest that MnO_(2)/Mn^(2+)conversion in neutral electrolytes is a crucial aspect that needs to be addressed to achieve high-performance Zn||MnO_(2)batteries.These approaches could lead to breakthroughs in the future development of Zn||MnO_(2)batteries,off ering a more sustainable,costeff ective,and high-performance alternative to traditional batteries.

The Periodic Table of Primes

Over millennia, nobody has been able to predict where prime numbers sprout or how they spread. This study establishes the Periodic Table of Primes (PTP) using four prime numbers 2, 3, 5, and 7. We identify 48 integers out of a period 2×3×5×7=210 to be the roots of all primes as well as composites without factors of 2, 3, 5, and 7. Each prime, twin primes, or composite without factors of 2, 3, 5, and 7 is an offspring of the 48 integers uniquely allocated on the PTP. Three major establishments made in the article are the Formula of Primes, the Periodic Table of Primes, and the Counting Functions of Primes and Twin Primes.

Effect of pre-deformation on microstructure and mechanical properties of WE43 magnesium alloy II: Aging at 250 and 300℃

In this work,the microstructural evolution and mechanical properties of a pre-deformed WE43 magnesium alloy when aged at 250 and 300℃ were further investigated.It is found that the abundant deformation twins introduced by pre-deformation were maintained within the alloy during the aging treatment.Second particles formed at the twin boundaries and coarsened with aging time,especially at 300℃.When peak-aged at 250℃,the fine metastable β'''and β' precipitates formed in the un-deformed alloy have been transformed into relatively large β1 and β precipitates by the pre-deformation.While peak-aged at 300℃,the pre-deformation obviously refined the β precipitates.Mechanical properties indicate that pre-deformation can increase the yield strength by 19MPa and 54MPa for the peak-aged alloy at 250℃ and 300℃,respectively,and will not obviously deteriorate the tensile elongations.

Nanostructured steels for advanced structural applications

This vision summarizes the recent advancement of nanostructured steels foradvanced structural applications, foresees possible challenges and pinpoints futuredirections as well as opportunities in this new era of industrial revolution 4.0.

Thermal stability and deformation mechanisms in Ni-Co-Fe-Cr-Al-Ti-Nb-type nanoparticle-strengthened high-entropy alloys

The precipitate morphologies,coarsening kinetics,elemental partitioning behaviors,grain structures,and tensile properties were explored in detail for L1_(2)-strengthened Ni_(39.9)Co_(20)Fe_(15)Cr_(15)Al_(6)Ti_(4-x)Nb_(x)B_(0.1)(x=0 at.%,2 at.%,and 4 at.%)high-entropy alloys(HEAs).By substituting Ti with Nb,the spheroidal-to-cuboidal precipitate morphological transition,increase in the coarsening kinetics,and phase decomposition upon aging at 800°C occurred.The excessive addition of Nb brings about the grain boundary precipitation of an Nb-rich phase along with the phase decomposition from the L1_(2)to lamellar-structured D019 phase upon the long-term aging duration.By partially substituting Ti with Nb,the chemically complex and thermally stable L12 phase with a composition of(Ni_(58.8)Co_(9.8)Fe_(2.7))(Al_(12.7)Ti_(5.8)Nb_(7.5)Cr_(2.3))ensures the stable phase structure and clean grain boundaries,which guarantees the superb high-temperature mechanical properties(791±7 MPa for yielding and 1013±11 MPa for failure)at 700℃.Stacking faults(SFs)were observed to prevail during the plastic deformation,offering a high work-hardening capability at 700°C.An anomalous rise in the yield strength at 800℃was found,which could be ascribed to the multi-layered super-partial dislocations with a cross-slip configuration within the L1_(2)particles.

Specialising neural network potentials for accurate properties and application to the mechanical response of titanium

Large scale atomistic simulations provide direct access to important materials phenomena not easily accessible to experiments or quantum mechanics-based calculation approaches.Accurate and efficient interatomic potentials are the key enabler,but their development remains a challenge for complex materials and/or complex phenomena.Machine learning potentials,such as the Deep Potential(DP)approach,provide robust means to produce general purpose interatomic potentials.Here,we provide a methodology for specialising machine learning potentials for high fidelity simulations of complex phenomena,where general potentials do not suffice.As an example,we specialise a general purpose DP method to describe the mechanical response of two allotropes of titanium(in addition to other defect,thermodynamic and structural properties).The resulting DP correctly captures the structures,energies,elastic constants andγ-lines of Ti in both the HCP and BCC structures,as well as properties such as dislocation core structures,vacancy formation energies,phase transition temperatures,and thermal expansion.The DP thus enables direct atomistic modelling of plastic and fracture behaviour of Ti.The approach to specialising DP interatomic potential,DPspecX,for accurate reproduction of properties of interest“X”,is general and extensible to other systems and properties.

Equation of motion for grain boundaries in polycrystals

Grain boundary(GB)dynamics are largely controlled by the formation and motion of disconnections(with step and dislocation characters)along with the GB.The dislocation character gives rise to shear coupling;i.e.the relative tangential motion of two grains meeting at the GB during GB migration.In a polycrystal,the shear coupling is constrained by the presence of other grains and GB junctions,which prevents large-scale sliding of one grain relative to the other.We present continuum equations of motion for GBs that is based upon the underlying disconnection dynamics and accounts for this mechanical constraint in polycrystals.This leads to a reduced-order(zero-shear constrained)model for GB motion that is easily implemented in a computationally efficient framework,appropriate for the large-scale simulation of the evolution of polycrystalline microstructures.We validated the proposed reducedorder model with direct comparisons to full multi-disconnection mode simulations.

Advances of machining techniques for gradient structures in multi-principal-element alloys

Multi-principal-element alloys(MPEAs)are attracting increasing attentions because of their high strength and ductility,high fracture toughness,excellent corrosion resistance,outstanding thermal-softening resistance and high oxidation resistance.Moreover,gradient structures(GSs)have been shown to be effective in alleviating the strength-ductility trade-off although strength and ductility are mutually exclusive properties for metals,which provides an opportunity for developing highperformance MPEAs.Here,we summarized four processing methods for creating GSs in MPEAs,including rotationally accelerated shot peening(RASP),ultra-precision machining technology(UPMT),cyclic dynamic torsion(CDT),and ultrasonic surface rolling processing(USRP).Principles,advantages,disadvantages,and typical applications of these methods are discussed in this work.

Effect of interstitial carbon and nitrogen on corrosion of FeCoCrNi multi-principal element alloys made by selective laser melting

The corrosion behaviors of selective laser melted(SLMed)FeCoCrNi multi-principal element alloys(MPEAs)with carbon or nitrogen addition in 0.5 M H_(2)SO_(4) solution were investigated.Both C and N ad-dition refined the grains and introduced a heterogeneous structure in SLMed FeCoCrNi MPEA,but they had opposite effects on the corrosion behavior.The doped carbon participated as nano-sized carbides in SLMed MPEA,and localized galvanic corrosion occurred,degrading the corrosion resistance.The doped nitrogen was gathered with chromium and formed CrN chemical clusters in SLMed MPEA,and a protec-tive passive film with a higher Cr_(2)O_(3)/Cr(OH)_(3) ratio formed,which improved corrosion resistance.

Simultaneously improving mechanical properties and oxidation resistance of Ti-bearing high-entropy superalloys at intermediate temperature via silicon addition

Ti-bearing high-entropy superalloys(HESAs)often suffer from severe intergranular embrittlement and terrible oxidation degradation at intermediate temperatures.Here we showcase that minor Si addition can effectively mitigate the intergranular embrittlement and improve the oxidation resistance of the a(Ni_(2)Co_(2)FeCr)_(92) Ti_(4)Al_(4) HESA at 700℃ simultaneously.Experimental analysis revealed that the intergranu-lar G phase induced by 2 at%Si addition can effectively suppress the inward diffusion of oxygen along grain boundaries at 700℃,thus enhancing the tensile ductility of the alloy from∼8.3%to∼13.4%.Be-sides,the 2 at%Si addition facilitated the formation of a continuous Al_(2)O_(3) layer during oxidation,con-tributing to a remarkable reduction in the growth rate of the oxide scale to a quarter of the Si-free HESA.Our results demonstrate that Si can be a favorable alloying element to design advanced HESAs with syn-ergistically improved thermal-mechanical performance.

锌负极和锂负极在不同温度下的电化学行为

本文研究表明锂金属负极的枝晶问题在较低温度下会加剧,在较高温度下会受到抑制;而对于水系可充电锌基电池中锌金属负极的枝晶演变,温度的影响则恰恰相反.对两种负极的电化学行为的研究结果表明,界面反应速率和离子扩散率的匹配程度以及副反应综合影响了金属负极的枝晶生长和循环寿命.研究发现有机电解质和水电解质在上述影响因素上的不同性质导致相反的温度影响.本文进一步对混合电解质(有机和水性)进行了详细研究,以调节离子扩散率和副反应,同时扩大水系可充锌基电池的工作温度窗口.本文揭示了有机锂金属负极和水系锌基电池完全相反的温度影响,并揭示了潜在的影响机制,有助于加深对金属负极的理解,从而促进水系锌基电池的大规模应用.

Unifying colors by primes

RGB and CYMK are two major coloring schemes currently available for light colors and pigment colors,respectively.Both systems use letter-based color codes that require a large range of values to represent different colors.The problem is that these two systems are hard to use for manipulating any operations involving combinations of colors,and they lack the capacity for inter-changeability or unification.Based on prime number theory and Goldbach's conjecture,this study presents a universal color system(C235)using a number-based structure to encode,compute and unify all colors on a color wheel.The proposed C235 system offers a unified representation for the efficient encoding and effective manipulation of color.It can be applied to designing a high-rate LCD system and colorizing objects with multiple attributes and DNA codons,opening the door to manipulating colors and lights for even broader applications.

Off-stoichiometry-guided design of high-strength chemically complex intermetallic-based alloys with outstanding ductility

1.Introduction The lasting drive for improved energy efficiency in power gen-eration encourages the innovative design of advanced structural materials with superb mechanical properties[1-6].Among these materials,ordered intermetallic alloys[7-9],as a unique class of metallic materials,have drawn increasing concern from both the scientific and industrial communities due to their intriguing high-temperature properties,strong chemical binding,and low atomic mobility[10,11].However,in light of the insufficient number of slip systems and/or intrinsically weak grain boundary(GB),they are usually brittle at ambient temperature,severely hindering their practical use in engineering systems[12].Previous studies reported that the change in alloy stoichiometry has a significant beneficial effect on the ductility of intermetallic alloys.For instance,Liu et al.

Compositionally complex coherent precipitation-strengthened high-entropy alloys:a critical review

The coherent precipitation-strengthened high-entropy alloys(CPS-HEAs)as a new type of structural materials are expected to possess many unique mechanical properties,such as the outstanding strength-ductility com-bination at cryogenic and room temperatures.Apart from this,most of their strengths can even be well retained at elevated temperatures.The compositionally complex matrix and nanoprecipitation phases,as well as the coherent interfaces between them,can potentially bring novel merits of these CPS-HEAs,including sluggish dif-fusion,excellent thermal stability,and controlled magnetic properties.Note that the ductile coherent L1_(2)-nanoparticles can improve the strength of alloys without too much reduction of plasticity,while the coherent B2-nanoparticles strengthened HEAs display completely brittle failure upon tensile test at room temperature.An overview of the alloy design,microstructure evolution,oxidation resistance,mechanical and magnetic properties of CPS-HEAs are briefly discussed here.The advantages of multicomponent coherent precipitation-strengthened HEAs as well as the limitations in this field are also summarized.In addition,this review also points out the future research directions and prospects.

金属合金中的类分子化学结构单元

本文引入Friedel振荡理论,揭示固溶体合金中存在类似分子式的结构单元,指出在特定的成分下,合金中的原子在近程序上倾向于聚集为理想的有序结构,这个结构包括最近邻壳层原子(记作团簇)和次近邻壳层原子(记作连接原子),用团簇式:[团簇](连接原子)来表示.这种近程序结构被称为化学结构单元,类似于固溶体中的"分子".本文给出了FCC结构固溶体合金中化学结构单元的计算公式,通过计算得到Cu基二元体系的理想化学结构单元,包括CuZn、Cu-Al、Cu-Ni、Cu-Be和Cu-Sn,均为工业中最常用的合金成分.此外,工业上常用的多元合金,如Al合金5083和7075、高温合金TMS-196和TMS-82、马氏体时效不锈钢Cutom-465和奥氏体不锈钢310s,其成分均满足模型的预测,表明本模型可以为FCC结构复杂固溶体合金的成分设计提供理论指导.

新型低碳纳米钢:微观组织、机械性能与应用

新型低碳纳米钢已被开发且广泛应用于各种结构工程,包括桥梁、汽车和其他重要高强度应用,如核电站反应堆压力容器.纳米钢的机械性能与应用,在很大程度上取决于其微观组织.通过控制析出物的大小、数量密度、分布和类型,可以生产出抗拉强度高达2 GPa的纳米钢,同时保持10%以上的良好拉伸延伸率及40%的面积缩小率.此外,通过调控各种强化机制,纳米钢可以避免回火脆性,从而具有优异的强度和低温冲击韧性.通过添加适当的锰(Mn),纳米钢可以在不牺牲其强度下(屈服强度, YS为~1100-1300 MPa;极限抗拉强度, UTS为~1300-1400 MPa),延展性提高3倍(总拉伸延伸率, TE约为30%).更重要的是,这些纳米钢有良好的可加工性和可焊性.本文全面综述了先进纳米钢的微观结构及其性能关系.此外,本文对纳米钢的当前局限和未来发展进行了详细的探讨和概述.