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Design and optimization of the composition and mechanical properties for non-equiatomic CoCrNi medium-entropy alloys

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journal of Materials Science & Technology 2023年第8期139卷 232-244页

作者： j.X.Yan Z.j.Zhang P.Zhang j.h.liu h.Yu Q.M.hu j.B.Yang Z.F.Zhang Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering Chongqing Jiaotong UniversityChongqing 400074China chool of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China School of Information Science and Engineering Shenyang University of TechnologyShenyang 111003China

The development of multi-principal element alloys(MPEAs,also called as high-or medium-entropy al-loys,hEAs/MEAs)provides tremendous possibilities for materials ***,designing MPEAs with desirable mechanical properties confronts great challenges due to their vast composition *** this work,we provide an essential criterion to efficiently screen the CoCrNi MEAs with outstanding strength-ductility *** negative Gibbs free energy difference△E_(FCC-BCC)between the face-centered cubic(FCC)and body-centered cubic(BCC)phases,the enhancement of shear modulus G and the decline of stacking fault energy(SFE)γ_(isf)are combined as three requisites to improve the FCC phase stability,yield strength,deformation mechanisms,work-hardening ability and ductility in the *** effects of chemical composition on△E_(FCC-BCC),G andγisf were investigated with the first principles calculations for Co_(x)Cr_(33)Ni_(67-x),Co_(33)Cr_(y)Ni_(67-y)and Co_(z)Cr_(66-z)Ni_(34)(0≤x,y≤67 and 0≤z≤66)*** on the essential criterion and the calculation results,the composition space that displays the neg-ative Gibbs free energy difference△E_(FCC-BCC),highest shear modulus G and lowest SFEγ_(isf)was screened with the target on the combination of high strength and excellent *** this context,the optimal composition space of Co-Cr-Ni alloys was predicted as 60 at.%-67 at.%Co,30 at.%-35 at.%Cr and 0 at.%-6 at.%Ni,which coincides well with the previous experimental evidence for Co_(55)Cr_(40)Ni_(5)*** valid-ity of essential criterion is further proved after systematic comparison with numerous experimental data,which demonstrates that the essential criterion can provide significant guidance for the quick exploitation of strong and ductile MEAs and promote the development and application of MPEAs.

关键词： Medium-entropy alloys First-principles calculations Phase stability Stacking-fault energy Strength Ductility

Study on the fatigue and wear characteristics of four wheel materials

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维普期刊数据库

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journal of Modern Transportation 2013年第3期21卷 182-193页

作者： G.Y.Zhou j.h.liu W.j.Wang G.Wen Q.Y.liu State Key Laboratory of Traction Power Tribology Research Institute Southwest Jiaotong University

The fatigue and wear characteristics of four different steel wheel materials are investigated in detail by using rolling contact fatigue and wear bench tests on a jD-1 apparatus, analyzing chemical composition and hardness, and performing profile analysis and micro-morphology analysis. The wear and fatigue behavior of one of the materials under different operation speeds is also investigated. The results show that the wear resistance of the materials has a positive correlation with their carbon content, while fatigue resistance has a negative correlation. Based on hardness analysis as a function of depth into the specimen, the thickness of layers with a steep hardness gradient has a negative correlation with the initial surface hardness in the tests using different materials. The hardness increments, however, have a positive correlation with initial surface hardness. The rolling tests on one material using different rotation speeds show that the hardness increments and the thickness of layers with a steep hardness gradient increase with the rotation speed. The analyses and experimental results demonstrate that two of the four materials exhibit good wear resistance and rolling contact fatigue resistance, making them suitable for either highspeed or heavy axle railroad operations.

关键词： Wheel material . Fatigue . Wear . hardness

Experimental study of a single-cylinder engine fuelled with natural gas-hydrogen mixtures

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Experimental study of a single-cylinder engine fuelled with ...

INFLUENCE OF TOP- TEMPERATURE OF ThERMAL CYCLE ON ThERMAL STRESS/STRAIN AND ThERMAL FATIGUE BEhAVIOR OF PURE IRON

第九届全国氢能学术会议

作者： j.Xu,X.Zhang,j.h.liu Beijing jiao tong University,China

＜正＞The objective of this study is to evaluate the power,efficiency and emissions of an electronic-controlled single-cylinder engine fuelled with pure natural gas and natural gas-hydrogen blends,*** using the orthogonal tests method,a range of engine conditions were *** results show that under certain engine conditions the

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来源： cnki会议评论

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cnki会议

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Acta Metallurgica Sinica(English Letters) 1999年第5期12卷 852-855页

作者： j.h.liu 1) and S.h.jiang 1) and M.Yao 2) 1) Department of mechanical Engineering, Engineering college, Yangzhou University, Yangzhou 225009, China 2) Department of Material Science, Yanshan University, Qinhuangdao 066000, China

By using a self-made thermal fatigue test machine of outer-constraint mode, the influence of top-temperature of thermal cycle T t on thermal stress-strain and thermal fatigue behavior of an industrial pure iron was investigated. The T t was varied from stress/strain 773K to 1073K. The results show that, increasing of T t , the thermal stress-strain cycles can be classified into four types, they are: compressive stress cycle; compressive strain-tensile stress cycle; compressive strain-tensile stress cycle than changing to compressive tensile plastic strain cycle; and finally, compressive tensile plastic strain cycle. It is also revealed that certain relationship does exist between thermal fatigue life and characteristics of thermal stress/strain cycle. When compressive tensile plastic strain cycle were appear by increasing of T t , thermal fatigue life decreasing rapidly. The concept of thermal fatigue transition temperature, and determining method were put up in this thesis.

关键词： thermal fatigue thermal stress-strain

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黄河上游盆地重组所导致的快速侵蚀下切

世界地震译丛 2019年第4期50卷 351-358页

作者： W.h.Craddock E.Kirby N.W.harkins h.P.Zhang X.h.Shi j.h.liu 贾伟(译) 张波(译) 苏琦(校) 不详海南省地震局中国地震局地质研究所南京大学

高起伏的造山高原边缘的快速剥蚀常被用来指代区域地表隆升^(1～3)。然而,诸如岩体隆升的空间差异~4,降雨的地形效应以及冰川~5、滑坡导致的河道堵塞^(6,7)等阻碍河流下切的因素,可能会使剥蚀作用严重滞后于地表抬升~8。本文中,我们通... 详细信息

高起伏的造山高原边缘的快速剥蚀常被用来指代区域地表隆升^(1～3)。然而,诸如岩体隆升的空间差异~4,降雨的地形效应以及冰川~5、滑坡导致的河道堵塞^(6,7)等阻碍河流下切的因素,可能会使剥蚀作用严重滞后于地表抬升~8。本文中,我们通过研究青藏高原东北缘黄河沿岸沉积盆地的地层学、年代学和地貌学特征,重建黄河上游侵蚀下切的时间、速率以及模式。我们发现河流下切的起始时间明显晚于山体开始隆升的时间(14～8Ma)~9。高原边缘的河流下切始于1.8Ma^(10),然后以大约350km/Ma的速度向上游传递^(11)。我们认为该地区在气候驱动下的湖泊扩张并溢出作用是黄河上游快速下切的主要原因,并最终导致了现代黄河地貌的形成。

关键词：黄河上游沉积盆地侵蚀青藏高原东北缘重组起始时间剥蚀作用空间差异

Effects of the Reversely Rotating Assisted Shoulder on Microstructures During the Reverse Dual-rotation Friction Stir Welding

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journal of Materials Science & Technology 2015年第4期31卷 375-383页

作者： j.Q.Li h.j.liu State Key Laboratory of Advanced Welding and joining Harbin Institute of Technology Capital Aerospace Machinery Company

The reverse dual-rotation friction stir welding(RDR-FSW) has the capability to adjust the heat generation because of the separately designed tool shoulder and tool *** welding torque exerted on the workpiece by the reversely rotating shoulder is opposite to that exerted by the rotating tool pin,so the total welding torque is reduced,which is beneficial to reducing the clamping requirement of *** the present paper,a RDR-FSW joint was welded in a condition similar to the optimal welding condition of conventional FSW,and microstructures in various zones were investigated by comparison,aiming to highlight effects of the reversely rotating assisted *** to the heat conduction of the middle cylinder and the bottom end cover on which the assisted shoulder was machined,the thermal effect of RDR-FSW was smaller than that of the conventional ***,the effect of assisted shoulder on the plastic flow or deformation of material or was constrained in a thin layer near the weld top surface,and thus the flow of material especially along the thickness direction was clearly decreased in the *** the heat-affected zone(hAZ),the precipitate coarsening was the main evolution and was completed through the dissolution of small precipitates and the continuous growth of large *** contrast,the dissolution degree of precipitates increased significantly in the thermomechanically affected zone(TMAZ),and a small amount of original meta-stable precipitates transformed to block-shaped stable *** evolutions in the shoulder affected zone(SAZ)and the weld nugget zone were similar,*** majority of original meta-stable precipitates dissolved into the matrix and the remainder transformed to stable precipitates,though the dissolution degree was greater in the *** with the conventional FSW joint,the coarsening degrees of precipitates in the hAZ and TMAZ of RDR-FSW joint were much smaller,as well as the dissolution degrees of p

关键词： Friction stir welding Reverse dual-rotation fricti

Relativistic hartree-Fock model and its recent progress on the description of nuclear structure

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Communications in Theoretical Physics 2022年第9期74卷 257-274页

作者： W h Long j Geng j liu Z h Wang School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China joint Department for Nuclear Physics Lanzhou University and Institute of Modern PhysicsCASLanzhou 730000China Frontier Science Center for Rare Isotope Lanzhou UniversityLanzhou 730000China

Regarding the stage progress on the relativistic hartree-Fock(RhF)model achieved recently,we review the extensive developments of the model itself,including the descriptions of axially deformed unstable nuclei and nuclear spin-isospin excitations,which shows that a complete RhF framework is now available for exploring the tensor force effects in both ground state and excited states of unstable ***,the recent RhF descriptions of the pseudo-spin symmetry restoration and the new magicity are also *** shows that the Fock terms,particularly theρ-tensor coupling and naturally introduced tensor force components,bring about significant improvements in maintaining the delicate in-medium balance of nuclear attractions and repulsions,and uniformly interpreting the emergence of new magicity *** revealed microscopic mechanisms not only deepen our understanding on the properties of nuclear structure,but also help to guide the further development of the effective nuclear force.

关键词： RhF approach tensor force deformation unstable nuclei

Sora文生视频大模型对学术期刊出版的机遇、挑战及应对

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新疆师范大学学报（哲学社会科学版） 2025年第2期46卷 79-88页

作者：刘娟新疆师范大学期刊社新疆乌鲁木齐830017

随着Sora文生视频大模型的迅猛发展,学术期刊出版正在经历深刻的变革与重塑。Sora技术的多模态特征与智能化能力,一方面促进学术信息的动态整合与开放获取,推动传统出版模式向协同创新与知识共享的新范式转型;另一方面,赋予著作权归属... 详细信息

随着Sora文生视频大模型的迅猛发展,学术期刊出版正在经历深刻的变革与重塑。Sora技术的多模态特征与智能化能力,一方面促进学术信息的动态整合与开放获取,推动传统出版模式向协同创新与知识共享的新范式转型;另一方面,赋予著作权归属和著作权风险治理等新的价值意蕴。面对Sora文生视频大模型对学术期刊出版带来的机遇和挑战,学术期刊应构建跨学科协作网络、重塑基于价值的学术评价标准、创新人才培养机制,强化全球学术出版治理。文本通过系统分析大语言模型、文生视频大模型驱动下的新兴学术生态,旨在为学术界提供理论视角和实践样态,实现知识生产的原创性与伦理性,推动学术出版在新技术环境中的学术治理现代化及可持续高质量发展。

关键词： Sora 学术期刊出版技术伦理学术伦理学术生态系统

Internal Structure Visualization of Flow and Flame by Process Tomography and PLIF Data Fusion

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journal of Thermal Science 2018年第1期27卷 64-73页

作者： liu j. liu Shi SUN S. PAN X I.h.I Schlaberg North China Electric Power University 2 Beinong RoadChangping DistrictBeijing 102206China

To address the increasing demands on pollution control and energy saving, the study of low-emission and high-efficiency burners has been emphasized worldwide. Swirl-induced environmental burners(EV-burners), have notable features aligned with these requirements. In this study, an EV burner is investigated by both an ECT system and an Oh-PLIF system. The aim is to detect the structure of a flame and obtain more information about the combustion process in an EV burner. 3D ECT sensitivity maps are generated for the measurement and Oh-PLIF images are acquired in the same combustion zone as for the ECT measurements. The experimental images of a flame by ECT are in good agreement with the Oh radical distribution pictures captured by Oh-PLIF, which provide a mutual verification of the visualization method.

关键词： Tomographic measurement EV burner ECT Oh-PLIF