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Data-driven rational design of single-atom materials for hydrogen evolution and sensing

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Nano Research 2024年第4期17卷 3352-3358页

作者： Lei Zhou Pengfei Tian Bowei Zhang Fu-Zhen Xuan Shanghai key laboratory of Intelligent Sensing and Detection Technology East China University of Science and TechnologyShanghai 200237China School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai 200237China key laboratory of pressure Systems and safety of Ministry of Education East China University of Science and TechnologyShanghai 200237China

Herein we proposed a data-driven high-throughput principle to screen high-performance single-atom materials for hydrogen evolution reaction(HER)and hydrogen sensing by combing the theoretical computations and a topology-based multi-scale convolution kernel machine learning *** the rational training by 25 groups of data and prediction of all 168 groups of single-atom materials for HER and sensing,respectively,a high prediction accuracy(>0.931 R^(2) score)was achieved by our *** show that the promising HER catalysts include Pt atoms in C_(4) and Sc atoms in C_(1)N_(3) coordination ***,Y atoms in C_(4) coordination environment and Cd atoms in C_(2)N_(2)-ortho coordination environment were predicted with great potential as hydrogen sensing *** method provides a way to accelerate the discovery of innovative materials by avoiding the time-consuming empirical principles in experiments.

关键词： machine learning single-atom materials sensing hydrogen evolution

Accurate atomic scanning transmission electron microscopy analysis enabled by deep learning

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Nano Research 2024年第4期17卷 2971-2980页

作者： Tianshu Chu Lei Zhou Bowei Zhang Fu-Zhen Xuan Shanghai key laboratory of Intelligent Sensing and Detection Technology East China University of Science and TechnologyShanghai 200237China School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai 200237China key laboratory of pressure Systems and safety of Ministry of Education East China University of Science and TechnologyShanghai 200237China

Currently,the machine learning(ML)-based scanning transmission electron microscopy(STEM)analysis is limited in the simulative stage,its application in experimental STEM is needed but ***,we built up a universal model to analyze the vacancy defects and single atoms accurately and rapidly in experimental STEM images using a full convolution *** our model,the unavoidable interference factors of noise,aberration,and carbon contamination were fully considered during the training,which were difficult to be considered in the *** toward the simultaneous identification of various vacancy types and low-contrast single atoms in the low-quality STEM images,our model showed rapid process speed(45 images per second)and high accuracy(>95%).This work represents an improvement in experimental STEM image analysis by ML.

关键词： deep learning low-dimensional materials atomic defects single atoms

Hugoniot equation of state of olivine and its geodynamic implications

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Science China Earth Sciences 2016年第3期59卷 619-625页

作者： HUANG Xiao Ge YUAN Xian Hao CHEN Zu An LIU Fu Sheng BAI Wu Ming key laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences Institute of High Temperature and High pressure Physics Key Laboratory of Advanced Technologies of Materials Ministry of Education of China Southwest Jiaotong University

Large olivine samples were hot-pressed synthesized for shock wave experiments. The shock wave experiments were carried out at pressure range between 11 and 42 GPa. Shock data on olivine sample yielded a linear relationship between shock wave velocity D and particle velocity u described by D=3.56(?0.13)+2.57(?0.12)u. The shock temperature is determined by an energy relationship which is approximately 790°C at pressure 28 GPa. Due to low temperature and short experimental duration, we suggest that no phase change occurred in our sample below 30 GPa and olivine persisted well beyond its equilibrium boundary in metastable phase. The densities of metastable olivine are in agreement with the results of static compression. At the depth shallower than 410 km, the densities of metastable olivine are higher than those of the PREM model, facilitating cold slab to sink into the mantle transition zone. However, in entire mantle transition zone, the shock densities are lower than those of the PREM model, hampering cold slab to flow across the "660 km" phase boundary.

关键词： Hugonite density Shock temperature Olivine Mantle transition zone

A Higher-Efficient Non-Hydrostatic Finite Volume Model for Strong Three-Dimensional Free Surface Flows and Sediment Transport

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China Ocean Engineering 2017年第6期31卷 736-746页

作者： LIU Xin MA Dian-guang ZHANG Qing-he State key laboratory of Hydraulic Engineering Simulation and safety Tianjin University key laboratory of Engineering Sediment of Ministry of Communications Tianjin Research Institute for Water Transport Engineering

In order to accurately simulate strong three-dimensional （3-D） free surface flows and sediment transport, the fully 3- D non-hydrostatic pressure models are developed based on the incompressible Navier-Stokes equations and convection-diffusion equation of sediment concentration with the mixing triangle and quadrilateral grids. The governing equations are discretized with the unstructured finite volume method in order to provide conservation properties of mass and momentum, and flexibility with practical application. It is shown that it is first-order accurate on nonuniform plane two-dimensional （2-D） grids and second-order accurate on uniform plane grids. A third-order approximation of the vertical velocity at the top-layer is applied. In such a way, free surface zero stress boundary condition is satisfied maturely, and very few vertical layers are needed to give an accurate solution even for complex discontinuous flow and short wave simulation. The model is applied to four examples to simulate strong 3-D free surface flows and sediment transport where non-hydrostatic pressures have a considerable effect on the velocity field. The newly developed model is verified against analytical solutions with an excellent agreement.

关键词： higher-efficient non-hydrostatic strong 3-D free surface flows sediment transport 3-D numerical model

Effects of Stress Level and Stress State on Creep Ductility:Evaluation of Different Models

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Journal of Materials Science & Technology 2016年第8期32卷 695-704页

作者： Jian-Feng Wen Shan-Tung Tu Fu-Zhen Xuan Xue-Wei Zhang Xin-Lin Gao key laboratory of pressure Systems and safety (Ministry of Education) School of Mechanical and Power Engineering East China University of Science and Technology Department of Materials Science and Engineering Texas A&M UniversityCollege Station Department of Mechanical Engineering Southern Methodist University

The last few decades have witnessed an increasing emphasis on the development of strain-based ap- proach for predicting the creep life or damage of components operating at elevated temperatures. Creep ductility, as a key parameter in this approach, may vary with a number of factors including strain rate, state of stress, operating temperature, material microstructure, etc. The present paper, however, is focused on reviewing the state-of-the-art understanding of the effects of stress level and stress state on the creep ductility. Mechanisms involving the void growth and coalescence are presented to describe the role of stress level in the variation of uniaxial creep ductility. The prediction capacity of existing empirical duc- tility models is also assessed in light of uniaxial test data. On the other hand, a vast body of multiaxial creep test data, collected from open literature, is utilized to examine the influence of the state of stress on the creep ductility. Then, a variety of multiaxial ductility factor models are introduced and evaluated with the available experimental data. Finally, a brief discussion on the dependence of creep ductility on the stress triaxiality and Lode parameter, predicted by numerical methods, is provided.

关键词： Creep Creep ductility Multiaxial stress state Ductility exhaustion

Synthesis and nitrogen content regulation of diamond in a high-pressure hydrogen-rich environment

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Chinese Physics B 2024年第6期33卷 541-546页

作者：黄国锋陈良超房超 Inner Mongolia key laboratory of High-pressure Phase Functional Materials Chifeng UniversityChifeng 024000China key laboratory of Material Physics of Ministry of Education School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China

The regulating nitrogen content of diamond in a hydrogen-rich high-temperature and high-pressure(HPHT) growth environment was systematically investigated in this work by developing three growth systems,namely, "FeNi+Ti", "FeNi+G_(3)N_(6)H_(6)",and "FeNi+Ti+C_(3)N_(6)H_(6)".Optical microscopy,infrared spectroscopy,and photoluminescence(PL)spectroscopy measurements were conducted to analyze the spectroscopic characteristics of diamonds grown in these three *** our analysis,it was demonstrated that the presence of hydrogen in the sp^(3) hybrid C-H does not directly affect the color of the diamond and facilitates the increase of the nitrogen-vacancy(NV) center concentration in a highnitrogen-content *** addition,titanium plays an important role in nitrogen removal,while its impact on hydrogen doping within the diamond lattice is *** importantly,by regulating the ratio of nitrogen impurities that coexist in the nitrogen and hydrogen HPHT environment,the production of hydrogenous Ⅱa-type diamond,hydrogenous Ib-type diamond,and hydrogenous high-nitrogen-type diamonds was achieved with a nitrogen content of less than 1 ppm to 1600 ppm.

关键词： diamond HPHT superhard material hydrogen-rich environment

Surperhard monoclinic BC6N allotropes:First-principles investigations

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Chinese Physics B 2019年第9期28卷 303-310页

作者： Nian-Rui Qu Hong-Chao Wang Qing Li Yi-Ding Li Zhi-Ping Li Hui-Yang Gou Fa-Ming Gao key laboratory of Applied Chemistry Yanshan UniversityQinhuangdao 066004China Center for High pressure Science and Technology Advanced Research Beijing 100094China

Via structural searching methodology and first-principles calculations, we predicted two new BC6N allotropes, a Ccentered monoclinic BC6N（Cm-BC6N） and a primitive-centered monoclinic BC6N（Pm-BC6N）.The lattice vibrations,elastic properties, ideal strength, theoretical hardness, and electronic structure of the predicted BC6N were investigated *** results reveal that Cm-BC6N is more favorable energetically than graphite-like g-BC6N above 20.6 GPa,which is lower than the transition pressures of r-BC6N, t-BC6N, and *** Cm-BC6N and Pm-BC6N are indirect semiconductors with band gaps of 2.66 eV and 0.36 eV, ***-BC6N exhibits the excellent ideal shear strength of 53.9 GPa in（011）■, much greater than that of Pm-BC6N（25.0 GPa in（010）[101] shear direction）, and Cm-BC6N shows a much lower anisotropy in shear strength than *** Vickers hardness of Cm-BC6N is estimated to be above 80 GPa, which is more outstanding than those of t-BC6N and r-BC6N.

关键词： superhard materials elastic properties boron-carbon-nitride ideal strength

pressure effects on metal/covalent-organic frameworks:structural and optical properties

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Science China Chemistry 2024年第9期67卷 2890-2903页

作者： Yixuan Wang Yunfeng Yang Xinyi Yang Bo Zou Synergetic Extreme Condition High-pressure Science Center State Key Laboratory of Superhard MaterialsCollege of PhysicsJilin UniversityChangchun 130012China

Metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)with highly ordered porous structure,tunable bandgap,large specific surface area and structural diversity,provide an appealing platform for the development of stimulus response,sensing,imaging and *** various tuning methods,pressure engineering using the diamond anvil cell is a highly powerful in-situ technique,which can efficiently modulate the structural and optical properties of MOFs/*** is beyond the realization of traditional chemical *** review outlines the research progress in the experimentoriented discovery of new phases or unique properties under high pressure,including phase transition,abnormal compression,photoluminescence(PL)discoloration and ***,the improvement of PL quantum yield in MOFs could be achieved by pressure-treated engineering and hydrogen-bonding cooperativity *** also propose and establish the relationship between structure and optical properties under high ***,the challenge and outlook of the current fields are *** hope that this review will supply guidance for comprehending the development of high-pressure MOF/COF-related research fields,and offer novel strategies for designing more high-performance MOF/COF materials to ultimately expand their applications.

关键词： metal/covalent-organic frameworks pressure engineering phase transition abnormal compressive behaviors piezochromic behaviors emission enhancement

Superconducting ternary hydrides: progress and challenges

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National Science Review 2024年第7期11卷 47-61页

作者： Wendi Zhao Xiaoli Huang Zihan Zhang Su Chen Mingyang Du Defang Duan Tian Cui Institute of High pressure Physics School of Physical Science and Technology Ningbo University State key laboratory of Superhard Materials College of Physics Jilin University

Since the discovery of the high-temperature superconductors H3S and LaH10under high pressure,compressed hydrides have received extensive attention as promising candidates for room-temperature superconductors. As a result of current high-pressure theoretical and experimental studies, it is now known that almost all the binary hydrides with a high superconducting transition temperature（Tc） require extremely high pressure to remain stable, hindering any practical application. In order to further lower the stable pressure and improve superconductivity, researchers have started exploring ternary hydrides and had many achievements in recent years. Here, we discuss recent progress in ternary hydrides, aiming to deepen the understanding of the key factors regulating the structural stability and superconductivity of ternary hydrides, such as structural motifs, bonding features, electronic structures, electron–phonon coupling, ***, the current issues and challenges of superconducting ternary hydrides are presented, together with the prospects and opportunities for future research.

关键词： high pressure ternary hydrides conventional superconductivity electron–phonon coupling