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Thermal conductivity of iron under the Earth’s inner core pressure

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Chinese physics B 2024年第10期33卷 343-348页

作者： Cui-E hu Mu-Xin Jiao Xue-Nan Yang Zhao-Yi Zeng jun Chen College of physics and Electronic Engineering Chongqing Normal UniversityChongqing 400047China Laboratory of computational physics Institute of Applied Physics and Computational MathematicsBeijing 100088China Center for applied physics and Technology Peking UniversityBeijing 100071China

The thermal conductivity ofε-iron at high pressure and high temperature is a key parameter to constrain the dynamics and thermal evolution of the Earth’s *** this work,we use first-principles calculations to study the hugoniot sound velocity and the thermal transport properties ofε-*** total thermal conductivity considering lattice vibration is 200 W/mK at the Earth’s inner core *** suppressed anharmonic interactions can significantly enhance the lattice thermal conductivity under high pressure,and the contribution of the lattice thermal conductivity should not be ignored under the Earth’s core conditions.

关键词： thermal conductivity first-principles high pressure and high temperature

Transient growth in Poiseuille-Rayleigh-Bénard flows of binary fluids with Soret effect

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applied mathematics and Mechanics(English Edition) 2016年第9期37卷 1203-1218页

作者： jun hu D.HENRY H.BENHADID xieyuan yin institute of applied physics and computational mathematics Beijing 100088China Laboratoire de Mecanique des Fluides et d'Acoustique CNRS/Universitd de LyonEcole Centrale de Lyon/universite Lyon 1/INSA de LyonECL36 avenue Guy de Collongue69134 Ecully CedexFrance Department of Modern Mechanics University of Science and Technology of ChinaHefei 230027China

The transient growth due to non-normMity is investigated for the Poiseuille- Rayleigh-Benard problem of binary fluids with the Soret effect. For negative separation factors such as ψ = -0.1, it is found that a large transient growth can be obtained by the non-normal interaction of the two least-stable-modes, i.e., the upstream and downstream modes, which determine the linear critical boundary curves for small Reynolds numbers. The transient growth is so strong that the optimal energy amplification factor G（t） is up to 10^2 - 10^3. While for positive separation factors such as ψ = 0.1, the transient growth is weak with the order O（I） of the amplification factor, which can even be computed by the least-stable-mode. However, for both cases, the least-stable-mode can govern the long-term behavior of the amplification factor for large time. The results also show that large Reynolds numbers have stabilization effects for the maximum amplification within moderate wave number regions. Meanwhile, much small negative or large positive separation factors and large Rayleigh numbers can enlarge the maximum transient growth of the pure streamwise disturbance with the wavenumber α= 3.14. Moreover, the initial and evolutionary two-dimensional spatial patterns of the large transient growth for the pure streamwise disturbance are exhibited with a plot of the velocity vector, spanwise vorticity, temperature, and concentration field. The initial three-layer cell vorticity struc- ture is revealed. When the amplification factor reaches the maximum Gmax, it develops into one cell structure with large amplification for the vorticity strength.

关键词： binary fluid Soret effect transient growth Poiseuille-Rayleigh-Benard flow

Numerical study on rotordynamic coefficients of the seal of molten salt pump

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Nuclear Science and Techniques 2016年第5期27卷 168-178页

作者： Yao-Yu hu De-Zhong Wang Yuan Fu jun-Lian yin School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China Shanghai institute of applied physics Shanghai 201800China

Molten salt pump is applied to pump high-temperature molten salt as the primary coolant of a molten salt *** pump,generally a vertical rotor system,suffers from radial force generated by the liquid seal component,and the rotordynamic characteristics of the pump are affected *** this paper,the rotordynamic coefficients of the tooth-on-stator liquid seal in molten salt pump are *** flow in the seal region is simulated using computational fluid dynamics *** of the inlet loss and the pre-swirl at the inlet region of the seal are *** coefficients of resistance and the wall parameters are obtained from the simulation results by data fitting *** rotordynamic coefficients are analyzed based on the bulk-flow model of liquid *** rotordynamic characteristics,with and without the liquid seal,of the objective molten salt pump are *** first critical speed of the rotor is found to *** analysis shows that the pump,being sensitive to unbalance force though,can operate safely under its design specifications.

关键词：动力特性系数泵密封熔盐泵数值研究转子动力特性转子系统整体流动液体密封

Roadmap for rechargeable batteries:present and beyond

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Science china Chemistry 2024年第1期67卷 13-42页

作者： Sen Xin Xu Zhang Lin Wang Haijun Yu Xin Chang Yu-Ming Zhao Qinghai Meng Pan Xu Chen-Zi Zhao Jiahang Chen huichao Lu Xirui Kong Jiulin Wang Kai Chen Gang huang Xinbo Zhang Yu Su Yao Xiao Shu-Lei Chou Shilin Zhang Zaiping Guo Aobing Du Guanglei Cui Gaojing Yang Qing Zhao Liubing Dong Dong Zhou Feiyu Kang hu Hong Chunyi Zhi Zhizhang Yuan Xianfeng Li Yifei Mo Yizhou Zhu Dongfang Yu Xincheng Lei Jianxiong Zhao Jiayi Wang Dong Su Yu-Guo Guo Qiang Zhang jun Chen Li-jun Wan CAS Key Laboratory of Molecular Nanostructure and Nanotechnology CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular Sciences(BNLMS)Institute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China University of Chinese Academy of Sciences.beijing 100049 China institute of Advanced Battery Materials and Devices Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Key Laboratory of Advanced Functional Materials Ministry of EducationBeijing University of TechnologyBeijing 100124China beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China State Key Laboratory of Chemistry and Utilization of Carbon-Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830046China Department of Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChangchun 130022China institute for Carbon Neutralization College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China School of Chemical Engineering and Advanced Materials The University of AdelaideAdelaide 5000Australia Qingdao Industrial Energy Storage Research institute Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China Frontiers Science Center for New Organic Matter Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)College of ChemistryNankai UniversityTianjin 300071China College of Chemistry and Materials Science Jinan UniversityGuangzhou 511443China Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China Division of Energy Storage Dalian National Laboratory for Clean Energy(DNL)Dalian Institute of Chem

Rechargeable batteries currently hold the largest share of the electrochemical energy storage market,and they play a major role in the sustainable energy transition and industrial decarbonization to respond to global climate *** to the increased popularity of consumer electronics and electric vehicles,lithium-ion batteries have quickly become the most successful rechargeable batteries in the past three decades,yet growing demands in diversified application scenarios call for new types of rechargeable *** efforts are made to developing the next-generation post-Li-ion rechargeable batteries,which include,but are not limited to solid-state batteries,lithium–sulfur batteries,sodium-/potassium-ion batteries,organic batteries,magnesium-/zinc-ion batteries,aqueous batteries and flow *** the great achievements,challenges persist in precise understandings about the electrochemical reaction and charge transfer process,and optimal design of key materials and interfaces in a *** roadmap tends to provide an overview about the current research progress,key challenges and future prospects of various types of rechargeable *** computational methods for materials development,and characterization techniques will also be discussed as they play an important role in battery research.

关键词： energy storage rechargeable batteries battery materials electrochemistry

Global sensitivity analysis based on high-dimensional sparse surrogate construction

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applied mathematics and Mechanics(English Edition) 2017年第6期38卷 797-814页

作者： jun hu Shudao ZHANG institute of applied physics and computational mathematics

Surrogate models are usually used to perform global sensitivity analysis （GSA） by avoiding a large ensemble of deterministic simulations of the Monte Carlo method to provide a reliable estimate of GSA indices. However, most surrogate models such as polynomial chaos （PC） expansions suffer from the curse of dimensionality due to the high-dimensional input space. Thus, sparse surrogate models have been proposed to alleviate the curse of dimensionality. In this paper, three techniques of sparse reconstruc- tion are used to construct sparse PC expansions that are easily applicable to computing variance-based sensitivity indices （Sobol indices）. These are orthogonal matching pursuit （OMP）, spectral projected gradient for L1 minimization （SPGL1）, and Bayesian compressive sensing with Laplace priors. By computing Sobol indices for several benchmark response models including the Sobol function, the Morris function, and the Sod shock tube problem, effective implementations of high-dimensional sparse surrogate construction are exhibited for GSA.

关键词： global sensitivity analysis (GSA) curse of dimensionality sparse surrogate construction polynomial chaos (PC) compressive sensing

基于Ginzburg-Landau方法的快速结构复振幅展开晶体相场模型

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计算物理 2024年第5期41卷 547-558页

作者：王昆陈军王裴祝文军钟正湖南大学材料科学与工程学院湖南长沙410082 北京应用物理与计算数学研究所北京100094 流体物理研究所四川绵阳621900

利用Ginzburg-Landau模型思路推广了传统复振幅扩展晶体相场(APFC)模型的发展思路,提出一种描述不同晶体结构的简单有效方法,即快速结构APFC模型。以方形相和矩形相为例,系统地确定了快速结构APFC模型中与结构相关的模型参数,并通过数... 详细信息

利用Ginzburg-Landau模型思路推广了传统复振幅扩展晶体相场(APFC)模型的发展思路,提出一种描述不同晶体结构的简单有效方法,即快速结构APFC模型。以方形相和矩形相为例,系统地确定了快速结构APFC模型中与结构相关的模型参数,并通过数值算例检验了该方法的有效性。特别是在处理矩形相的过程中,研究发现这种方法不仅可以解决矩形相结构稳定性的问题,还可以描述矩形相和正交层状相之间的结构相变,证明了该模型具有描述多结构相变的能力。最后,通过模拟研究经典的圆形晶粒转动-收缩问题,检验了该模型对物理规律的准确预测能力,并揭示了不同晶体对称性对晶粒转动-收缩规律的影响。

关键词：晶体相场 Ginzburg-Landau模型位错晶界晶体各向异性

室外风环境视角下的高层住宅项目规划指标研究（英文）

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Journal of Zhejiang University-Science A(applied physics & Engineering) 2016年第5期17卷 378-388页

作者： Xiao-yu yinG Grace DING Xiao-jun hu yin-qi ZHANG Department of Architecture Zhejiang University City College School of the Built Environment University of Technology Sydney Department of Building Innovation Technology Shanghai Research Institute of Building Sciences (Group) Co. Ltd.

目的：确定建筑容积率、建筑密度和建筑层数之间的关系,并将其作为主要的规划指标,研究其对室外风环境的影响。创新点：在以高层、高密度为特点的城市建设中,一个地块的用地规划指标可直接影响居住区的室外物理环境质量。一个高层建筑... 详细信息

目的：确定建筑容积率、建筑密度和建筑层数之间的关系,并将其作为主要的规划指标,研究其对室外风环境的影响。创新点：在以高层、高密度为特点的城市建设中,一个地块的用地规划指标可直接影响居住区的室外物理环境质量。一个高层建筑群的规划设计不应该只关注建筑物,还应考虑室外物理环境的品质。本研究从室外风环境角度出发,对13种＂容积率-建筑密度-建筑层数＂指标组合形成的高层建筑群布局进行对比,从而得到可直接服务于城市建设项目的规划策略。方法：1.通过确定建筑容积率、建筑密度和建筑层数之间的关系,建立三维高层建筑群布局模型,列出19种可能的指标组合（图2）;2.通过日照模拟分析工具Tarch和建筑消防间距计算筛选出13种符合当前规划要求的指标组合;3.运用风环境模拟软件Phoenics,对13种指标组合形成的高层建筑群布局进行风环境模拟运算;利用图形分析软件Photoshop CS,计算出舒适风面积比值,并进行相互对比（图3和4）;4.根据土建造价对不同建筑群布局的总造价进行对比（图6）。结论：在规划设计中,通常认为较低的容积率和较低的建筑高度意味着建筑体量较小,室外物理环境会更好。但是,本研究发现建筑层数越多、建筑高度越高,行人高度的室外舒适风区面积越大。不过,建筑层数从25层升到30层,舒适风区面积增加有限。加之考虑层数越高导致造价越高的因素,当面对容积率为2.0~4.0的高层地块时,不能简单地认为建筑层数最高的规划方案就是最好的方案。

关键词：室外风环境规划指标建筑群布局高层建筑

Shock-induced migration of asymmetry tilt grain boundary in iron bicrystal: A case study of Σ3 [110]

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Chinese physics B 2019年第12期28卷 273-279页

作者： Xueyang Zhang Kun Wang jun Chen Wangyu hu Wenjun Zhu Shifang Xiao huiqiu Deng Mengqiu Cai Department of applied physics School of Physics and ElectronicsHunan UniversityChangsha 410082China Laboratory of computational physics Institute of Applied Physics and Computational MathematicsBeijing 100088China Center for applied physics and Technology Peking UniversityBeijing 100087China College of Materials Science and Engineering Hunan UniversityChangsha 410082China National Key Laboratory of Shock Wave and Detonation physics Institute of Fluid PhysicsMianyang 621900China

Many of our previous studies have discussed the shock response of symmetrical grain boundaries in iron *** this paper, the molecular dynamics simulation of an iron bicrystal containing Σ3 [110] asymmetry tilt grain boundary(ATGB) under shock-loading is performed. We find that the shock response of asymmetric grain boundaries is quite different from that of symmetric grain boundaries. Especially, our simulation proves that shock can induce migration of asymmetric grain boundary in iron. We also find that the shape and local structure of grain boundary(GB) would not be changed during shock-induced migration of Σ3 [110] ATGB, while the phase transformation near the GB could affect migration of GB. The most important discovery is that the shock-induced shear stress difference between two sides of GB is the key factor leading to GB migration. Our simulation involves a variety of piston velocities, and the migration of GB seems to be less sensitive to the piston velocity. Finally, the kinetics of GB migration at lattice level is discussed. Our work firstly reports the simulation of shock-induced grain boundary migration in iron. It is of great significance to the theory of GB migration and material engineering.

关键词： shock-loading grain boundary migration iron phase transition

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界面水与催化

物理学报 2019年第1期68卷 36-44页

作者：胡钧高嶷中国科学院上海应用物理研究所上海201800 中国科学院上海高等研究院上海201210

水的催化反应在界面进行,对新能源开发和环境保护等领域具有至关重要的作用.理解催化反应中材料界面水分子的结构、物性和分子机制,对于解决清洁能源、污水处理等关系国计民生的重大问题具有关键意义.由于水的复杂性,对于水分子在催化... 详细信息

水的催化反应在界面进行,对新能源开发和环境保护等领域具有至关重要的作用.理解催化反应中材料界面水分子的结构、物性和分子机制,对于解决清洁能源、污水处理等关系国计民生的重大问题具有关键意义.由于水的复杂性,对于水分子在催化反应中的作用至今仍存在很大争议.界面水分子在催化反应中作为反应物、催化剂、溶剂,或是兼而有之,一直是科学界争论的热点话题.近年来,随着原位实验技术和计算机能力的快速提高,人们已经能够在原子尺度对催化反应中的界面水分子行为进行实时观测和理论模拟,为解析水在催化反应中的作用提供了实验依据和理论基础.本文简述当前催化反应中界面水研究面临的巨大机遇和挑战,以及现有实验和理论方法的最新进展和所遇到的困难,为设计优化与水应用相关的高效催化剂提供可行的思路.

关键词：界面水催化原位实验理论模拟