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Theoretical understanding of correlation between magnetic phase transition and the superconducting dome in high-Tc cuprates

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 167-173页

作者： Chen Zhang Cai-Xin Zhang Su-huai wei Haiqing Lin Hui-Xiong Deng State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Computational Science Research Center Beijing 100193China

Many issues concerning the origin of high-temperature superconductivity(HTS)are still under *** example,how the magnetic order varies with doping and its relationship with the superconducting temperature(Tc);and why Tcalways peaks near the quantum critical *** this paper,taking hole-doped La_(2)CuO_(4)as a classical example,we employ the first-principles band structure and total energy calculations with Monte Carlo simulations to explore how the symmetry-breaking magnetic ground state evolves with hole doping and the origin of a dome-shaped superconductivity region in the phase *** demonstrate that the local antiferromagnetic order and doping play key roles in determining the electron-phonon coupling,thus ***,the La_(2)CuO_(4)possesses a checkerboard local antiferromagnetic ground *** the hole doping increases,Tcincreases with the enhanced electron-phonon coupling *** as the doping increases further,the strength of the antiferromagnetic interaction weakens and spin fluctuation *** the critical doping level,a magnetic phase transition occurs that reduces the local antiferromagnetism-assisted electron-phonon coupling,thus diminishing the *** superconductivity disappears in the heavily overdoped region when the ferromagnetic order *** observations could account for why cuprates have a dome-shaped superconductivity region in the phase *** study,thus,contributes to a fundamental understanding of the correlation between doping,local magnetic order,and superconductivity of HTS.

关键词： high-temperature superconductivity antiferromagnetic order electron-phonon coupling doping effect cuprates

Origin of the Disparity between the Stability of Transmutated Mix-Cation and Mix-Anion Compounds

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Chinese Physics Letters 2024年第5期41卷 53-60页

作者：野仕伟耿松源梁汉普张燮魏苏淮 Beijing Computational Science Research Center Beijing 100193China Advanced Materials Thrust Function HubHong Kong University of Science and TechnologyGuangzhou 511458China School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China

Transmutation is an efficient approach for material design. For example, ternary compound CuGaSe_(2) in chalcopyrite structure is a promising material for novel optoelectronic and thermoelectric device applications. It can be considered as formed from the binary host compound ZnSe in zinc-blende structure by cation transmutation(i.e., replacing two Zn atoms by one Cu and one Ga). While cation-transmutated materials are common, aniontransmutated ternary materials are rare, for example, Zn_(2)As Br(i.e., replacing two Se atoms by one As and one Br)is not reported. The physical origin for this puzzling disparity is unclear. In this work, we employ first-principles calculations to address this issue, and find that the distinct differences in stability between cation-transmutated(mix-cation) and anion-transmutated(mix-anion) compounds originate from their different trends of ionic radii as functions of their ionic state, i.e., for cations, the radius decreases with the increasing ionic state, whereas for anions, the radius increases with the increasing absolute ionic state. Therefore, for mix-cation compounds,the strain energy and Coulomb energy can be simultaneously optimized to make these materials stable. In contrast, for mix-anion systems, minimization of Coulomb energy will increase the strain energy, thus the system becomes unstable or less stable. Thus, the trend of decreasing strain energy and Coulomb energy is consistent in mix-cation compounds, while it is opposite in mix-anion compounds. Furthermore, the study suggests that the stability strategy for mix-anion compounds can be controlled by the ratio of ionic radii r3/r1, with a smaller ratio indicating greater stability. Our work, thus, elucidates the intrinsic stability trend of transmutated materials and provides guidelines for the design of novel ternary materials for various device applications.

关键词： stability stability ternary

Comparative study of nudged elastic band and molecular dynamics methods for diffusion kinetics in solid-state electrolytes

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Chinese Physics B 2024年第8期33卷 96-100页

作者：林啊鸣石晶魏苏淮孙宜阳 State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 201899China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Department of Physics Jiangxi Normal UniversityNanchang 330022China Eastern Institute of Technology Ningbo 315200China

Considerable efforts are being made to transition current lithium-ion and sodium-ion batteries towards the use of solid-state *** methods,specifically nudged elastic band(NEB)and molecular dynamics(MD)methods,provide powerful tools for the design of solid-state *** MD method is usually the choice for studying the materials involving complex multiple diffusion paths or having disordered ***,it relies on simulations at temperatures much higher than working *** paper studies the reliability of the MD method using the system of Na diffusion in MgO as a *** carefully study the convergence behavior of the MD method and demonstrate that total effective simulation time of 12 ns can converge the calculated diffusion barrier to about 0.01 *** calculated diffusion barrier is 0.31 eV from both *** diffusion coefficients at room temperature are 4.3×10^(-9) cm^(2)⋅s^(−1) and 2.2×10^(-9) cm^(2)⋅s^(−1),respectively,from the NEB and MD *** results justify the reliability of the MD method,even though high temperature simulations have to be employed to overcome the limitation on simulation time.

关键词： nudged elastic band method molecular dynamics solid electrolyte ion transport density func-tional theory

Prospect of Hexagonal CsMg(I1-xBrx)3 Alloys for Deep-Ultraviolet Light Emission

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Chinese Physics Letters 2024年第9期41卷 52-56页

作者： Siyuan Xu Zheng Liu Xun Xu Su-huai wei Yuzheng Guo Xie Zhang School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China Beijing Computational Science Research Center Beijing 100193China School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China

Materials for deep-ultraviolet(DUV)light emission are extremely rare,significantly limiting the development of efficient DUV light-emitting *** we report CsMg(I_(1−x)Br_(x))3 alloys as potential DUV light *** on rigorous first-principles hybrid functional calculations,we find that CsMgI3 has an indirect bandgap,while CsMgBr3 has a direct ***,we employ a band unfolding technique for alloy supercell calculations to investigate the critical Br concentration in CsMg(I_(1−x)Br_(x))3 associated with the crossover from an indirect to a direct bandgap,which is found to be∼***,CsMg(I_(1−x)Br_(x))3 alloys with 0.366≤6≤1 cover a wide range of direct bandgap(4.38–5.37 eV;284–231 nm),falling well into the DUV *** study will guide the development of efficient DUV light emitters.

关键词： alloys alloy Deep

Profiling Electronic and Phononic Band Structures of Semiconductors at Finite Temperatures: Methods and Applications

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Chinese Physics Letters 2024年第2期41卷 57-68页

作者：张燮康俊魏苏淮 School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China Beijing Computational Science Research Center Beijing 100193China

Semiconductor devices are often operated at elevated temperatures that are well above zero Kelvin,which is the temperature in most first-principles density functional *** approaches to com-puting and understanding the properties of semiconductors at finite temperatures are thus in critical *** this review,we discuss the recent progress in computationally assessing the electronic and phononic band structures of semiconductors at finite *** an emerging semiconductor with particularly strong temperature-induced renormalization of the electronic and phononic band structures,halide perovskites are used as a representative example to demonstrate how computational advances may help to understand the band struc-tures at elevated ***,we briefly illustrate the remaining computational challenges and outlook promising research directions that may help to guide future research in this field.

关键词： Finite struc directions

我国主要河流水系硝态氮污染特征及定量源解析

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环境科学 2024年第2期45卷 755-767页

作者：韦英怀胡敏鹏陈丁江浙江大学环境与资源学院杭州310058 浙江大学环境修复与生态健康教育部重点实验室杭州310058 浙江大学浙江省农业资源与环境重点实验室杭州310058

准确定量污染来源组成是有效控制水体硝态氮污染的关键科学基础.采用荟萃分析的方法,收集了2000~2022年我国167条主要水系河流的硝态氮浓度和硝态氮的氮氧同位素等数据,分析了七大主要河流水系硝态氮污染的时空变异规律及其转化特征,定... 详细信息

准确定量污染来源组成是有效控制水体硝态氮污染的关键科学基础.采用荟萃分析的方法,收集了2000~2022年我国167条主要水系河流的硝态氮浓度和硝态氮的氮氧同位素等数据,分析了七大主要河流水系硝态氮污染的时空变异规律及其转化特征,定量识别了河流硝态氮的污染来源组成.结果表明,我国主要河流水系ρ(NO_(3)^(-)-N)平均值为(4.54±3.99)mg·L_(-1),其中9.6%的河流硝态氮浓度超过我国地表水环境质量标准(GB 3838-2002)规定的限值(10.0 mg·L_(-1)),海河水系的硝态氮污染最为严重.东部地区河流水系的硝态氮浓度总体高于西部,各大河流水系支流的硝态氮浓度高于干流.除黄河水系以外,其他水系枯水期的硝态氮浓度总体高于丰水期.珠江水系、黄河水系中下游地区、辽河水系中游地区、松花江水系,以及海河水系河流水体存在显著的硝化作用,而长江水系、淮河水系和珠江水系下游地区存在显著的反硝化作用.污水/粪肥是长江水系、海河水系、辽河水系,以及东南诸河水系硝态氮的主要来源(>50%),土壤氮是松花江水系硝态氮的主要来源(56.4%),化肥氮、土壤氮和污水/粪肥对珠江水系、淮河水系和黄河水系硝态氮的污染贡献为20%~40%.污水/粪肥对水系支流硝态氮贡献率总体大于干流的,土壤氮对干流硝态氮的贡献总体大于支流的.土壤氮、化肥氮和大气沉降氮对丰水期河流硝态氮的贡献率高于枯水期,而污水/粪肥对枯水期河流硝态氮的污染贡献率高于丰水期.因此,海河水系、长江水系、辽河水系、黄河水系支流与下游干流地区和珠江水系下游地区应重点控制生活和生产的污水排放等点源污染,而淮河水系、松花江水系、黄河水系中游干流地区和珠江水系中上游地区要重点控制化肥和土壤氮等流失造成的非点源污染.研究结果可为有效控制我国各河流水系硝态氮的污染提供科学依据.

关键词：硝态氮源解析河流氮氧同位素非点源污染点源污染

知识生产模式Ⅲ视野下专业博士教育治理的进程与走向

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高等工程教育研究 2024年第2期 129-134页

作者：熊华军韦怀广东技术师范大学教育科学学院重庆文化艺术职业学院西北师范大学教育科学学院

知识生产从模式Ⅰ向模式Ⅱ到模式Ⅲ转型过程中,专业博士教育模式历经囿于学科、服务需求和走向共生的嬗变,趋于学术性、职业性与场域性的融合。知识生产模式Ⅲ视野下的专业博士教育治理从工具导向的功能治理走向生态指向的场域治理,表... 详细信息

知识生产从模式Ⅰ向模式Ⅱ到模式Ⅲ转型过程中,专业博士教育模式历经囿于学科、服务需求和走向共生的嬗变,趋于学术性、职业性与场域性的融合。知识生产模式Ⅲ视野下的专业博士教育治理从工具导向的功能治理走向生态指向的场域治理,表征为治理目的从知识创新到行动开端、治理内容从知识经济到知识民主、治理方式从三螺旋到五螺旋、治理评价从问责到负责。专业博士教育治理应以世界为中心,创设一种联合生活和共同交流经验的行动场域,让专业博士通过五螺旋在场域中行动,在行动中成人成己。

关键词：知识生产模式Ⅲ 专业博士教育治理

中国水下隧道数据统计与分析(截至2023年底)

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隧道建设（中英文） 2024年第4期44卷 826-881,I0031-I0086页

作者：陈建芹冯晓燕魏怀中铁隧道勘察设计研究院有限公司广东广州511457

对截至2023年底中国水下隧道的数据进行统计,截至2023年底中国共修建(含开工未建成)水下隧道(水下段长度L≥100 m)333条。从开工年份、所在省级行政区、穿越水域、施工方法、用途、断面尺寸、水下段长度、设计单位、施工单位、水头高度... 详细信息

对截至2023年底中国水下隧道的数据进行统计,截至2023年底中国共修建(含开工未建成)水下隧道(水下段长度L≥100 m)333条。从开工年份、所在省级行政区、穿越水域、施工方法、用途、断面尺寸、水下段长度、设计单位、施工单位、水头高度、最大水深、最小埋深、结构形式、车道数/轨道数等方面对截至2023年底我国建成或开工的水下隧道的情况进行分析。结果如下:1)2000年前水下隧道发展较慢,共开建12条水下隧道;2000—2023年这24年,水下隧道发展迅猛,开工的水下隧道数量达321条,是2000年前修建的水下隧道总量的近27倍,其中2019年最多(34条),2022年其次(32条);广东省修建的水下隧道数量最多(74条);穿越长江、黄浦江、珠江的水下隧道数量最多,分别达31、28、25条。2)采用的施工方法主要为盾构法、明挖法、沉管法,采用这3种方法修建的水下隧道占水下隧道总数的93.1%,其中采用盾构法最多,占76.6%。3)水下隧道主要用作地铁和市政道路/公路,这2种分别占水下隧道总数的40%和38%,合计占78%。4)采用盾构法修建的水下隧道,盾构直径d<7 m的隧道数量最多,占水下盾构隧道总数的44%,7 m≤d<10 m的隧道占11%,10 m≤d<14 m的隧道占24%,d≥14 m的隧道占21%;采用非盾构法修建的水下隧道,断面面积最大的是深中通道沉管隧道,达587.88 m^(2),断面面积在200 m^(2)≤A<300 m^(2)的水下隧道占比最多,达35%。5)水下段长度在100≤L<500和1000≤L<3000的水下隧道占比较大,均为35%。6)水头高度在10 m≤h_(1)<30 m,最大水深在10 m≤h_(2)<20 m、最小埋深在10 m≤h_(3)<20 m的水下隧道占比较大。7)地铁隧道有67%采用单线,市政道路/公路隧道有60%采用双向6车道,铁路隧道有82%采用双线。水下隧道因其独特优势已成为当今跨越江河湖海的重要选择,并逐步从浅水窄域向深水宽域进军。

关键词：水下隧道数据统计

课堂生命活性的生成逻辑——德勒兹“根茎”思想的昭示

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山西大学学报(哲学社会科学版) 2024年第2期47卷 127-134页

作者：王兆璟韦怀西北师范大学教育科学学院

课堂教学关乎教育实践，蕴含着巨大的生命活性。“根茎”思想作为一种后现代思维方式，为探究课堂的实存状态及应然走向提供了新的视角。运用“根茎”思维，透视课堂“辖域”“层化”等局限，以游牧的方式开启“逃逸”的路线，激活个体... 详细信息

课堂教学关乎教育实践，蕴含着巨大的生命活性。“根茎”思想作为一种后现代思维方式，为探究课堂的实存状态及应然走向提供了新的视角。运用“根茎”思维，透视课堂“辖域”“层化”等局限，以游牧的方式开启“逃逸”的路线，激活个体生命，绵延自由意志，激发课堂创造力，呈现一种生命意向的敞开，昭示着活性课堂的主体性、之间性、流动性和生成性特征。建构充满生命活性的课堂图景，需反思并改造当下的课堂。通过构筑平滑的课堂空间，开启课堂的生命姿态，转向他者的教学交往，允许流变的自由生成，把课堂归还给教育，方可走向广阔的教育意义世界。

关键词：课堂生命活性生成根茎