检索结果-南通市图书馆

General compliance transformation relations for all seven crystal systems

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2013年第4期56卷 694-700页

作者： ZHANG Yan ji vincent ICMMO/LEMHE UMR CNRS 8182 Université Paris-Sud 11Orsay Cedex 91405 France

For crystals, the compliance (sij) and the stiffness (cij) matrices are specified in the orthogonal coordinate systems (Yi), which do not coincide with the crystal axes (Xi) commonly used except for cubic and orthorhombic crystal systems. Transformations have been done in this paper and the general compliance transformation relations from the orthogonal coordinate systems (Yi) to the measurement systems (Mi) are given for all seven crystal systems. Accordingly, useful expressions for Young's modulus E and Poisson's ratio are also derived.

关键词： elasticity theory compliance Young’s modulus Poisson’s ratio

First-principles study of the structural, electronic, and magnetic properties of double perovskite Sr2FeReO6 containing various imperfections

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第5期25卷 410-417页

作者：张研段理 vincent ji 徐可为 School of Materials Science and Engineering Chang'an University Xi 'an 710061 China ICMMO/SP2M UMR CNRS 8182 Universite Paris- Sud 91405 Orsay Cedex France State Key Laboratory for Mechanical Behavior of Materials Xi' an Jiaotong University Xi' an 710049 China

The structural, electronic, and magnetic properties of double perovskite Sr_2FeReO_6 containing eight different imperfections of FeReor ReFeantisites, Fe1–Re1 or Fe1–Re4 interchanges, V_（Fe）, V_（Re）, VOor V_（Sr） vacancies have been studied by using the first-principles projector augmented wave（PAW） within generalized gradient approximation as well as taking into account the on-site Coulomb repulsive interaction（GGA＋U）. No obvious structural changes are observed for the imperfect Sr_2FeReO_6 containing FeReor ReFeantisites, Fe1–Re1 or Fe1–Re4 interchanges, or VSrvacancy defects. However, the six（eight） nearest oxygen neighbors of the vacancy move away from（close to） VFeor V_（Re）（VO） vacancies. The half-metallic（HM） character is maintained for the imperfect Sr_2FeReO_6 containing FeReor ReFeantisites, Fe1–Re4 interchange, V_（Fe）,VO or V_（Sr） vacancies, while it vanishes when the Fe1–Re1 interchange or VRevacancy is presented. So the Fe1–Re1 interchange and the VRevacancy defects should be avoided to preserve the HM character of Sr_2FeReO_6 and thus usage in spintronic devices. In the FeReor ReFeantisites, Fe1–Re1 or Fe1–Re4 interchanges cases, the spin moments of the Fe（Re）cations situated on Re（Fe） antisites are in an antiferromagnetic coupling with those of the Fe（Re） cations on the regular sites. In the V_（Fe）, V_（Re）, VO, or V_（Sr） vacancies cases, a ferromagnetic coupling is obtained within each cation sublattice,while the two cation sublattices are coupled antiferromagnetically. The total magnetic moments μtot（μB/f.u.） of the imperfect Sr_2FeReO_6 containing eight different defects decrease in the sequence of VSrvacancy（3.50）, VRevacancy（3.43）,FeReantisite（2.74）, VOvacancy（2.64）, VFevacancy（2.51）, ReFeantisite（2.29）, Fe1–Re4 interchange（1.96）, Fe1–Re1interchange（1.87）, and the mechanisms of the saturation magnetization reduction have been analyzed.

关键词： double perovskite imperfections electronic properties magnetic properties

Young’s modulus surface and Poisson’s ratio curve for tetragonal crystals

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2008年第5期17卷 1565-1573页

作者：张建民张研徐可为 ji vincent College of Physics and Information Technology Shaanxi Normal University State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University ICMMO/LEMHE UMR CNRS 8182 Universit'e Paris-Sud 11 91405 Orsay Cedex France

This paper gives the general expressions for the compliance s′ijkl, Young＇s modulus E（hkl） and Poisson＇s ratio v（hkl, θ） along arbitrary loading direction [hkl] for tetragonal crystals. The representation surface for which the length of the radius vector in the [hkl] direction equals E（hkl） and representation curve for which the length of the radius vector with angle θ deviated from the reference directions [001^-], [100], [001^-], [101^-] and [112^-] equals v（100, θ）, v（001, θ）, v（110,θ）, v（101,θ） and v（111, θ） respectively, are constructed for nine tetragonal crystals （ammonium dihydrogen arsenate, ammonium dihydrogen phosphate, barium titanate, indium, nickel sulfate, potassium dihydrogen arsenate, potassium dihydrogen phosphate, tin and zircon）. The characteristics of them are analysed in detail.

关键词： tetragonal crystals elastic properties representation surfaces representation curves

The synergistic role of Ti microparticles and CeO_(2) nanoparticles in tailoring microstructures and properties of high-quality Ni matrix nanocomposite coating

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第10期105卷 182-193页

作者： Lianbo Wang Shilong Xing Zizhen Shen Huabing Liu Chuanhai jiang vincent ji Yuantao Zhao School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China ICMMO/SP2M Universite Paris-SaclayOrsay 91405France Zhejiang Scientific Research Institute of Transport Hangzhou 310023China Merchant Marine College Shanghai Maritime UniversityShanghai 201306China

In current work,Ni-Ti-CeO_(2) nanocomposite coatings were achieved by co-adding Ti microparticles and CeO_(2) *** experiments and COMSOL computer simulation were applied to reveal the synergistic role of Ti microparticles and CeO_(2) nanoparticles in tailoring the spatial microstructures and properties of Ni-Ti-CeO_(2) nanocomposite ***,the conductive Ti microparticles conducted the growth behavior of Ni grains by current density concentration,distorting electronic feld lines and heterogeneous *** domains consisting of inner nanograins and outer radial columnar grains surrounded Ti microparticles,where Ti microparticles acted as *** microparticles tended to be aggregated,leading to spatial heterogeneity of *** deposits buried the Ti microparticles in forms of“covering model”,contributing to the formation of inside voids and rough surface and aggregation of Ti microparticles;on the other hand,the non-conductive CeO_(2)microparticles hardly changed the distribution of current density and electronic feld lines on the cathode *** deposits buried the CeO_(2)microparticle in forms of“stacking model”,avoiding the inside voids and aggregation of *** incorporation of CeO_(2)microparticle brought in microstructure evolutions only on its top side without disturbing the growth behavior of Ni grains on its lateral side or bottom,suggesting the limited *** was correlated with the presence of current concentration above the CeO_(2) microparticle at the last stage of burying CeO_(2) *** co-addition of Ti microparticles and CeO_(2) nanoparticles into Ni deposits exploited the complementary action of the two particles,which gave birth to satisfed spatial microstructures and improved *** microparticles took major responsibility for microstructure evolutions,while the CeO_(2) nanoparticles were mainly in charge of the microstructure homogeneity.

关键词： Nanocomposite coating CeO_(2)nanoparticle Ti microparticles Grain growth behavior COMSOL computer simulation Spatial microstructure and spatial hardness

Toughening effects of Mo and Nb addition on impact toughness and crack resistance of titanium alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第20期79卷 147-164页

作者： Shixing Huang Qinyang Zhao Yongqing Zhao Cheng Lin Cong Wu Weiju jia Chengliang Mao vincent ji School of Materials Science and Engineering Northeastern UniversityShenyangLiaoning110819China School of Material Science and Engineering Chang’an UniversityXi’anShaanxi710064China Northwest Institute for Nonferrous Metal Research Xi’anShaanxi710016China School of Mechanical Engineering Liaoning Shihua UniversityFushunLiaoning113001China ICMMO/SP2M UMR CNRS 8182UniversitéParis-SaclayOrsay91405France

Ti-6Al,Ti-6Al-2Mo and Ti-6Al-3Nb alloys were prepared to investigate the toughening effects ofβstabilizers Mo and Nb on impact toughness and crack resistance of titanium *** Charpy impact tests showed that the total impact absorbed energy of Ti-6Al-2Mo and Ti-6Al-3Nb(∼64 J)were two times higher than that of Ti-6Al(∼30 J),indicating the higher impact toughness of Ti-6Al-2Mo and Ti-6Al-3Nb *** of load-displacement curves revealed the similar crack initiation energy of Ti-6Al,Ti-6Al-2Mo and Ti-6Al-3Nb(15.4 J,16.1 J and 15.0 J,respectively).However,the higher crack propagation energy of Ti-6Al-2Mo and Ti-6Al-3Nb(46.7 J and 48.3 J,respectively)were about three times higher than that of Ti-6Al(14.4 J),indicating the stronger resistance to crack propagation in Ti-6Al-2Mo and ***-mortem analysis of impact samples demonstrated that the increased dislocation density and deformation twinning were mainly responsible for the stronger resistance to crack propagation in Ti-6Al-2Mo and *** to the invisibility of dislocation activation and deformation twinning during the Charpy impact process,a mathematical model has been proposed to evaluate the effects of Al,Mo and Nb elements on dislocation mobility based on the Yu Rui-huang electron *** of Mo and Nb elements significantly improved the dislocation mobility in Ti-6Al-2Mo and Ti-6Al-3Nb compared to that in Ti-6Al ***,more dislocations were activated in Ti-6Al-2Mo and Ti-6Al-3Nb which supplied the larger plastic deformation under impact loading.A dislocation-based model also has been proposed to interpret the nucleation and propagation of deformation twinning under the impact *** pileup atα/βinterfaces provided potential sites for nucleation of deformation twinning in Ti-6Al-2Mo and ***,deformation twinning facilitated the dislocation motion inαgrains with hard *** increased dislocation mobility and deformation

关键词： Titanium alloy Impact toughness Crack resistance Dislocation mobility Deformation twinning

在线全文

学校读者我要写书评

暂无评论

钛的晶体结构和结构转变研究进展

稀有金属材料与工程 2022年第12期51卷 4398-4409页

作者：李磊郭荻子应扬洪权 vincent ji 西北有色金属研究院陕西西安710016 巴黎萨克雷大学法国奥赛91405

钛具有高强度,低密度,耐腐蚀等特性,并在多个领域得到应用。多年来,钛的同素异构体的晶体结构和结构转变受到了学者的广泛关注。除了密排六方结构的平衡相(α-Ti),面心立方结构的高温相(β-Ti)和六方结构的高压相(ω-Ti)外,学者通过各... 详细信息

钛具有高强度,低密度,耐腐蚀等特性,并在多个领域得到应用。多年来,钛的同素异构体的晶体结构和结构转变受到了学者的广泛关注。除了密排六方结构的平衡相(α-Ti),面心立方结构的高温相(β-Ti)和六方结构的高压相(ω-Ti)外,学者通过各种方法尝试在极端条件下制备钛的其他亚稳相结构。在过去的几十年中,人们在超高压条件下发现了γ-Ti和δ-Ti,并通过高压扭转实验、激光冲击实验和超薄薄膜实验等方法制备了在室温条件下可以稳定存在的ω-Ti和fcc-Ti。综述了钛的同素异构体(不包括合金)的晶体结构和结构转变类型,并介绍了不同结构钛的稳定性以及结构转变机理。

关键词：晶体结构结构转变高压面心立方钛

Computer simulation of symmetrical tilt grain boundaries in noble metals with MAEAM

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2007年第1期16卷 210-216页

作者：张建民黄育红徐可为 ji vincent College of Physics and information Technology Shannxi Normal University Xian 710062 China State Key Laboratory for Mechanical Behavior of Materials Xian Jiaotong University Xian 710049 China LIM UMR 8006 ENSAM 151 bd. de L'H6pital Paris 75013 France

This paper reports that an atomic scale study of [^-110] symmetrical tilt grain boundary （STGB） has been made with modified analytical embedded atom method （MAEAM） for 44 planes in three noble metals Au, Ag and Cu. For each metal, the energies of two crystals ideally joined together are unrealistically hlgh due to very short distance between atoms near the grain boundary （GB） plane. A relative slide between grains in the GB plane results in a significaut decrease in GB energy and a minimum value is obtained at specific translation distance. The minimum energy of Cu is much higher than that of Ag and Au, while the minimum energy of Ag is slightly higher than that of Au. For all the three metals, the three lowest energies correspond to identical （111）, （113） and （331） boundary successively for two translations considered; from minimization of GB energy, these boundaries should be preferable in [^-110] STGB for noble metals. This is consistent with the experimental results. In addition, the minimum energy increases with increasing reciprocal planar coincidence density ∑, but decreases with increasing relative interplanar distance d/a.

关键词： noble metals STGB grain boundary energy translation MAEAM

中子衍射法研究单晶镍基高温合金热机械疲劳引起的应力和晶格错配

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

物理学报 2009年第4期58卷 2549-2555页

作者：孙光爱陈波陈华吴二冬张俊 vincent ji Darren Hughes Thilo Pirling 四川大学原子与分子物理研究所成都610065 中国工程物理研究院核物理与化学研究所绵阳621900 中国科学院金属研究所材料科学国家实验室沈阳110016 巴黎第十一大学奥赛分子化学与材料学院巴黎91405 法国劳厄-朗之万研究所格勒诺贝尔38042

采用中子衍射法对热机械疲劳后的单晶镍基高温合金样品内部中心点进行了实验测量,数据处理采用了双相叠加峰和单峰分析两种方法,计算得到了样品材料的宏观等效应力、应力偏量、γ相和γ′相的等效应力和晶格错配度等.实验结果表明,两种... 详细信息

采用中子衍射法对热机械疲劳后的单晶镍基高温合金样品内部中心点进行了实验测量,数据处理采用了双相叠加峰和单峰分析两种方法,计算得到了样品材料的宏观等效应力、应力偏量、γ相和γ′相的等效应力和晶格错配度等.实验结果表明,两种分析方法得到的宏观等效应力基本一致.在热机械疲劳循环100周出现最大宏观等效应力和应力偏量,此时位错等微缺陷达到饱和,偏离中心点处γ′相应力减小显著;在热机械疲劳开始阶段负错配度明显减小,随循环周次增多基体塑性应变累积又使负错配度以每次8.1×10-6的速度逐渐线形增大.

关键词：中子衍射单晶高温合金等效应力应力偏量

喷丸处理对TiB2／Al复合材料表面基体力学性能的影响

在线全文

学校读者我要写书评

暂无评论

材料研究学报 2009年第3期23卷 237-241页

作者：栾卫志姜传海嵇宁上海交通大学材料科学与工程学院上海200240 LEMHE/ICMMO UMR 8182Universite Paris-Sud 1191405 Orsay France

通过X射线衍射线形分析表征了喷丸表面的组织结构,利用原位拉伸X射线衍射应力分析研究了TiB_2/6351Al复合材料喷丸表面基体的力学行为。结果表明,喷丸后复合材料表面基体的屈服强度提高了26%,整体强度提高约28%,显微硬度提高50%以上。... 详细信息

通过X射线衍射线形分析表征了喷丸表面的组织结构,利用原位拉伸X射线衍射应力分析研究了TiB_2/6351Al复合材料喷丸表面基体的力学行为。结果表明,喷丸后复合材料表面基体的屈服强度提高了26%,整体强度提高约28%,显微硬度提高50%以上。喷丸前、后复合材料基体承载系数分别为81%和83%,喷丸后的基体承载系数略有提高。喷丸表面基体的晶块尺寸及位错密度分别约51 nm和3.05×10^(14)m^(-2),晶块细化及位错密度增高是导致表面基体力学性能提高的主要原因。

关键词：复合材料喷丸强化基体性能 X射线衍射金属基复合材料组织结构