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First-principles study on the electronic structure of Pb_(10−x)Cu_(x)(PO_(4))_(6)O(x=0,1)

Journal of Materials Science & Technology 2024年第4期171卷 66-70页

作者： Junwen Lai jiangxu li Peitao liu Yan Sun Xing-Qiu Chen Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Recently,Lee et *** the experimental discovery of room-temperature ambient-pressure super-conductivity in a Cu-doped lead-apatite(LK-99)(arXiv:2307.12008,arXiv:2307.12037).Remarkably,the claimed superconductivity can persist up to 400 K at ambient *** the experimental im-plication,the electronic structure of LK-99 has not yet been ***,we investigate the electronic structures of LK-99 and its parent compound using first-principles calculations,aiming to elucidate the doping effects of *** results reveal that the parent compound Pb_(10)(PO_(4))_(6)O is an insulator,while Cu doping induces an insulator-metal transition and thus volume *** band structures of LK-99 around the Fermi level are featured by a half-filled flat band and a fully-occupied flat *** two very flat bands arise from both the 2p orbitals of 1/4-occupied O atoms and the hybridization of the 3d orbitals of Cu with the 2p orbitals of its nearest-neighboring O ***,we observe four van Hove singularities on these two flat ***,we show that the flat band structures can be tuned by including electronic correlation effects or by doping different *** find that among the considered doping elements(Ni,Cu,Zn,Ag,and Au),both Ni and Zn doping result in the gap opening,whereas Au exhibits doping effects more similar to Cu than *** work establishes a foundation for fu-ture studies to investigate the role of unique electronic structures of LK-99 in its claimed superconducting properties.

关键词： First-principles calculations Density functional theory Electronic structur e Superconductivity Flat bands Strongly correlated electrons

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金属间化合物Pt_(7)Sb投影Berry相位与析氢催化关联的第一性原理计算

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金属学报 2024年第6期60卷 837-847页

作者：周彦余李江旭刘晨赖俊文高强马会孙岩陈星秋中国科学院金属研究所沈阳材料科学国家研究中心沈阳110016 中国科学技术大学材料科学与工程学院沈阳110016

高效催化材料的设计是能源材料领域的重要任务之一。本工作根据寻找具有低Pt负载量的高效析氢反应(HER)催化剂的指导原则,结合投影Berry相位描述符,设计发现了性能优异的HER催化剂立方Pt_(7)Sb,其氢吸附Gibbs自由能(ΔG_(H^(*)))甚至小... 详细信息

高效催化材料的设计是能源材料领域的重要任务之一。本工作根据寻找具有低Pt负载量的高效析氢反应(HER)催化剂的指导原则,结合投影Berry相位描述符,设计发现了性能优异的HER催化剂立方Pt_(7)Sb,其氢吸附Gibbs自由能(ΔG_(H^(*)))甚至小于Pt元素。因此,在降低Pt负载量的情况下,其HER催化活性有望提高。从电子结构分析来看,2个描述符ΔG_(H^(*))和投影Berry相位之间有很好的一致性。由于投影Berry相位完全由体态(波函数相位)决定,这种一致性意味着良好的催化性能与本征电子结构的拓扑性质之间存在着密切的关系。该结果提供了一个很好的HER催化剂候选材料,降低了Pt的负载量,并为展示催化剂本征拓扑性质的作用提供了参考。

关键词：析氢反应催化剂投影Berry相位第一性原理计算

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Segregation of Re at theγ/γ'boundary of Ni-based single crystal superalloys revealed by first-principles calculations based Monte-Carlo simulations

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Journal of Materials Science & Technology 2023年第12期143卷 54-61页

作者： Heyu Zhu Jiantao Wang Lei Wang Yongpeng Shi Mingfeng liu jiangxu li Yun Chen Yingche Ma Peitao liu Xing-Qiu Chen Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China CAS Key Laboratory of Nuclear Materials and Safety Assessment IMR(NMSA)Shenyang 110016China

Nickel-based single crystal superalloys have been widely used in aero-engines and gas turbine *** improve the creep resistance,rhenium is often added to the ***,it is not yet fully under-stood how the added Re elements distribute in the alloys and how the microstructure evolves with the addition of ***,we performed extensive first-principles calculations based Monte-Carlo simulated annealing of Ni-Al-Re ternary alloys with different Re concentrations ranging from 0.5 at.%to 6.0 at.%.The results demonstrate that with the decreasing temperature,most of Re atoms stay in theγphase,while a few of Re atoms stay in theγ'phase and tend to occupy the Al *** low temperatures,the Re atoms segregate at theγ/γ'boundary,in good agreement with *** find that the disorder-order transition temperature of the Ni-Al-Re ternary alloys increases with the Re concentration due to the Re-enhanced Al-Al ordering *** addition,we observe that at low temperatures the Re segregation at theγ/γ'boundary promotes the formation of Ni 4 Re-or Ni 8 Re-like local structures as the Re concentration is over 2 at.%.The formation of a large amount of these local structures consumes the Re atoms in solid solutions,and thus from the solid-solution strengthening point of view,this would have a negative influence on the creep resistance of the *** work provides important atomistic insights on the Re distribution and its effects on the stability of superalloys.

关键词： creep alloys resistance

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Topological phononic materials:Computation and data

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The Innovation 2021年第3期2卷 21-23页

作者： Xing-Qiu Chen Jiaxi liu jiangxu li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of ScienceShenyang 110016China

Considering the current volume of materials data,it is impossible to investigate each compound by trial-and-error experiments involving labor-intensive *** scientists in the Shenyang National Laboratory for Materials Science developed a home-made software,HT-PHONON,selecting over 5,000 topological phononic(TP)materials out of 13,000 materials within high-throughput computational materials design combined with a big data ***,an online database for TP materials has been constructed,which is now freely open to the public community through the website *** this perspective,we review this platform and discuss exciting consequences of TP materials that are expected from manipulating the phonons,linking fundamental research to potential applications.

关键词： consequences linking selecting

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Mobility Support for Content Source in Content-Centric Networking

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China Communications 2015年第3期12卷 95-105页

作者： HUANG Tao li jiangxu liU Jiang ZHANG Yunyong liU Yunjie State Key Laboratory of Networking and Switching Technology Beijing University of Post and Telecommunications China Unicom Research Institute

Content-centric networking(CCN) is rising to solve the problems suffered by traditional networks,especially in terms of content *** of the critical issues for basic CCN is supporting *** of Mobile Content Source(MCS) will result in a large scale routing update,which generates huge amount of routing overhead and leads to service *** of the existing CCN mobility mechanisms are transplanted from the IP mobility solutions,which are unnaturally integrated with *** from previous works,a mobility strategy from the perspective of CCN architecture is proposed to support the handoff of MCS in this ***,we define the critical network routers that can limit the routing update scale effectively when MCS handoff is *** on the defined critical network routers,the proposed scheme can provide lower routing update overhead,faster routing convergence and shorter service interruption ***,series of simulations are conducted to validate the effectiveness of our proposed scheme.

关键词：网络移动性路由更新网络路由器越区切换流动机制 CCN MCS 中断

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机电传动控制模块化实验设计

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流体测量与控制 2022年第6期3卷 63-69页

作者：李江旭秦皇岛首创思泰意达环保科技有限公司河北秦皇岛066000

关于电机的仿真控制有多重方法及手段,电机控制最早采用模拟比例-积分-微分(PID)的形式,对其具体关键参数进行设定后,整个传动系统在运行过程中便不再改变。近年来,数字PID得以快速发展,除达到基本的控制要求外,PID技术更具有灵活的可... 详细信息

关于电机的仿真控制有多重方法及手段,电机控制最早采用模拟比例-积分-微分(PID)的形式,对其具体关键参数进行设定后,整个传动系统在运行过程中便不再改变。近年来,数字PID得以快速发展,除达到基本的控制要求外,PID技术更具有灵活的可控性及可靠性。本次设计以PID为主要控制算法,单片机为控制器,产生由占空比控制的脉宽调制(PWM)技术波信号,进而对电机进行操控,组成位移随动系统。此外,利用霍尔传感器进行信号转换,将速度转换为波信号并通过控制系统反馈机制反馈至控制器,以此来检测电机的转速。

关键词：比例-积分-微分(PID)算法控制系统机械自动化模块化

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基于PLC的环保除尘工程中供水泵系统设计及自动化

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流体测量与控制 2023年第1期4卷 85-90页

作者：李江旭秦皇岛首创思泰意达环保科技有限公司河北秦皇岛066000

近年来我国综合国力大幅提升,科教文卫的水平也有很大提升,工业环保越来越被重视。煤矿、钢厂等行业是我国支柱性产业,其资源勘探、开采为国民经济起到积极的影响。但随着环保理念的发展及国家政策的出台,煤炭企业也更加重视环保方面的... 详细信息

近年来我国综合国力大幅提升,科教文卫的水平也有很大提升,工业环保越来越被重视。煤矿、钢厂等行业是我国支柱性产业,其资源勘探、开采为国民经济起到积极的影响。但随着环保理念的发展及国家政策的出台,煤炭企业也更加重视环保方面的工作,新技术、新设备不断地投入企业使用,使环保工作更加完善。本次设计主要针对煤矿勘测、开采中的供水水泵进行设计研究,使用可编程逻辑控制器(PLC)、变频器等工具对供水水泵进行变频控制,利用外界输入控制供水量大小。基于PLC技术,通过变频器将频率信号进行A/D转换,PLC识别相应的信号后调节输出脉冲信号的频率,控制水泵的转速,进而控制矿井工程水流流速。

关键词：变频器水泵调速可编程逻辑控制器(PLC) 环保除尘

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轻量级脑机接口AR探究工具的科学课堂应用研究

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开放教育研究 2023年第1期29卷 81-90页

作者：蔡苏李江旭柳昌灏周海涛刘紫凤北京师范大学教育学部北京100875

本研究在心流理论的指导下,开发了一款基于轻量级脑机接口的增强现实科学探究工具,对两组参与基于脑机接口和无脑机接口的AR科学探究活动的41名小学生开展实验。结果显示,基于脑机接口的AR探究工具提高了学生科学探究成绩和参与自我效能... 详细信息

本研究在心流理论的指导下,开发了一款基于轻量级脑机接口的增强现实科学探究工具,对两组参与基于脑机接口和无脑机接口的AR科学探究活动的41名小学生开展实验。结果显示,基于脑机接口的AR探究工具提高了学生科学探究成绩和参与自我效能,而对认知负荷无显著影响。访谈结果也表明,学生对脑机接口的AR探究工具持正面态度。本研究的发现可为未来虚实融合学习环境的学习监测系统构建提供参考。

关键词：增强现实脑机接口科学探究心流理论

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General principles to high-throughput constructing two-dimensional carbon allotropes

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Chinese Physics B 2020年第3期29卷 375-384页

作者：谢庆王磊李江旭李荣汉陈星秋 Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

We propose general principles to construct two-dimensional(2D)single-atom-thick carbon *** can be viewed as the generalization of patterning Stone–Walse defects(SWDs)by manipulating bond rotation and of patterning inverse SWDs by adding(or removing)carbon pairs on the pristine graphene,*** these principles,numerous 2D allotropes of carbon can be systematically *** 20 constructed 2D allotropes as prototypical and benchmark examples,besides nicely reproducing all well-known ones,such as pentaheptites,T-graphene,OPGs,etc,we still discover 13 new *** structural,thermodynamic,dynamical,and electronic properties are calculated by means of first-principles *** these allotropes are metastable in energy compared with that of graphene and,except for OPG-A and C3-10-H allotropes,the other phonon spectra of 18 selected allotropes are dynamically *** particular,the proposed C3-11 allotrope is energetically favorable than graphene when the temperature is increased up to 1043 K according to the derived free *** electronic band structures demonstrate that(i)the C3-8 allotrope is a semiconductor with an indirect DFT band gap of 1.04 e V,(ii)another unusual allotrope is C3-12 which exhibits a highly flat band just crossing the Fermi level,(iii)four allotropes are Dirac semimetals with the appearance of Dirac cones at the Fermi level in the lattices without hexagonal symmetry,and(vi)without the spin–orbit coupling(SOC)effect,the hexagonal C3-11 allotrope exhibits two Dirac cones at K and K points in its Brillouin zone in similarity with graphene.

关键词： graphene allotropes phonon spectra semimetal dirac Fermions modeling

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Structural, elastic, and electronic properties of topological semimetal WC-type MX family by first-principles calculation

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Chinese Physics B 2019年第7期28卷 78-86页

作者： Sami Ullah 王磊李江旭李荣汉陈星秋 Shenyang Nutionul Laboratory for Materials Science Institute of Metal Research. Chinese Academy ot Sciences Shenyang 110016. China University of Chinese Academy of Sciences Beijing 100049 China School of Materials Science and Engineering University of Science and Technology of Chinn. Shenyang 110016. China

Recently, the non-centrosymmetric WC-type materials(i.e., MoP, ZrTe, TaN, etc) have attracted extensive interest due to the discovery of their topological *** means of the first-principles calculations, here we have investigated the structural, thermodynamic, elastic, and electronic properties of the WC-type MX compounds(TiS, TiSe, TiTe, ZrS, ZrSe,ZrTe, HfS, HfSe, and HfTe).Among these nine compounds, five of them(TiS, ZrS, ZrSe0.9, ZrTe, and Hf0.92 Se) have been experimentally synthesized to crystallize in the WC-type structure and other four members have never been *** calculations demonstrated that they are all structurally, thermodynamically, and dynamically stable, indicating that all of them should be possibly *** have also derived their elastic constants of single crystalline and their bulk and shear moduli in terms of the *** ***, in similarity to ZrTe, all these compounds have been theoretically derived to be topological *** TiS is unique because of the coexistence of the Dirac nodal lines(DNLs) and sixfold degenerate nodal points(sixfold DNPs), the other eight members are revealed to exhibit coexisted Weyl nodes(WPs) and triply degenerate nodal points(TDNPs).Their electronic and topological properties have been further discussed.

关键词： topological semimetals WC-type materials MX family elastic properties

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