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Million-scale data integrated deep neural network for phonon properties of heuslers spanning the periodic table

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npj Computational Materials 2023年第1期9卷 2155-2166页

作者： Alejandro Rodriguez Changpeng Lin Hongao Yang Mohammed Al-Fahdi Chen Shen Kamal Choudhary Yong Zhao Jianjun Hu Bingyang Cao Hongbin Zhang Ming Hu Department of Mechanical Engineering University of South CarolinaColumbiaSC 29208USA Theory and Simulation of Materials(THEOS) École Polytechnique Fédérale de LausanneCH-1015 LausanneSwitzerland Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China Institute of Materials Science Technical University of DarmstadtDarmstadt 64287Germany Materials Science and Engineering Division National Institute of Standards and TechnologyGaithersburgMD 20899USA Department of Computer Science and Engineering University of South CarolinaColumbiaSC 29208USA

Existing machine learning potentials for predicting phonon properties of crystals are typically limited on a material-to-materialbasis, primarily due to the exponential scaling of model complexity with the number of atomic species. We address this bottleneckwith the developed Elemental Spatial Density Neural Network Force Field, namely Elemental-SDNNFF. The effectiveness andprecision of our Elemental-SDNNFF approach are demonstrated on 11,866 full, half, and quaternary Heusler structures spanning 55elements in the periodic table by prediction of complete phonon properties. Self-improvement schemes including active learningand data augmentation techniques provide an abundant 9.4 million atomic data for training. Deep insight into predicted ultralowlattice thermal conductivity (<1 Wm^(−1) K^(−1)) of 774 Heusler structures is gained by p–d orbital hybridization analysis. Additionally, aclass of two-band charge-2 Weyl points, referred to as “double Weyl points”, are found in 68% and 87% of 1662 half and 1550quaternary Heuslers, respectively.

关键词： properties phonon spanning

Silver Dopant-Induced Effect on Structural and Optoelectronic properties of CdSe Thin Films

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Acta Metallurgica Sinica(English Letters) 2019年第5期32卷 541-549页

作者： Jagdish Kaur Ramneek Kaur S.K.Tripathi PG Department of Physics DAV College Department of Physics Akal University Department of Physics Panjab University

Thin films of CdSe and silver(Ag)-doped CdSe have been prepared on glass substrates by thermal evaporation in argon gas atmosphere. X-ray diffraction pattern indicates the presence of hexagonal structure with preferred orientation along (100) plane. Elemental composition of the thin films has been analyzed using energy dispersive X-ray analysis. Scanning electron microscopy has been used to investigate the morphology of the thin films. Transmission electron microscope reveals spherical nature of nanoparticles. A decrease in the band gap due to the formation of band tails in the band gap with increase in Ag doping in CdSe lattice has been observed. Photoluminescence spectra indicate redshift in band edge emission peak with increase in Ag doping in CdSe. Electrical conductivity measurements are also studied, and two types of conduction mechanisms taking part in the transport phenomena are observed. Hall measurements indicate n-type behavior of undoped and Ag-doped CdSe thin films.

关键词： Semiconductors Thin films Vapor deposition Electron microscopy Electrical properties

Microstructural Evolution, Mechanical properties and Thermal Stability of Gradient Structured Pure Nickel

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Acta Metallurgica Sinica(English Letters) 2019年第8期32卷 951-960页

作者： Xiao Li Bo Guan Yun-Fei Jia Yun-Chang Xin Cheng-Cheng Zhang Xian-Cheng Zhang Shan-Tung Tu Key Laboratory of Pressure Systems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China School of Materials Science and Engineering Chongqing UniversityChongqing 400044China AECC Commercial Aircraft Engine Co.LTD Shanghai Engineering Research Center for Commercial Aircraft EngineShanghai 20110&China

The microstructural evolution of pure nickel treated by deep rolling(DR)technique with different indent depths was investigated by means of optical microscopy and transmission electron microscopy.The surface roughness,hardness and residual stress distribution along the depth from surface were measured.Moreover,the DR-treated sample was annealed at temperatures from 300 to 700℃for 2 h.The results reveal that dislocation movements are the fundamental mechanisms of gradient grain refinement during the DR process.With increasing indent depth of the DR,the gradient microhardness on the cross section of sample significantly increases,the maximum compressive residual stress decreases,and the affecting region of residual stress increases.The results of thermal stability depict that the microstructure can be stable as temperature up to 300℃,and the abnormal grain growth and annealing twins are observed at 600℃.

关键词： Deep rolling Pure nickel-Microstructural evolution Mechanical properties Thermal stability

properties Correlations and Characterization of Athabasca Oil Sands-derived Synthetic Crude Oil

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Petroleum Science 2007年第3期4卷 84-90页

作者： Wang Jun Zhao Suoqi Xu Chunming Chung Keng H. State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China Petrochemical Institute of PetroChina Beijing 10083 China EnergyINet Calgary Alberta Canada

Narrow fractions of Athabasca oil sands-derived synthetic crude oil （SCO） from Canada were obtained by distillation at 20 ℃ to 500 ℃ and characterized. The yield and properties, such as density, refractive index, viscosity, freezing point, sulfur and nitrogen content and UOP K-index, were correlated as a function of boiling temperature （Tb）. The properties of naphtha fractions, jet fuel and diesel fractions could be predicted accurately with the correlations, which are useful for process design considerations, such as optimizing operating conditions of refinery processing units. The other key properties and characteristics of naphtha fractions, jet fuel, diesel and vacuum gas oil were also determined.

关键词： SCO properties correlation characterization

Effect of microwave treatment on tensile properties of sugar palm fibre reinforced thermoplastic polyurethane composites

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Defence Technology（防务技术） 2018年第4期14卷 287-290页

作者： A.A.Mohammed D.Bachtiar M.R.M.Rejab J.P.Siregar Structural Materials and Degradation Focus Group Faculty of Mechanical EngineeringUniversity of Malaysia Pahang Materials Engineering Department University of TechnologyBaghdadIraq

The effect of microwave treatment on the tensile properties of treated sugar palm fibre with 6% NaOH reinforced thermoplastic polyurethane composites was investigated. Firstly, the sugar palm fibres were treated by 6% alkali solution. Then, microwave treatment was used to treat the alkali treated sugar palm fibres. Three types of temperatures(i.e. 70, 80 and 90℃) were applied in microwave treatment. The extruder and hot press machines were used to mixing the sugar palm fibres and polyurethane resin, and fabricate the composites. Tensile properties(i.e. tensile strength, tensile modulus and elongation at break) were studied by following the ASTM D-638 standard. The highest tensile strength was recorded 18.42 MPa with microwave temperature at 70℃ and 6% alkali pre-treatment. Therefore, the temperature 70℃ of microwave treatment may consider the best degree cent grate.

关键词： Tensile properties Sugar palm fibre Thermoplastic polyurethane Alkali treatment Microwave method

Structure and magnetic properties of nanocrystalline dysprosium powders

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Rare Metals 2020年第1期39卷 28-35页

作者： Hong-Jian Li Qiong Wu Ming Yue Yu-Qing Li Rong-Chun Zhu Jing-Ming Liang Jiu-Xing Zhang College of Materials Science and Engineering Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing100124China

In this current study,nanocrystalline Dy powders were prepared by melt-spinning and subsequent highenergy ball-milling.The effect of ball-milling time on the structure and magnetic properties of the powders was studied.The crystal structure and microstructure of the melt-spun ribbons and ball-milled powders were observed by X-ray diffraction(XRD),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).Magnetic measurement of all samples was performed with vibrating sample magnetometer(VSM).XRD results indicate that the average crystal grain size of the powders decreases from 90.09 nm of the ribbons to 10.42 nm of the4-h ball-milled powders.Further TEM observation shows that the grains are fine and uniform.The Neel temperature(TN)decreases from 182 K of the ribbons to 172 K of the powders,while the Curie temperature(TC)increases from100 to 130 K,demonstrating that the grain size has substantial influence on the magnetic transition process.Moreover,at 60 K,as the ball-milling time increases,the coercivity of the powders increases first,peaking at 0.48 T for 2-h milling,then drops again,while the remanence of the powders decreases monotonic ally.As a result,the powders milled for 2 h exhibit an optimal maximum energy product of 64.0 kJ·m-3,demonstrating the good potential of these powders as a permanent magnet at low temperatures.

关键词： Dysprosium Nanocrystalline Low temperature Magnetic properties

An intelligent SVM modeling process for crude oil properties prediction based on a hybrid GA-PSO method

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Chinese Journal of Chemical Engineering 2019年第8期27卷 1888-1894页

作者： Kexin Bi Tong Qiu Department of Chemical Engineering Tsinghua UniversityBeijing 100084China Beijing Key Laboratory of Industrial Big Data System and Application Beijing 100084China

properties prediction of crude oil remains an essential issue for refineries. In this communication, an exhaustive and extendable support vector machine(SVM) intelligent prediction process has been proposed to solve this problem. A novel hybrid genetic algorithm-particle swarm optimization(GA-PSO)method was applied to optimize the SVM model. The optimization process and result demonstrated that the newly proposed GA-PSO-SVM method was more accurate and time-saving than the classical GA or PSO method. Compared with the classical Grid-search SVM, the combined GA-PSO-SVM model appeared to be more applicable for the properties prediction task. The TBP distillation curve fitting was exampled to evaluate the performance of the developed model. The regression result demonstrated the high accuracy and efficiency of the proposed process. The model can be applied in the Industrial Internet as a plugin, and the adaptability and flexibility is demonstrated by the implement of crude oil molecular reconstruction employing the intelligent prediction process.

关键词： Intelligent properties prediction Support vector machine Hybrid GA-PSO TBP distillation curve fitting

Microstructure and properties of Sm-substituted BiFeO_3 ceramics

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Journal of Rare Earths 2012年第11期30卷 1123-1128页

作者：代海洋陈镇平李涛李永 Department of Technology and Physics Zhengzhou University of Light Industry

Bi1-xSmxFeO3 （x=0.00-0.15） ceramics were synthesized by sol-gel technique with rapid liquid phase sintering process to study the effects of samarium （Sm） substitution on their microstructure and properties. X-ray diffraction （XRD） and Raman studies showed that the structure of BiFeO3 was changed from rhombohedral to orthorhombic at the samarium substitution concentration about x=0.10. The SEM investigation suggested that the Sm substitution hindered the grain growth. Magnetic measurements showed that all the samples studied had a weak ferromagnetism, and the ferromagnetic property of BiFeO3 was improved by Sm substitution due to the suppressed or broken cycloid spin structure caused by the changes in the crystalline structure and size effect. The leakage current was found to be reduced with increasing Sm concentration. The dielectric and ferroelectric measurements showed that dielectric constant, dielectric loss and ferroelectric properties were strongly dependent on the Sm content, Sm substitution could significantly improve the dielectric constant, remnant polarization and decrease the dielectric loss due to the significant decrease of the electric leakage of the samples.

关键词： Bi1-xSmxFeO3 sol-gel method microstructure properties rare earths

Effect of Co element on microstructure and mechanical properties of FeCo_x NiCuAl alloys

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Acta Metallurgica Sinica(English Letters) 2012年第2期25卷 124-130页

作者： Yanxin ZHUANG Wenjie LIU Pengfei XING Fei WANG Jicheng HE Key Laboratory of Electromagnetic Processing of Materials （Ministry of Education） Northeastern University Shenyang 110819 China School of-Materials and Metallurgy Northeastern University Shenyang 110819 China

FeCoxNiCuAl （x values in molar ratio, x=0.2, 0.5, 1, 1.5, 2 and 3） alloys were pre- pared using a suck-casting method. The effect of Co element on phase constituents, microstructure and mechanical properties of the FeCox NiCuA1 alloys was investigated using X-ray diffraction, scanning electron microscopy, optical microscopy and com- pressive tests. It was found that the Co addition has a significant influence on the structure and properties of the FeCo^NiCuA1 alloys. The alloys have typical den- drite microstructure, and are composed of a simple fcc structure and bcc structure. The addition of Co promotes the formation of fcc phase in the alloys, retards the compressive strength and hardness of the alloys, and enhances the plasticity of the alloys.

关键词： High entropy alloy Co element Microstructure properties