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Evaluation of dynamic development of grain structure during friction stir welding of pure copper using a quasi in situ method

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Journal of Materials Science & Technology 2019年第7期35卷 1412-1421页

作者： X.C.Liu y.f.sun T.Nagira K.Ushioda H.fujii Joining and Welding Research Institute Osaka University11-1 MihogaokaIbarakiOsaka567-0047Japan School of Materials Science and Engineering Northwestern Polytechnical UniversityXi'an710072China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou450001China

By employing a quasi in situ method, we investigated the dynamic evolution of the grain structure con-sidering the material flow, strain, and strain rate in the friction stir welding of pure copper. The tool' stop action' and rapid cooling were employed and a brass foil was used as a marker to show the material flow path. The grain structure along the material flow path was characterised using electron backscatter diffraction. Static recrystallization occurs for the work-hardened base material in the preheating stage in front of the tool In the acceleration flow stage, grains are significantly refined by plastic deforma-tion, discontinuous dynamic recrystallization, annealing twinning during the strain-induced boundary migration and slight continuous dynamic recrystallization. In the deceleration flow stage, due to a strain reversal, the grain first coarsens, and is thereafter refined again. finally, the hot-deformed material in the shoulder-affected zone is ‘frozen’ directly whereas that in the probe-affected zone undergoes signif-icant annealing;thus, the recrystallized microstructure and 45°-rotated cube texture are obtained in the probe-affected zone.

关键词： friction stir welding Grain structure Material flow Pure copper EBSD

Shock compression and spallation damage of high-entropy alloy Al_(0.1)CoCrfeNi

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Journal of Materials Science & Technology 2022年第33期128卷 1-9页

作者： N.B.Zhang J.Xu Z.D.feng y.f.sun J.y.Huang X.J.Zhao X.H.yao S.Chen L.Lu S.N.Luo Key Laboratory of Advanced Technologies of Materials Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China The Peac Institute of Multiscale Sciences Chengdu 610031China Department of Engineering Mechanics South China University of TechnologyGuangzhou 510641China

Shock compression and spallation damage of a face-center cubic phase high-entropy alloy(HEA)Al_(0.1)CoCrfeNi were investigated via plate impact experiments along with free surface velocity *** samples were characterized with transmission electron microscopy and electron backscatter *** Hugoniot equation of state and spall strength at different impact strengths were *** exists a power-law relation between spall strength and strain *** spall strength of Al_(0.1)CoCrfeNi HEA is about 50%higher than those of previously studied HEAs and comparable to those widely applied structural stainless steels at the same shock *** glide and stacking faults are the important deformation mechanisms in the Al_(0.1)CoCrfeNi *** are only observed at high shock *** in the Al_(0.1)CoCrfeNi HEA is ductile in *** are nucleated preferentially in grain interiors,and the intragranular voids show a strong dependence on grain boundary misorientation and peak stress.

关键词： Al_(0.1)CoCrfeNi High-entropy alloy Hugoniot Spall damage Microstructure

在SrTiO3,NdGaO3衬底上生长的HgBa2CaCu2Oy超导薄膜

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低温物理学报 1999年第1期21卷 51-54页

作者：孙云峰郭建栋徐晓林王永忠熊光成北京大学物理系

通过两步法，在ＳｒＴｉＯ３，ＮｄＧａＯ３衬底上制备了ＨｇＢａ２ＣａＣｕ２Ｏｙ高温超导薄膜，Ｘ射线衍射实验结果证明了薄膜是ｃ轴外延生长的．电阻温度测量表明薄膜的超导零电阻转变温度（Ｔｃ）＞１１５Ｋ和临界电流Ｊｃ＞０．... 详细信息

通过两步法，在ＳｒＴｉＯ３，ＮｄＧａＯ３衬底上制备了ＨｇＢａ２ＣａＣｕ２Ｏｙ高温超导薄膜，Ｘ射线衍射实验结果证明了薄膜是ｃ轴外延生长的．电阻温度测量表明薄膜的超导零电阻转变温度（Ｔｃ）＞１１５Ｋ和临界电流Ｊｃ＞０．４ＭＡ／ｃｍ２（７７Ｋ，零磁场），而且重复性很好．扫描电镜实验揭示了薄膜是层状生长的，晶粒是四方形和八角形的，实验证实基于碳酸盐的靶也是适合于制备汞系铜氧化物高温超导膜的

关键词：衬底基片 SrTiO3,NdGaO3 HgBa2CaCu2Oy

Joint feature Encoding and Task Alignment Mechanism for Emotion-Cause Pair Extraction

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Computers, Materials & Continua 2025年第1期82卷 1069-1086页

作者： Shi Li Didi sun College of Computer and Control Engineering Northeast Forestry UniversityHarbin150040China

With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant ***-cause pair extraction enables the identification of causal relationships between emotions and their triggers within a text,facilitating a deeper understanding of expressed sentiments and their underlying *** comprehension is crucial for making informed strategic decisions in various business and societal ***,recent research approaches employing multi-task learning frameworks for modeling often face challenges such as the inability to simultaneouslymodel extracted features and their interactions,or inconsistencies in label prediction between emotion-cause pair extraction and independent assistant tasks like emotion and cause *** address these issues,this study proposes an emotion-cause pair extraction methodology that incorporates joint feature encoding and task alignment *** model consists of two primary components:first,joint feature encoding simultaneously generates features for emotion-cause pairs and clauses,enhancing feature interactions between emotion clauses,cause clauses,and emotion-cause ***,the task alignment technique is applied to reduce the labeling distance between emotion-cause pair extraction and the two assistant tasks,capturing deep semantic information interactions among *** proposed method is evaluated on a Chinese benchmark corpus using 10-fold cross-validation,assessing key performance metrics such as precision,recall,and f1 *** results demonstrate that the model achieves an f1 score of 76.05%,surpassing the state-of-the-art by 1.03%.The proposed model exhibits significant improvements in emotion-cause pair extraction(ECPE)and cause extraction(CE)compared to existing methods,validating its *** research introduces a novel approach based on joint feature encoding and task alignment mechanisms,contributing to advancements in emotion-c

关键词： Emotion-cause pair extraction interactive information enhancement joint feature encoding label consistency task alignment mechanisms

Constructing Donor–Acceptor‑Linked COfs Electrolytes to Regulate Electron Density and Accelerate the Li^(+)Migration in Quasi‑Solid‑State Battery

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Nano-Micro Letters 2025年第1期17卷 456-471页

作者： Genfu Zhao Hang Ma Conghui Zhang yongxin yang Shuyuan yu Haiye Zhu yongjiang sun Hong Guo School of Materials and Energy International Joint Research Center for Advanced Energy Materials of Yunnan ProvinceYunnan UniversityKunming 650091People’s Republic of China yunnan yuntianhua Co. LtdR&D CenterKunming 650228People’s Republic of China Southwest United Graduate School Kunming 650091People’s Republic of China

Regulation the electronic density of solid-state electrolyte by donor–acceptor(D–A)system can achieve highly-selective Li^(+)transportation and conduction in solid-state Li metal *** study reports a high-performance solid-state electrolyte thorough D–A-linked covalent organic frameworks(COfs)based on intramolecular charge transfer *** other reported COfbased solid-state electrolyte,the developed concept with D–A-linked COfs not only achieves electronic modulation to promote highly-selective Li^(+)migration and inhibit Li dendrite,but also offers a crucial opportunity to understand the role of electronic density in solid-state Li metal *** introduced strong electronegativity f-based ligand in COf electrolyte results in highlyselective Li^(+)(transference number 0.83),high ionic conductivity(6.7×10^(-4)S cm^(−1)),excellent cyclic ability(1000 h)in Li metal symmetric cell and high-capacity retention in Li/LifePO_(4)cell(90.8%for 300 cycles at 5C)than substituted C-and N-based *** is ascribed to outstanding D–A interaction between donor porphyrin and acceptor f atoms,which effectively expedites electron transferring from porphyrin to f-based ligand and enhances Li^(+)***,we anticipate that this work creates insight into the strategy for accelerating Li^(+)conduction in high-performance solid-state Li metal batteries through D–A system.

关键词： Electronic modulation engineering Donor-acceptor-linked covalent organic frameworks Quasi-solid-state Li metal battery

Effect of post-bond heat treatment on the microstructure and high temperature mechanical property of a TLP bonded γ'-strengthened co-based single crystal superalloy

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Journal of Materials Science & Technology 2021年第21期80卷 244-258页

作者： S.y.Wang y.sun C.y.Cui X.f.sun y.Z Zhou y.M.Ma H.L.An Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Harbin Welding Institute China Academy of Machinery Science and TechnologyHarbin 150028China

Post-bond heat treatment(PBHT) applied to a transient liquid phase(TLP) bonding joint is an effective approach to remove the brittle borides and improve its ***,we proposed two types of PBHT strategies to obtain a TLP bonded γ'-strengthened Co-based single crystal superalloy,and the microstructural characteristics and tensile properties of the two heat treated joints were compared to identify the optimal PBHT *** evolution of the brittle boride in the joint after the PBHT was studied by using in-situ *** experimental results allowed to provide a theoretic model to quantitatively evaluate the distribution of the brittle phase after the optimal PBHT and analyze the joint fractures to understand the failure *** obtained results revealed that a post-bond solid solution treatment performed to the joint at a high temperature(over 1275℃) could decrease the area fraction of the boride from 7.2 % to 1.4 % and increase the elongation from 1.9 % to 7.8 %.This work emphasizes the relevance of solid solution temperature when a PBHT strategy is applied.

关键词： Transient liquid phase(TLP) γ'-strengthened co-based single crystal superalloy Heat treatment sequence Brittle boride Tensile property

IMPROVED METHOD Of PARTIAL SIMILARITy Of BOUNDARy LAyER ALONG CURVED SURfACE

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Journal of Hydrodynamics 2001年第2期13卷 77-79页

作者： sun, f.Z. Shi, y.T. sun, H.J. Ping, y.M. Zhang, M.y. Inst. of Energy and Power Shandong Univ. Jinan 250061 China

The solution of boundary layer along a curved surface was discussed in this article. According to the principle of the theory of similarity, the method of partial similarity was proposed, in which the profile of object is divided into many tiny sections, the method of similarity was used in each section and the error in each section was fully considered. This method is proved to be feasible.

关键词： Cylinders (shapes) Differential equations Error analysis Surfaces

fORMATION Of fe-N COMPOUNDS By LASER NITRIDATION IN AN ATMOSPHERIC AMBIENT

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Acta Metallurgica Sinica(English Letters) 2003年第2期16卷 139-144页

作者： y.L.yang f.J.sun D.Zhang College of Science Northeastern UniversityShenyang 110004ChinaCollege of ScienceNortheastern UniversityShenyang 110004ChinaCollege of ScienceNortheastern UniversityShenyang 110004China

The formation of fe-N compounds by laser nitriding in an atmospheric ambient was reported. By CW-CO2 laser irradiation on pure ferrite iron in the atmospheric ambient, fe-N compounds (including fe2N, .fe3AT and fe4N) are formed as a result of a laser-enhanced and temperature-enhanced reactions. The samples were analyzed with X-ray diffraction. It is found that the laser power density, scanning speed and nitrogen temperature are the main factors influencing the formation of fe-N compounds. Nitrogen can be activated by pre-heating at some temperature. Nitrogen activation and sample surface melting by CW-CO2 laser greatly enhance the reaction between the sample surface and nitrogen beam. After annealing at 500℃for 3h, some fe2N and fe3N converted into more stable fe4N.

关键词： laser nitriding nitride fe-N compound

STUDy ON THE VARIATION MECHANISM Of CARBON CONTENT Of LIQUID IRON IN MELTING GASIfIER

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Acta Metallurgica Sinica(English Letters) 2003年第2期16卷 132-138页

作者： Q.Lu L.f sun y.Xu Q.f.Chan Hebei University of Technology Tangshan 063009ChinaHebei University of TechnologyTangshan 063009ChinaHebei University of TechnologyTangshan 063009ChinaHebei Institute of Vocation and TechnologvShiiiazhuang 050031China

This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen was poured into the melting gasifier from its tuyere to cool down quickly. And then seven cross sections were made to study the carburization reaction and its characteristics of the solid iron and the liquid iron, and also the reaction of carbon between the slag and the metal. According to the results, the influences of the thickness of the semi-coke layer and the temperature on the carbon content of liquid iron in the COREX melting gasifier were confirmed.

关键词： melting gasifier direct reduction iron (DRI) liquid iron carbon content