Detecting tiny deformations or vibrations, particularly those associated with strains below 1%, is essential in various technological applications. Traditional intrinsic materials, including metals and semiconductors,...Detecting tiny deformations or vibrations, particularly those associated with strains below 1%, is essential in various technological applications. Traditional intrinsic materials, including metals and semiconductors, face challenges in simultaneously achieving initial metallic state and strain-induced insulating state, hindering the development of highly sensitive mechanical sensors. Here we report an ultrasensitive mechanical sensor based on a strain-induced tunable ordered array of metallic and insulating states in the single-crystal bronze-phase vanadium dioxide [VO_(2)(B)] quantum material. It is shown that the initial metallic state in the VO_(2)(B) flake can be tuned to the insulating state by applying a weak uniaxial tensile strain. Such a unique property gives rise to a record-high gauge factor of above 607970, surpassing previous values by an order of magnitude, with excellent linearity and mechanical resilience as well as durability. As a proof-of-concept application, we use our proposed mechanical sensor to demonstrate precise sensing of the micro piece, gentle airflows and water droplets. We attribute the superior performance of the sensor to the strain-induced continuous metal-insulator transition in the single-crystal VO_(2)(B) flake, evidenced by experimental and simulation results. Our findings highlight the potential of exploiting correlated quantum materials for next-generation ultrasensitive flexible mechanical sensors, addressing critical limitations in traditional materials.展开更多
Evidence for metallization in dense oxygen has been reported for over 30 years[Desgreniers et al.,J.Phys.Chem.94,1117(1990)]at a now routinely accessible 95 GPa[Shimizu et al.,Nature 393,767(1998)].However,despite the...Evidence for metallization in dense oxygen has been reported for over 30 years[Desgreniers et al.,J.Phys.Chem.94,1117(1990)]at a now routinely accessible 95 GPa[Shimizu et al.,Nature 393,767(1998)].However,despite the longevity of this result and the technological advances since,the nature of the metallic phase remains poorly constrained[Akahama et al.,Phys.Rev.Lett.74,4690(1995);Goncharov et al.,Phys.Rev.B 68,224108(2003);Ma,Phys.Rev.B 76,064101(2007);and Weck et al.,Phys.Rev.Lett.102,255503(2009)].In this work,through Raman spectroscopy,we report the distinct vibrational characteristics of metallicζ-O_(2) from 85 to 225 GPa.In comparison with numerical simulations,wefind reasonable agreement with the candidate structure up to about 150 GPa.At higher pressures,the C2/mstructure is found to be unstable and incompatible with experimental observations.Alternative candidate structures,and Ci,with C2/m C2/conly two molecules in the primitive unit cell,are found to be stable and more compatible with measurements above 175 GPa,indicative of the dissociation of(O_(2))4 units.Further,we report and discuss a strong hysteresis and metastability with the precursory phaseϵ-O_(2).Thesefindings will reinvigorate experimental and theoretical work into the dense oxygen system,which will have importance for oxygen-bearing chemistry,prevalent in the deep Earth,as well as fundamental physics.展开更多
Entropy production in quasi-isentropic compression (QIC) is critically important for understanding the properties of materials under extremeconditions. However, the origin and accurate quantification of entropy in thi...Entropy production in quasi-isentropic compression (QIC) is critically important for understanding the properties of materials under extremeconditions. However, the origin and accurate quantification of entropy in this situation remain long-standing challenges. In this work, a framework is established for the quantification of entropy production and partition, and their relation to microstructural change in QIC. Cu50Zr50is taken as a model material, and its compression is simulated by molecular dynamics. On the basis of atomistic simulation-informed physicalproperties and free energy, the thermodynamic path is recovered, and the entropy production and its relation to microstructural change aresuccessfully quantified by the proposed framework. Contrary to intuition, entropy production during QIC of metallic glasses is relativelyinsensitive to the strain rate ˙γ when ˙γ ranges from 7.5 × 10^(8) to 2 × 10^(9)/s, which are values reachable in QIC experiments, with a magnitudeof the order of 10^(−2)kB/atom per GPa. However, when ˙γ is extremely high (>2 × 10^(9)/s), a notable increase in entropy production rate with˙γ is observed. The Taylor–Quinney factor is found to vary with strain but not with strain rate in the simulated regime. It is demonstrated thatentropy production is dominated by the configurational part, compared with the vibrational part. In the rate-insensitive regime, the increase inconfigurational entropy exhibits a linear relation to the Shannon-entropic quantification of microstructural change, and a stretched exponential relation to the Taylor–Quinney factor. The quantification of entropy is expected to provide thermodynamic insights into the fundamentalrelation between microstructure evolution and plastic dissipation.展开更多
In this work,a new ZnO/CoNiO_(2)/CoO/C metal oxides composite is prepared by cost-effective hydrothermal method coupled with annealing process under N_(2) atmosphere.Notably,the oxidation-defect annealing environment ...In this work,a new ZnO/CoNiO_(2)/CoO/C metal oxides composite is prepared by cost-effective hydrothermal method coupled with annealing process under N_(2) atmosphere.Notably,the oxidation-defect annealing environment is conducive to both morphology and component of the composite,which flower-like ZnO/CoNiO_(2)/CoO/C is obtained.Benefited from good chemical stability of ZnO,high energy capacity of CoNiO_(2) and CoO and good conductivity of C,the as-prepared sample shows promising electrochemical behavior,including the specific capacity of 1435 C·g^(-1) at 1 A·g^(-1),capacity retention of 87.3%at 20 A·g^(-1),and cycling stability of 90.5%for 3000 cycles at 5 A·g^(-1),respectively.Furthermore,the prepared ZnO/CoNiO_(2)/CoO/C/NF//AC aqueous hybrid supercapacitors device delivers the best specific energy of 55.9 W·h·kg^(-1) at 850 W·kg^(-1).The results reflect that the as-prepared ZnO/CoNiO_(2)/CoO/C microflowers are considered as high performance electrode materials for supercapacitor,and the strategy mentioned in this paper is benefit to prepare mixed metal oxides composite for energy conversion and storage.展开更多
Melt treatment is well known to have an important influence on the properties of metallic glasses(MGs).However,for the MGs quenched from different melt temperatures with a quartz tube,the underlying physical origin re...Melt treatment is well known to have an important influence on the properties of metallic glasses(MGs).However,for the MGs quenched from different melt temperatures with a quartz tube,the underlying physical origin responsible for the variation of properties remains poorly understood.In the present work,we systematically studied the influence of melt treatment on the thermal properties of a Zr50Cu36Al14 glass-forming alloy and unveiled the microscopic origins.Specifically,we quenched the melt at different temperatures ranging from 1.1Tl to 1.5Tl(Tl is the liquidus temperature)to obtain melt-spun MG ribbons and investigated the variation of thermal properties of the MGs upon heating.We found that glass transition temperature,Tg,increases by as much as 36 K,and the supercooled liquid region disappears in the curve of differential scanning calorimetry when the melt is quenched at a high temperature up to 1.5Tl.The careful chemical analyses indicate that the change in glass transition behavior originates from the incorporation of oxygen and silicon in the molten alloys.The incorporated oxygen and silicon can both enhance the interactions between atoms,which renders the cooperative rearrangements of atoms difficult,and thus enhances the kinetic stability of the MGs.展开更多
In the present work,seven Mg-Zn-Ag alloys with the nominal composition of Mg_(96-x)Zn_(x)Ag_(4)(x=17,20,23,26,29,32,35 in at.%)were prepared by induction melting and single-roller melt-spinning.The X-ray diffraction(X...In the present work,seven Mg-Zn-Ag alloys with the nominal composition of Mg_(96-x)Zn_(x)Ag_(4)(x=17,20,23,26,29,32,35 in at.%)were prepared by induction melting and single-roller melt-spinning.The X-ray diffraction(XRD)analyses indicate the metallic glasses with three composition of Mg_(73)Zn_(23)Ag_(4),Mg_(70)Zn_(26)Ag_(4),and Mg_(67)Zn_(29)Ag_(4)were obtained successfully.The differential scanning calorimetry(DSC)measurement was used to obtain the characteristic temperature of Mg-Zn-Ag metallic glasses for the glass-forming ability analysis.The maximum glass transition temperature(Trg)was found to be 0.525 with a composition close to Mg_(67)Zn_(29)Ag_(4),which results in the best glass-forming ability.Moreover,the immersion test in simulated body fluid(SBF)demonstrate the relative homogeneous corrosion behavior of the Mg-Zn-Ag metallic glasses.The corrosion rate of Mg-Zn-Ag metallic glasses in SBF solution decreases with the increase of Zn content.The sample Mg_(67)Zn_(29)Ag_(4)has the lowest corrosion rate of 0.19mm/yr,which could meet the clinical application requirement well.The in vitro cell experiments show that the Madin-Darby canine kidney(MDCK)cells cultured in sample Mg_(67)Zn_(29)Ag_(4)and its extraction medium have higher activity.However,the Mg-Zn-Ag metallic glasses exhibit obvious inhibitory effect on human rhabdomyosarcoma(RD)tumor cells.The present investigations on the glass-forming ability,corrosion behavior,cytocompatibility and tumor inhibition function of the Mg-Zn-Ag based metallic glass could reveal their biomedical application possibility.展开更多
The early stage evolution of local atomic structures in a multicomponent metallic glass during its crystallization process has been investigated via molecular dynamics simulation.It is found that the initial thermal s...The early stage evolution of local atomic structures in a multicomponent metallic glass during its crystallization process has been investigated via molecular dynamics simulation.It is found that the initial thermal stability and earliest stage evolution of the local atomic clusters show no strong correlation with their initial short-range orders,and this leads to an observation of a novel symmetry convergence phenomenon,which can be understood as an atomic structure manifestation of the ergodicity.Furthermore,in our system we have quantitatively proved that the crucial factor for the thermal stability against crystallization exhibited by the metallic glass is not the total amount of icosahedral clusters,but the degree of global connectivity among them.展开更多
Lithium-ion batteries(LIBs)with fast-charging capability are essential for enhancing consumer experience and accelerating the global market adoption of electric vehicles.However,achieving fast-charging capability with...Lithium-ion batteries(LIBs)with fast-charging capability are essential for enhancing consumer experience and accelerating the global market adoption of electric vehicles.However,achieving fast-charging capability without compromising energy density,cycling lifespan,and safety of LIBs remains a significant challenge due to the formation of dendritic Li metal on graphite anode under fast charging condition.In view of this,the fundamentals for the dendritic metallic Li formation and the strategies for suppressing metallic Li plating based on analyzing the entire Li^(+)transport pathway at the anode including electrolyte,pore structure of electrode,and surface and bulk of materials are summarized and discussed in this review.Besides,we highlight the importance of designing thick electrodes with fast Li^(+)transport kinetics and comprehensively understanding the interaction between solid electrolyte interphase(SEI)and Li^(+)migration in order to avoid the formation of dendritic Li metal in practical fast-charging batteries.Finally,the regulation of Li metal plating with plane morphology,instead of dendritic structure,on the surface of graphite electrode under fast-charging condition is analyzed as a future direction to achieve higher energy density of batteries without safety concerns.展开更多
High-aspect-ratio metallic surface microstructures are increasingly demanded in breakthrough applications,such as high-performance heat transfer enhancement and surface plasmon devices.However,the fast and cost-effect...High-aspect-ratio metallic surface microstructures are increasingly demanded in breakthrough applications,such as high-performance heat transfer enhancement and surface plasmon devices.However,the fast and cost-effective fabrication of high-aspect-ratio microstructures on metallic surfaces remains challenging for existing techniques.This study proposes a novel cutting-based process,namely elliptical vibration chiseling(EV-chiseling),for the high-efficiency texturing of surface microstructures with an ultrahigh aspect ratio.Unlike conventional cutting,EV-chiseling superimposes a microscale EV on a backward-moving tool.The tool chisels into the material in each vibration cycle to generate an upright chip with a high aspect ratio through material deformation.Thanks to the tool’s backward movement,the chip is left on the material surface to form a microstructure rather than falling off.Since one microstructure is generated in one vibration cycle,the process can be highly efficient using ultrafast(>1 kHz)tool vibration.A finite element analysis model is established to explore the process mechanics of EV-chiseling.Next,a mechanistic model of the microstructured surface generation is developed to describe the microstructures’aspect ratio dependency on the process parameters.Then,surface texturing tests are performed on copper to verify the efficacy of EV-chiseling.Uniformed micro ribs with a spacing of 1–10μm and an aspect ratio of 2–5 have been successfully textured on copper.Compared with the conventional EV-cutting that uses a forward-moving tool,EV-chiseling can improve the aspect ratio of textured microstructure by up to 40 times.The experimental results also verify the accuracy of the developed surface generation model of microstructures.Finally,the effects of elliptical trajectory,depth of cut,tool shape,and tool edge radius on the surface generation of micro ribs have been discussed.展开更多
An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering equipment.The impact res...An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering equipment.The impact response and the energy dissipation mechanism of hat-shaped EWMD under different quasi-static compression deformations(2-7 mm)and impact heights(100-200 mm)are investigated using experimental and numerical methods.The results demonstrate distinct stages in the quasi-static mechanical characteristics of hat-shaped EWMD,including stiffness softening,negative stiffness,and stiffness hardening.The loss factor gradually increases with increasing compression deformation before entering the stiffness hardening stage.Under impact loads,the hat-shaped EWMD exhibits optimal impact energy absorption when it enters the negative stiffness stage(150 mm),resulting in the best impact isolation effect of metallic buffer.However,the impact energy absorption significantly decreases when hat-shaped EWMD enters the stiffness hardening stage.Interestingly,quasi-static compression analysis after experiencing different impact loads reveals the disappearance of the negative stiffness phenomenon.Moreover,with increasing impact loads,the stiffness hardening point progressively shifts to an earlier stage.展开更多
The dramatic temperature-dependence of liquids dynamics has attracted considerable scientific interests and efforts in the past decades, but the physics of which remains elusive. In addition to temperature, some other...The dramatic temperature-dependence of liquids dynamics has attracted considerable scientific interests and efforts in the past decades, but the physics of which remains elusive. In addition to temperature, some other parameters, such as pressure, loading and size, can also tune the liquid dynamics and induce glass transition, which makes the situation more complicated. Here, we performed molecular dynamics simulations for Ni_(50)Zr_(50) bulk liquid and nanodroplet to study the dynamics evolution in the complex multivariate phase space, especially along the isotherm with the change of pressure or droplet size. It is found that the short-time Debye–Waller factor universally determines the long-time relaxation dynamics no matter how the temperature, pressure or size changes. The basic correlation even holds at the local atomic scale. This finding provides general understanding of the microscopic mechanism of dynamic arrest and dynamic heterogeneity.展开更多
Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass exhibited excellent magnetic refrigeration material with a wide temperature range and high refrigeration capacity(RC)was reported.Er_(20)Ho_(20)Dy_(20)Cu_...Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass exhibited excellent magnetic refrigeration material with a wide temperature range and high refrigeration capacity(RC)was reported.Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass was observed with typical spin glass behavior around 15.5 K.In addition,we find that the magnetic entropy change(-△S_(M))originates from the sample undergoing a ferromagnetic(FM)to paramagnetic(PM)transition around 20 K.Under a field change from 0 T to 7 T,the value of maximum magnetic entropy change(-△S_(M)^(max))reaches 12.5 J/kg·K,and the corresponding value of RC reaches 487.7 J/kg in the temperature range from 6 K to 60 K.The large RC and wide temperature range make the Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass be a promising material for application in magnetic refrigerators.展开更多
Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of equipment.Based on the capillary property en...Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of equipment.Based on the capillary property entangled porous metallic wire materials(EPMWM),this paper designed a composite buffer which uses EPMWM and viscous fluid as cushioning materials under the low-speed impact of the recoil force device of weapon equipment(such as artillery,mortar,etc.).Combined with the capillary model,porosity,hydraulic diameter,maximum pore diameter and pore distribution were used to characterize the pore structure characteristics of EPMWM.The calculation model of the damping force of the composite buffer was established.The low-speed impact test of the composite buffer was conducted.The parameters of the buffer under low-speed impact were identified according to the model,and the nonlinear model of damping force was obtained.The test results show that the composite buffer with EPMWM and viscous fluid can absorb the impact energy from the recoil movement effectively,and provide a new method for the buffer design of weapon equipment(such as artillery,mortar,etc.).展开更多
Batik fabric is an integral part of the traditional cloth culture of the Ghanaian traditional setting. However, the batik fabric has marginal usage due to its casual visual appearance. This studio practice seeks to ex...Batik fabric is an integral part of the traditional cloth culture of the Ghanaian traditional setting. However, the batik fabric has marginal usage due to its casual visual appearance. This studio practice seeks to explore the epiphanic revival in the use of metallic finishes on batik substrate to create an enhanced visual appearance with embellished aesthetic sensibilities and diversified use. The researchers adopted the studio-based approach of the qualitative design to manipulate handmade tools, techniques (collagraph) and the batik fabrics through experimentation to produce a glittering mercurial batik fabric which is typically an industrial practice. The studio practice took place at the Textile Design and Technology studio, Takoradi Technical University, Ghana. The traditional batik fabric was manipulated through fabric decoration techniques in accordance with studio-based practices. The Addie model was adopted as a methodological approach in the analysis, design, development, implementation, and evaluation processes of the experimentation processes of the study. Findings revealed that the hand techniques used in the production process for the metallic prints produced interesting accidentals finishes and effects that machine work cannot achieve, producing new discoveries of visual enhancements of traditional batik fabric. Traditional batiks became mercurial with glittery effects. The metallic prints on the fabric also changed its consumption pattern from mere casual fabric to classic and cosmopolitan fabric for varied uses suitable for wearable to non-wearable.展开更多
Recently,a description on a practicability of the Wöhler Curve Method for low-cycle fatigue of metals was given by the author.By the description and the low cycle fatigue test data of 16 MnR steel,it is important...Recently,a description on a practicability of the Wöhler Curve Method for low-cycle fatigue of metals was given by the author.By the description and the low cycle fatigue test data of 16 MnR steel,it is important to show that,for low cycle fatigue of metals,such a way that a stress-based intensity parameter calculated by the linear-elastic analysis is taken to be a stress intensity parameter,S,to establish a relationship between the stress intensity parameter,S,and the fatigue life,N,is practicable.In this paper,many metallic materials from the literature are given to show that the Wöhler Curve Method is well suitable for low-cycle fatigue analysis of metals.展开更多
The monomolecular surface layer of acceptor doped CeO_(2) may become neutral and metallic or charged and semiconducting.This is revealed in the theoretical analysis of the oxygen pressure dependence of the surface def...The monomolecular surface layer of acceptor doped CeO_(2) may become neutral and metallic or charged and semiconducting.This is revealed in the theoretical analysis of the oxygen pressure dependence of the surface defects concentration in acceptor doped ceria with two different dopant types and operated under different oxygen pressures.Recently published experimental data for highly reduced Sm0.2Ce0.8O1.9-x(SDC)containing a fixed valence dopant Sm3+are very different from those published for Pr0.1Ce0.9O_(2)-x(PCO) with the variable valence dopant Pr4+/Pr3+being reduced under milder conditions.The theoretical analysis of these experimental results fits very well the experimental results of SDC and PCO.It leads to the following predictions:the highly reduced surface of SDC is metallic and neutral,the metallic surface electron density of state is gs=0.9×10^(38)J-1·m^(-2)(1.4×1015eV^(-1)·cm^(-2)),the electron effective mass is meff,s=3.3me,and the phase diagram of the reduced surface has theα(fcc)structure as in the bulk.In PCO a double layer is predicted to be formed between the surface and the bulk with the surface being negatively charged and semiconducting.The surface of PCO maintains high Pr^(3+) defect concentration as well as relative high oxygen vacancy concentration at oxygen pressures higher than in the bulk.The reasons for the difference between a metallic and semiconducting surface layer of acceptor doped CeO_(2) are reviewed,as well as the key theoretical considerations applied in coping with this problem.For that we make use of the experimental data and theoretical analysis available for acceptor doped ceria.展开更多
This paper presents a study on CO<sub>2</sub> atmospheric transformation which was reacted directly with lithium hydroxide solution and metallic lithium. This solution was obtained through the reaction bet...This paper presents a study on CO<sub>2</sub> atmospheric transformation which was reacted directly with lithium hydroxide solution and metallic lithium. This solution was obtained through the reaction between metallic lithium and deionized water where hydrogen is produced and by exposing the metal at ambient conditions. In the transformation process, atmospheric CO<sub>2</sub> gas reacts directly with LiOH solution, in both cases, the CO<sub>2</sub> transformation kinetics was different. For this purpose, reactions between CO<sub>2</sub> and LiOH solution were carried out under controlled temperature and the second process only with metallic lithium, which was exposed at room temperature, however, in these two processes lithium carbonate oxide was formed and identified. According to the results, the efficiency in CO<sub>2</sub> transformation is a function of temperature value which was variable until completely obtaining the by-product, its XRD characterization indicated the formation only of Li<sub>2</sub>CO<sub>3</sub> in both procedures. Under laboratory conditions lithium compounds selectively reacted with CO<sub>2</sub>. In the same way, there is an alternative procedure to obtain LiOH and Li<sub>2</sub>CO<sub>3</sub> for different applications in various areas.展开更多
In the past few decades,inspired by the superhydrophobic surfaces(SHPS)of animals and plants such as lotus leaves,rose petals,legs of water striders,and wings of butterflies,preparing metal materials with metallic SHP...In the past few decades,inspired by the superhydrophobic surfaces(SHPS)of animals and plants such as lotus leaves,rose petals,legs of water striders,and wings of butterflies,preparing metal materials with metallic SHPS(MSHPS)have attracted great research interest,due to the great prospect in practical applications.To obtain SHPS on conventional metal materials,it is necessary to construct rough surface,followed by modification with low surface energy substances.In this paper,the action mechanism and the current research status of MSHPS were reviewed through the following aspects.Firstly,the model of wetting theory was presented,and then the progress in MSHPS preparation through chemical etching method was discussed.Secondly,the applications of MSHPS in self-cleaning,anti-icing,corrosion resistance,drag reduction,oil-water separation,and other aspects were introduced.Finally,the challenges encountered in the present application of MSHPS were summarized,and the future research interests were discussed.展开更多
The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great sign...The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.展开更多
Aqueous rechargeable zinc batteries are very attractive for energy storage applications due to their low cost and high safety.However,low operating voltages limit their further development.For the first time,this work...Aqueous rechargeable zinc batteries are very attractive for energy storage applications due to their low cost and high safety.However,low operating voltages limit their further development.For the first time,this work proposes a unique approach to increase the voltages of aqueous zinc batteries by using tri-functional metallic bipolar electrode with good electrochemical activity and ultrahigh electronic conductivity,which not only participates in redox reactions,but also functions as an electrical highway for charge transport.Furthermore,bipolar electrode can replace expensive ion selective membrane to separate electrolytes with different pH;thus,redox couples with higher potential in acid condition and Zn=Zn(OH)^(2-)_(4) couple with lower potential in alkaline condition can be employed together,leading to high voltages of aqueous zinc batteries.Herein,two types of metallic bipolar electrodes of Cu and Ag are utilized based on three kinds of aqueous zinc batteries:Zn–MnO_(2),Zn–I_(2),and Zn–Br_(2).The voltage of aqueous Zn–MnO_(2) battery is raised to 1.84 V by employing one Cu bipolar electrode,which shows no capacity attenuation after 3500 cycles.Moreover,the other Ag bipolar electrode can be adopted to successfully construct Zn–I_(2) and Zn–Br_(2) batteries exhibiting much higher voltages of 2.44 and 2.67 V,which also show no obvious capacity degradation for 1000 and 800 cycles,representing decent cycle stability.Since bipolar electrode can be applied in a large family of aqueous batteries,this work offers an elaborate high-voltage concept based on tri-functional metallic bipolar electrode as a model system to open a door to explore high-voltage aqueous batteries.展开更多
基金supported in part by the National Key R&D Program of China (Grant Nos.2023YFF1203600 and 2023YFF0718400)the National Natural Science Foundation of China (Grant Nos.62122036,12322407,62034004,61921005,and 12074176)+2 种基金the Leading-edge Technology Program of Jiangsu Natural Science Foundation (Grant No.BK20232004)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDB44000000)support from the AIQ Foundation and the eScience Center of Collaborative Innovation Center of Advanced Microstructures。
文摘Detecting tiny deformations or vibrations, particularly those associated with strains below 1%, is essential in various technological applications. Traditional intrinsic materials, including metals and semiconductors, face challenges in simultaneously achieving initial metallic state and strain-induced insulating state, hindering the development of highly sensitive mechanical sensors. Here we report an ultrasensitive mechanical sensor based on a strain-induced tunable ordered array of metallic and insulating states in the single-crystal bronze-phase vanadium dioxide [VO_(2)(B)] quantum material. It is shown that the initial metallic state in the VO_(2)(B) flake can be tuned to the insulating state by applying a weak uniaxial tensile strain. Such a unique property gives rise to a record-high gauge factor of above 607970, surpassing previous values by an order of magnitude, with excellent linearity and mechanical resilience as well as durability. As a proof-of-concept application, we use our proposed mechanical sensor to demonstrate precise sensing of the micro piece, gentle airflows and water droplets. We attribute the superior performance of the sensor to the strain-induced continuous metal-insulator transition in the single-crystal VO_(2)(B) flake, evidenced by experimental and simulation results. Our findings highlight the potential of exploiting correlated quantum materials for next-generation ultrasensitive flexible mechanical sensors, addressing critical limitations in traditional materials.
基金The computational resources were provided by the Cambridge Tier-2 sys-tem operated by the University of Cambridge Research Computing Service and funded by the UK EPSRC(Grant No.EP/P020259/1).
文摘Evidence for metallization in dense oxygen has been reported for over 30 years[Desgreniers et al.,J.Phys.Chem.94,1117(1990)]at a now routinely accessible 95 GPa[Shimizu et al.,Nature 393,767(1998)].However,despite the longevity of this result and the technological advances since,the nature of the metallic phase remains poorly constrained[Akahama et al.,Phys.Rev.Lett.74,4690(1995);Goncharov et al.,Phys.Rev.B 68,224108(2003);Ma,Phys.Rev.B 76,064101(2007);and Weck et al.,Phys.Rev.Lett.102,255503(2009)].In this work,through Raman spectroscopy,we report the distinct vibrational characteristics of metallicζ-O_(2) from 85 to 225 GPa.In comparison with numerical simulations,wefind reasonable agreement with the candidate structure up to about 150 GPa.At higher pressures,the C2/mstructure is found to be unstable and incompatible with experimental observations.Alternative candidate structures,and Ci,with C2/m C2/conly two molecules in the primitive unit cell,are found to be stable and more compatible with measurements above 175 GPa,indicative of the dissociation of(O_(2))4 units.Further,we report and discuss a strong hysteresis and metastability with the precursory phaseϵ-O_(2).Thesefindings will reinvigorate experimental and theoretical work into the dense oxygen system,which will have importance for oxygen-bearing chemistry,prevalent in the deep Earth,as well as fundamental physics.
基金supported by the NSAF under Grant No.U1830206,the National Key R&D Program of China under Grant No.2017YFA0403200the National Natural Science Foundation of China under Grant Nos.11874424 and 12104507the Science and Technology Innovation Program of Hunan Province under Grant No.2021RC4026.
文摘Entropy production in quasi-isentropic compression (QIC) is critically important for understanding the properties of materials under extremeconditions. However, the origin and accurate quantification of entropy in this situation remain long-standing challenges. In this work, a framework is established for the quantification of entropy production and partition, and their relation to microstructural change in QIC. Cu50Zr50is taken as a model material, and its compression is simulated by molecular dynamics. On the basis of atomistic simulation-informed physicalproperties and free energy, the thermodynamic path is recovered, and the entropy production and its relation to microstructural change aresuccessfully quantified by the proposed framework. Contrary to intuition, entropy production during QIC of metallic glasses is relativelyinsensitive to the strain rate ˙γ when ˙γ ranges from 7.5 × 10^(8) to 2 × 10^(9)/s, which are values reachable in QIC experiments, with a magnitudeof the order of 10^(−2)kB/atom per GPa. However, when ˙γ is extremely high (>2 × 10^(9)/s), a notable increase in entropy production rate with˙γ is observed. The Taylor–Quinney factor is found to vary with strain but not with strain rate in the simulated regime. It is demonstrated thatentropy production is dominated by the configurational part, compared with the vibrational part. In the rate-insensitive regime, the increase inconfigurational entropy exhibits a linear relation to the Shannon-entropic quantification of microstructural change, and a stretched exponential relation to the Taylor–Quinney factor. The quantification of entropy is expected to provide thermodynamic insights into the fundamentalrelation between microstructure evolution and plastic dissipation.
基金supported by the National Natural Science Foundation of China(22078215)Research Project by Shanxi Scholarship Council of China(2021-055)。
文摘In this work,a new ZnO/CoNiO_(2)/CoO/C metal oxides composite is prepared by cost-effective hydrothermal method coupled with annealing process under N_(2) atmosphere.Notably,the oxidation-defect annealing environment is conducive to both morphology and component of the composite,which flower-like ZnO/CoNiO_(2)/CoO/C is obtained.Benefited from good chemical stability of ZnO,high energy capacity of CoNiO_(2) and CoO and good conductivity of C,the as-prepared sample shows promising electrochemical behavior,including the specific capacity of 1435 C·g^(-1) at 1 A·g^(-1),capacity retention of 87.3%at 20 A·g^(-1),and cycling stability of 90.5%for 3000 cycles at 5 A·g^(-1),respectively.Furthermore,the prepared ZnO/CoNiO_(2)/CoO/C/NF//AC aqueous hybrid supercapacitors device delivers the best specific energy of 55.9 W·h·kg^(-1) at 850 W·kg^(-1).The results reflect that the as-prepared ZnO/CoNiO_(2)/CoO/C microflowers are considered as high performance electrode materials for supercapacitor,and the strategy mentioned in this paper is benefit to prepare mixed metal oxides composite for energy conversion and storage.
基金The work was financially supported by the National Key Research and Development Program of China(Grant Nos.2018YFA0703600,2021YFA0716302,and 2021YFA0718703)the National Natural Science Foundation of China(Grant Nos.51825104 and 52192602)China Postdoctoral Science Foundation(Grant No.2022T150691).
文摘Melt treatment is well known to have an important influence on the properties of metallic glasses(MGs).However,for the MGs quenched from different melt temperatures with a quartz tube,the underlying physical origin responsible for the variation of properties remains poorly understood.In the present work,we systematically studied the influence of melt treatment on the thermal properties of a Zr50Cu36Al14 glass-forming alloy and unveiled the microscopic origins.Specifically,we quenched the melt at different temperatures ranging from 1.1Tl to 1.5Tl(Tl is the liquidus temperature)to obtain melt-spun MG ribbons and investigated the variation of thermal properties of the MGs upon heating.We found that glass transition temperature,Tg,increases by as much as 36 K,and the supercooled liquid region disappears in the curve of differential scanning calorimetry when the melt is quenched at a high temperature up to 1.5Tl.The careful chemical analyses indicate that the change in glass transition behavior originates from the incorporation of oxygen and silicon in the molten alloys.The incorporated oxygen and silicon can both enhance the interactions between atoms,which renders the cooperative rearrangements of atoms difficult,and thus enhances the kinetic stability of the MGs.
基金National Key Research and Development Program of China(2018YFC1106702)Guangdong Basic and Applied Basic Research Foundation(2020A1515011301,2019A1515110067 and 2020A1515110055)+1 种基金Shenzhen Basic Research Project(JCYJ20210324120001003,JCYJ20200109144608205 and JCYJ20200109144604020)IER Foundation(HT-JDCXY-201902 and HT-JD-CXY-201907)for financial support.
文摘In the present work,seven Mg-Zn-Ag alloys with the nominal composition of Mg_(96-x)Zn_(x)Ag_(4)(x=17,20,23,26,29,32,35 in at.%)were prepared by induction melting and single-roller melt-spinning.The X-ray diffraction(XRD)analyses indicate the metallic glasses with three composition of Mg_(73)Zn_(23)Ag_(4),Mg_(70)Zn_(26)Ag_(4),and Mg_(67)Zn_(29)Ag_(4)were obtained successfully.The differential scanning calorimetry(DSC)measurement was used to obtain the characteristic temperature of Mg-Zn-Ag metallic glasses for the glass-forming ability analysis.The maximum glass transition temperature(Trg)was found to be 0.525 with a composition close to Mg_(67)Zn_(29)Ag_(4),which results in the best glass-forming ability.Moreover,the immersion test in simulated body fluid(SBF)demonstrate the relative homogeneous corrosion behavior of the Mg-Zn-Ag metallic glasses.The corrosion rate of Mg-Zn-Ag metallic glasses in SBF solution decreases with the increase of Zn content.The sample Mg_(67)Zn_(29)Ag_(4)has the lowest corrosion rate of 0.19mm/yr,which could meet the clinical application requirement well.The in vitro cell experiments show that the Madin-Darby canine kidney(MDCK)cells cultured in sample Mg_(67)Zn_(29)Ag_(4)and its extraction medium have higher activity.However,the Mg-Zn-Ag metallic glasses exhibit obvious inhibitory effect on human rhabdomyosarcoma(RD)tumor cells.The present investigations on the glass-forming ability,corrosion behavior,cytocompatibility and tumor inhibition function of the Mg-Zn-Ag based metallic glass could reveal their biomedical application possibility.
基金supported by the National Natural Science Foundation of China (Grant Nos. 52031016 and 11804027)the China Scholarship Council for financial support during part of this work
文摘The early stage evolution of local atomic structures in a multicomponent metallic glass during its crystallization process has been investigated via molecular dynamics simulation.It is found that the initial thermal stability and earliest stage evolution of the local atomic clusters show no strong correlation with their initial short-range orders,and this leads to an observation of a novel symmetry convergence phenomenon,which can be understood as an atomic structure manifestation of the ergodicity.Furthermore,in our system we have quantitatively proved that the crucial factor for the thermal stability against crystallization exhibited by the metallic glass is not the total amount of icosahedral clusters,but the degree of global connectivity among them.
基金the support by the National Natural Science Foundation of China(52072137 and 52272207)。
文摘Lithium-ion batteries(LIBs)with fast-charging capability are essential for enhancing consumer experience and accelerating the global market adoption of electric vehicles.However,achieving fast-charging capability without compromising energy density,cycling lifespan,and safety of LIBs remains a significant challenge due to the formation of dendritic Li metal on graphite anode under fast charging condition.In view of this,the fundamentals for the dendritic metallic Li formation and the strategies for suppressing metallic Li plating based on analyzing the entire Li^(+)transport pathway at the anode including electrolyte,pore structure of electrode,and surface and bulk of materials are summarized and discussed in this review.Besides,we highlight the importance of designing thick electrodes with fast Li^(+)transport kinetics and comprehensively understanding the interaction between solid electrolyte interphase(SEI)and Li^(+)migration in order to avoid the formation of dendritic Li metal in practical fast-charging batteries.Finally,the regulation of Li metal plating with plane morphology,instead of dendritic structure,on the surface of graphite electrode under fast-charging condition is analyzed as a future direction to achieve higher energy density of batteries without safety concerns.
基金support for this research provided by the National Natural Science Foundation of China(Grant No.52105458)Beijing Natural Science Foundation(Grant No.3222009)+1 种基金Huaneng Group Science and Technology Research Project(No:HNKJ22-H105)China Postdoctoral Science Foundation(Grant No.2022M711807)。
文摘High-aspect-ratio metallic surface microstructures are increasingly demanded in breakthrough applications,such as high-performance heat transfer enhancement and surface plasmon devices.However,the fast and cost-effective fabrication of high-aspect-ratio microstructures on metallic surfaces remains challenging for existing techniques.This study proposes a novel cutting-based process,namely elliptical vibration chiseling(EV-chiseling),for the high-efficiency texturing of surface microstructures with an ultrahigh aspect ratio.Unlike conventional cutting,EV-chiseling superimposes a microscale EV on a backward-moving tool.The tool chisels into the material in each vibration cycle to generate an upright chip with a high aspect ratio through material deformation.Thanks to the tool’s backward movement,the chip is left on the material surface to form a microstructure rather than falling off.Since one microstructure is generated in one vibration cycle,the process can be highly efficient using ultrafast(>1 kHz)tool vibration.A finite element analysis model is established to explore the process mechanics of EV-chiseling.Next,a mechanistic model of the microstructured surface generation is developed to describe the microstructures’aspect ratio dependency on the process parameters.Then,surface texturing tests are performed on copper to verify the efficacy of EV-chiseling.Uniformed micro ribs with a spacing of 1–10μm and an aspect ratio of 2–5 have been successfully textured on copper.Compared with the conventional EV-cutting that uses a forward-moving tool,EV-chiseling can improve the aspect ratio of textured microstructure by up to 40 times.The experimental results also verify the accuracy of the developed surface generation model of microstructures.Finally,the effects of elliptical trajectory,depth of cut,tool shape,and tool edge radius on the surface generation of micro ribs have been discussed.
基金the financial support by the National Natural Science Foundation of China(No.12272094)the Natural Science Foundation of Fujian Province of China(No.2022J01541)Natural Science Foundation of Hubei Province of China(No.2022CFB441)。
文摘An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering equipment.The impact response and the energy dissipation mechanism of hat-shaped EWMD under different quasi-static compression deformations(2-7 mm)and impact heights(100-200 mm)are investigated using experimental and numerical methods.The results demonstrate distinct stages in the quasi-static mechanical characteristics of hat-shaped EWMD,including stiffness softening,negative stiffness,and stiffness hardening.The loss factor gradually increases with increasing compression deformation before entering the stiffness hardening stage.Under impact loads,the hat-shaped EWMD exhibits optimal impact energy absorption when it enters the negative stiffness stage(150 mm),resulting in the best impact isolation effect of metallic buffer.However,the impact energy absorption significantly decreases when hat-shaped EWMD enters the stiffness hardening stage.Interestingly,quasi-static compression analysis after experiencing different impact loads reveals the disappearance of the negative stiffness phenomenon.Moreover,with increasing impact loads,the stiffness hardening point progressively shifts to an earlier stage.
基金Project supported by the National Natural Science Foundation of China (Grant No.52031016)。
文摘The dramatic temperature-dependence of liquids dynamics has attracted considerable scientific interests and efforts in the past decades, but the physics of which remains elusive. In addition to temperature, some other parameters, such as pressure, loading and size, can also tune the liquid dynamics and induce glass transition, which makes the situation more complicated. Here, we performed molecular dynamics simulations for Ni_(50)Zr_(50) bulk liquid and nanodroplet to study the dynamics evolution in the complex multivariate phase space, especially along the isotherm with the change of pressure or droplet size. It is found that the short-time Debye–Waller factor universally determines the long-time relaxation dynamics no matter how the temperature, pressure or size changes. The basic correlation even holds at the local atomic scale. This finding provides general understanding of the microscopic mechanism of dynamic arrest and dynamic heterogeneity.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52371203 and 52271192)the Ministry of Science and Technology of China(Grant No.2021YFB3501201)。
文摘Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass exhibited excellent magnetic refrigeration material with a wide temperature range and high refrigeration capacity(RC)was reported.Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass was observed with typical spin glass behavior around 15.5 K.In addition,we find that the magnetic entropy change(-△S_(M))originates from the sample undergoing a ferromagnetic(FM)to paramagnetic(PM)transition around 20 K.Under a field change from 0 T to 7 T,the value of maximum magnetic entropy change(-△S_(M)^(max))reaches 12.5 J/kg·K,and the corresponding value of RC reaches 487.7 J/kg in the temperature range from 6 K to 60 K.The large RC and wide temperature range make the Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass be a promising material for application in magnetic refrigerators.
基金supported by the National Natural Science Foundation of China (Grant No.51805086)。
文摘Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of equipment.Based on the capillary property entangled porous metallic wire materials(EPMWM),this paper designed a composite buffer which uses EPMWM and viscous fluid as cushioning materials under the low-speed impact of the recoil force device of weapon equipment(such as artillery,mortar,etc.).Combined with the capillary model,porosity,hydraulic diameter,maximum pore diameter and pore distribution were used to characterize the pore structure characteristics of EPMWM.The calculation model of the damping force of the composite buffer was established.The low-speed impact test of the composite buffer was conducted.The parameters of the buffer under low-speed impact were identified according to the model,and the nonlinear model of damping force was obtained.The test results show that the composite buffer with EPMWM and viscous fluid can absorb the impact energy from the recoil movement effectively,and provide a new method for the buffer design of weapon equipment(such as artillery,mortar,etc.).
文摘Batik fabric is an integral part of the traditional cloth culture of the Ghanaian traditional setting. However, the batik fabric has marginal usage due to its casual visual appearance. This studio practice seeks to explore the epiphanic revival in the use of metallic finishes on batik substrate to create an enhanced visual appearance with embellished aesthetic sensibilities and diversified use. The researchers adopted the studio-based approach of the qualitative design to manipulate handmade tools, techniques (collagraph) and the batik fabrics through experimentation to produce a glittering mercurial batik fabric which is typically an industrial practice. The studio practice took place at the Textile Design and Technology studio, Takoradi Technical University, Ghana. The traditional batik fabric was manipulated through fabric decoration techniques in accordance with studio-based practices. The Addie model was adopted as a methodological approach in the analysis, design, development, implementation, and evaluation processes of the experimentation processes of the study. Findings revealed that the hand techniques used in the production process for the metallic prints produced interesting accidentals finishes and effects that machine work cannot achieve, producing new discoveries of visual enhancements of traditional batik fabric. Traditional batiks became mercurial with glittery effects. The metallic prints on the fabric also changed its consumption pattern from mere casual fabric to classic and cosmopolitan fabric for varied uses suitable for wearable to non-wearable.
文摘Recently,a description on a practicability of the Wöhler Curve Method for low-cycle fatigue of metals was given by the author.By the description and the low cycle fatigue test data of 16 MnR steel,it is important to show that,for low cycle fatigue of metals,such a way that a stress-based intensity parameter calculated by the linear-elastic analysis is taken to be a stress intensity parameter,S,to establish a relationship between the stress intensity parameter,S,and the fatigue life,N,is practicable.In this paper,many metallic materials from the literature are given to show that the Wöhler Curve Method is well suitable for low-cycle fatigue analysis of metals.
基金financially supported by the Technion V.P.for Research Fund(No.2023320)。
文摘The monomolecular surface layer of acceptor doped CeO_(2) may become neutral and metallic or charged and semiconducting.This is revealed in the theoretical analysis of the oxygen pressure dependence of the surface defects concentration in acceptor doped ceria with two different dopant types and operated under different oxygen pressures.Recently published experimental data for highly reduced Sm0.2Ce0.8O1.9-x(SDC)containing a fixed valence dopant Sm3+are very different from those published for Pr0.1Ce0.9O_(2)-x(PCO) with the variable valence dopant Pr4+/Pr3+being reduced under milder conditions.The theoretical analysis of these experimental results fits very well the experimental results of SDC and PCO.It leads to the following predictions:the highly reduced surface of SDC is metallic and neutral,the metallic surface electron density of state is gs=0.9×10^(38)J-1·m^(-2)(1.4×1015eV^(-1)·cm^(-2)),the electron effective mass is meff,s=3.3me,and the phase diagram of the reduced surface has theα(fcc)structure as in the bulk.In PCO a double layer is predicted to be formed between the surface and the bulk with the surface being negatively charged and semiconducting.The surface of PCO maintains high Pr^(3+) defect concentration as well as relative high oxygen vacancy concentration at oxygen pressures higher than in the bulk.The reasons for the difference between a metallic and semiconducting surface layer of acceptor doped CeO_(2) are reviewed,as well as the key theoretical considerations applied in coping with this problem.For that we make use of the experimental data and theoretical analysis available for acceptor doped ceria.
文摘This paper presents a study on CO<sub>2</sub> atmospheric transformation which was reacted directly with lithium hydroxide solution and metallic lithium. This solution was obtained through the reaction between metallic lithium and deionized water where hydrogen is produced and by exposing the metal at ambient conditions. In the transformation process, atmospheric CO<sub>2</sub> gas reacts directly with LiOH solution, in both cases, the CO<sub>2</sub> transformation kinetics was different. For this purpose, reactions between CO<sub>2</sub> and LiOH solution were carried out under controlled temperature and the second process only with metallic lithium, which was exposed at room temperature, however, in these two processes lithium carbonate oxide was formed and identified. According to the results, the efficiency in CO<sub>2</sub> transformation is a function of temperature value which was variable until completely obtaining the by-product, its XRD characterization indicated the formation only of Li<sub>2</sub>CO<sub>3</sub> in both procedures. Under laboratory conditions lithium compounds selectively reacted with CO<sub>2</sub>. In the same way, there is an alternative procedure to obtain LiOH and Li<sub>2</sub>CO<sub>3</sub> for different applications in various areas.
基金the financial support of Shanghai Pujiang Program(22PJD001)the Scientific Research Project from Science and Technology Commission of Shanghai Municipality(19DZ1204903)the Fundamental Research Funds for the Central Universities(2232021G-11)。
文摘In the past few decades,inspired by the superhydrophobic surfaces(SHPS)of animals and plants such as lotus leaves,rose petals,legs of water striders,and wings of butterflies,preparing metal materials with metallic SHPS(MSHPS)have attracted great research interest,due to the great prospect in practical applications.To obtain SHPS on conventional metal materials,it is necessary to construct rough surface,followed by modification with low surface energy substances.In this paper,the action mechanism and the current research status of MSHPS were reviewed through the following aspects.Firstly,the model of wetting theory was presented,and then the progress in MSHPS preparation through chemical etching method was discussed.Secondly,the applications of MSHPS in self-cleaning,anti-icing,corrosion resistance,drag reduction,oil-water separation,and other aspects were introduced.Finally,the challenges encountered in the present application of MSHPS were summarized,and the future research interests were discussed.
基金supported by the Science and Technology Research Project to Henan Provincial Department of Natural Resources(Henan Natural Resources Letter[2019]373–10)。
文摘The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.
基金The authors would like to acknowledge the financial support sponsored by Ten-thousand Talents Program,K.C.Wong Pioneer Talent Program,Shanghai Pujiang Program (Grant No.19PJ1410600)the National Natural Science Foundation of China (Grant No.51901240).
文摘Aqueous rechargeable zinc batteries are very attractive for energy storage applications due to their low cost and high safety.However,low operating voltages limit their further development.For the first time,this work proposes a unique approach to increase the voltages of aqueous zinc batteries by using tri-functional metallic bipolar electrode with good electrochemical activity and ultrahigh electronic conductivity,which not only participates in redox reactions,but also functions as an electrical highway for charge transport.Furthermore,bipolar electrode can replace expensive ion selective membrane to separate electrolytes with different pH;thus,redox couples with higher potential in acid condition and Zn=Zn(OH)^(2-)_(4) couple with lower potential in alkaline condition can be employed together,leading to high voltages of aqueous zinc batteries.Herein,two types of metallic bipolar electrodes of Cu and Ag are utilized based on three kinds of aqueous zinc batteries:Zn–MnO_(2),Zn–I_(2),and Zn–Br_(2).The voltage of aqueous Zn–MnO_(2) battery is raised to 1.84 V by employing one Cu bipolar electrode,which shows no capacity attenuation after 3500 cycles.Moreover,the other Ag bipolar electrode can be adopted to successfully construct Zn–I_(2) and Zn–Br_(2) batteries exhibiting much higher voltages of 2.44 and 2.67 V,which also show no obvious capacity degradation for 1000 and 800 cycles,representing decent cycle stability.Since bipolar electrode can be applied in a large family of aqueous batteries,this work offers an elaborate high-voltage concept based on tri-functional metallic bipolar electrode as a model system to open a door to explore high-voltage aqueous batteries.