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Experimental Investigation on the LCF Behavior Affected by Manufacturing Defects and Creep Damage of One Selective Laser Melting Nickel-Based Superalloy at 815℃

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Acta Metallurgica Sinica(English Letters) 2020年第4期33卷 514-527页

作者： Xiao-An Hu Gao-Le Zhao Yun Jiang Xian-Feng Ma Fen-cheng liu Jia Huang cheng-li dong School of Aircraft Engineering Nanchang Hangkong UniversityNanchang 330063China Jiangxi Key Laboratory of Micro Aeroengine Technology Nanchang 330063China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China National Defence Key Discipline Laboratory of light Alloy Processing Science and Technology Nanchang 330063China School of Aeronautics and Astronautics Central South UniversityChangsha 410083China Materials Evaluation Center for Aeronautical and Aeroengine Application AECC Beijing Institute of Aeronautical MaterialsBeijing 100095China

Uniaxial tensile tests and stress-controlled low-cycle fatigue(LCF) and creep-fatigue interaction(CFI) tests of Inconel 625 alloy manufactured by selective laser melting(SLM) were performed at 815℃ in air *** microstructure was characterized by optical microscopy and scanning electron microscopy after *** results confirmed that significant embrittlement and large scatter in LCF life are resulted from manufacturing *** CFI life is decreased sharply to approximately dozens of cycles with the accumulated creep strain;however,the selected dwell time(i.e.,60 s and 300 s)exhibits low sensitivity to the fracture time and elongation to *** embrittlement of SLM Inconel 625 was proposed to be due to the low grain uniformity and precipitation of carbides at the grain *** to the quality of the SLM process,the accelerated initiation and propagation of fatigue crack are caused by the present unmelted powder particles,which result in the large dispersion of LCF ***,due to the accumulation of creep damage,cracks in the CFI test are initiated along the grain boundaries and then linked together,contributing to a significant decline in fatigue life.

关键词： Selective laser melting Low-cycle fatigue Creep-fatigue interaction Failure analysis

Viscosity Measurements of Fe-Si-B-Cu-Nb-C Metallic Glass Melts by an Oscillating Crucible Method

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Chinese Physics Letters 2003年第3期20卷 395-397页

作者： li cheng-dong Tian Xue-Lei Chen Xi-Chen A.G. Ilinsky Key Laboratory of liquid Structure and Heredity of Materials Ministry of Education Shandong University Ji'nan 250061 Institute of Metal Physics National Academy of Sciences Ukraine Ukr 36 Vernadsky Blvd. UA-03680 Kiev Ukraine

Dependence of the dynamic viscosity of new type of Fe-based amorphous alloy (Fe68.5Si13.5B9Cu1Nb3C5) melt on temperature is investigated by using a torsional oscillation viscometer. The temperature dependence of the viscosity can be fitted by the Arrhenius relation and Fulcher expression as ln η = 0.082 + 1463.48/T and ln η = 6.75×10-5 + 954.71/(T-608.36), where η is the viscosity in units of cP and T is the temperature in units of K. The results show that the Arrhenius relation is more suitable in high temperature region, while the Fulcher expression is more appropriate in undercooled region. Combining the Differential scanning calorimetry data and free-volume model, the glass forming ability of Fe68.5Si13.5B9Cu1Nb3C5 alloy is discussed.

关键词： Viscosity

The mass of the Galactic dark matter halo from-9000 LAMOST DR5 K giants

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Research in Astronomy and Astrophysics 2018年第9期18卷 89-100页

作者： Meng Zhai Xiang-Xiang Xue Lan Zhang cheng-dong li Gang Zhao cheng-Qun Yang National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

We constrain the mass of the Milky Way＇s dark matter halo, based on the kinematics of 9627 K giants at Galactocentric distances ranging over 5 kpc 〈 r 〈 120 kpc drawn from LAMOST *** substructure in this sample has been identified and removed carefully to enable construction of the underlying line-of-sight velocity dispersion at different radii from the Galactic center. We interpret the radial profile of the line-of-sight velocity dispersion using a spherical Jeans equation under the assumptions of anisotropy/isotropy and that radial velocity dispersion is approximately equal to line-ofsight velocity dispersion σ_r（r）≈σ_（los）（r）. If we assume that the dark matter halo follows an NFW profile and the stellar halo is isotropic（β = 0）, then σlos（r） can be directly used to estimate the virial mass of the Galactic dark matter halo, M_（vir） = 1.08_（-0.14）^（＋0.17） ×10^（12） M⊙, and concentration parameter c = 18.5＋-2.***.3.6 In case that the stellar halo is anisotropic, we cannot avoid differentiation of sparse velocity dispersions according to the Jeans equation, which may cause overestimation of the mass. We use an isotropic case to test and find that d ln（σ_（los）~2 （r））/d ln r overestimates the virial mass by 15% but within 1-σ error. We use d ln（σ2 los（r））/d ln r to fit the NFW profile and get M_（vir） = 1.11_（-0.20）^（＋0.24） ×10^（12） M⊙and c = 13.8-2.2＋3.0 in case of β = 0.3.

关键词： dark matter - Galaxy halo - stars kinematics and dynamics

Synthesis and characterization of new soluble poly(aryl ether nitrile)s containing phthalazinone moiety

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Chinese Chemical Letters 2007年第5期18卷 595-597页

作者： Ming Jing Wang cheng liu li Ming dong Xi Gao Jian Department of Polymer Science ＆ Materials Dalian University of Technology Dalian 116012 China

A series of novel poly（aryl ether nitrile）s containing phthalazinone moiety were synthesized by the nucleophilic displacement reaction of bisphenol-like monomers （I） with 2,6-difluorobenzonitrile. The inherent viscosities ranged from 0.46 to 1.07 dL g^-1. The glass transition temperatures were in the range of 277-295℃, and the temperatures for 10% weight loss in nitrogen atmosphere were found between 495 and 527 ℃. The structures of these resultant polymers were confirmed by FT-IR and 1^H NMR. Moreover, the properties of poly（aryl ether nitrile）s including solubility and crystallinity were also studied.

关键词： Poly(aryl ether nitrile)s Phthalazinone Heat-resistance Solubility

An Al-12Si/ZnS powder inoculant for eutectic silicon in Al-12Si alloy

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China Foundry 2022年第2期19卷 149-157页

作者： Ying Wang Pan-yu Chen Yu-hui lin Mei Zhao cheng-dong li College of Materials Science and Engineering Qingdao University of Science&TechnologyQingdao 266042China

To obtain high-performance Al-Si-based cast alloys,refinement and modification of Si phases are *** Al-12Si/ZnS powder inoculant was designed and fabricated using a chemical bath deposition *** efficiency of the inoculant for modifying the eutectic Si phase in as-cast Al-12Si alloy was *** show that Al-12Si/ZnS powder can significantly refine the eutectic Si in Al-Si cast *** best refinement effect for eutectic Si is achieved with 17.5wt.%Al-12Si/ZnS *** long needle-shaped eutectic Si with a length of 18μm was modified into approximately spherical shape with a diameter of 6.53μm,which is evenly distributed throughout the *** E2EM model calculation indicates that the inter-plane misfit(F_(p))and inter-atomic spacing misfit(F_(r))between ZnS and Si are all less than 0.5%,which confirms that ZnS is a potential nucleation site for Si *** hardness,tensile strength,and elongation of Al-12Si alloys modified with 17.5%Al-12Si/ZnS powder increase 6.30%,16.18%and 55.45%,respectively,compared to the unmodified Al-12Si *** fracture behavior of the alloy with 17.5wt.%Al-12Si/ZnS powder is dominated by transgranular fracture supplemented by intergranular fracture.

关键词： Al-Si Al-Si/ZnS refinement eutectic silicon

Controllable synthesis of Tb-based metal-organic frameworks as an efficient fluorescent sensor for Cu^(2+)detection

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Rare Metals 2021年第2期40卷 505-512页

作者： cheng-li dong Ming-Feng li Ting Yang li Feng Ying-Wei Ai Zhang-Lei Ning Meng-Jiao liu Xin Lai Dao-Jiang Gao College of Chemistry and Materials Science Sichuan Normal UniversityChengdu610068China China Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education College of Life SciencesSichuan UniversityChengdu610065China

A series of Tb-based metal-organic frameworks(Tb-MOFs)were successfully synthesized by a solvothermal *** size and morphology of the as-obtained Tb-MOFs can be effectively controlled via regulating the experimental conditions such as the volume fraction of DMF and the molar ratio of Tb^(3+)to *** is found that all the samples exhibit strong green emissions under ultraviolet excitation,corresponding to^(5)D_(4)→^(7)F_(J)transitions of Tb^(3+).Interestingly,Tb-MOFs displayed an efficient and distinct luminescence quenching by Cu^(2+)in aqueous *** competitive fluorescence detection experiments indicate that these Tb-MOFs sensors can be used as a high selective and sensitive sensor of Cu^(2+)detection with the detection limit of 10μmol·L^(-1),which can be used as a promising fluorescence sensor for Cu^(2+)detection in daily life.

关键词： Metal-organic frameworks Controllable synthesis Luminescence Sensor Detection

Microstructure and mechanical properties of magnesium matrix composite reinforced with carbon nanotubes by ultrasonic vibration

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Rare Metals 2022年第7期41卷 2331-2336页

作者： cheng-dong li Xiao-Jun Wang Wei-Qing liu Ku Wu Hai-Long Shi Chao Ding Ming-Yi Zheng School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

A novel approach was successfully developed to fabricate bulk carbon nanotube-reinforced Mg matrix com-posites with uniform carbon nanotubes(CNTs).The approach consists of pre-dispersion and ultrasonic ***-neous and single CNTs on flake Zn powder can be achieved simply by slurry *** pre-dispersed CNTs were added to Mg melt,and then,the melt was ultrasonically *** ultrasonic vibration,the CNTs/Mg-6Zn melt was cast into a metal *** CNTs distribute homoge-neously and singly in the bulk ***,good interfacial bonding is achieved,and Raman spectroscopy analysis shows that the damage to CNTs is ***,CNTs evidently improve the ultimate tensile strength,yield strength and *** Kelly-Tyson formula agrees well with the experimental tensile value,and the load-transfer efficiency is nearly equal to 1.

关键词： Magnesium matrix composite Carbon nanotubes Ultrasonic vibration Microstructure Mechanical properties

Inverse Control of Cable-driven Parallel Mechanism Using Type-2 Fuzzy Neural Network

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自动化学报 2010年第3期36卷 459-464页

作者： li cheng-dong YI Jian-Qiang YU Yi ZHAO dong-Bin Institute of Automation Chinese Academy of Sciences Beijing100190 P. R. China

The level adjustment of cable-driven parallel mechanism is challenging due to the diffculty in obtaining an accurate mathematical model and the fact that different sources of uncertainties exist in the adjustment process. This paper presents a type-2 fuzzy neural network(T2FNN)based inverse control scheme for the level adjustment process. The T2FNN, whose consequent interval weights are trained by the iterative least squares estimation method,is used to approximate the inverse dynamics of the process and to handle uncertainties. Finally, the proposed control scheme and its counterpart--type-1 fuzzy neural network based inverse control scheme--are compared and implemented for leveling the cable-driven parallel mechanism

关键词：机器人数学模型最小二乘法动力学

Properties and Data-driven Design of Perceptual Reasoning Method Based linguistic Dynamic Systems

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自动化学报 2014年第10期40卷 2221-2232页

作者： li cheng-dong ZHANG Gui-Qing WANG Hui-dong REN Wei-Na School of Information and Electrical Engineering ShandongJianzhu University Jinan 250101 China School of Management Science and Engineering Shandong University of Finance andEconomics Jinan 250014 China

The linguistic dynamic systems (LDSs) based on type-1 fuzzy sets can provide a powerful tool for modeling, analysis, evaluation and control of complex systems. However, as pointed out in earlier studies, it is much more reasonable to take type-2 fuzzy sets to model the existing uncertainties of linguistic words. In this paper, the LDS based on type-2 fuzzy sets is studied, and its reasoning process is realized through the perceptual reasoning method. The properties of the perceptual reasoning method based LDS (PR-LDS) are explored. These properties demonstrated that the output of PR-LDS is intuitive and the computation complexity can be reduced when the consequent type-2 fuzzy numbers in the rule base satisfy some conditions. Further, a data driven method for the design of the PR-LDS is provided. At last, the effectiveness and rationality of the proposed data-driven method are verified by an example.

关键词：建模语言推理方法驱动设计动力系统知觉性能 fuzzy集驱动方法