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Enhanced helium ion irradiation tolerance in a Fe-Co-Ni-Cr-Al-ti high-entropy alloy with L12 nanoparticles

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Journal of Materials Science & technology 2023年第12期143卷 169-177页

作者： Y.L.Zhao F.L.Meng t.Yang J.H.Luan S.F.Liu G.M.Yeli w.t.lin w.H.Liu X.J.Liu C.t.Liu J.J.Kai School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and Engineering Mechanical Behavior Division of Shenyang National Laboratory for Materials ScienceCity University of Hong KongHong KongChina Department of Mechanical Engineering City University of Hong KongHong KongChina Institute of Nuclear&New Energy technology Tsinghua UniversityBeijing 100084China

L12-strengthened high entropy alloys(HEAs)with excellent room and high-temperature mechanical prop-erties have been proposed as promising candidates as structural materials for advanced nuclear systems.However,knowledge about their radiation response is fairly limited.In the present work,a novel HEA with a high density of L12 nanoparticles was irradiated with He ion at 500°C.transmission electron microscope(tEM)and atom probe tomography(APt)were employed to study the evolution of mi-crostructural stability and radiation-induced segregation.Similar to the single-phase FeCoNiCr HEA,the main microstructural features were numerous large faulted dislocation loops and helium bubbles.while the irradiation resistance of the present L12-strengthened HEA is much improved in terms of reduced bubble size,which could be attributed to the considerable He trapping efficiency of the coherent pre-cipitate/matrix interface and the enhanced capability of the interface for damage elimination when the matrix channel width is narrow.APt analysis revealed that an inverse-Kirkendall-mechanism-dominated radiation-induced segregation(RIS)occurs around bubbles,where a significant Co enrichment and Ni de-pletion can be clearly observed.In addition,the competing dynamics of ballistic mixing and elemental clustering that raised from the irradiation-enhanced diffusion in a highly supersaturated matrix,along with the low precipitation nucleation barrier due to the small lattice misfit,lead to a dynamical pre-cipitation dissolution and re-precipitation appears under irradiation.Such a promising phenomenon is expected to promote a potential self-healing effect and could in turn provide a sustainable irradiation tolerance over the operational lifetime of a reactor.

关键词： L12 nanoparticles High-entropy alloy Helium bubble Phase stability Radiation-induced segregation

He-enhanced heterogeneity of radiation-induced segregation in FeNiCoCr high-entropy alloy

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Journal of Materials Science & technology 2022年第6期101卷 226-233页

作者： w.t.lin G.M.Yeli G.wang J.H.lin S.J.Zhao D.Chen S.F.Liu F.L.Meng Y.R.Li F.He Y.Lu J.J.Kai Department of Mechanical Engineering City University of Hong KongHong KongChina Institute of Nuclear&New Energy technology Tsinghua UniversityBeijingChina Department of Physics Southern University of Science and TechnologyShenzhenChina Centre for Advanced Nuclear Safety and Sustainable Development City University of Hong KongHong KongChina School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhenChina School of Materials Science and Engineering Shanghai UniversityShanghaiChina Nano-Manufacturing Laboratory(NML) City University of Hong Kong Shenzhen Research InstituteShenzhenChina

Radiation-induced segregation(RIS) is a typical non-equilibrium process that can dramatically alter the behavior of defect sinks and material properties under irradiation. However, RIS mechanisms have been rarely studied around small He bubbles owing to the technical challenges involved in direct measurements of local chemistry. Here, using state-of-the-art atom probe tomography, we report the RIS behavior near He bubbles in the Fe Ni Co Cr high-entropy alloy that indicates Co segregates most strongly, followed by weaker Ni segregation, whereas Fe and Cr are depleted almost to the same degree. Exceptionally, the magnitude of Co segregation around He bubbles is higher than previously measured values at voids and dislocation loops. Electron energy-loss spectroscopy was used to measure the He density and pressure inside individual bubbles. we demonstrate that He bubbles are over-pressurized at the irradiation temperature that could result in the vacancy bias and the subsequent vacancy-dominated RIS mechanism.First-principles calculations further reveal that there are repulsive interactions between He and Co atoms that may reduce the frequency of Co-vacancy exchange. As a result, He atoms likely retard Co diffusion via the vacancy mechanism and enhance the heterogeneity of RIS in Co-containing multicomponent alloys. these insights could provide the basis for understanding He effects in nuclear materials and open an avenue for tailoring the local chemical order of medium-and high-entropy alloys.

关键词： High-entropy alloy Radiation-induced segregation He bubbles Atom probe tomography Electron energy-loss spectroscopy

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.t.Jeong S.w.Lee w.J.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

the superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 K.the microstructural refinement of this alloy was achieved by employing high-ratio differential speed rolling.the best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were obtained.During the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 K.therefore,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and mechanisms.In the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation mechanism.It was concluded that solute drag creep is unlikely to occur.During the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain hardening.Deformation mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

MicroRNAs in hepatocellular carcinoma treatment:Charting the path forward

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world Journal of Gastroenterology 2024年第11期30卷 1470-1474页

作者： Hong t lin Antonio F Alvarez Castaneda Somashekar G Krishna Khalid Mumtaz Division of Gastroenterology Hepatology and NutritionDepartment of MedicineThe Ohio State University Wexner Medical CenterColumbusOH 43210United States

MicroRNAs(miRNAs)are recognized for their involvement in the regulation of gene expression and exhibit significant potential in both the prognostic assessment and treatment of hepatocellular carcinoma(HCC).HCC,like other tumors,seldom occurs in isolation;instead,it evolves within a microenvironment featuring oncogenic and tumor-suppressive elements.when combined with suitable delivery vehicles,miRNA technology provides the capability to directly engage with these elements,thereby hindering tumor formation and progression.Ongoing research in this domain holds the promise of enabling a more efficacious and multi-modal treatment approach for HCC in the near future.

关键词： Hepatocellular carcinoma tumor microenvironment MicroRNA Mesenchymal stem cell Exosome

VOC emitted by biopharmaceutical industries:Source profiles,health risks,and secondary pollution

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Journal of Environmental Sciences 2024年第1期135卷 570-584页

作者： Jiawei Ma lin Li State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China National Engineering Laboratory for VOCs Pollution Control Material&technology University of Chinese Academy of SciencesBeijing 101408China

the biopharmaceutical industry contributes substantially to volatile organic compounds(VOCs)emissions,causing growing concerns and social developmental conflicts.this study conducted an on-site investigation of the process-based emission of VOCs from three biopharmaceutical enterprises.In the workshops of the three enterprises,26 VOCs were detected,which could be sorted into 4 classes:hydrocarbons,aromatic hydrocarbons,oxygen-containing compounds,and nitrogen-containing compounds.Ketones were the main components of waste gases,accounting for 44.13%-77.85%of the overall VOCs.Process-based source profiles were compiled for each process unit,with the fermentation and extraction units of tiamulin fumarate being the main source of VOC emissions.Dimethyl heptanone,vinyl acetate,diethylamine,propylene glycol methyl ether(PGME),and benzene were screened as priority pollutants through a fuzzy comprehensive evaluation system.Ground level concentration simulation results of the Gauss plume diffusion model demonstrated that the diffusivity of VOCs in the atmosphere was relatively high,indicating potential non-carcinogenic and carcinogenic risks 1.5-2 km downwind.Furthermore,the process-based formation potentials of ozone and secondary organic aerosols(SOAs)were determined and indicated that N-methyl-2-pyrrolidone,dimethyl heptanone,and PGME should be preferentially controlled to reduce the ozone formation potential,whereas the control of benzene and chlorobenzene should be prioritized to reduce the generation of SOAs.Our results provide a basis for understanding the characteristics of VOC emission by biopharmaceutical industries and their diffusion,potentially allowing the development of measures to reduce health risks and secondary pollution.

关键词： Biopharmaceutical Volatile organic compound Priority pollutant Exposure risk Secondary pollution

Construction of algal-bacterial consortia using green microalgae Chlorella vulgaris and As(Ⅲ)-oxidizing bacteria:As tolerance and metabolomic profiling

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Journal of Environmental Sciences 2024年第5期139卷 258-266页

作者： Xiaoman He Guobing lin Jiayuan Zeng Zhaoguang Yang lin wang College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for water Environment and Agriculture Product Safety Central South UniversityChangsha 410083China

Bioremediation became a promising technology to resolve arsenic(As)contamination in aquatic environment.Since monoculture such as microalgae or bacteria was sensitive to environmental disturbance and vulnerable to contamination,green microalgae Chlorella vulgaris and arsenite(As(Ⅲ))-oxidizing bacteria Pseudomonas sp.SMS11 were co-cultured to construct algal-bacterial consortia in the current study.the effects of algae-bacteria(A:B)ratio and exposure As(Ⅲ)concentration on algal growth,As speciation and metabolomic profile were investigated.Algal growth arrested when treated with 100 mg/L As(Ⅲ)without the co-cultured bacteria.By contrast,co-cultured with strain SMS11 significantly enhanced As tolerance in C.vulgaris especially with A:B ratio of 1:10.All the As(Ⅲ)in culture media of the consortia were oxidized into As(Ⅴ)on day 7.Methylation of As was observed on day 14.Over 1% and 0.5% of total As were converted into dimethylarsinic acid(DMA)after 21days cultivation when the initial concentrations of As(Ⅲ)were 1 and 10 mg/L,respectively.Metabolomic analysis was further performed to reveal the response of consortia metabolites to external As(Ⅲ).the enriched metabolomic pathways were associated with carbohydrate,amino acid and energy metabolisms.tricarboxylic acid cycle and glyoxylate and dicarboxylate metabolism were upregulated under As stress due to their biological functions on alleviating oxidative stress and protecting cells.Both carbohydrate and amino acid metabolisms provided precursors and potential substrates for energy production and cell protection under abiotic stress.Alterations of the pathways relevant to carbohydrate or amino acid metabolism were triggered by energy requirement.

关键词： Microalgae Algal-bacterial consortia As(Ⅲ)-oxidizing bacteria Metabolomics Energy metabolism

A fast forward computational method for nuclear measurement using volumetric detection constraints

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Nuclear Science and techniques 2024年第2期35卷 47-63页

作者： Qiong Zhang lin-Lv lin University of Electronic Science and technology of China Chengdu 610000China

Owing to the complex lithology of unconventional reservoirs,field interpreters usually need to provide a basis for interpretation using logging simulation models.Among the various detection tools that use nuclear sources,the detector response can reflect various types of information of the medium.the Monte Carlo method is one of the primary methods used to obtain nuclear detection responses in complex environments.However,this requires a computational process with extensive random sampling,consumes considerable resources,and does not provide real-time response results.therefore,a novel fast forward computational method(FFCM)for nuclear measurement that uses volumetric detection constraints to rapidly calculate the detector response in various complex environments is proposed.First,the data library required for the FFCM is built by collecting the detection volume,detector counts,and flux sensitivity functions through a Monte Carlo simulation.then,based on perturbation theory and the Rytov approximation,a model for the detector response is derived using the flux sensitivity function method and a one-group diffusion model.the environmental perturbation is constrained to optimize the model according to the tool structure and the impact of the formation and borehole within the effective detection volume.Finally,the method is applied to a neutron porosity tool for verification.In various complex simulation environments,the maximum relative error between the calculated porosity results of Monte Carlo and FFCM was 6.80%,with a rootmean-square error of 0.62 p.u.In field well applications,the formation porosity model obtained using FFCM was in good agreement with the model obtained by interpreters,which demonstrates the validity and accuracy of the proposed method.

关键词： Nuclear measurement Fast forward computation Volumetric constraints

Responses of growth performance,antioxidant function,small intestinal morphology and mRNA expression of jejunal tight junction protein to dietary iron in yellow-feathered broilers

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Journal of Integrative Agriculture 2024年第4期23卷 1329-1337页

作者： Kaiwen Lei Hao wu Jerry w Spears Xi lin Xi wang Xue Bai Yanling Huang Key Laboratory of Animal Science of State Ethnic Affairs Commission Southwest Minzu UniversityChengdu 610041China Key Laboratory of Qinghai-tibetan Plateau Animal Genetic Resource Reservation and Utilization Southwest Minzu UniversityChengdu 610041China Department of Animal Science North Carolina State UniversityRaleighNC 27695-7621USA

this study aimed to investigate the dose-effect of iron on growth performance,antioxidant function.intestinal morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.A total of 7201-d-old yellow-feathered maleb roilers were allocated to 9 treatments with 8 replicate cages of 10 birds per cage.the dietary treatments were consisted of a basal diet(contained 79.6 mg Fe kg^(-1))supplemented with 0,20,40,60,80,160,320,640,and 1,280 mg Fe kg^(-1)in the form of FeSO_(4)·7H_(2)O.Compared with the birds in the control group,birds supplemented with 20mg Fe kg^(-1)had higher average daily gain(ADG)(Ptly decreased ADG(Ptake(ADFI)(Pwith supplementation of 20mg Fe kg^(-1).Malondialdehyde(MDA)concentration in plasma and duodenum increased linearly(Pt MDA concentration in liver and jejunum increased linearly(Ptically(Pwith increased dietary Fe concentration.the villus height(VH)in duodenum and jejunum,and the ratio of villus height to crypt depth(V/C)in duodenum decreased linearly(P?0.05)as dietary Feincreased.As dietary Fe increased,the jejunal relative mRNA abundance of claudin-1 decreased linearly(P=0.001),but the jejunal relative mRNA abundance of zona occludens-1(ZO-1)and occludin decreased linearly(P?0.05)or quadratically(P?0.05).Compared with the supplementation of 20 mg Fe kg^(-1),the supplementation of640 mg Fe kg^(-1)or higher increased(P?0.05)MDA concentrations in plasma,duodenum,and jejunum,decreased VH in the duodenum and jejunum,and the addition of 1,280 mg Fe kg^(-1)reduced(P?0.05)the jejunal tight junction protein(claudin-1,ZO-1,occludin)mRNA abundance.In summary,640 mg of supplemental Fe kg^(-1)or greater was associated with decreased growth performance,increased oxidative stress,disrupted intestinal morphology,and reduced mRNA expression of jejunal tight junction protein.

关键词： iron yellow-feathered broiler antioxidant function intestinal morphology tight junction protein

SMILE soft X-ray Imager flight model CCD370 pre-flight device characterisation

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Earth and Planetary Physics 2024年第1期8卷 25-38页

作者： S.Parsons D.J.Hall O.Hetherington t.w.Buggey t.Arnold M.w.J.Hubbard A.Holland Centre for Electronic Imaging the Open UniversityMilton KeynesMK76AAUK

throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance level.three CCDs have been characterised,the two flight devices and the flight spa re.this has been carried out at the Open University in a bespo ke cleanroom measure ment facility.the results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe rature.However at the nominal ope rating tempe rature(-120℃) it is within the procure ment specifications.Overall,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science mode.the se rial charge transfer inefficiency degrades with temperature in full frame mode.However any charge losses are recovered when binning/frame transfer is implemented.

关键词： CCD soft X-ray imager characterisation SMILE