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Distribution of TiN inclusions in Ti-stabilized ultra-pure ferrite stainless steel slab

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Journal of Iron and Steel Research International 2019年第9期26卷 962-972页

作者： Hao-jian Duan Ying Zhang Ying ren Li-feng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

In order to clarify and control the silver defect on surface of cold-rolled sheet of the Ti-stabilized ultra-pure ferrite stainless steel, the distribution of TiN inclusions on the cross section of hot-rolled plate was studied using automated scanning electron microscopy/energy-dispersive X-ray spectroscopy inclusion analysis (ASPEX 1020 system). It was found that the number density decreases sharply from the surface to the center of the hot-rolled plate, whereas the average size increases. Then, the distribution of TiN inclusions on the cross section of continuously cast slab was investigated. Similarly, numerous small-sized TiN inclusions were generated at the subsurface of the slab. The average size rapidly increased and the number density dramatically decreased from the subsurface to 1/4 thickness, while from 1/4 thickness to 1/2 thickness, the increase in average size and the decrease in number density were slight. Thermodynamics results showed that TiN inclusion was formed below the liquidus temperature, which indicated that TiN inclusions could not be formed during secondary refining. Considering the microsegregation of solute elements and the equilibrium of TiN formation during solidification, TiN precipitated in the mushy zone when the solid fraction was close to 0.2. The growth of TiN was analyzed based on the diffusion-controlled growth model. With the increase in cooling rate, the time for TiN growth decreased and the size of TiN inclusions was diminished, which revealed the size distribution of TiN inclusions in the cast slab qualitatively.

关键词： TiN inclusion Ti-stabilized ultra-pure ferrite stainless steel Distribution in slab Thermodynamics Diffusion-controlled growth model

Magnetism and superconductivity in Eu(Fe_(1-x)Ni_x)As_2(x= 0,0.04)

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Science China(Physics,Mechanics & Astronomy) 2018年第12期61卷 37-44页

作者： YaBin Liu Yi Liu Wenhe Jiao Zhi ren GuangHan Cao Department of Physics Zhejiang University Department of Physics Zhejiang University of Science and Technology Institute for Natural Sciences Westlake Institute for Advanced Study Collaborative Innovation Centre of Advanced Microstructures Nanjing University State Key Lab of Silicon Materials Zhejiang University

We report Eu-local-spin magnetism and Ni-doping-induced superconductivity(SC)in a 112-type ferroarsenide system Eu(Fe_(1-x)Ni_x)As_*** non-doped EuFeAs_2exhibits two primary magnetic transitions at ~100 and ~40 K,probably associated with a spin-density-wave(SDW)transition and an antiferromagnetic ordering in the Fe and Eu sublattices,*** additional successive transitions possibly related to Eu-spin modulations appear at 15.5 and 6.5 *** the Ni-doped sample with x=0.04,the SDW transition disappears,and SC emerges at T_c=17.5 *** Eu-spin ordering remains at around 40 K,followed by the possible reentrant magnetic modulations with enhanced spin ***,SC coexists with a weak spontaneous magnetization below 6.2 K in Eu(Fe_(0.96)Ni_(0.04))As_2,which provides a complementary playground for the study of the interplay between SC and magnetism.

关键词： superconductivity magnetism Ni doping iron-based superconductors Eu(Fe1-xNix)As2

High-Lift Effect of Bionic Slat Based on Owl Wing

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Journal of Bionic Engineering 2013年第4期10卷 456-463页

作者： Changjiang Ge Luquan ren Ping Liang Chengchun Zhang Zhihui Zhang Key Laboratory of Bionic Engineering (Ministry of Education China) Jilin University Changchun 130022 P. R. China

A slat without a cove is built on the basis of a bionic airfoil （i.e. stowed multi-element airfoil）, which is extracted from a long-eared owl wing. The three-dimensional models with a deployed slat and a stowed slat are measured in a low-turbulence wind tunnel. The results are used to characterize high-lift effect： compared with the stowed slat, the deployed slat works more like a spoiler at low angles of attack, but like a conventional slat or slot at high angles of attack. In addition, it can also increase stall angle and maximum lift coefficient, and postpone the decrease in the gradient of the lift coefficient. At the same time, the flow field visualized around both three-dimensional models suggests the leading-edge separation associated with the decrease in the gradient of the lift coefficient, Furthermore, the related two-dimensional simulation well agrees with the analysis of the lift coefficient, as the complement to the experiment. The bionic slat may be used as reference in the design of leading-edge slats without a cove.

关键词： alula bionic slat high-lift effect leading-edge separation low Reynolds number

Band Offset and Optical Property of (ZnS)_(n)/(Si2)_(n) (110) Superlattice

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Chinese Physics Letters 1996年第6期13卷 458-460页

作者： LI Kai-hang HUANG Mei-chun WANG ren-zhi Department of Physics Xiamen UniversityXiamen 361005

Supercell self-consistent calculation of band structures of(ZnS)_(n)/(Si_(2))_(n) (110) (n=2,3,4,5)has been performed by means of linear muffin-tin orbitals *** valence-band offset of such systems is calculated by frozen optential method and their Joint density of states has been computed by tetrahedron *** results show that the(ZnS)n/(Si_(2))n(110)superlattices have a large valence-band offset and their optical properties integrate exellent optical properties of bulk ZnS and that of Si.

关键词： method Si_(2)

Effect of Tb Doping on Structural and Electrical Properties of BiFeO_3 Thin Films Prepared by Sol-Gel Technique

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Journal of Materials Science & Technology 2014年第4期30卷 365-370页

作者： Guohua Dong Guoqiang Tan Wenlong Liu Ao Xia Huijun ren Key Laboratory of Auxiliary Chemistry & Technology for Chemical Industry Ministry of EducationShaanxi University of Science & Technology

Bil_xTbxFe03 thin films were prepared on Sn02 （fluorine doped tin oxide） substrates by a sol-gel method. The structural and electrical properties of the BiFe03 thin films were characterized and tested. The results indicated that the diffraction peak of the Tb-doped BiFe03 films was shifted towards right as the doping amounts were increased. The structure was transformed from the rhombohedral to tetragonal/orthorhombic phase. The ***.11Fe03 thin film showed the well-developed P-E loops, which enhanced remnant polarization （Pr = 88.05 μC/cm2） at room temperature. The dielectric constant and dielectric loss of ***03 thin film at 100 kHz were 185 and 0.018, respectively. Furthermore, the ***03 thin film showed a relatively low leakage current density of 2.07×10-5 A/cm2 at an applied electric field of 150 kV/cm. The X- ray photoelectron spectroscopy （XPS） spectra indicated that the presence of Fe2＋ ions in the ***.11Fe03 thin film was less than that in the pure BiFe03.

关键词： BiFeO3 thin films Tb doping Sol-gel method Ferroelectric properties

Recent Advances of Catalytic Enantioselective heck Reactions and Reductive-heck Reactions

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Chinese Journal of Chemistry 2021年第3期39卷 710-728页

作者： Jia-Qi Xie ren-Xiao Liang Yi-Xia Jia College of Chemical Engineering State Key Laboratory Breeding Base of Green-Chemical Synthesis TechnologyZhejiang University of TechnologyHangzhouZhejiang 310014China

heck reaction is one of the most important carbon-carbon bond forming reactions with wide applications in organic *** advances of enantioselective heck reaction have been achieved in the past *** review focuses on recent development of catalytic asymmetric heck reaction and reductive heck reaction,which covers intermolecular and intramolecular versions since *** article is organized in terms of the cat-alysts and olefin substrates.

关键词： heck reaction Asymmetric catalysis Palladium Nickel Reductive heck reaction

Evolution of medium-range order and its correlation with magnetic nanodomains in Fe-Dy-B-Nb bulk metallic glasses

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Journal of Materials Science & Technology 2024年第9期176卷 224-235页

作者： Jiacheng Ge Yao Gu Zhongzheng Yao Sinan Liu Huiqiang Ying Chenyu Lu Zhenduo Wu Yang ren Jun-ichi Suzuki Zhenhua Xie Yubin Ke Jianrong Zeng he Zhu Song Tang Xun-Li Wang Si Lan herbert Gleiter Institute of Nanoscience School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Department of Physics City University of Hong KongHong Kong SARChina City University of Hong Kong(Dongguan) Dongguan 523000China Japan Proton Accelerator Research Complex Japan Atomic Energy AgencyTokaiJapan Spallation Neutron Source Science Center Dongguan 523803China Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology DalangDongguan 523803China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Center for Neutron Scattering City University of Hong Kong Shenzhen Research InstituteShenzhen 518057China

Fe-based metallic glasses are promising functional materials for advanced magnetism and sensor *** magnetic performance in amorphous materials requires a thorough knowledge of the correlation between structural disorder and magnetic order,which remains *** practical difficulties remain:the first is directly observing subtle magnetic structural changes on multiple scales,and the second is precisely regulating the various amorphous *** we propose a novel approach to tailor the amorphous structure through the liquid-liquid phase ***-situ synchrotron diffraction has unraveled a medium-range ordering process dominated by edge-sharing cluster connectivity during the liquid-liquid phase ***,nanodomains with topological order have been found to exist in composition with liquid-liquid phase transition,manifesting as hexagonal patterns in small-angle neutron scattering *** liquid-liquid phase transition can induce the nanodomains to be more locally ordered,generating stronger exchange interactions due to the reduced Fe–Fe bond length and the enhanced structural order,leading to the increment of saturation ***,the increased local heterogeneity at the medium-range scale enhances the magnetic anisotropy,promoting the permeability response under applied stress and leading to a better stress-impedance *** experimental results pave the way to tailor the magnetic structure and performance through the liquid-liquid phase transition.

关键词： Fe-based metallic glass Liquid-liquid phase transition Medium-range ordering Magnetic nanodomain

Numerical simulation and experimental verification of silicone oil flow over magnetic fluid under applied magnetic field

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China Particuology 2007年第1期5卷 93-102页

作者： Ruoyu Hong Zhiqiang ren Shizhong Zhang Jianmin Ding Hongzhong Li Chemical Engineering Department & Key Laboratory of Organic Synthesis Soochow University Dushuh SIP Suzhou 215123 China MPR Laboratory Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China IBM HYDA/050-3 C202 3605 Highway 52 North Rochester MN 55901 USA

Two-layer flow of magnetic fluid and non-magnetic silicone oil was simulated numerically. The continuity equation, momentum equations, kinematic equation, and magnetic potential equation were solved in two-dimensional Cartesian coordinate. PLIC （piecewise linear integration calculation） VOF （volume of fluid） scheme was employed to track the free interface. Surface tension was treated via a continuous surface force （CSF） model that ensures robustness and accuracy. The influences of applied magnetic field, inlet velocity profile, initial surface disturbance of interface and surface tension were analyzed. The computed interface shapes at different conditions were compared with experimental observation.

关键词： Magnetic fluid Volume of fluid (VOF) Two-layer flow

Design and Analysis of S-CO_2 Cycle and Radial Turbine for SOFC Vehicle Waste-heat Recovery

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Journal of Thermal Science 2019年第3期28卷 559-570页

作者： XIA Liu LI Xuesong SONG Jian ren Xiaodong GU Chunwei Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power Engineering Tsinghua University Clean Energy Processes (CEP) Laboratory Department of Chemical Engineering Imperial College London

Solid oxide fuel cell(SOFC) vehicles are considered to have broad prospects for development, and the high operating temperature of SOFC results in great potential for waste-heat recovery. Many concepts for utilizing waste heat of SOFC have been suggested and studied, and most of them directly couple an SOFC to a gas turbine, which require the SOFC to operate at an elevated pressure and make the system less flexible and thus harder to operate. In recent years, with the development of turbine and heat exchanger technology, the supercritical carbon dioxide(S-CO_2) power cycle has raised widespread attractions for the waste recovery. This study explores the potential of S-CO_2 Brayton cycle to realize waste-heat recovery for an SOFC vehicle. The SOFC can operate at atmospheric pressure, and the hybrid system is easier to operate than the directly coupled systems. In this paper, a simple recuperated S-CO_2 Brayton cycle is proposed and the key component, radial inflow turbine is designed and focused. The flow state of the designed turbine is analyzed in detail based on computational fluid dynamics(CFD) numerical simulation. Five cases with different impeller tip clearances are numerically simulated to study its influence on the turbine performance. In addition, off-design performance analysis of the radial inflow turbine is conducted considering the temperature fluctuation of SOFC in practical applications.

关键词： SOFC waste-heat recovery supercritical carbon dioxide radial turbine