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A unified model for ductile-to-brittle transition in body-centered cubic Metals

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Journal of Materials Science & Technology 2023年第10期141卷 193-198页

作者： Yu-Heng Zhang En Ma Jun Sun Wei-Zhong Han State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China

Ductile-to-brittle transition(DBT)is a well-known phenomenon in body-centered-cubic(BCC)Metals,in-termetallics and semiconductor materials.A quantitative prediction of the DBT temperature,however,has so far remained intractable.Here,we propose a unified model based on the efficacy of dislocation multi-plication as the controlling factor for DBT,with the dislocation source efficiency governed by the relative mobility of screw versus edge dislocations.The model successfully predicts the DBT temperature of iron,molybdenum and tungsten,and also covers the influence of grain size,initial dislocation density,and the multiplicity of dislocation sources.A comparison with experiments indicates that the model captures the key DBT features,providing new insight into the toughness of BCC Metals.

关键词： Metals Ductile Brittle Dislocation Mobility

Liquid ordering induced heterogeneities in homogeneous nucleation during solidification of pure Metals

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Journal of Materials Science & Technology 2022年第11期106卷 77-89页

作者： Avik Mahata Tanmoy Mukhopadhyay Mohsen Asle Zaeem School of Engineering Brown UniversityProvidenceRI02912USA Department of Engineering Science University of OxfordOxfordOX13PJUK Department of Aerospace Engineering Indian Institute of Technology KanpurKanpurIndia Department of Mechanical Engineering Colorado School of MinesCO80401USA

Homogeneous crystal nucleation is prone to formation of defects and often experiences heterogeneities,the inferences of which are crucial in processing crystalline materials and controlling their physical properties. It has been debated in literature whether the associated heterogeneities are an integral part of the homogenous nucleation. In this study by integrating a probabilistic approach with large-scale molecular dynamics simulations based on the most advanced high-temperature interatomic potentials, we attempt to address the ambiguity over the sources and mechanisms of heterogeneities in homogenous nucleation during solidification of pure melts. Different classes of structured Metals are investigated for this purpose,including face-centered cubic aluminum, body-centered cubic iron, and hexagonal close-packed magnesium. The results reveal, regardless of the element type or the solidified crystal structure, that the densification process of liquid Metals is accompanied by short-range orderings of atoms prior to the formation of crystals, controlling the heterogeneities during homogenous nucleation.

关键词： Homogeneous nucleation Heterogeneity Solidification Metals Molecular dynamics simulation Probability density

Chemical speciation,bioavailability and risk assessment of potentially toxic Metals in soils around petroleum product marketing company as environmental degradation indicators

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Petroleum Research 2022年第2期7卷 286-296页

作者： Festus M.Adebiyi Dayo A.Ayeni Dangote Oil Refinery Company Ltd. 1Alfred Rewane RoadFalomoIkoyiLagosNigeria Department of Chemistry Obafemi Awolowo UniversityIle-IfeNigeria

The study aims at investigating chemical speciation,bioavailability and risk assessment of some selected Metals in soils around refined petroleum depot using the concentrations of the Metals as variables to ascertain the impacts of the activities within the petroleum depot.Surface-soils(0e15 cm)were collected from within the premises of Pipelines and Product Marketing Company,Ibadan,Nigeria,while control samples were collected at 200 m away from the study location.Electrical conductivity and pH were measured using a calibrated dual purpose meter,while elemental analysis was done using Atomic absorption spectroscopy analytical technique.The results showed that the soils exhibited low ecological risk;minor enrichment for Mn,moderately severe enrichment for Ni and Co,severe enrichment for Cr and extremely severe enrichment for Pb,Zn and Cd.There was low contamination factor for Pb,Ni,Mn,Cr,Co,and Fe and moderate contamination by Zn and Cd.Geo-accumulation index results indicated unpolluted with Ni,Mn,Cr,Co,and Fe,unpolluted to moderately polluted with Pb and Zn and moderately to strongly polluted with Cd.Inter-element clustering results indicated chemical affinity and/or similar genetic origin among the elements.Speciation analysis suggested that Fe,Co,Cr,Cd,and Ni occurred in the residual fraction;Pb,and Zn in the carbonate fraction,while Mn have its highest percentage in the Fe eMn oxides fraction.Percentage mobility and bioavailability showed that most of the Metals are immobile and non-bioavailable.Study concluded that the oil-impacted soils were contaminated with most of the Metals,but with low ecological risk.

关键词： Atomic absorption spectrometry Chemical speciation Metals Refined petroleum product Risk assessment Soil

Baseline establishment for Metals in the western Clarion-Clipperton Zone

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Acta Oceanologica Sinica 2022年第11期41卷 12-22页

作者： Cai Lin Yang Liu Ronggen Jiang Jinmin Chen Baohong Chen Weili Wang Kaiwen Zhou Hui Lin Third Institute of Oceanography Ministry of Natural ResourcesXiamen 361005China

Resource exploitation in the Clarion-Clipperton Zone(CCZ)is of major research interest worldwide,but its influence on the environment is poorly understood,especially due to the lack of baseline values for Metals in the surrounding sediment.This work aimed to establish the baseline values of 17 Metals(Ba,Ca,K,Mg,Mn,Na,Ag,As,B,Cd,Co,Cr,Cu,Hg,Ni,Pb,and Zn)using normalization,the cumulative frequency curve method considering a total of 172 samples taken from 8 multitube cores and 1 box sediment core collected in the western CCZ during the COMRA-45 cruise campaign from August to September 2017.The baseline values of the evaluated Metals were as follows:1932 mg/kg for Ba,29512 mg/kg for Ca,18150 mg/kg for K,17120 mg/kg for Mg,6747 mg/kg for Mn,28546 mg/kg for Na,0.571 mg/kg for Ag,5.00 mg/kg for As,94.4 mg/kg for B,0.626 mg/kg for Cd,104 mg/kg for Co,76.1 mg/kg for Cr,370 mg/kg for Cu,0.028 mg/kg for Hg,190 mg/kg for Ni,27.5 mg/kg for Pb and 156 mg/kg for Zn.Our findings would fill the baseline value gap in the study area and further improve accuracy of environmental impact assessments on the impact of resource exploitation.

关键词： baseline Metals normalization cumulative frequency curve

Preface to the special topic on Metals and their compounds for lithium ion/metal batteries

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Tungsten 2024年第1期6卷 162-163页

作者： Ying-Ze Song Wen-Long Cai Gao-Ran Li State Key Laboratory of Environment-Friendly Energy Materials Southwest University of Science and TechnologyMianyang 621010China College of Materials Science and Engineering Sichuan UniversityChengdu 610064China School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China

The fast development of electronics and electric devices has inspired the practical application of lithium ion/metal batteries.Along this line,the Metals and their compounds as electrode materials as well as the corresponding mechanism for energy storage have gained extensive international attention.The as-organized special topic focuses on W,Mo,Co,Zr,Hf,Re,Ta,Nb,V-based Metals and their compounds for lithium ion/metal batteries.This special topic involves four reviews and four research papers totally,providing the latest advances of transition Metals and their related compounds for rechargeable lithium ion/metal batteries.

关键词： lithium Metals gained

Spectral absorption control of femtosecond laser-treated Metals and application in solar-thermal devices

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Light(Science & Applications) 2020年第1期9卷 1851-1859页

作者： Sohail A.Jalil Bo Lai Mohamed ElKabbash Jihua Zhang Erik M.Garcell Subhash Singh Chunlei Guo The Institute of Optics University of RochesterRochesterNY 14627USA These authors contributed equally:Sohail A.JalilBo Lai

Direct femtosecond(fs)laser processing is a maskless fabrication technique that can effectively modify the optical,electrical,mechanical,and tribological properties of materials for a wide range of potential applications.However,the eventual implementation of fs-laser-treated surfaces in actual devices remains challenging because it is difficult to precisely control the surface properties.Previous studies of the morphological control of fs-laser-processed surfaces mostly focused on enhancing the uniformity of periodic microstructures.Here,guided by the plasmon hybridisation model,we control the morphology of surface nanostructures to obtain more control over spectral light absorption.We experimentally demonstrate spectral control of a variety of Metals[copper(Cu),aluminium(Al),steel and tungsten(W)],resulting in the creation of broadband light absorbers and selective solar absorbers(SSAs).For the first time,we demonstrate that fs-laser-produced surfaces can be used as high-temperature SSAs.We show that a tungsten selective solar absorber(W-SSA)exhibits excellent performance as a high-temperature solar receiver.When integrated into a solar thermoelectric generation(TEG)device,W-SSA provides a 130%increase in solar TEG efficiency compared to untreated W,which is commonly used as an intrinsic selective light absorber.

关键词： steel absorber Metals

Distribution and relationship between antimicrobial resistance genes and heavy Metals in surface sediments of Taihu Lake,China

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Journal of Environmental Sciences 2019年第3期31卷 323-335页

作者： Okugbe E.Ohore Felix Gyawu Addo Songhe Zhang Nini Han Kwaku Anim-Larbi Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes College of Environment Hohai University

Heavy Metals, pharmaceuticals, and other wastes released into the environment can significantly influence environmental antibiotic resistance. We investigated the occurrence of 22 antimicrobial resistance genes(ARGs) and 10 heavy metal concentrations, and the relationship between ARGs and heavy Metals in surface sediment from seven sites of Lake Taihu. The results showed significant correlations(p Metals(Fe, Mn, Cr, Cu, Zn, among others) in the Lake. In the surface sediments, heavy Metals showed an interaction with resistance genes, but the strength of interaction was diminished with increasing depth. For most of the heavy Metals, the concentration of elements in the top sediments was higher than that in other depths.Tetracycline resistance genes(tet(A), tet(B), tet(D), tet(E) and tet(O), β-lactam resistance genes(SHV, TEM, CTX, OXA and OXY) and sulfonamide resistance genes(sulA, sul1, sul2, sul3 and int-1) were detected. They showed a trend which inferred a statistically significant increase followed by decreases in the relative abundance of these ARGs(normalized to 16 S rRNA genes) with increasing depth. This study revealed that tet(A), tet(O), TEM, OXY, int-1, sul1 and sul3 were widespread in surface sediments with high abundance, indicating that these genes deserve more attention in future work.

关键词： Antibiotic resistance genes Heavy Metals Surface sediments Taihu Lake Wastewater treatment plants Pollution

Cumulative Risk Assessment of Exposure to Heavy Metals through Aquatic Products in China

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Biomedical and Environmental Sciences 2021年第8期34卷 606-615页

作者： WANG Hui MAO Wei Feng JIANG Ding Guo LIU Si Jie ZHANG Lei NHC Key Laboratory of Food Safety Risk Assessment Chinese Academy of Medical Science Research UnitChina National Center for Food Safety Risk AssessmentBeijing 100022China Department of Physical and Chemical Test Jilin Provincial Center for Disease Control and PreventionChangchun 130062JilinChina

Objective This study aimed to assess the risk of cumulative exposure to Pb,Cd,Hg,and iAs through aquatic products consumed by Chinese people.Methods Heavy metal concentration data were obtained from the national food contamination monitoring program during 2013–2017.Consumption data were derived from the China National Food Consumption Survey in 2014 and the relative potency factor(RPF)method was used to estimate cumulative exposure for neurotoxicity and nephrotoxicity.Results The results demonstrated that the cumulative exposure based on neurotoxicity was below the lower confidence limit on benchmark doses of lead(BMDL01)for nephrotoxicity and the cumulative exposures were all lower than the provisional tolerable monthly intake(PTMI)of Cd.However,the margin of exposure values(MOEs)of the cumulative exposures for neurotoxicity in the 2–6 year-old group was close to 1 and the cumulative exposure level for nephrotoxicity accounted for 90.21%of the PTMI.Conclusion The cumulative exposures of the 2–6 year-old group to the four heavy Metals did not reach(but came close to)the corresponding safety threshold for both neurotoxicity and nephrotoxicity.Given that there are still other food sources of these four heavy Metals,it is necessary to more closely study their cumulative health effects.

关键词： Arsenic Lead Cadmium Mercury Aquatic products Heavy Metals

Water incubation-induced fluctuating release of heavy Metals in two smelter-contaminated soils

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Journal of Environmental Sciences 2019年第8期31卷 14-23页

作者： Bin Yang Yunzhe Cao Jie Ren Mei Wang Huilong Luo Fasheng Li College of Water Science Beijing Normal University State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences School of Ecology and Environment Inner Mongolia University

The soil moisture regime can affect the release of heavy Metals in soil. In the previous studies, slightly polluted soils or artificially contaminated soil samples were considered to investigate the effect of soil moisture. We used highly smelter-contaminated and aged soils to study the release of typical heavy Metals(Cu, Zn, Cd and Pb) induced by water incubation in batch experiments with characterization via speciation and X-ray diffraction analyses(XRD). The results show that the leachable concentrations of the heavy Metals increased slightly in the first 30 days, decreased drastically between 30 and 90 days, and immobilized relatively constant thereafter. The fluctuation was ascribed to the changes of soil Eh and pH, the reductive dissolution of crystalline iron oxides, the formation of new amorphous iron oxides, the absorption of dissolved organic matter and the precipitation of metal sulfide. Speciation analysis indicated that a proportion of the soil heavy Metals was transformed from an exchangeable fraction to a less labile fraction after water incubation. And the presence of a lead iron oxide phase and the peak increasing of zinc sulfide were observed via XRD analyses. Finally, water incubation restrained the release of heavy Metals after 180 days of incubation, and reduced the leachability of Cu, Zn, Cd and Pb by as much as 1.61%–7.21% for soil A and 0.43%–3.36% for soil B, respectively. The study findings have implications for the formulation of risk control and management strategies for heavy Metals in smelter-contaminated soils.

关键词： Smelter-contaminated soil Heavy Metals Water incubation Release Fraction