检索结果-南通市图书馆

Strong electron correlation-induced Mott-insulating electrides of Ae_(5)X_(3)(Ae=Ca,Sr,and Ba;X=As and Sb)

Matter and Radiation at Extremes 2024年第3期9卷 74-82页

作者： Ya Xu Lu Zheng Yunkun Zhang Zhuangfei Zhang QianQian Wang Yuewen Zhang Liangchao Chen Chao Fang Biao Wan Huiyang Gou Key Laboratory of Material Physics of Ministry of Education School of Physics and Laboratory of Zhongyuan LightZhengzhou UniversityZhengzhou 450052China School of Mechanical and Equipment Engineering Hebei University of EngineeringHandan 056038China Center for High Pressure Science and Technology Advanced Research Beijing 100094China

The presence of interstitial electrons in electrides endows them with interesting attributes,such as low work function,high carrier concentration,and unique magnetic properties.Thorough knowledge and understanding of electrides are thus of both scientific and technological significance.Here,we employ first-principles calculations to investigate Mott-insulating Ae_(5)X_(3)(Ae=Ca,Sr,and Ba;X=As and Sb)electrides with Mn_(5)Si_(3)-type structure,in which half-filled interstitial electrons serve as ions and are spin-polarized.The Mott-insulating property is induced by strong electron correlation between the nearest interstitial electrons,resulting in spin splitting and a separation between occupied and unoccupied states.The half-filled antiferromagnetic configuration and localization of the interstitial electrons are critical for the Mott-insulating properties of these materials.Compared with that in Intermetallic electrides,the orbital hybridization between the half-filled interstitial electrons and the surrounding atoms is weak,leading to highly localized magnetic centers and pronounced correlation effects.Therefore,the Mott-insulating electrides Ae_(5)X_(3)have very large indirect bandgaps(0.30 eV).In addition,high pressure is found to strengthen the strong correlation effects and enlarge the bandgap.The present results provide a deeper understanding of the formation mechanism of Mott-insulating electrides and provide guidance for the search for new strongly correlated electrides.

关键词： Intermetallic filled occupied

来源：

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

Off-stoichiometry-guided design of high-strength chemically complex Intermetallic-based alloys with outstanding ductility

引用

Journal of Materials Science & Technology 2023年第29期160卷 28-33页

作者： Bo Xiao Jixun Zhang Shaofei Liu Yilu Zhao Lianyong Xu C.T.Liu Tao Yang Department of Materials Science and Engineering Mechanical Behavior Division of Shenyang National Laboratory for Materials ScienceCity University of Hong KongHong KongChina Center for Advanced Nuclear Safety and Sustainable Development City University of Hong KongHong KongChina Hong Kong Institute for Advanced Study City University of Hong KongHong KongChina School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Materials Science and Engineering Tianjin UniversityTianjin 300350China

1.Introduction The lasting drive for improved energy efficiency in power gen-eration encourages the innovative design of advanced structural materials with superb mechanical properties[1-6].Among these materials,ordered Intermetallic alloys[7-9],as a unique class of metallic materials,have drawn increasing concern from both the scientific and industrial communities due to their intriguing high-temperature properties,strong chemical binding,and low atomic mobility[10,11].However,in light of the insufficient number of slip systems and/or intrinsically weak grain boundary(GB),they are usually brittle at ambient temperature,severely hindering their practical use in engineering systems[12].Previous studies reported that the change in alloy stoichiometry has a significant beneficial effect on the ductility of Intermetallic alloys.For instance,Liu et al.

关键词： Intermetallic ductility alloys

来源：

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

Intermetallic CuAu nanoalloy for stable electrochemical CO_(2) reduction

引用

Chinese Chemical Letters 2023年第7期34卷 226-229页

作者： Siyu Kuang Minglu Li Xiaoyi Chen Haoyuan Chi Jianlong Lin Zheng Hu Shi Hu Sheng Zhang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Tianjin Key Laboratory of Molecular Optoelectronic Science School of ScienceTianjin UniversityTianjin 300072China

Copper is one of the most efficient catalysts widely investigated in electrochemical CO_(2) reduction, however, the further development of copper-based catalysts is constrained by severe stability problems. In this work, we developed a method for the synthesis of highly ordered Cu Au Intermetallic nanoalloys(o-CuAu) under mild conditions(Intermetallic nanoalloy. In addition, XPS results, Tafel slope and in situ IR spectroscopy demonstrate that high valence gold atoms on o-CuAu surface promote the reduction of CO_(2). In contrast, the disordered CuAu nanoalloy(d-CuAu) underwent atomic rearrangement to form a Cu-rich structure on the surface, leading to reduced stability. These findings may provide insight into the rational design of stable CO_(2) RR electrocatalysts through proper structural engineering.

关键词： CO_(2)reduction CuAu nanoalloy Intermetallic Stability Electrocatalysts

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

面向碱性析氢反应的原子级优化Fe-Pt金属间化合物催化剂表面终结态探索

引用

Science Bulletin 2024年第8期69卷 1091-1099页

作者：梁庆孟繁玲李文文邹旭宋可心葛昕姜周刘玉华刘美琦李振宇董韬文陈中军张伟郑伟涛 Key Laboratory of Automobile Materials(Ministry of Education) School of Materials Science and EngineeringElectron Microscopy CenterInternational Center of Future ScienceJilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy MaterialsJilin UniversityChangchun 130012China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Controlling the atomic arrangement of elemental atoms in Intermetallic catalysts to govern their surface and subsurface properties is a crucial but challenging endeavor in electrocatalytic reactions.In hydrogen evolution reaction(HER),adjusting the d-band center of the conventional noble-metallic Pt by introducing Fe enables the optimization of catalytic performance.However,a notable gap exists in research on the effective transition from disordered Fe/Pt alloys to highly ordered Intermetallic compounds(IMCs)such as FePt_(3)in the alkaline HER,hampering their broader application.In this study,a series of catalysts FePt_(3-x)H(x=5,6,7,8 and 9)supported on carbon nanotubes(CNTs)were synthesized via a simple impregnation method,along with a range of heat treatment processes,including annealing in a reductive atmosphere,to regulate the order degree of the arrangement of Fe/Pt atoms within the FePt_(3)catalyst.By using advanced microscopy and spectroscopy techniques,we systematically explored the impact of the order degree of FePt_(3)in the HER.The as-prepared FePt_(3)-8H exhibited notable HER catalytic activity with low overpotentials(η=37 mV in 1.0 mol L^(-1)KOH)at j=10 mA cm^(-2).The surface of the L1_(2)FePt_(3)-8H catalyst was demonstrated to be Pt-rich.The Pt on the surface was not easily oxidized due to the unique Fe/Pt coordination,resulting in significant enhancement of HER performance.

关键词： Intermetallic Hydrogen evolution reaction Surface Catalyst

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CeO_(2)表面工程与PtBi纳米板间p-d轨道杂化的协同效应在甲醇电氧化中的应用

引用

Science China Materials 2024年第6期67卷 1975-1984页

作者：张衍澳王帅司飞燕薛瑞昕吕一品陈国柱高道伟* School of Chemistry and Chemical Engineering University of JinanJinan 250022China

调控铂(Pt)电子结构是增强Pt基电催化剂活性和耐久性的关键策略.本研究开发了CeO_(2)/PtBi金属间纳米板(NPs),这种结构通过Pt和Bi之间的强p-d轨道杂化,显著提高了催化剂在甲醇电氧化反应(MOR)中的活性和稳定性.CeO_(2)的表面沉积不仅进... 详细信息

调控铂(Pt)电子结构是增强Pt基电催化剂活性和耐久性的关键策略.本研究开发了CeO_(2)/PtBi金属间纳米板(NPs),这种结构通过Pt和Bi之间的强p-d轨道杂化,显著提高了催化剂在甲醇电氧化反应(MOR)中的活性和稳定性.CeO_(2)的表面沉积不仅进一步优化了Pt的电子结构,还提供了额外的羟基吸附位点.特别是,在酸性和碱性环境下,CeO_(2)/PtBi NPs展现出超越商业Pt/C的甲醇电氧化质量活性,分别提高了1.62和7.65倍.在经历了1000次耐久性测试后,CeO_(2)/PtBi NPs在酸碱环境下的活性仅分别下降了20.1%和39.8%,相比之下,商业Pt/C的活性在相同条件下分别下降了55.4%和78.5%.CeO_(2)/PtBi NPs的这一卓越性能得益于Pt与Bi之间的p-d轨道杂化以及CeO_(2)表面工程对催化剂电子结构的有效调节.本研究为Pt基电催化剂设计提供了新的电子结构调控策略和深入见解.

关键词： electrocatalysis Intermetallic p-d orbital hybridiza-tion CeO_(2)deposition methanol electro-oxidation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Single-phase high-entropy Intermetallic compounds(HEICs): bridging high-entropy alloys and ceramics

引用

Science Bulletin 2019年第12期64卷 856-864页

作者： Naixie Zhou Sicong Jiang Timothy Huang Mingde Qin Tao Hu Jian Luo Department of Nanoengineering Program of Materials Science and EngineeringUniversity of CaliforniaSan DiegoCA 92093-0448USA Oerlikon Metco Inc. San DiegoCA 92121USA State Key Laboratory of High Performance and Complex Manufacturing School of Materials Science and EngineeringCentral South UniversityChangsha 410083China

High-entropy Intermetallic compounds(HEICs)were fabricated by mechanical alloying and spark plasma sintering to fill a knowledge gap between the traditional high-entropy alloys(HEAs)and emerging highentropy ceramics(HECs).Notably,several four-or five-component equimolar aluminides,such as the B2-phase(Fe1/5 Co1/5 Ni1/5 Mn1/5 Cu1/5)Al,have been made into single-phase HEICs for the first time.Thermodynamic modeling and a reversible,temperature-dependent,phase-stability experiment suggest that such B2-phase HEICs are entropy-stabilized phases.The structure of these HEICs resembles that of HECs with high-entropy mixing of fo ur or five elements of nearly equal fractions in one and only one sublattice,but with significant(10%)anti-site defects(differing from typical HECs).A new phase stability rule for forming single B2-phase HEICs is proposed.Five additional HEICs of predominantly D022 phases have also been made.This study broadens the families of equimola r,single-phase,high-entropy materials that have been successfully fabricated.

关键词： High-entropy Intermetallic compound Aluminide Phase stability High-entropy alloy High-entropy ceramic

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Selective hydrogenation of acetylene on SiO_2-supported Ni-Ga alloy and Intermetallic compound

引用

Journal of Energy Chemistry 2019年第2期28卷 40-49页

作者： Lei Wang Fengxu Li Yanjun Chen Jixiang Chen Tianjin Key Laboratory of Applied Catalysis Science and Technology Department of Catalysis Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin University

Ni/Si O_2 and bimetallic Ni_xGa/SiO_2 catalysts with different Ni/Ga atomic ratios(x = 10～2) were investigated for the selective hydrogenation of acetylene.It was found that Ni_xGa/SiO_2 showed higher selectivity to ethylene than Ni/Si O_2.This is attributed to the formation Ni-Ga alloy and Ni3 Ga Intermetallic compound(IMC) where there was a charge transfer from Ga to Ni,which is favorable for reducing the adsorption strength and amount of ethylene on Ni atoms.As a result,the over-hydrogenation,the C–C bond hydrogenolysis and the polymerization were suppressed,and subsequently the selectivity to ethylene was enhanced.With the decrease of Ni/Ga atomic ratio,the activity and stability of the Ni_xGa/SiO_2 catalysts increased first and then decreased,while the ethylene selectivity tended to increase.Ni_5 Ga/SiO_2 exhibited the best performance.Under the conditions of 180 °C,0.1 MPa,and a reactant(1.0 vol% acetylene,5.0 vol% H_2 and 94 vol% N_2) with the space velocity of 36,000 m L h^(-1) g^(-1),the acetylene conversion maintained at 100% on Ni_5 Ga/SiO_2 during 120 h time on stream and the selectivity to ethylene was 75%～81%after reaction for 68 h.It was also found that the formation of Ni-Ga alloy and Ni_3 Ga IMC suppressed the incorporation of carbon to form NiCx,subsequently enhancing the catalyst stability.Additionally,with increasing the Ga content,the catalyst acid amount and strength tended to increase,which promoted the polymerization and carbon deposition and so the catalyst deactivation.

关键词： Selective hydrogenation Acetylene Ni-Ga alloy Ni3Ga Intermetallic compound

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of heat treatment on the Intermetallic compounds and mechanical properties of the stainless steel 321–aluminum 1230 explosive-welding interface

引用

International Journal of Minerals,Metallurgy and Materials 2017年第11期24卷 1267-1277页

作者： Mohammadreza Khanzadeh Gharah Shiran Gholamreza Khalaj Hesam Pouraliakbar Mohamma dreza Jandaghi Hamid Bakhtiari Masoud Shirazi Center for Advanced Engineering Research Majlesi Branch Islamic Azad University Isfahan *** Iran Young Researchers and Elite Club Saveh Branch Islamic Azad University Saveh *** Iran Young Researchers and Elite Club Science and Research Branch Islamic Azad University Tehran *** Iran Advanced Materials Research Center Faculty of Materials Engineering Najafabad Branch Islamic Azad University Najafabad *** Iran

The effects of heat treatment on the microstructure and mechanical properties of Intermetallic compounds in the interface of stainless steel 321 explosively bonded to aluminum 1230 were investigated in this study. Experimental investigations were performed by optical microscopy, scanning electron microscopy, and microhardness and shear tensile strength testing. Prior to heat treatment, increasing the stand-off distance between samples from 1 to 2.5 mm caused their interface to become wavy and the thickness of Intermetallic layers to increase from 3.5 to 102.3 μm. The microhardness increased from HV 766 in the sample prepared at a stand-off distance of 1 mm to HV 927 in the sample prepared at a stand-off distance of 2.5 mm; in addition, the sample strength increased from 103.2 to 214.5 MPa. Heat treatment at 450°C for 6 h increased the thickness of Intermetallic compound layers to 4.4 and 118.5 μm in the samples prepared at stand-off distances of 1 and 2.5 mm, respectively. These results indicated that increasing the duration and temperature of heat treatment decreased the microhardness and strength of the interface of explosively welded stainless steel 321-Al 1230 and increased the thickness of the Intermetallic region.

关键词： Intermetallic compounds explosive welding heat treatment stand-off distance mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Growth rate and composition of directionally solidified Intermetallic TiAl–Nb alloys with different solidification conditions

引用

Rare Metals 2016年第1期35卷 54-64页

作者： Li-Wei Zhang Jun-Pin Lin Xiang-Jun Xu Jian-Ping He Xian-Fei Ding Xiao-Ou Jin State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Materials and Chemistry School Zhongyuan University of Technology National Center for Materials Service Safety University of Science and Technology Beijing School of Architecture and Engineering Heilongjiang University

Intermetallic Ti-xAl-8Nb（x = 41,43,45,47,49;at%） alloys were solidified unidirectionally upwards with a constant temperature gradient of G=3.8 K·mm^（-1）at wide range of growth rates of v=10-400 μm·s^（-1）using a Bridgman directional solidification（DS） furnace.Microstructural parameters including the primary dendrite arm spacing（λ_1）,secondary dendrite arm spacing（λ_2）,dendrite tip radius（R） and mushy zone depth（d） were measured statistically.The values of λ_1,λ_2,R and d decrease as the growth rate increases for a given composition（x）.The values of λ_1,λ_2,R and v increase with the increase in x value,while the value of d firstly increases and then decreases with the increase in x value for a given v.The relationships between λ_1,λ_2 and R were analyzed by the linear regression.The average growth rate exponent of λ_1 is 0.29,which is in accordance with the previous experimental observations,and that of λ_2 is close to the previous experimental results,while those of R and d are lower than the results in other alloy systems.In addition,theoretical models for λ_1,λ_2 and R were compared with the experimental observations,and a comparison of the present experimental results with the theoretical models and previous experimental results was also made.

关键词： TiAl-Nb alloys Intermetallic Directionalsolidification Microstructural parameters Soluteconcentration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of Intermetallic compounds on the fracture behavior of dissimilar friction stir welding joints of Mg and Al alloys

引用

International Journal of Minerals,Metallurgy and Materials 2019年第10期26卷 1285-1298页

作者： Amir Hossein Baghdadi Zainuddin Sajuri Nor Fazilah Mohamad Selamat Mohd Zaidi Omar Yukio Miyashita Amir Hossein Kokabi Centre for Materials Engineering and Smart Manufacturing Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia43600 UKM BangiSelangor 43600Malaysia Department of Mechanical Engineering Nagaoka University of TechnologyNagaoka940-2188Japan Department of Materials Science and Engineering Sharif University of TechnologyTehran 11365-11155Iran

Joining Mg to Al is challenging because of the deterioration of mechanical properties caused by the formation of Intermetallic compounds(IMCs) at the Mg/Al interface. This study aims to improve the mechanical properties of welded samples by preventing the fracture location at the Mg/Al interface. Friction stir welding was performed to join Mg to Al at different rotational and travel speeds. The microstructure of the welded samples showed the IMCs layers containing Al12Mg17(γ) and Al3Mg2(β) at the welding zone with a thickness(< 3.5 μm). Mechanical properties were mainly affected by the thickness of the IMCs, which was governed by welding parameters. The highest tensile strength was obtained at 600 r/min and 40 mm/min with a welding efficiency of 80%. The specimens could fracture along the boundary at the thermo-mechanically affected zone in the Mg side of the welded joint.

关键词： aluminum alloy magnesium alloy Intermetallic compounds dissimilar welded joint friction stir welding

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：