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A high-throughput data analysis and materials discovery tool for strongly correlated materials

npj Computational Materials 2018年第1期4卷 138-146页

作者： Hasnain Hafiz Adnan Ibne Khair Hongchul Choi Abdullah Mueen Arun Bansil Stephan Eidenbenz John Wills Jian-Xin Zhu Alexander V.Balatsky Towfiq Ahmed Department of Physics Northeastern UniversityBostonMA 02119USA Department of Computer Science University of New MexicoAlbuquerqueNM 87131USA Theoretical Division Los Alamos National LaboratoryLos AlamosNM 87545USA The Information Science and Technology institute Los Alamos National LaboratoryLos AlamosNM 87545USA Nordita KTH Royal Institute of Technology and Stockholm UniversityRoslagstullsbacken 23Stockholm SE-10691Sweden Department of Physics University of ConnecticutStorrsCT 06269USA Department of Mechanical Engineering Carnegie Mellon UniversityPittsburghPA 15213USA

Modeling of f-electron systems is challenging due to the complex interplay of the effects of spin–orbit coupling,electron–electron interactions,and the hybridization of the localized f-electrons with itinerant conduction *** complexity drives not only the richness of electronic properties but also makes these materials suitable for diverse technological *** this context,we propose and implement a data-driven approach to aid the materials discovery *** deploying state-of-the-art algorithms and query tools,we train our learning models using a large,simulated dataset based on existing actinide and lanthanide *** machine-learned models so obtained can then be used to search for new classes of stable materials with desired electronic and physical *** discuss the basic structure of our f-electron database,and our approach towards cleaning and correcting the structure data *** examples of the applications of our database include successful prediction of stable superstructures of double perovskites and identification of a number of physically-relevant trends in strongly correlated features of f-electron based materials.

关键词： database desired conduction

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The dominant driving force for supercontinent breakup: Plume push or subduction retreat?

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Geoscience Frontiers 2018年第4期9卷 997-1007页

作者： Nan Zhang Zhuo Dang Chuan Huang Zheng-Xiang Li Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking University Earth Dynamics Research Group ARC Center of Excellence for Core to Crust Fluid Systems(CCFS)and The Institute for Geoscience Research(TIGeR)School of Earth and Planetary SciencesCurtin University

Understanding the dominant force responsible for supercontinent breakup is crucial for establishing Earth＇s geodynamic evolution that includes supercontinent cycles and plate tectonics. Conventionally,two forces have been considered： the push by mantle plumes from the sub-continental mantle which is called the active force for breakup, and the dragging force from oceanic subduction retreat which is called the passive force for breakup. However, the relative importance of these two forces is unclear. Here we model the supercontinent breakup coupled with global mantle convection in order to address this question. Our global model features a spherical harmonic degree-2 structure, which includes a major subduction girdle and two large upwelling（superplume） systems. Based on this global mantle structure,we examine the distribution of extensional stress applied to the supercontinent by both subsupercontinent mantle upwellings and subduction retreat at the supercontinent peripheral. Our results show that：（1） at the center half of the supercontinent, plume push stress is ～3 times larger than the stress induced by subduction retreat;（2） an average hot anomaly of no higher than 50 K beneath the supercontinent can produce a push force strong enough to cause the initialization of supercontinent breakup;（3） the extensional stress induced by subduction retreat concentrates on a ～600 km wide zone on the boundary of the supercontinent, but has far less impact to the interior of the supercontinent. We therefore conclude that although circum-supercontinent subduction retreat assists supercontinent breakup, sub-supercontinent mantle upwelling is the essential force.

关键词： Supercontinent breakup Plume push Subduction retreat

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Robust video question answering via contrastive cross-modality representation learning

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Science China(Information Sciences) 2024年第10期67卷 211-226页

作者： Xun YANG Jianming ZENG Dan GUO Shanshan WANG Jianfeng DONG Meng WANG School of Information Science and Technology University of Science and Technology of China institute of Artificial Intelligence Hefei Comprehensive National Science Center School of Computer Science and Information Engineering Hefei University of Technology institutes of Physical Science and Information Technology Anhui University School of Computer Science and Technology Zhejiang Gongshang University

Video question answering(VideoQA) is a challenging yet important task that requires a joint understanding of low-level video content and high-level textual semantics. Despite the promising progress of existing efforts, recent studies revealed that current VideoQA models mostly tend to over-rely on the superficial correlations rooted in the dataset bias while overlooking the key video content, thus leading to unreliable results. Effectively understanding and modeling the temporal and semantic characteristics of a given video for robust VideoQA is crucial but, to our knowledge, has not been well investigated. To fill the research gap, we propose a robust VideoQA framework that can effectively model the cross-modality fusion and enforce the model to focus on the temporal and global content of videos when making a QA decision instead of exploiting the shortcuts in datasets. Specifically, we design a self-supervised contrastive learning objective to contrast the positive and negative pairs of multimodal input, where the fused representation of the original multimodal input is enforced to be closer to that of the intervened input based on video perturbation. We expect the fused representation to focus more on the global context of videos rather than some static keyframes. Moreover, we introduce an effective temporal order regularization to enforce the inherent sequential structure of videos for video representation. We also design a Kullback-Leibler divergence-based perturbation invariance regularization of the predicted answer distribution to improve the robustness of the model against temporal content perturbation of videos. Our method is model-agnostic and can be easily compatible with various VideoQA backbones. Extensive experimental results and analyses on several public datasets show the advantage of our method over the state-of-the-art methods in terms of both accuracy and robustness.

关键词： video question answering cross-modality fusion contrastive learning cross-media reasoning

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Crystal-KMC： Parallel Software for Lattice Dynamics Monte Carlo Simulation of Metal Materials

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Tsinghua Science and Technology 2018年第4期23卷 501-510页

作者： Jianjiang Li Peng Wei Shaofeng Yang Jie Wu Peng Liu Xinfu He the Department of Computer Science and Technology University of Science and TechnologyBeijing 100083 China the Department of Computer and Information Sciences Temple University Philadelphia PA 19122 USA School of Computer Science and Technology Hangzhou Dianzi University Hangzhou310018 China the China institute of Atomic Energy Beijing 102413 China

Kinetic Monte Carlo （KMC） is a widely used method for studying the evolution of materials at the microcosmic level. At present, while there are many simulation software programs based on this algorithm, most focus on the verification of a certain phenomenon and have no analog-scale requirement, so many are serial in nature. The dynamic Monte Carlo algorithm is implemented using a parallel framework called SPPARKS, but Jt does not support the Embedded Atom Method （EAM） potential, which is commonly used in the dynamic simulation of metal materials. Metal material - the preferred material for most containers and components -- plays an important role in many fields, including construction engineering and transportation. In this paper, we propose and describe the development of a parallel software program called CrystaI-KMC, which is specifically used to simulate the lattice dynamics of metallic materials. This software uses MPI to achieve a parallel multiprocessing mode, which avoid the limitations of serial software in the analog scale. Finally, we describe the use of the paralleI-KMC simulation software CrystaI-KMC in simulating the diffusion of vacancies in iron, and analyze the experimental results. In addition, we tested the performance of CrystaI-KMC in ＂meta -Era＂ supercomputing clusters, and the results show the CrystaI-KMC parallel software to have good parallel speedup and scalability.

关键词： Kinetic Monte Carlo (KMC) communication optimization parallel computation Message PassingInterface (MPI)

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Surface strain-enhanced MoS_(2)as a high-performance cathode catalyst for lithium-sulfur batteries

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eScience 2022年第4期2卷 405-415页

作者： Chao Yue Zhang Chaoqi Zhang Jiang Long Pan Guo Wen Sun Zude Shi Canhuang Li Xingqi Chang Geng Zhi Sun Jin Yuan Zhou Andreu Cabot School of Physical Science&Technology Lanzhou UniversityLanzhou730000China Catalonia institute for Energy Research-IREC Sant Adriàde BesòsBarcelona08930Spain College of Chemistry and Chemical Engineering Hunan UniversityChangsha410082China institute of Advanced Materials Nanjing Tech UniversityNanjing211816China ICREA Pg.Lluís Companys 2308010BarcelonaSpain

Lithium-sulfur batteries(LSBs)are one of the main candidates for the next generation of energy storage *** improve the performance of LSBs,we herein propose the use of strained MoS_(2)(s-MoS_(2))as a catalytically active sulfur *** introduction of strain in the MoS_(2)surface,which alters its atomic positions and expands the S-Mo-S angle,shifts the d-band center closer to the Fermi level and provides the surface with abundant and highly active catalytic sites;these enhance the catalyst's ability to adsorb lithium polysulfides(LiPS),accelerating its catalytic conversion and promoting lithium-ion *** is generated through the synthesis of core-shell nanoparticles,using different metal sulfides as strain-inducing cores.s-MoS_(2)nanoparticles are supported on carbon nanofibers(CNF/s-MoS_(2)),and the resulting electrodes are characterized by capacities of 1290 and 657 mAh g−1 at 0.2 and 5 C,respectively,with a 0.05%capacity decay rate per cycle at 8 C during 700 ***,this work not only provides an ingenious and effective strategy to regulate LiPS adsorption and conversion through strain engineering,but also indicates a path toward the application of strain engineering in other energy storage and conversion fields.

关键词： Strain engineering MoS_(2) Lithium polysulfide Electrospinning Core-shell nanocrystal Lithium-sulfur battery Sulfur cathode

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A chiral salen-Co(Ⅱ)complex as soluble redox mediator for promoting the electrochemical performance of Li-O_(2) batteries

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Nano Research 2022年第9期15卷 8101-8108页

作者： Hao Wan Yingjie Sun Jia Yu Qianqi Shi Yongchun Zhu Yitai Qian Hefei National Laboratory for Physical Science at Microscale and Department of Chemistry University of Science and Technology of ChinaHefei 230026China Hebei Key Laboratory of Photoelectric Control on Surface and Interface College of ScienceHebei University of Science and TechnologyShijiazhuang 050018China Materials Genome institute Shanghai UniversityShanghai 200444China

Low discharge capacity and poor cycle stability are the major obstacles hindering the operation of Li-O_(2)batteries with *** obstacles are mainly caused by the cathode passivation behaviours and the accumulation of *** the discharge process in solution and accelerating the decomposition of discharge products and by-products are able to alleviate above problems to some ***,chiral salen-Co(Ⅱ)complex,(1R,2R)-(-)-N,N-bis(3,5-di-t-butylsalicylidene)-1,2-cyclohexanediaminocobalt(Ⅱ)(Co(Ⅱ))as a multi-functional redox mediator was introduced into electrolyte to induce solution phase formation of Li_(2)O_(2)and catalyze the oxidation of Li_(2)O_(2)and main by-products Li_(2)*** to the Co(Ⅱ)has the solvation effect towards Li+,it can drive solution phase formation of Li_(2)O_(2),to prevent electrode from passivation and then increase the discharge capacity with a high Li_(2)O_(2)yield of 96.09%.Furthermore,the Co(Ⅱ)possesses suitable redox couple potentials,and it does so while simultaneously boosting the oxidization of Li_(2)O_(2)and the decomposition of Li_(2)CO3,reducing charge overpotential,and promoting cycle ***,a cell with Co(Ⅱ)achieved a long cycling stability at low charge plateau(3.66 V)over 252 cycles with a specific capacity of 500 mAh·gcarbon^(−1).

关键词： chiral salen-Co(Ⅱ)complex soluble redox mediator multi-redox potential trifunctional Li-O_(2)batteries

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Nicotine and its metabolite cotinine target MD2 and inhibit TLR4 signaling

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The Innovation 2021年第2期2卷 139-147页

作者： Hongyuan Li Yinghua Peng Cong Lin Xiaozheng Zhang Tianshu Zhang Yibo Wang Yuanpeng Li Siru Wu Hongshuang Wang Mark RHutchinson Linda RWatkins Xiaohui Wang Laboratory of Chemical Biology Changchun Institute of Applied ChemistryChinese Academy of SciencesJilin 130022China institute of Special Animal and Plant Sciences Chinese Academy of Agricultural SciencesJilin 130112China Discipline of Physiology Adelaide Medical SchoolUniversity of AdelaideAdelaideSAAustralia Department of Psychology and Neuroscience and the Center for NeuroscienceUniversity of Colorado at BoulderBoulderCO 80309USA Department of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China ARC Centre of Excellence for Nanoscale Biophotonics University of AdelaideAdelaideSA 5000Australia

Nicotine is the principal alkaloid of tobacco often manufactured into cigarettes and belongs to a highly addictive class of *** attenuates the neuroinflammation induced by microglial ***,the molecular target(s)underlying anti-inflammatory action of nicotine has not been fully *** the psychoactive substances morphine,cocaine,and methamphetamine act as xenobiotic-associated molecular patterns and can be specifically sensed by the innate immune receptor Toll-like receptor 4(TLR4),here we sought to delineate whether nicotine and/or its metabolite cotinine may be recognized by the innate immune system via myeloid differentiation protein 2(MD2).

关键词： belongs alkaloid system

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Resonant four-photon photoemission from SnSe_(2)(001)

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Frontiers of physics 2024年第3期19卷 83-92页

作者： Chengxiang Jiao Kai Huang Hongli Guo Xingxia Cui Qing Yuan Cancan Lou Guangqiang Mei Chunlong Wu Nan Xu Limin Cao Min Feng School of Physics and Technology and Key Laboratory of Artificial Micro-and Nano-Structures of Ministry of Education Wuhan UniversityWuhan 430072China Department of Physics and Astronomy California State University NorthridgeNorthridgeCA 91330-8268USA institute for Advanced Study Wuhan UniversityWuhan 430072China

High-order nonlinear multiphoton absorption is usually inefficient,but can be enhanced by designing resonant excitations between occupied and unoccupied energy *** conducted angle-resolved multi-photon photoemission(mPPE)studies on the SnSe_(2)(001)surfaces excited by ultrashort laser *** tuning photon energy and light polarization,we demonstrate the presence of a resonant four-photon photoemission(4PPE)process involving the occupied valence band(VB),the unoccupied second conduction band(CB2)and the unoccupied image-potential state(IPs)of SnSe_(2).In this 4PPE process,VB electrons of SnSe_(2) are resonantly excited into CB2 by adsorbing two photons,followed by the adsorption of another photon to populate the n=1 IPs before being emitted out to the vacuum by adsorbing one more *** results in a double-resonant 4PPE process,which exhibits approximately a 40 times enhancement in photoemission yields compared to cases where one of the resonant pathways,CB2→IPs,is inhibited by involving a virtual state instead of the IPs in the *** double-resonant 4PPE process efficiently excite the bulk VB electrons outside the vacuum,like taking advantage of resonant“ladders”through two real empty electronic states of SnSe_(2).Our results highlight the important applications of mPPE in probing the band-structure,particularly the unoccupied states,of recently emerging main group dichalcogenide ***,the discovered resonant mPPE process contributes to the exploration of their promising optoelectronic applications.

关键词： multi-photon photoemission four-photon photoemission SnSe_(2) unoccupied states resonant excitation

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Thermodynamics and dielectric response of BaTiO_(3)by data-driven modeling

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npj Computational Materials 2022年第1期8卷 1998-2014页

作者： Lorenzo Gigli Max Veit Michele Kotiuga Giovanni Pizzi Nicola Marzari Michele Ceriotti Laboratory of Computational Science and Modeling(COSMO) Institute of MaterialsÉcole Polytechnique Fédérale de LausanneCH-1015LausanneSwitzerland Theory and Simulation of Materials(THEOS)and National Centre for Computational Design and Discovery of Novel Materials(MARVEL) École Polytechnique Fédérale de LausanneCH-1015LausanneSwitzerland

Modeling ferroelectric materials from first principles is one of the successes of density-functional theory and the driver of much development effort,requiring an accurate description of the electronic processes and the thermodynamic equilibrium that drive the spontaneous symmetry breaking and the emergence of macroscopic *** demonstrate the development and application of an integrated machine learning model that describes on the same footing structural,energetic,and functional properties of barium titanate(BaTiO_(3)),a prototypical *** model uses ab initio calculations as a reference and achieves accurate yet inexpensive predictions of energy and polarization on time and length scales that are not accessible to direct ab initio *** predictions allow us to assess the microscopic mechanism of the ferroelectric *** presence of an order-disorder transition for the Ti off-centered states is the main driver of the ferroelectric transition,even though the coupling between symmetry breaking and cell distortions determines the presence of intermediate,partly-ordered ***,we thoroughly probe the static and dynamical behavior of BaTiO_(3)across its phase diagram without the need to introduce a coarse-grained description of the ferroelectric ***,we apply the polarization model to calculate the dielectric response properties of the material in a full ab initio manner,again reproducing the correct qualitative experimental behavior.

关键词： transition ferroelectric dielectric

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β-PtO2: Phononic,thermodynamic,and elastic properties derived from first-principles calculations

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Frontiers of physics 2019年第5期14卷 89-97页

作者： Quan Chen Wei Li Yong Yang Key Laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of SciencesHefei 230031China institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China Science Island Branch of Graduate School University of Science and Technology of ChinaHefei 230026China

β-PtO2 is a useful transition metal dioxide,but its fundamental thermodynamic and elastic properties remain *** first-principles calculations,we systematically studied the structure,phonon,thermodynamic and clastic properties of β-*** lattice dynamics and structural stability of β-PtO2 under pressure were studied using the phonon spectra and vibrational density of *** vibrational frequencies of the optical modes of β-PtO2 increase with elevating pressure;this result is comparable with the available experimental ***,the heat capacities and thoir pressure responses were determined based on the phonon *** pressure dependence of the Debye temperature was studied,and the results were compared in two distinct *** elastic moduli of β-PtO2 were estimated through the Voigt-Reuss-Hill *** bulk modulus of β-PtO2 increases linearly witli pressure,but the shear modulus is nearly independent of *** study revealed that the clastic stiffness coefficients C44,C55 and C66 play a primal role in the slow variation of the shear modulus.

关键词： phonons thermodynamic and elastic properties β-PtO2 first-principles calculations

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