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Gradient age-precipitation behavior induced by gradient nano-grain in Mg-Gd-Ag-Zr alloy

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Journal of Iron and Steel Research International 2025年第1期32卷 19-24页

作者： Bang-jun Li jia-peng Sun Jing Han Guo-song wu College of Materials Science and Engineering Hohai UniversityNanjing 210024JiangsuChina School of Mechanical and Electrical Engineering China University of Mining and TechnologyXuzhou 221116JiangsuChina

Gradient nano-grained structure is frequently engineered into metallic materials,including Mg alloys,to achieve superior combination of strength and ***,the influence of this microstructural feature on aging precipitation behavior remains inadequately *** this study,the age-precipitation behavior of a gradient nano-grained Mg-Gd-Ag-Zr alloy prepared via ultrasonic severe surface rolling was *** result indicates that the aging precipitation behavior exhibits a depth-dependent variation within this *** the nano-grained surface layer,hierarchicalβnano-precipitates are predominant,while at greater depths,the precipitates consist ofβnanoparticles located at grain boundaries,along with intragranularβ′andγ″*** formation ofβnano-precipitates deviates from the conventional precipitation behavior observed in Mg-Gd-Ag alloys,and is attributed to the high density of defects induced by the surface nano-grained *** finding advances our understanding of the precipitation behavior in the alloys with heterogeneous microstructure.

关键词： Mg alloy Gradient Precipitation Aging behavior Microstructure

Quantitative Effects of Velocity and Residual Pressure Level on Aerodynamic Noise of Ultra-High-Speed Maglev Trains

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Fluid Dynamics & Materials Processing 2025年第1期21卷 205-220页

作者： Lanxi Zhang Yuming peng Yudong wu School of Mechanical Engineering Southwest Jiaotong UniversityChengdu610031China School of Intelligent Manufacturing Chengdu Technological UniversityChengdu610031China

The challenge of aerodynamic noise is a key obstacle in the advancement of low-pressure tube ultra-high-speed maglev transportation,demanding urgent *** study utilizes a broadband noise source model to perform a quantitative analysis of the aerodynamic noise produced by ultra-high-speed maglev trains operating in low-pressure ***,an external flow field calculation model for the ultra-high-speed maglev train is ***,numerical simulations based on the broadband noise source model are used to examine the noise *** impact of the train speed and pressure level on noise generation is investigated ***,a correlation formula is *** results reveal that the amplitude of sound source changes in the streamlined region of the head and tail cars of the train is large,and the amplitude of changes for the middle car is *** noise source strength increases with speed,with a quadrupole noise source becoming dominant when the train speed exceeds 600 km/*** a speed of 1000 km/h,the noise source intensity from the streamlined area at the rear of the train overcomes that at the ***,the noise source decreases as the pressure level in the tube *** the pressure level drops to 0.01 atm,the quadrupole noise source intensity of a train running at 600 km/h significantly weakens and falls below that of the dipole noise source.

关键词： Low-pressure tube aerodynamic noise train speed quantitative analysis

Observation of acoustic hybrid topological phases induced by the p-d orbital interactions

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 128-135页

作者： Xiao Xiang Feng Gao Yu-Gui peng peng wu Zong-Lin Li Xue-Feng Zhu School of Physics and Innovation Institute Huazhong University of Science and TechnologyWuhan 430074China

In spinless systems,growing attention has recently been attracted to synthetic gauge fields,which redefine the fundamental crystal symmetries by utilizing the projective algebraic ***,synthetic gauge fields have been commonly investigated in single orbital systems,and explorations on hybrid orbitals remain elusive in ***,we report the experimental observation of hybrid topological phases induced by hybrid synthetic gauge flux,which is formed by the interaction between p and d orbitals embedded in acoustic *** breaking the translation symmetries of L_(x) and/or L_(y),we unambiguously demonstrate the first-order Möbius edge states and higher-order corner *** work establishes a platform for seeking exotic topological phases induced by hybrid-orbitals interactions and initializing the framework of hybrid-orbitalsrelated topological *** applications can be anticipated in scenarios such as high-quality sensing and robust wave trapping due to the stepwise energy distribution of the hybrid topological phase.

关键词： topological insulator synthetic gauge field projective symmetry corner states

Alumina supported platinum-ceria catalyst for reverse water gas shift reaction

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Journal of Rare Earths 2025年第2期43卷 284-294页

作者： Na jiang Weiwei Wang Haoxin Liu Meiyao wu Chunjiang jia Key Laboratory for Colloid and Interface Chemistry Key Laboratory of Special Aggregated MaterialsSchool of Chemistry and Chemical EngineeringShandong University

The activation of CO2molecules is a fundamental step for their effective *** highdensity oxygen vacancies on the surface of reducible oxides is pivotal for the activation of *** this work,we prepared a series of 0.5PtxCe/Al2O3（x=1,5,10,or 20） catalysts with varying Ce loading and 0.5 wt% of Pt for the reverse water gas shift（RWGS） *** size of CeO2particle increases with Ce ***,the 0.5Pt5Ce/Al2O3catalyst with an average CeO2particle size of 5.5 nm exhibits a very high CO2conversion rate(116.4×10-5molCO2/(gcat·s)) and CO selectivity（96.1%） at 600℃.Our experimental findings reveal that the small-size CeO2in 0.5Pt5Ce/Al2O3possesses a greater capacity to generate reactive oxygen vacancies,promoting the adsorption and activation of *** addition,the oxygen vacancies are cyclically generated and consumed during the reaction,which contributes to the elevated catalytic performance of the *** work provides a general strategy to construct rich oxygen vacancies on CeO2for designing high-performance catalysts in C1chemistry.

关键词： CO 2 activation Ceria Oxygen vacancies Size-effect Reverse water gas shift reaction Rare earths

Crevice corrosion of reinforcing steel in carbonated simulated concrete pore solutions contaminated by chloride

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Journal of Iron and Steel Research International 2025年第1期32卷 293-311页

作者： peng-peng wu Yuan-pei Gong Shao-hua Zhang Yue-zhong Zhang Bao-sheng Liu Guang-ling Song College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024ShanxiChina College of Chemical Engineering and Technology Taiyuan University of Science and TechnologyTaiyuan030024ShanxiChina Department of Ocean Science and Engineering Southern University of Science and TechnologyShenzhen518055GuangdongChina School of Mechanical and Mining Engineering Centre for Advanced Materials Processing and Manufacturing(AMPAM)The University of QueenslandSt LuciaQLD4072Australia State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen UniversityXiamen361005FujianChina

The crevice corrosion of the reinforcing steel in the carbonated simulated concrete pore solutions(SCPSs)containing 0.04 mol/L chloride was *** comparison,the steel without crevice covered on its surface was also *** showed that the crevice corrosion in the uncarbonated SCPS was not triggered and the steel remained passivity by suppressing the anodic dissolution in the crevice *** SCPS was carbonated to have pH values of 10.5 and 11.5,the crevice corrosion was easier to be activated than the widely reported pitting corrosion owing to the rapid oxygen depletion within the crevice,but the crevice corrosion damage might be alleviated to a certain extent due to the relative compact surface film formed inside the *** further carbonation led to the activation dissolution of both the crevice interior and exterior,causing the more serious corrosion *** process of the crevice corrosion was systematically analyzed by combining the electrochemical measurement results and Evens polarization diagram.

关键词： Crevice corrosion Reinforcing steel Carbonation Electrochemical test Rust Evens polarization diagram

High-dense nanocrystalline W-based alloy prepared by hot isostatic pressing with uniform microstructure, ultrahigh hardness and good thermal stability

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Tungsten 2025年第1期7卷 120-136页

作者： Zao-Ming wu Lin He Lin-Sen Ye Xiao-Feng Yang jia-jia Zhang Hong-Bo Lei Institute of Materials China Academy of Engineering Physics

High-density uniform microstructure nanocrystalline W-10wt.% Cr-5wt.% Y（W-10Cr-5Y） alloy with an average grain size of 85 nm and a relative density of 99.8% was successfully prepared.W-Cr-Y alloys with different amounts of second-phase particles were prepared by high-energy ball milling and hot isostatic pressing *** effects of composition design,ball milling parameters,and sintering parameters on the microstructure of W-Cr-Y alloys were studied.A feasible technology for controlling the synthesis of high-density nanocrystalline W-based alloys has been *** microstructure analysis of nanocrystalline W-10Cr-5Y alloy shows that there are two types of doping in the second phase:intergranular doping and intragranular *** "uniform distribution YOx-rich particles" effectively suppresses the grain growth of W and leads to the formation of nanocrystalline W-10Cr-5Y alloy.W-10Cr-5Y has an ultra-high hardness,with a Vickers hardness of 1312±12 kgf·***-temperature annealing treatment shows that W-10Cr-5Y has good thermal stability at 1000 and1100℃,as demonstrated by the comparison of Vickers hardness and grain size between annealed and unannealed alloys.

关键词： Hot isostatic pressing Microstructure Nanocrystalline tungsten Thermal stability Vickers hardness

Exploration of evolutionary mechanisms shaping KZFP and retrotransposon interactions

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Science Bulletin 2025年第3期70卷 328-332页

作者： Qian wu Junqin Xu jiaxin Zeng Yixuan Wang peng Yang Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation Clinical Research Center for Anesthesiology and Perioperative MedicineTranslational Research Institute of Brain and Brain-Like IntelligenceShanghai Fourth People’s HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghai 200092China Institute for Regenerative Medicine State Key Laboratory of Cardiology and Medical Innovation CenterShanghai East HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghai 200092China

Retrotransposon expansion has profoundly reshaped genomes[1],[2].As crucial defense mechanisms that counteract retrotransposons in humans,members of the Krüppel-associated box(KRAB)zinc finger(ZF)protein(KZFP)family ... 详细信息

关键词： shaped expansion mechanisms

Role of Surface Processes and Mantle Plumes in the Formation of Microcontinents:Insights from Numerical Modeling and the Seychelles Microcontinent Case Study

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Journal of Earth Science 2025年第1期36卷 233-249页

作者： Zhijie jia Pietro Sternai jianbing peng School of Geological Engineering and Geomatics Chang'an UniversityXi'an 710054China Key Laboratory of Western Mineral Resources and Geological Engineering Ministry of Education Chang'an UniversityXi'an 710064China Department of Earth and Environmental Sciences University of Milan-BicoccaMilan 20126Italy

Mantle plumes and surface erosion and sediment deposition affect the modes of continental lithospheric rupturing in extensional tectonic settings,modulating the evolution of rifting ***,their relative contributions to the overall evolution of rifting margins and possible roles in the formation of microcontinent are still ***,we use coupled geodynamic and surface processes numerical modeling to assess the extent to which surface processes may determine the formation of microcontinent during lithospheric stretching in presence or absence of a mantle plume *** modeling results indicate that fast extension rates and hillslope(i.e.,diffusion)erosion promote ridge jump events and therefore the formation of *** the contrary,efficient fluvial erosion and far-reaching sediment transport(i.e.,stream power erosion)inhibits ridge jump events and the formation of *** ridge jump event and overall evolution in our numerical models is consistent with the shift from the Mascarene Ridge to the Carlsberg Ridge that determined the formation of the Seychelles *** therefore speculate that hillslope erosion,rather than fluvial erosion,was predominant during the formation of the Seychelles,a possible indication of overall dry local climate conditions.

关键词： continental rifting surface processes mantle plume seychelles microcontinent surface reactions

Advantages of the Multimodel Ensemble Approach for Subseasonal Precipitation Prediction in China and the Driving Factor of the MJO

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Advances in Atmospheric Sciences 2025年第3期42卷 551-563页

作者： Li GUO Jie wu Qingquan LI Xiaolong jia China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Collaborative Innovation Centre On Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210066China

Based on the hindcasts from five subseasonal-to-seasonal(S2S)models participating in the S2S Prediction Project,this study evaluates the performance of the multimodel ensemble(MME)approach in predicting the subseasonal precipitation anomalies during summer in China and reveals the contributions of possible driving *** results suggest that while single-model ensembles(SMEs)exhibit constrained predictive skills within a limited forecast lead time of three pentads,the MME illustrates an enhanced predictive skill at a lead time of up to four pentads,and even six pentads,in southern *** on both deterministic and probabilistic verification metrics,the MME consistently outperforms SMEs,with a more evident advantage observed in probabilistic *** superior performance of the MME is primarily attributable to the increase in ensemble size,and the enhanced model diversity is also a contributing *** reliability of probabilistic skill is largely improved due to the increase in ensemble members,while the resolution term does not exhibit consistent ***,the Madden–Julian Oscillation(MJO)is revealed as the primary driving factor for the successful prediction of summer precipitation in China using the *** improvement by the MME is not solely attributable to the enhancement in the inherent predictive capacity of the MJO itself,but derives from its capability in capturing the more realistic relationship between the MJO and subseasonal precipitation anomalies in *** study establishes a scientific foundation for acknowledging the advantageous predictive capability of the MME approach in subseasonal predictions of summer precipitation in China,and sheds light on further improving S2S predictions.

关键词： multimodel ensemble subseasonal predictions summer precipitation S2S model MJO