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Effect of yttrium Addition on Microstructural Characteristics and Superplastic Behavior of Friction Stir Processed zK60 Alloy

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Journal of Materials Science & Technology 2013年第12期29卷 1116-1122页

作者： z.A.Luo g.M.Xie z.y.Ma g.L.Wang g.D.Wang State Key Laboratory of Rolling and Automation Northeastern University Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences

As-extruded zK60 and zK60-y magnesium alloy plates were successfully processed via friction stir processing （FSP） at a tool rotation rate of 1600 r/rain and a traverse speed of 200 mm/min. FSP resulted in the formation of equiaxed recrystallized microstructures with the average grain sizes of ,-8.5 and -4.7 μm in the zK60 and zK60-y alloys, respectively. Moreover, FSP broke and dispersed the Mgzn2 and W-phase （Mg3zn3y2） particles and dissolved Mgzn2 phase in the FSP zK60 alloy. With the addition of rare earth element yttrium （y） into the zK60 alloy, the ratio of the high angle grain boundaries （HAgBs） in the FSP alloys increased from 64% to 90%, and a certain amount of twins appeared in the FSP zK60-y alloy. The maximum elongation of 1200% and optimum strain rate of 3 X 10-3 s-1 achieved at 450 °C in the FSP zK60-y alloy were substantially higher than those of the FSP zK60 alloy. This is attributed to the fine grains with high ratio of HAgBs and the distribution of a large number of dispersed second phase particles with high thermal stability in the FSP zK60-y alloy. grain boundary sliding was identified as the primary deformation mechanism in the FSP zK60 and zK60-y alloys from the superplastic data analyses and surficial morphology observations.

关键词： Magnesium alloy Friction stir processing Rare earth element Microstructure Superplasticity

Endophytic Occupation in Nodules of Rhynchosia Plants from Semiarid Regions of Argentina

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Phyton-International Journal of Experimental Botany 2024年第6期93卷 1081-1099页

作者： Cinthia T.Lucero María de los Á.Ruíz Fabiola Pagliero Carolina Castaño Mariela L.Ambrosino graciela S.Lorda Facultad de Ciencias Exactas y Naturales Universidad Nacional de La PampaRuta Nacional 35km 330Santa RosaLa PampaCP6300Argentina INTA EEA Anguil“Ing.Agr.guillermo Covas”Ruta Nacional 5 km 580AnguilLa PampaCC116326Argentina

Beneﬁcial microbes can improve soil health by promoting soil structure,nutrient cycling,and disease *** addition,a wide array of rhizospheric microbes are responsible for producing metabolically active compounds including various types of plant growth ***,microbial biodiversity studies could contribute to the improvement of agricultural practices in deprived areas,such as the Pampean semiarid *** vast majority of studies conducted on endophytic microorganisms have focused on intensive crop legume *** contrast,little attention has been paid to microorganisms of native legumes,whose ecology is not directly affected by human *** this study,endophytic microorganisms isolated from root nodules of a selected native legume of the genus Rhynchosia were *** isolates were studied with a focus on their plant growth-pro-moting rhizobacteria(PgPR)*** the edaphic characteristics of the Pampean semiarid region,the isolates obtained were evaluated for their ability to grow under three salt stress conditions(50,100,and 200 mM NaCl)and four different pH values(6,7,8,and 9).Based on their PgPR activities,the selected strains were phylogenetically grouped using *** results showed great variability among the isolates in terms of the characteristics *** legumes manifested a wide endophytic variability and remarkable perfor-mance in PgPR *** conclude that they could be used as potential bioinoculants for legume cultivation,an excellent alternative to the use of chemical fertilizers that currently pollute the environment.

关键词： Native strains endophytes PgPR native legumes stress

MRI对于cT3和cT4期直肠癌病人新辅助放化疗后肿瘤沉积的检出作用

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国际医学放射学杂志 2024年第4期 495-496页

作者： y.T.Que y.Chen X.y.yang y.R.Ma y.y.Liu z.Q.Wen 徐文睿

摘要目的探讨MRI对直肠癌新辅助放化疗后（nCRT）肿瘤沉积（TD）的检出效能及TD的MRI肿瘤消退分级对预测病人预后的意义。方法回顾性分析2014年8月—2020

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MECHANISM OF SOUND gENERATION By FLOW OVER TWO CAVITIES IN TWO DIMENSIONS

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Journal of Hydrodynamics 2001年第1期13卷 58-63页

作者： Liu, X.z. Liu, y.z. Miao, g.P. Sch. of Naval Archit. and Ocean Eng. Shanghai Jiaotong Univ. Shanghai 20030 China

The mechanism of sound generation by flow over two cavities in two dimensions is studied by examining the evolution of vorticity, pressure level, spectra and directivity of the generated sound. The study shows that the sound pressure level for two cavities is higher than that for a single cavity. When the distance between the two cavities is large, the interaction between vortices caused by cavities is weak enough to be negligible, so that the results from the acoustic analogy approach coincide with those from the superposition principle. When the distance between the two cavities is relatively small, however, the interaction between vortices becomes stronger and the results from acoustic analogy approach are then larger than those from the superposition principle. Regarding the nonlinear interaction of sound waves in the far field, high harmonic waves can occur when the dimensions of the two cavities are equal, while the sum and difference frequency waves besides the high harmonic waves appear when the dimensions of the two cavities are different.

关键词： Cavitation Computer simulation Hydrodynamics

Effect of Rotation Rate on Microstructures and Mechanical Properties of FSW Mg-zn-y-zr Alloy Joints

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Journal of Materials Science & Technology 2011年第12期27卷 1157-1164页

作者： g.M. Xie z.y. Ma z.A. Luo P. Xue g.D. Wang The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110819 China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China

Friction stir welding （FSW） of Mg-zn-y-zr plates with 6 mm in thickness was successfully carried out under a wide range of rotation rates of 600-1200 r/rain with a constant traverse speed of 100 mm/min. After FSW, the coarse grains in the parent material （PM） were changed into fine equiaxed recrystallized grains at the＇nugget zone （Nz）. Furthermore, the coarse Mg-zn-y particles （W-phase） were broken up and dispersed homogenously into the Mg matrix. With increasing rotation rates, the size of the W-phase particles at the Nz significantly decreased, but the recrystallized grain size tended to increase. The hardness values of the Nzs for all the FSW joints were higher than those of the PM, and the lowest hardness values were detected in the heat affected zone （HAz）. The fracture occurred in the thermo-mechanical affected zone （TMAz） on the advancing side for all the FSW joints in the tensile test, due to the incompatibility of the plastic deformation between the Nz and TMAz caused by remarkably different orientation of grains and W-phase particles. The strength of FEW ioint reaches 90% of that of its PM

关键词： Friction stir welding Magnesium alloys Microstructure Mechanical property

Dislocation ordering and texture strengthening of naturally aged Al-Cu-Mg alloy

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Journal of Materials Science & Technology 2022年第23期118卷 1-14页

作者： F.Liu z.y.Liu g.y.He L.N.Ou School of Materials Science and Engineering Central South UniversityChangsha 410083China Key Laboratory of Nonferrous Metal Materials Science and Engineering Ministry of EducationCentral South UniversityChangsha 410083China National Key Laboratory of Science and Technology on High-Strength Structural Materials Central South UniversityChangsha 410083China

Stability of grain structure,dislocation ordering and strengthening mechanisms of the naturally aged AlCu-Mg alloy after solution treatment are investigated by using optical microscope(OM),scanning electron microscope(SEM),electron back-scattered diffraction(EBSD),X-ray diffraction(XRD) and transmission electron microscope(TEM).Results show that {100},{100},{110} and {110}slip systems can be activated after solution treatment,which can promote the formation of {110}goss *** combination effect of T-Al_(20)Cu_(2) Mn_(3) phase and goss-oriented grains with large Taylor factor makes the solution-treated alloys display excellent stability of grain *** enhanced yield strength of the alloy is ascribed to grain-refine strengthening,dispersed particles strengthening,dislocation strengthening and texture *** coarsening of the second phase is responsible for softening of the alloy after annealing at 400 ℃+solution treatment at 475 ℃.

关键词： Al-Cu-Mg alloy Dislocation ordering goss texture grain structure stability Texture strengthening

3D bare-hand interactions enabling ubiquitous interactions with smart objects

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Advances in Manufacturing 2020年第2期8卷 133-143页

作者： S.K.ong X.Wang A.y.C.Nee Department of Mechanical Engineering Faculty of EngineeringNational University of SingaporeSingapore

Ubiquitous augmented reality(UAR)implementation can benefit smart shop floor operations *** from a user's first-person view can support and provide the user with suitable and comprehensive information without him/her being distracted from ongoing tasks.A natural hand-based interaction interface,namely,a mobile bare-hand interface(MBHI),is proposed to assist a user in exploring and navigating a large amount of information for a task in the user's first-person *** integration of a smart shop floor and UAR-based MBHI is particularly challenging.A real shop floor environment is composed of challenging conditions for the implementation of UAR,e.g.,messy backgrounds and significant changes in illumination ***,the MBHI is required to provide precise and quick responses to minimize the dificulty of a user's *** this study,a wearable UAR system integrated with an MBH is proposed to augment the shop floor environment with smart information.A case study is implemented to demonstrate the practicality and effectiveness of the proposed UAR and MBHI system.

关键词： Augmented reality(AR) Mobile bare-hand interaction(MBH) Smart objects(SOs) Manufacturing shop-floor

CONTROL TECHNIQUES FOR DIgESTION IN BAyER PROCESS

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Acta Metallurgica Sinica(English Letters) 2000年第6期13卷 1174-1178页

作者： g.y.gan L.z.Wang Pingguo Aluminum Company Pingguo 531400China

The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling digestion status and energy consumption. Very good performances and technical and technical and economical figures for digestion process have been obtained by carefully applying these comprehensive control techniques in Pingguo alumina refinery.

关键词： control technique digestion Bayer process

基于状态空间模型的激光再制造熔池温度控制系统

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表面工程与再制造 2024年第2期24卷 50-50页

作者： yang g.-z. Liu T.-M. Song B.-X. Jiang X.-y. Wang z.-S. Chen K.-Q. Liu W.-J. School of Mechanical Engineering Shenyang University of Technology Shenyang China

激光再制造是用于再制造的一项重要技术,在航空航天、冶金、能源等领域应用广泛。然而,形状控制问题一直是制约其规模化和工业化应用的瓶颈。在激光再制造过程中,熔池温度是决定再制造件形状和性能稳定性的关键。基于此,本文提出了一种... 详细信息

激光再制造是用于再制造的一项重要技术,在航空航天、冶金、能源等领域应用广泛。然而,形状控制问题一直是制约其规模化和工业化应用的瓶颈。在激光再制造过程中,熔池温度是决定再制造件形状和性能稳定性的关键。基于此,本文提出了一种基于状态空间模型的激光再制造熔池温度实时在线控制方法,解决了控制机理模型难以建立和多变量约束的问题。

关键词：状态空间模型激光再制造熔池温度航空航天形状控制控制系统变量约束性能稳定性