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Structural,mechanical,thermodynamic and electronic properties of Pt_(3)M(M=Al,Co,Hf,Sc,Y,Zr)compounds under high pressure

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Rare Metals 2021年第5期40卷 1208-1218页

作者： Zong-Bo Li Kai Xiong Cheng-Chen Jin Ying-Jie Sun Bao-Wen Wang Shun-Meng Zhang Jun-Jie He Yong Mao materials Genome Institute National Center for International Research on Photoelectric and Energy MaterialsSchool of Materials and EnergyYunnan UniversityKunming 650091China

In this work,the impacts of pressure on the structural,mechanical,thermodynamic and electronic properties of typical Pt_(3)M(M=Al,Co,Hf,Sc,Y,Zr)compounds were investigated systematically by the firstprinciples density function theory *** calculated lattice parameters,volume and elastic constants of Pt_(3)M compounds are in good agreement with available experimental and calculation *** the increase in pressure,the lattice parameters and volume of Pt_(3)M compounds decrease,while the elastic constants,bulk modulus,shear modulus and Young’s modulus *** variations in Pugh’s ratio and Poisson’s ratio indicate that these Pt_(3)M compounds are mechanically stable and *** mechanical anisotropy of these Pt_(3)M compounds is enhanced by rising *** analysis indicates that sound velocity and Debye temperature increase with the increase in *** charge distribution does not change obviously,implying that no phase transition occurs in the range of 0-100 GPa.

关键词： Platinum intermetallic compounds Elastic constants Anisotropy Debye temperature First-principles

Thermal expansion properties of Lu2-xFexMo3O12

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Chinese Physics B 2012年第11期21卷 348-353页

作者：武梅梅彭杰祖勇刘荣灯胡中波刘蕴韬陈东风 China Institute of Atomic energy Experimental Physics center Institute of High Energy PhysicsChinese Academy of Sciences College of materials and Photoelectric Technology Graduate University of Chinese Academy of Sciences

The structures and thermal expansion properties of Lu2-xFexMo3O12 have been investigated by X-ray diffraction(XRD).XRD patterns at room temperature indicate that compounds Lu2-xFexMo3O12 with x≤1.3 exhibit an orthorhombic structure with space group Pnca;compounds with x=1.5 and 1.7 have a monoclinic structure with space group P21/*** on thermal expansion properties show that the linear thermal expansion coefficients of orthorhombic phase vary from negative to positive with increasing Fe *** to make zero thermal expansion materials indicate that zero thermal expansion can be observed in Lu1.3Fe0.7Mo3O12 in the temperature range of 200-400℃.

关键词： X-ray diffraction thermal expansion crystal structure

Hot deformation behavior of GH4945 superalloy using constitutive equation and processing map

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Journal of Iron and Steel Research International 2017年第6期24卷 625-633页

作者： Zhao-xia Shi Xiao-feng Yan Chun-hua Duan Jin-gui Song Ming-han Zhao Jue Wang high temperature materials Research Institute Central Iron and Steel Research Institute Beijing 100081 China Beijing Key Laboratory of Advanced high temperature materials Central Iron and Steel Research Institute Beijing 100081China Shenyang Liming Aero-Engine (Group) Corporation Ltd. Shenyang 110043 Liaoning China School of materials Science and Engineering Nanjing Institute of Technology Nanjing 211167 Jiangsu China

The hot deformation behavior of GH4945 superalloy was investigated by isothermal compression test in the temperature range of 1000--1200 ℃with strain rates of 0.001 10.000 s 1 toa total strain of 0.7. Dynamic recrystallization is the primary softening mechanism for GH4945 superalloy during hot deformation. The constitutive equation is established, and the calculated apparent activation energy is 458. 446 kJ/moh The processing maps at true strains of 0.2, 0.4 and 0.6 are generally similar, dem- onstrating that strain has little influence on processing map. The power dissipation efficiency and in- stability factors are remarkably influenced by deformation temperature and strain rate. The optimal hot working conditions are determined in temperature range of 1082 -1131 ℃ with strain rates of 0.004--0.018 s-1. Another domain of1134--1150 ℃ and 0. 018 0.213s ^- can also be selected as the optimal hot working conditions. The initial grains are replaced by dynamically reerystallized ones in optimal domains. The unsafe domains locate in the zone with strain rates above 0, 274 s^- 1, mainly characterized by uneven microstructure. Hot working is not recommended in the unsafe domains.

关键词： Hot deformation behaviorConstitutive equationProcessing mapGH4945 superalloy

Horava–Lifshitz Type Quantum Field Theory and Hierarchy Problem

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Communications in Theoretical Physics 2016年第6期65卷 743-746页

作者：晁伟 center for high energy Physics Peking University

We study the Lifshitz type extension of the standard model(SM) at the UV, with dynamical critical exponent z = 3. One loop radiative corrections to the Higgs mass in such a model are calculated. Our result shows that,the Hierarchy problem, which has initiated many excellent extension of the minimal SM, may be weakened in the z = 3 Lifshitz type quantum field theory.

关键词： Lifshitz Hierarchy problem radiative corrections

Microstructure and thermoelectric properties of Bi_(0.5)Na_(0.02)Sb_(1.48-x)In_xTe_3 alloys fabricated by vacuum melting and hot pressing

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Rare Metals 2015年第11期34卷 770-775页

作者： Xing-Kai Duan Kong-Gang Hu Da-Hu Ma Wang-Nian Zhang Yue-Zhen Jiang Shu-Chao Guo center for New energy materials Research School of Mechanical and Materials Engineering Jiujiang University

The Bi0.5Na0.02Sb1.48-xInxTe3alloys（x =0.02-0.20） were synthesized by vacuum melting and hot pressing methods at 753 K,60 MPa for 30 *** of Na and In dual partial substitutions for Sb on the thermoelectric properties were investigated from 300 to 500 *** Sb with Na and In can enhance the Seebeck coefficient effectively near room *** electrical resistivity of the Na and In dual-doping samples is higher within the whole test temperature *** Bi0.5Na0.02Sb1.48-xInxTe3samples（x = 0.02,0.06） play a great role in optimizing the thermal *** for the Bi0.5Na0.02Sb1.46In0.02Te3alloy,the minimum value of thermal conductivity reaches 0.53 W·m-1·K-1at 320 *** thermoelectric performance of the Na and In dualdoped samples is greatly improved,and a figure of merit ZT of 1.26 is achieved at 300 K for the Bi0.5Na0.02Sb1.42In0.06Te3,representing 26%enhancement with respect to ZT = 1.0 of the undoped sample.

关键词： Microstructure Dual doping Hot pressing Thermal co

Sintering behavior and thermal conductivity of Y_(2)O_(3) fully stabilized HfO_(2) ceramics

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Rare Metals 2021年第5期40卷 1255-1266页

作者： Chun Li Jian He Yue Ma School of materials Science and Engineering Beihang UniversityBeijing 100191China School of energy and Power Engineering Beihang UniversityBeijing 100191China Key Laboratory of high-temperature Structural materials and Coatings Technology(Ministry of Industry and Information Technology) Beihang UniversityBeijing 100191China

A series of Y_(2)O_(3) fully stabilized HfO2 ceramics(Hf_(1-x)Y_(x)O_(2-0.5x),x=0.20,0.24,0.28,0.32,0.36 and 0.40)were synthesized by solid-state reaction at 1500℃.The phase composition,thermal conductivity and sintering behavior at 1400℃ of the ceramic bulks were *** Hf_(1-x)Y_(x)O_(2-0.5x) ceramics were comprised of pure cubic phase with disordered fluorite *** phase transformation occurred in the ceramics with Y3+doping concentration ranging from 0.24 to *** Hf_(0.64)Y_(0.36)O_(1.82) and Hf_(0.6)Y_(0.4)O_(1.8) samples revealed the lowest grain growth rate when sintered at 1400℃,indicating good resistance to ***,the Vicker’s hardness and Young’s modulus after annealed for 96 h at 1400℃ for the Hf_(0.64)Y_(0.36)O_(1.82) sample were 8.97 and 200 GPa,respectively,much lower than those of the Hf_(0.6)Y_(0.4)O_(1.8)(14.51 and 237 GPa,respectively).The thermal conductivity of Hf_(1-x)Y_(x)O_(2-0.5x) first decreased and then increased slowly as the Y3+content increased,and the associated mechanism was discussed.

关键词： Yttria fully stabilized hafnia Sintering Mechanical properties Thermal conductivity

Massive neutrinos:where we are standing and where we are going

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Science Bulletin 2015年第23期60卷 2077-2079页

作者： Shun Zhou Institute of high energy Physics Chinese Academy of Sciences center for high energy Physics Peking University

Neutrinos are the most elusive particles that we have ever discovered in *** are fermions of spin one-half and have no electric *** they interact with matter rather weakly,it is extremely difficult to catch them even ... 详细信息

关键词：中微子相互作用心理特性自然界费米子探测器电荷自旋

RF trapping and acceleration in CSNS/RCS

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Chinese Physics C 2008年第6期32卷 437-441页

作者：魏涛傅世年秦庆唐靖宇 Institute of high energy Physics Accelerator Research CenterCAS

In this paper, two injection scenarios with different chopping rate are discussed. The waveforms of the RF voltage are studied and optimized, respectively. Some suggestions are made, concerning chopping and momentum painting of the injected beam. Furthermore, the momentum spread and transverse tune shift are calculated so that the beam aperture and the beam loss can be estimated. Finally, the beam loss with magnet field error is analyzed.

关键词： chopping beam loss bunching factor

Micro-nano structured VNb_(9)O_(25)anode with superior electronic conductivity for high-rate and long-life lithium storage

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Journal of materials Science & Technology 2021年第24期83卷 66-74页

作者： Mingxing Liang Yongcong Huang Yuda Lin Guisheng Liang Cihui Huang Lan Chen Jiaxin Li Qian Feng Chunfu Lin Zhigao Huang College of Physics and energy Fujian Normal UniversityFujian Provincial Solar Energy Conversion and Energy Storage Engineering Technology Research CenterFuzhou 350117China Institute of materials for energy and Environment School of Materials Science and EngineeringQingdao UniversityQingdao 266071China Fujian Provincial Key Laboratory of Quantum Manipulation and New energy materials Fuzhou 350117China Fujian Provincial Collaborative Innovation center for Advanced high-Field Superconducting materials and Engineering Fuzhou 350117China

The oxygen vacancies and micro-nano structure can optimize the electron/Li+migration kinetics in anode materials for lithium batteries(LIBs).Here,porous micro-nano structured VNb_(9)O_(25)composites with rich oxygen vacancies were reasonably prepared via a facile solvothermal method combined with annealing treatment at 800℃for 30 h(VNb_(9)O_(25)-30 h).This micro-nano structure can enhance the contact of active material/electrolyte,and shorten the Li+diffusion *** introduction of oxygen vacancies can further boosts the intrinsic conductivity of VNb_(9)O_(25)-30 h for achieving excellent LIB *** as-prepared VNb_(9)O_(25)-30 h anode showed advanced rate capability with reversible capacity of 122.2 m A h g^(-1)at 4 A g^(-1),and delivered excellent capacity retention of~100%after 2000 ***,VNb_(9)O_(25)-30 h provides unexpected long-cycle life(i.e.,reversible capacity of 165.7 m A h g^(-1)at 1 A g^(-1)with a high capacity retention of 85.6%even after 8000 cycles).Additionally,coupled with the Li Fe PO4 cathode,the Li Fe PO4//VNb_(9)O_(25)-30 h full cell delivers superior LIB properties with high reversible capacities of 91.6 m A h g^(-1)at 5 C for 1000 ***,such reasonable construction method can assist in other high-performance niobium-based oxides in LIBs.

关键词： Lithium-ion batteries VNb_(9)O_(25)anode Micro-nano structure Oxygen vacancies Electrochemical performance