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PHASE TRANSFORMATION AND CHARACTERISTICS IN FRECKLE AREAS FOR INCONEL 625 SUPERALLOy

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Acta Metallurgica Sinica(English Letters) 2005年第1期18卷 47-54页

作者： J.X.Dong M.C.Zhang y.P.Zeng X.S.xie UniversityofScienceandTechnologyBeijing Beijing100083China

The freckle formation and their phase characterizatics in freckle areas were investigated by means of microstructure analysis approaches and a thermodynamic equilibrium phase calculation method in an Inconel 625 allay. These results show that in freckle areas a large number of M6C, MC, Laves and δ phases precipitate in grain boundaries even within grain due to the enrichment and segregation of Mo and Nb during solidification, which results in almost of these freckle areas covered by these complex precipitated phases and induces small grains in freckle areas. Equilibrium phase and liquid segregation calculation can give a reasonable interpretation of the freckle feature for this alloy.

关键词： freckle superalloy Inconel 625 thermodynamic calculation

CREEP CRACK GROWTH BEHAVIOR OF ALLOy 718 DURIng HIGH TEMPERATURE EXPOSURE

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Acta Metallurgica Sinica(English Letters) 2005年第2期18卷 164-172页

作者： J.X.Dong M.C.Zhang y.P.Zeng X.S.xie DepartmentofMaterialScience UniversityofScienceandTechnologyBeijingBeijing100083China

Alloy 718 is a precipitation strengthened nickel-based superalloy based on the precipitation of γ″-Ni3Nb (DO22 structure) and γ′-Ni3(Al,Ti) (L12 structure) phases. Creep crack growth rate (CCGR) was investigated after high temperature exposure at 593, 650 and 677℃ for 2000h in Alloy 718. In addition to the coalescence of γ′/ γ″ and the amount increasing of δ phase, the existence of a bcc chromium enriched α-Cr phase was observed by SEM, and the weight fraction of α-Cr and other phases were determined by chemical phase analysis methods. The CCGR behavior and regulation have been analyzed by means of strength and structure analysis approaches. The experimental results show higher the exposure temperature and longer the exposure time, lower the CCGR. This is probably attributed to the interaction of material softening and brittling due to complex structure changes during high temperature exposure. Therefore, despite α-Cr phase formation and amount enhancement were run in this test range. It seems to us a small amount of α-Cr will be not harmful for creep crack propagation resistance, which is critical for disk application in aircraft and land-based gas turbine.

关键词： Alloy 718 creep crack growth rate α-Cr phase

Anisotropic Moser-Trudinger Inequality Involving L^(n) Norm in the Entire Space R^(n)

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Acta Mathematica Sinica,English Series 2023年第12期39卷 2427-2451页

作者： Ru Long xie Department of Mathematics Chaohu UniversityHefei 238000P.R.China School of Mathematical Sciences University of Science and Technology of ChinaHefei 236000P.R.China

Let F:R^(n)-→[0,+∞)be a convex function of class C^(2)(R^(n)/{0})which is even and positively homogeneous of degree 1,and its polar F0 represents a Finsler metric on R^(n).The anisotropic Sobolev norm in W^(1,n)(R^(... 详细信息

Let F:R^(n)-→[0,+∞)be a convex function of class C^(2)(R^(n)/ng)which is even and positively homogeneous of degree 1,and its polar F0 represents a Finsler metric on R^(n).The anisotropic Sobolev norm in W^(1,n)(R^(n))is defined by||u||F=(∫_(R_(n)(F^(n)(↓△u)+|u|^(n)dx)^(1/n)In this paper,the following sharp anisotropic Moser-Trudinger inequality involving L^(n)norm u∈W^(1,n)^(SUP)(R^(n),||u||F≤1∫_(R^(n))Ф(λ_(n)|u|n/n-1(1+a||u||^(n)_(n)1/n-1)dxy 0y for all α≥***,we prove the supremum is attained,that is,there exists a maximizer for the above supremum whenα>O is sufficiently small.

关键词： Moser-Trudinger inequality anisotropic Sobolev norm blow up analysis extremal func-tion unbounded domain

Guideline on Chinese Medicine Rehabilitation for Idiopathic Pulmonary Fibrosis

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World Journal of Traditional Chinese Medicine 2023年第4期9卷 475-484页

作者： Jian-Sheng Li Ming-Hang Wang y.ng xie 机构不祥

Foreword Note:Some of the elements of this document may be the subject of patent *** shall not be held responsible for identify.ng any or all such patent *** drafting organizations:Henan University of Chinese Medicine... 详细信息

关键词： Henan patent Medicine

Genetic architecture and molecular regulation of sorghum domestication

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aBIOTECH 2023年第1期4卷 57-71页

作者： Fengy.ng Ge Peng xie yaorong Wu Qi xie State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyThe Innovative Academy of Seed DesignChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Over time,wild crops have been domesticated by humans,and the knowledge gained from parallel selection and convergent domestication-related studies in cereals has contributed to current techniques used in molecular plant ***(Sorghum bicolor(L.)Moench)is the world’s fifth-most popular cereal crop and was one of the first crops cultivated by ancient *** recent years,genetic and genomic studies have provided a better understanding of sorghum domestication and ***,we discuss the origin,diversification,and domestication processes of sorghum based on archeological discoveries and genomic *** review also comprehensively summarized the genetic basis of key genes related to sorghum domestication and outlined their molecular *** highlights that the absence of a domestication bottleneck in sorghum is the result of both evolution and human ***,understanding beneficial alleles and their molecular interactions will allow us to quickly design new varieties by further de novo domestication.

关键词： Domestication Genetic basis Molecular mechanism Genes Sorghum

Modified cellular automaton model for modeling of microstructure and microsegregation in solidification of ternary alloys

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中国有色金属学会会刊：英文版 2006年第A02期16卷 180-185页

作者：朱鸣芳 CAO Wei-sheng CHEN Shuang-lin xie Fan-you HOng Chun-pyo CHAng y. Austin School of Materials Science and Engineering Southeast University Nanjing 210096 China Department of Materials Science and Engineering University of Wisconsin-Madison 1509 University Avenue Madison WI 53706 USA CompuTherm LLC 437 S. Yellowstone Dr. Suite 217 Madison WI 53719 USA Center for Computer-Aided Materials Processing （CAMP） Department of Metallurgical Engineering Yonsei University Shinchon-dong 134 Seodaemun-ku Seoul 120-749 Korea

A modified cellular automaton (MCA) model has been extended to the ternary alloy system by coupling thermodynamic and phase equilibrium calculation engine PanEngine. In the present model the dendrite growth is driven by the difference between the local equilibrium liquidus temperature and local actual temperature, incorporating the effect of curvature. The local equilibrium liquidus temperature is calculated with PanEngine according to the local liquid concentrations of two solutes, which are determined by numerically solving the species transport equation in the domain. Model validation was carried out through the comparison of the simulated values to the prediction of the Scheil model for solute profiles in the primary dendrites. The simulated data with zero solid diffusivity and limited liquid diffusivity were increasingly close to the Scheil profiles as the solidification rate decreased. The simulated microstructure and microsegregation in an Al-Cu-Mg ternary alloy were compared with those obtained experimentally.

关键词：三元合金体系凝固显微结构模型显微偏析细胞自动机

Efficient ultrafast laser writing with appropriate polarization

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Light(Science & Applications) 2023年第6期12卷 938-940页

作者： Xiujian Li Wenke xie College of Sciences National University of Defense TechnologyChangsha 410073China Tiansun National Lab Changsha 410073China School of Physics and Electronics Central South UniversityChangsha 410083China

Appropriate polarization utilization makes the electric field vector direction and the statistically oriented localized states suitable for enhancing light-matter interactions so as to improve the efficiency of ultrafast laser writing,which will remarkably reduce the pulse energy and increase the processing speed for high density optical data storage,as well as manufacturing three-dimensional integrated optics and geometric phase optical elements.

关键词： polarization laser optical

A GAME THEORETICAL STUDy OF COOPERATIVE ADVERTISIng WITH MULTIPLE RETAILERS IN A DISTRIBUTION CHANNEL

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Journal of Systems Science and Systems Engineering 2012年第1期21卷 37-55页

作者： Jihua ZHAng Jinxing xie Department of Mathematical Sciences Tsinghua UniversityBeijing100084China

Extant studies of cooperative advertising mainly consider a single-manufacturer-single-retailer channel structure. This can provide limited insights, because a manufacturer, in real practices, usually deals with multiple retailers simultaneously. In order to examine the impact of the retailer＇s multiplicity on channel members＇ decisions and on total channel efficiencies, this paper develops a multiple-retailer model. In this model, the manufacturer and the retailers play a Stackelberg game to make the optimal advertising decisions. Based on the quantitative results, it is observed that： 1） When there are multiple symmetric retailers, as the number of retailers scales up, the manufacturer＇s national advertising investment contributes increasingly to add to channel members＇ profits in equilibrium, but the total channel efficiency deteriorates quickly and converges down to a certain value; 2） When there are multiple asymmetric retailers, the distribution channel suffers from the manufacturer＇s uniform participation strategy due to the retailer＇s free-riding, and benefits with the manufacturer＇s retailer-specific participation strategy. This study derives equilibrium solutions in closed form for all games considered and measures explicitly the gains/losses of channel efficiencies under different game settings.

关键词： Cooperative advertising game theory multiple retailers scaling effect free-riding

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 Sheny.ng 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