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Impact of Mo/Ni alloying on microstructural modulation and low-temperature toughness of high-strength low-alloy steel

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Journal of Iron and Steel Research International 2024年第7期31卷 1746-1762页

作者： Wei Liu Hong-li Zhao Bing-xing Wang Yong Tian state Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina

The high-strength low-alloy steel plates with varying Ni/Mo contents were manufactured using the thermos-mechanical control *** investigation was conducted to explore the effect of Ni/Mo microalloying on microstructure evolution and mechanical properties of the *** results revealed that the increase in Ni content from 1 to 2 wt.%reduced the transition temperature of ferrite and the growth range of ferritic grain was narrowed,which promoted grain *** optimized combination of grain size,high-angle grain boundaries(HAGBs),and martensite-austenite(M-A)islands parameter contributed to the excellent impact toughness of S1 steel at-100℃(impact absorbed energy of 218.2 J at-100℃).As the Mo increases from 0 to 2 wt.%,the matrix structure changes from multiphase structure to granular bainite,which increases the average effective grain size to~4.62 pm and reduces HAGBs proportion to~36.22%.With these changes,the low-temperature impact toughness of S3 steel is *** addition,based on the analysis of the characteristics of crack propagation path,it was found that M-A islands with low content(~2.21%)and small size(~1.76 pm)significantly retarded crack propagation,and the fracture model of M-A islands with different morphologies was further ***,correlation between behaviour of delamination and toughness was further analysed by observing delamination size and impact energy parameters.

关键词： High-strength low-alloy steel Microstructural regulation Ni addition Mo addition Crack propagation Low-temperature toughness

Comparative analysis of frictional behavior and mechanism of molybdenum ditelluride with different structures

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Friction 2024年第1期12卷 110-119页

作者： Lina ZHANG Xinfeng TAN Jianguo JIAO Dan GUO Jianbin LUO state Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

Two-dimensional(2D)transition metal dichalcogenides(TMDCs)have layered structures with excellent tribological *** the energy difference between hexagonal-molybdenum ditelluride(2H-MoTe_(2))and distorted octahedral-molybdenum ditelluride(1T′-MoTe_(2))is very small among the transition metal dichalcogenides(TMDCs),MoTe_(2) becomes one of the most promising candidates for phase *** our experiment,we found that the friction force and friction coefficient(COF)of 2H-MoTe_(2) were an order of magnitude smaller than those of 1T′-MoTe_(2) by the atomic force microscope(AFM)*** friction difference between 1T′-MoTe_(2) and 2H-MoTe_(2) was further verified in molecular dynamics(MD)*** density functional theory(DFT)calculations suggest that the friction contrast is related to the difference in sliding energy barrier of the potential energy surface(PES)for a tip sliding across the *** PES obtained from the DFT calculation indicates that the maximum energy barrier and the minimum energy path(MEP)energy barrier of 2H-MoTe_(2) are both smaller than those of 1T′-MoTe_(2),which means that less energy needs to be dissipated during the sliding *** difference in energy barrier of the PES could be ascribed to its larger interlayer spacing and weaker Mo–Te interatomic interactions within the layers of 2H-MoTe_(2) than those of 1T′-MoTe_(2).The obvious friction difference between 1T′-MoTe_(2) and 2H-MoTe_(2) not only provides a new non-destructive means to detect the phase transition by the AFM,but also provides a possibility to tune friction by controlling the phase transition,which has the potential to be applied in extreme environments such as space lubrication.

关键词： friction two-dimensional(2D)materials distorted octahedral-molybdenum ditelluride(1T′-MoTe_(2)) hexagonal-molybdenum ditelluride(2H-MoTe_(2)) phase transition

Improving actionable warning identification via the refined warning-inducing context representation

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Science China(Information Sciences) 2024年第5期67卷 321-322页

作者： Xiuting GE Chunrong FANG Xuanye LI Quanjun ZHANG Jia LIU Zhihong ZHAO Zhenyu CHEN state Key Laboratory for Novel Software Technology Nanjing University

Static analysis tools(SATs) have shown potential ability in software quality assurance [1]. However, SATs report an overwhelming number of warnings, where most warnings are unactionable ones(i.e., warnings that are not acted on or fixed by developers). It is not a trivial task for developers to find actionable warnings(i.e., warnings that are acted on and fixed by developers) in all reported warnings. Hence,the excessive unactionable warnings seriously impede the usability of SATs [2].

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Phase diagram of muonium hydride:the significant effect of dimensionality

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Communications in Theoretical Physics 2024年第2期76卷 182-187页

作者： Jieru Hu Massimo Boninsegni Department of Physics University of Alberta state Key Laboratory of Precision Spectroscopy East China Normal University

We carry out a theoretical investigation of the low-temperature phase diagram of muonium hydride in two dimensions,using numerical *** is shown that the phase diagram of this substance is qualitatively different in two and three ***,while in three dimensions it is essentially identical to that of parahydrogen,i.e.,only displaying a single(crystalline)*** two dimensions it is very similar to that of^(4)He,with an equilibrium liquid phase that turns superfluid at a temperature as high as~2.2 K,and crystallizes under applied *** is a well-described case of a continuous-space condensed matter system whose ground state equilibrium phase is qualitatively altered by dimensional reduction.

关键词： quantum fuids and solids quantum Monte Carlo phase diagrams

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A critical review on solid-state welding of high entropy alloys-processing,microstructural characteristics and mechanical properties of joints

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Defence Technology（防务技术） 2024年第4期34卷 78-133页

作者： Tushar Sonar Mikhail Ivanov Evgeny Trofimov Aleksandr Tingaev Ilsiya Suleymanova Department of Welding Engineering Institution of Engineering and TechnologySouth Ural State University(National Research University)Chelyabinsk454080Russia Department of Materials Science Physical and Chemical Properties of MaterialsInstitution of Engineering and TechnologySouth Ural State University(National Research University)Chelyabinsk454080Russia

The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistance,high temperature strength and corrosion *** alloys are manufactured by the equal mixing or larger proportions of five or more alloying *** exhibit superior mechanical performance compared to traditional engineering alloys because of the extensive alloying composition and higher entropy of *** state welding(SSW)techniques such as friction stir welding(FSW),rotary friction welding(RFW),diffusion bonding(DB)and explosive welding(EW)have been efficiently deployed for improving the microstructural integrity and mechanical properties of welded HEA *** HEA interlayers revealed greater potential in supressing the formation of deleterious intermetallic phases and maximizing the mechanical properties of HEAs *** similar and dissimilar joining of HEAs has been manifested to be viable for HEA systems which further expands their industrial ***,the main objective of this review paper is to present a critical review of current state of research,challenges and opportunities and main directions in SSW of HEAs mainly CoCrFeNiMn and Al_xCoCrFeNi *** state of the art of problems,progress and future outlook in SSW of HEAs are critically reviewed by considering the formation of phases,microstructural evolution and mechanical properties of HEAs joints.

关键词： High entropy alloys Solid state welding Microstructure Mechanical properties

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An efficient and safe strategy for germ cell-specific automatic excision of foreign DNA in F1 hybrid transgenic silkworms

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Insect Science 2024年第1期31卷 28-46页

作者： Dingpei Long Rongpeng Liu Yang Huang Anyao Fu Yuli Zhang Zhanzhang Hao Qiang Li Hanfu Xu Zhonghuai Xiang Aichun Zhao state Key Laboratory of Resource Insects Institute of Sericulture and Systems BiologySouthwest UniversityChongqingChina Department of Biology Georgia State UniversityAtlantaGeorgiaUSA Guangxi Institute of Sericulture Science NanningGuangxiChina Department of Mathematics and Statistics Georgia State UniversityAtlantaGeorgiaUSA

The safety of transgenic technology is a major obstacle in the popularization and use of transgenic silkworms and their *** sericulture,only the first filial generation(F1)hybrid eggs produced by cross-breeding Japanese and Chinese original strains are usually used for the large-scale breeding of silkworms,but this may result in uncontrolled transgene dispersal during the popularization and application of the F1 hybrid transgenic *** address this issue,we developed a safe and efficient strategy using the GAL4/Upstream activating sequence(UAS)system,the FLP/flippase recognition target(FRT)system,and the gonad-specific expression gene promoters(RSHP1p and Nanosp)for the germ cell-specific automatic excision of foreign DNA in the F1 hybrid transgenic *** established 2 types of activator strains,R1p::GAL4-Gr and Nsp::GAL4-Gr,containing the testis-specific GAL4 gene expression cassettes driven by RSHP1p or Nanosp,respectively,and 1 type of effector strain,UAS::FLP-Rg,containing the UAS-linked FLP gene expression *** FLP recombinase-mediated sperm-specific complete excision of FRT-flanked target DNA in the F1 double-transgenic silkworms resulting from the hybridization of R1p::GAL4-Gr and UAS::FLP-Rg was 100%,whereas the complete excision efficiency resulting from the hybridization of Nsp::GAL4-Gr and UAS::FLP-Rg ranged from 13.73%to 80.3%.Additionally,we identified a gene,sw11114,that is expressed in both testis and ovary of Bombyx mori,and can be used to establish novel gonad-specific expression systems in transgenic *** strategy has the potential to fundamentally solve the safety issue in the production of F1 transgenic silkworm eggs and provides an important reference for the safety of transgenic technology in other insect species.

关键词： Bombyx mori FLP/FRT system GAL4/UAS system germ cell-specific excision safety of transgenic technology transgenic silkworm

Reconstruction of biomimetic ionic channels within covalent organic frameworks for ultrafast and selective uranyl capture

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Science China Chemistry 2024年第10期67卷 3423-3431页

作者： Cheng-Rong Zhang Xiao-Juan Chen Cheng-Peng Niu Cheng Meng Shun-Mo Yi Xin Liu Jia-Xin Qi Qiu-Xia Luo Ru-Ping Liang Jian-Ding Qiu state Key Laboratory of Nuclear Resources and Environment East China University of Technology College of Chemistry and Chemical Engineering Nanchang University

The efficient extraction of uranium, as the primary component of nuclear energy, holds significant implications. Drawing inspiration from the charge interaction observed in biological ion channels, we encapsulated negatively charged polystyrene sulfonate(PSS) or sodium polystyrene carboxylate(PVBA) into the nanochannels of amidoxime functionalized covalent organic framework(COF-AO) in-situ to alter the cavity environment of COF-AO. The synthesized COF-AO-PSS and COF-AO-PVBA are used for ultra-fast and highly selective uranium recovery. The negatively charged PSS/PVBA was confined in the COF-AO channel providing the driving force for uranium transport and blocking other ions, thus creating a highly selective “uranium highway”. Additionally, introducing sulfonate groups or carboxyl groups into COF-AO offers supplementary coordination environments and weak interactions with uranium. Due to charge-assisted migration and various interaction mechanisms, both COF-AO-PSS and COF-AO-PVBA exhibit faster adsorption kinetics and higher selectivity compared to COF-AO alone. Their adsorption capacities are 3.8 times and 2.4 times that of COF-AO alone respectively which highlights the necessity for constructing biomimetic ion channels in uranium adsorption processes. This work presents a bionic adsorbent based on covalent organic frameworks(COFs) for the first time, overcoming environmental and equipment limitations associated with traditional photocatalysis and electrocatalysis methods for uranium capture, opening up new avenues for designing multifunctional materials that mimic biological systems.

关键词： covalent organic frameworks Uranium biomimetic ion-channels adsorption

Theoretical Design of Defects as a Driving Force for Ion Transport in Li3OBr Solid Electrolyte

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Energy & Environmental Materials 2024年第3期7卷 147-157页

作者： Xingyun Luo Yanlu Li Xian Zhao state Key Lab of Crystal Materials and Institute of Crystal Materials Shandong University Center for Optics Research and Engineering Shandong University

Due to ever-increasing concerns about safety issues in using Li ionic batteries,solid electrolytes have extensively *** Li-rich antiperovskite Li3OBr has been considered as a promising solid electrolyte candidate,but it still suffers challenges to achieve a high ionic conductivity owing to the high intrinsic symmetry of the crystal ***,we presented a design strategy that introduces various point defects and grain boundaries to break the high lattice symmetry of Li3OBr crystal,and their effect and microscopic mechanism of promoting the migration of Li-ion were explored *** has been found that Liiare the dominant defects responsible for the fast Li-ion diffusion in bulk Li3OBr and its surface,but they are easily trapped by the grain boundaries,leading to the annihilating of the Frenkel defect pair V'Li+Li,and thus limits the V'Lidiffusion at the grain *** VBrdefect near the grain boundaries can effectively drive V'Liacross the grain boundary,thereby converting the carrier of Li+migration from Li,in the bulk and surface to V'Liat the grain boundary,and thus improving the ionic conductivity in the whole Li3OBr *** work provides a comprehensive insight into the Li+transport and conduction mechanism in the Li3OBr *** opens a new way of improving the conductivity for all-solid-state Li electrolyte material through the defect design.

关键词： defects density functional theory ionic migration solid electrolyte

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Performance of evolutionary optimized machine learning for modeling total organic carbon in core samples of shale gas fields

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Petroleum 2024年第1期10卷 150-164页

作者： Leonardo Goliatt C.M.Saporetti L.C.Oliveira E.Pereira Department of Computational and Applied Mechanics Federal University of Juiz de Fora Department of Computational Modeling Polytechnic Institute Rio de Janeiro State University Petrobras Department of Stratigraphy and Paleontology Rio de Janeiro State University

Rock samples' TOC content is the best indicator of the organic matter in source rocks. The origin rock samples' analysis is used to calculate it manually by specialists. This method requires time and resources because it relies on samples from many well intervals in source rocks. Therefore, research has been done to aid this effort. Machine learning algorithms can estimate total organic carbon instead of well logs and stratigraphic studies. In light of these efforts, the current work present a study on automating the total organic carbon estimation using machine learning approaches improved by an evolutionary methodology to give the model flexibility and precision. Genetic algorithms, differential evolution, particle swarm optimization, grey wolf optimization, artificial bee colony, and evolution strategies were used to improve machine learning models to predict TOC. The six metaheuristics were integrated into four machine learning methods: extreme learning machine, elastic net linear model, linear support vector regression, and multivariate adaptive regression splines. Core samples from the YuDong-Nan shale gas field, located in the Sichuan basin, were used to evaluate the hybrid strategy. The findings show that combining machine learning models with an evolutionary algorithms in a hybrid fashion produce flexible models that accurately predict TOC. The results show that, independent of the metaheuristic used to guide the model selection, optimized extreme learning machines attained the best performance scores according to six metrics. Such hybrid models can be used in exploratory geological research,particularly for unconventional oil and gas resources.

关键词： Total organic carbon Hybrid models Automated machine learning Evolutionary algorithms Geology