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Evolution of inclusions in vacuum induction melting of superalloys containing 70%return material

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Journal of Iron and Steel Research International 2024年第3期31卷 719-728页

作者： jin-guo Gao Shu-lei {1. Shu-feng {1. jing-she li Wei liu Meng-jing Zhao An-ren wang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Metallurgical and Building Materials Business Department China International Engineering Consulting CorporationBeijing 100048China

The variation law of inclusions type and size in the vacuum induction melting process and ingot of Ni-based superalloy containing 70%return material was studied by industrial test sampling,and the mechanism of inclusions formation was analyzed with thermodynamic *** results show that there are mainly two types of composite inclusions in the vacuum induction melting of Ni-based superalloys,which are nitride-and oxide-based composite inclusions,like Al_(2)O_(3)-SiO_(2)-Cr_(2)O_(3),TiN-(Mo,Nb)C,*** type and proportion of inclusions from the center to the edge of the vacuum induction ingot did not change *** number density of inclusions from the center to the edge of the ingot varied less,and the size of inclusions became smaller from the center to the *** addition,thermodynamic calculations show that oxides(M_(2)O_(3))are present in the liquid phase and mainly contain Al,Ti,Cr,Fe and O *** nitride consists mainly of Ti and N and contains small amounts of Cr,C,Nb,and Mo *** is consistent with the results of industrial *** the temperature decreases,the precipitation phases such as M_(2)O_(3),MN,γ,MC,δ,γ'andμphases are gradually precipitated,where oxides and nitrides are present in the liquid *** contents of O and N elements are the main influencing factors for the inclusions content and precipitation temperature;when the nitrogen content is reduced to below 0.001.%,it can make MN precipitate below the liquid-phase line.

关键词： Ni-based superalloy Vacuum induction melting Return material Inclusion Thermodynamic

Review on laser directed energy deposited aluminum alloys

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International Journal of Extreme Manufacturing 2024年第2期6卷 84-131页

作者： Tian-Shu liu Peng Chen {1. Qiu hong-Yu yang Nicholas Tan Yew jin Youxiang Chew Di wang Ruidi li Qi-Chuan Jiang Chaolin Tan Singapore Institute of Manufacturing Technology(SIMTech) Agency for ScienceTechnology and Research(A∗STAR)5 Cleantech LoopSingapore 636732Singapore State Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130025People’s Republic of China Key Laboratory of Automobile Materials Ministry of Education and Department of Materials Science and EngineeringJilin UniversityChangchun 130025People’s Republic of China School of Mechanical&Automotive Engineering South China University of TechnologyGuangzhou 510640People’s Republic of China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083People’s Republic of China

lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al *** a mainstream AM technique,laser-directed energy deposition(LDED)shows good scalability to meet the requirements for large-format component manufacturing and ***,LDED Al alloys are highly challenging due to their inherent poor printability(*** laser absorption,high oxidation sensitivity and cracking tendency).To further promote the development of LDED high-performance Al alloys,this review offers a deep understanding of the challenges and strategies to improve printability in LDED Al *** porosity,cracking,distortion,inclusions,element evaporation and resultant inferior mechanical properties(worse than laser powder bed fusion)are the key challenges in LDED Al *** parameter optimizations,in-situ alloy design,reinforcing particle addition and field assistance are the efficient approaches to improving the printability and performance of LDED Al *** underlying correlations between processes,alloy innovation,characteristic microstructures,and achievable performances in LDED Al alloys are *** benchmark mechanical properties and primary strengthening mechanism of LDED Al alloys are *** review aims to provide a critical and in-depth evaluation of current progress in LDED Al *** opportunities and perspectives in LDED high-performance Al alloys are also outlined.

关键词： additive manufacturing laser directed energy deposition(LDED) aluminum alloys printability aluminum matrix composite auxiliary fields mechanical properties

(DarkAI)Mapping the large-scale density field of dark matter using artificial intelligence

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 143-159页

作者： Zitong wang {1. Shi Xiaohu yang Qingyang li Yanming liu Xiaoping li School of Aerospace Science and Technology Xidian UniversityXi’an 710126China Department of Astronomy School of Physics and Astronomyand Shanghai Key Laboratory for Particle Physics and CosmologyShanghai Jiao Tong UniversityShanghai 200240China Tsung-Dao Lee Institute and Key Laboratory for Particle Physics Astrophysics and CosmologyMinistry of EducationShanghai Jiao Tong UniversityShanghai 200240China Institute for Astronomy University of EdinburghRoyal ObservatoryEdinburgh EH93HJUnited Kingdom

Herein,we present a deep-learning technique for reconstructing the dark-matter density field from the redshift-space distribution of dark-matter *** built a UNet-architecture neural network and trained it using the COmoving Lagrangian Acceleration fast simulation,which is an approximation of the N-body simulation with 51.3 particles in a box size of 500 h^(-1.***,we tested the resulting UNet model not only with training-like test samples but also with standard N-body simulations,such as the Jiutian simulation with 61.43particles in a box size of 1.00 h^(-1.Mpc and the ELUCID simulation,which has a different *** real-space dark-matter density fields in the three simulations can be reconstructed reliably with only a small reduction of the cross-correlation power spectrum at 1.and 1.%levels at k=0.1.and 0.3 h Mpc-1.*** reconstruction clearly helps to correct for redshift-space distortions and is unaffected by the different cosmologies between the training(Planck201.)and test samples(WMAP5).Furthermore,we tested the application of the UNet-reconstructed density field to obtain the velocity&tidal field and found that this approach provides better results compared with the traditional approach based on the linear bias model,showing a 1..2%improvement in the correlation slope and a 21.1.reduction in the scatter between the predicted and true ***,our method is highly efficient and has excellent extrapolation reliability beyond the training *** provides an ideal solution for determining the three-dimensional underlying density field from the plentiful galaxy survey data.

关键词： dark matter large-scale structure cosmology

Assessment of climate damage in China based on integrated assessment framework

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Advances in Climate Change Research 2024年第1期15卷 124-133页

作者： Jie liu Xiang-Zhen SHI {1. yang Chang-Yi liu jin-Cheng wang Rui-Min ZHU Xue-{1. SHI Qiu-feng liu International Business School Shanxi Normal UniversityXi'an 710062China University of Chinese Academy of Social Sciences Bejing 102488China School of Economics and Management Xinjiang UniversityUrumqi 830046China Global Energy Interconnection Development and Cooperation Organization(GEIDCO) Bejing 100031China Hubei Enshi College Enshi 445099China CMA Earth System Modeling and Prediction Centre China Meteorological AdministrationBeijing 100081China National Climate Centre China Meteorological AdministrationBeijing 100081China

Developing a localized and consistent model framework for climate loss and damage assessment is crucial for the policy-making of climate change mitigation and *** study introduces a comprehensive,multidisciplinary Integrated Assessment Model(IAM)framework for evaluating climate damage in China,utilizing BCC-SESM climate model and FUND sectoral climate damage model under the SSP2-RCPs *** a bottom-up approach,the research estimates climate damage across eight major sectors,recalibrates sectoral climate damage functions and parameters for China,and elucidates distinctions among direct climate loss,market climate loss,and aggregate climate *** findings reveal that the total climate damage function for China follows a quadratic pattern in response to temperature *** 2050,the estimated climate damage is projected to be 5.4%,5.7%,and 8.2%of GDP under RCP2.6,RCP4.5,and RCP8.5,***,both direct and market climate losses are projected to remain below 2%of GDP by 2050,while the aggregate climate loss could reach as high as 8.2%,which is predominantly attributed to non-market *** a sectoral perspective,under the RCP8.5 scenario,human health damage constitutes the largest share(61.9%)of the total climate loss by 2050,followed by sea-level rise damage(1..6%).This study sheds lights on the adaptation policy that should attach importance to the non-market sectors,particularly focusing on human health and sea-level rise.

关键词： Climate loss and damage Integrated assessment model(IAM) FUND model Representative concentration pathways(RCPs)scenario BCC-SESM

Effect of microalloying on wettability and interface characteristics of Zr-based bulk metallic glasses with W substrate

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China Foundry 2024年第4期21卷 352-359页

作者： Zhen Zhang lin-na {1. jin-he wang Zheng-kun li Hua-meng Fu hong li Zheng-wang Zhu Hai-{1. Zhang School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Metallurgy Northeastern UniversityShenyang 110004China

The infiltration casting method is widely employed for the preparation of ex-situ composite ***,the production of composite materials using this method must necessitates a comprehensive understanding of the wettability and interface characteristics between the reinforcing phase and the bulk metallic glasses(BMGs).This work optimized the composition of Zr-based BMGs through microalloying methods,resulting in a new set of Zr-based BMGs with excellent glass-forming *** experiments between the Zr-based BMGs melts and W substrates were conducted using the traditional sessile drop method,and the interfaces were characterized utilizing a scanning electron microscope(SEM)equipped with energy dispersive X-ray spectroscopy(EDS).The work demonstrates that the microalloying method substantially enhances the wettability of the Zr-based BMGs ***,the incorporation of Nb element impedes the formation of W-Zr phases,but the introduction of Nb element does not alter the extent of interdiffusion between the constituent elements of the amorphous matrix and W element,indicating that the influence of Nb element on the diffusion of individual elements is minute.

关键词： Zr-based BMGs infiltration casting method wettability interface characteristics W-Zr phases

Microstructural Evolutions and Mechanical Properties of Energetic Al_(1. (TiZrNbTaMoCr)_(1.) High-Entropy Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 620-632页

作者： Xuan-hong Cai Zhen-Hua {1. Ben Niu jin-feng li Qing {1. Show authors Key Laboratory of Materials Modification By Laser Ion and Electron Beams(Ministry of Education)Engineering Research Center of High Entropy Alloy Materials(Liaoning Province)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Institute of Materials China Academy of Engineering PhysicsMianyang621908China

The present study focuses on investigating the microstructural evolutions and mechanical properties of energetic Al_(1.(TiZrNbTaMoCr)_(1.) refractory high-entropy alloys with the different heat treatments at low Al content state. It is found that even with a reduction in the Al content, the strength of these alloys remains unaffected at room temperature and high temperature, while the plasticity improves significantly. In particular, the coherent BCC/B_(2) microstructure with needle-like B_(2) nanoprecipitates dispersed into the BCC matrix is formed in 873 K-aged Al_(1.Ti_(6)Zr_(2)Nb_(3)Ta_(3)Mo_(0.5)Cr_(0.5) alloy. Therefore, this alloy exhibits the highest compression yield strength (σ_(YS) = 1.33 and 71. MPa) at room temperature and 1.73 K, respectively. After 973 K-aged, the coherent BCC/B_(2) microstructure underwent destabilization, and the B_(2) phase transforms into the brittle Zr5Al3 phase which then coarsens and dominates the microstructure of S3-AlTa_(3) alloy after 1.73 K-aged. Moreover, these current alloys exhibit exceptionally high theoretical exothermic enthalpy (ΔH), surpassing 1.606 J·g^(−1., which highlights their significant potential as innovative high-performance energetic structural materials.

关键词： Refractory high-entropy alloy Coherent microstructure Mechanical property Exothermic enthalpy

Study of the spatial growth of stimulated Brillouin scattering in a gas-filled hohlraum via detecting the driven ion acoustic wave

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Matter and Radiation at Extremes 2024年第2期9卷 36-49页

作者： Chaoxin Chen Tao Gong Zhichao li liang Hao Yonggang liu Xiangming liu Hang Zhao Yaoyuan liu Kaiqiang Pan Qi li Sanwei li Zhijun li Sai jin feng wang Dong yang Laser Fusion Research Center China Academy of Engineering PhysicsMianyangSichuan 621900People’s Republic of China Institute of Applied Physics and Computational Mathematics Beijing 100094People’s Republic of China

In an experiment performed on the Shenguang-III prototype laser facility, collective Thomson scattering (TS) is used to study the spatialgrowth of stimulated Brillouin scattering (SBS) in a gas-filled hohlraum by detecting the SBS-driven ion acoustic wave. High-quality timeresolved SBS and TS spectra are obtained simultaneously in the experiment, and these are analyzed by a steady-state code based on theray-tracing model. The analysis indicates that ion–ion collisions may play an important role in suppressing SBS growth in the Au plasma;as aresult, the SBS excited in the filled gas region is dominant. In the early phase of the laser pulse, SBS originates primarily from the high-densityplasma at the edges of the interaction beam channel, which is piled up by the heating of the interaction beam. Throughout the duration of thelaser pulse, the presence of the TS probe beam might mitigate SBS by perturbing the density distribution around the region overlapping withthe interaction beam.

关键词： scattering filled Brillouin

Prediction for permeability index of blast furnace based on VMD-PSO-BP model

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Journal of Iron and Steel Research International 2024年第3期31卷 573-583页

作者： Xiao-jie liu Yu-jie Zhang Xin {1. Zhi-feng Zhang hong-yang {1. Ran liu Shu-jun Chen School of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210HebeiChina Chengde Branch HBIS Group Co.Ltd.Chengde 067000HebeiChina

The permeability index is one of the important production indicators to monitor the operation of blast *** is crucial to grasp the trends of changes in the new permeability index in *** the complex vibration spectrum of the permeability index,a prediction model of the permeability index based on the VMD-PSO-BP(variational mode decomposition-particle swarm optimization-back propagation)method was ***,the key factors that affect the permeability index of blast furnace were studied from multiple ***,the permeability index was divided into multiple sub-modes based on the difference of frequency bands by the VMD algorithm,and a PSO-BP prediction model was established for each ***,the prediction results of each sub-mode were summed to obtain the final *** results show that the composite prediction accuracy by using the VMD algorithm is 3%higher than that of the traditional prediction method,which has better applicability.

关键词： Big data-Blast furnace Air permeability Variational mode decomposition Particle swarm optimization Back propagation Model prediction

Video caching and scheduling with edge cooperation

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Digital Communications and Networks 2024年第2期10卷 450-460页

作者： Zhidu li Fuxiang li Tong Tang hong Zhang jin yang School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China Advanced Network and Intelligent Connection Technology Key Laboratory of C{1.qing Education Commission of China Chongqing400065China Key Laboratory of Ubiquitous Sensing and Networking in Chongqing Chongqing400065China

In this paper,we explore a distributed collaborative caching and computing model to support the distribution of adaptive bit rate video *** aim is to reduce the average initial buffer delay and improve the quality of user *** the difference between global and local video popularities and the time-varying characteristics of video popularity,a two-stage caching scheme is proposed to push popular videos closer to users and minimize the average initial buffer *** on both long-term content popularity and short-term content popularity,the proposed caching solution is decouple into the proactive cache stage and the cache update *** the proactive cache stage,we develop a proactive cache placement algorithm that can be executed in an off-peak *** the cache update stage,we propose a reactive cache update algorithm to update the existing cache policy to minimize the buffer *** results verify that the proposed caching algorithms can reduce the initial buffer delay efficiently.

关键词： Video service Distributed and collaborative caching Long-term popularity Short-term popularity