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Green Energy & Environment 2024年第1期9卷 71-80页

作者： Weijie Kou yafang Zhang Wenjia Wu Zibiao guo Quanxian Hua Jingtao Wang School of Chemical Engineering Zhengzhou UniversityZhengzhou450001China

Solid polymer electrolyte(SPE) shows great potential for all-solid-state batteries because of the inherent safety and flexibility;however, the unfavourable Li+deposition and large thickness hamper its development and application. Herein, a laminar MXene functional layer-thin SPE layer-cathode integration(MXene-PEO-LFP) is designed and fabricated. The MXene functional layer formed by stacking rigid MXene nanosheets imparts higher compressive strength relative to PEO electrolyte layer. And the abundant negatively-charged groups on MXene functional layer effectively repel anions and attract cations to adjust the charge distribution behavior at electrolyte–anode interface. Furthermore,the functional layer with rich lithiophilic groups and outstanding electronic conductivity results in low Li nucleation overpotential and nucleation energy barrier. In consequence, the cell assembled with MXene-PEO-LFP, where the PEO electrolyte layer is only 12 μm, much thinner than most solid electrolytes, exhibits uniform, dendrite-free Li+deposition and excellent cycling stability. High capacity(142.8 mAh g-1), stable operation of 140 cycles(capacity decay per cycle, 0.065%), and low polarization potential(0.5 C) are obtained in this Li|MXene-PEO-LFP cell,which is superior to most PEO-based electrolytes under identical condition. This integrated design may provide a strategy for the large-scale application of thin polymer electrolytes in all-solid-state battery.

关键词： MXene nanosheet Laminar functional layer Thin polymer electrolyte Dendrite-free Liþdeposition All-solid-state lithium battery

Analyze the Performance of Electroactive Anticorrosion Coating of Medical Magnesium Alloy Using Deep Learning

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Computers, Materials & Continua 2024年第4期79卷 263-278页

作者： Yashan Feng yafang Tian Yongxin Yang Yufang Zhang Haiwei guo Jing’an Li Advanced Functional Materials Laboratory Zhengzhou Railway Vocational and Technical CollegeZhengzhou450000China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou450000China

Electroactive anticorrosion coatings are specialized surface treatments that prevent or minimize corrosion. Thestudy employs strategic thermodynamic equilibriumcalculations to pioneer a novel factor in corrosion protection.A first-time proposal, the total acidity (TA) potential of the hydrogen (pH) concept significantly shapes medicalmagnesium alloys. These coatings are meticulously designed for robust corrosion resistance, blending theoreticalinsights and practical applications to enhance our grasp of corrosion prevention mechanisms and establisha systematic approach to coating design. The groundbreaking significance of this study lies in its innovativeintegration of the TA/pH concept,which encompasses the TA/pH ratio of the chemical environment. This approachsurpasses convention by acknowledging the intricate interplay between the acidity and pH levels within thecoating formulation, thereby optimizing metal-phosphate-based conversion coatings and transforming corrosionmitigation strategies. To authenticate the TA/pH concept, the study comprehensively compares its findings withexisting research, rigorously validating the theoretical framework and reinforcing the correlates among TA/pHvalues and observed corrosion resistance in the coatings. The influence of mutations that occur naturally inthe detergent solution on persistent phosphorus changes is shown by empirical confirmation, which improvescorrosion resistance. This realization advances the field ofmaterials and the field’s knowledge of coated generation,particularly anticorrosion converter layers.

关键词： Medical magnesium alloys hydrogen gas anticorrosion total acidity potential of the hydrogen(pH)

Evolution of misfit dislocation network and tensile properties in Ni-based superalloys:a molecular dynamics simulation

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Science China(Physics,Mechanics & Astronomy) 2012年第3期55卷 419-427页

作者： WU WenPing guo yafang WANG YueSheng Department of Engineering Mechanics Wuhan UniversityWuhan 430072China Department of Mechanical Engineering University of WuppertalWuppertal 42097Germany Institute of Engineering Mechanics Beijing Jiaotong UniversityBeijing 100044China

The structural evolution of dislocation network is closely related to ' rafting and tensile *** this work,the effects of strain rate and temperature on the structural evolution of interface dislocation network in Ni-based superalloys are studied by molecular dynamics *** correlation between the evolution of dislocation network and tensile properties is also *** results indicate that the dislocation network shows different degrees of deformation and damage at various strain rates and *** ' rafting depends on the damage structure of dislocation network at various strain rates and ***,the tensile properties of interface in Ni-based superalloys are closely related to the evolution of dislocation network and dislocation motion mechanisms.

关键词：分子动力学模拟镍基高温合金拉伸性能位错网演变网络结构失配温度条件

Atomistic simulation of tension deformation behavior in magnesium single crystal

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Acta Metallurgica Sinica(English Letters) 2010年第5期23卷 370-380页

作者： yafang guo Yuesheng WANG Honggang QI Dirk STEGLICH Institute of Engineering Mechanics Beijing Jiaotong University Beijing 100044 China GKSS Research Centre Institute of Materials Research Materials Mechanics D-21502 Geesthacht Germany Graduate Institute of Ferrous Technology Pohang University of Science and Technology Pohang Gyeongbuk 790-784 Korea

The deformation behavior in magnesium single crystal under c-axis tension is investigated in a temperature range between 250 K and 570 K by molecular dynamics simulations. At a low temperature, twinning and shear bands are found to be the main deformation mechanisms. In particular, the {102} tension twins with the reorientation angle of about 90 °are observed in the simulations. The mechanisms of {102} twinning are illustrated by the simulated motion of atoms. Moreover, grain nucleation and growth are found to be accompanied with the {102} twinning. At temperatures above 450 K, the twin frequency decreases with increasing temperature. The {102} extension twin almost disappears at the temperature of 570 K. The non-basal slip plays an important role on the tensile deformation in magnesium single crystal at high temperatures.

关键词： Atomistic simulations Magnesium Twinning c-axis tension

Atomistic simulation of the structural evolution in magnesium single crystal under c-axis tension

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Acta Metallurgica Sinica(English Letters) 2011年第6期24卷 487-494页

作者： Honggang QI yafang guo Xiaozhi TANG Shuang XU Institute of Engineering Mechanics Beijing Jiaotong University Beijing 100044 China

Molecalar dynamics simulation is applied to investigate the microstructure evolution of magnesium single crystals under c-axis extension at different temperatures. At low temperatures, both {1012} and {1011} twins are observed. At elevated temperatures, {1011} twining decreases quickly with increasing temperature, while the amount of {1012} twins increases. The （1012} twin is found to be the main deformation mechanism under the c-axis tension in the magnesium single crystal. Meanwhile, shear bands are also observed during deformation. When the temperature is beyond 500 K, the non-basal plane slip due to the thermal .activation is found. The stress-strain curves related with deformation behavior at atomistic scale are presented.

关键词： Magnesium single crystal Twinning Molecular dynamics simu-lation c-axis tension

Compression Deformation Mechanisms at the Nanoscale in Magnesium Single Crystal

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Acta Metallurgica Sinica(English Letters) 2013年第1期26卷 75-84页

作者： yafang guo Xiaozhi TANG Yuesheng WANG Zhengdao WANG Sidney YIP Institute of Engineering Mechanics Beijing Jiaotong University Department of Nuclear Science and Engineering Massachusetts Institute of Technology

The dominant deformation mode at low temperatures for magnesium and its alloys is generally regarded to be twinning because of the hcp crystal structure. More recently, the phenomenon of a ＂loss＂ of the twins has been reported in microcompression experiments of the magnesium single crystals. Molecular dynamics simulation of compression deformation shows that the pyramidal 〈α ＋ c〉 slip dominates compression behavior at the nanoscale. No compression twins are observed at different temperatures at different loadings and boundary conditions. This is explained by the analyses, that is, the {10^_12} and {10^11} twins can be activated under c-axis tension, while compression twins will not occur when the c/α ratio of the hcp metal is below √3. Our theoretical and simulation results are consistent with recent microcompression experiments of the magnesium （0001） single crystals.

关键词： Magnesium Compression Slip Molecular dynamics simulation

ELASTIC WAVE LOCALIZATION IN TWO-DIMENSIONAL PHONONIC CRYSTALS WITH ONE-DIMENSIONAL QUASI-PERIODICITY AND RANDOM DISORDER

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Acta Mechanica Solida Sinica 2008年第6期21卷 517-528页

作者： Ali Chen Yuesheng Wang Guilan Yu yafang guo Zhengdao Wang Institute of Engineering Mechanics Beijing Jiaotong University Beijing 100044 China School of Civil Engineering Beijing Jiaotong University Beijing 100044 China

The band structures of both in-plane and anti-plane elastic waves propagating in two-dimensional ordered and disordered （in one direction） phononic crystals are studied in this paper. The localization of wave propagation due to random disorder is discussed by introducing the concept of the localization factor that is calculated by the plane-wave-based transfer-matrix method. By treating the quasi-periodicity as the deviation from the periodicity in a special way, two kinds of quasi phononic crystal that has quasi-periodicity （Fibonacci sequence） in one direction and translational symmetry in the other direction are considered and the band structures are characterized by using localization factors. The results show that the localization factor is an effective parameter in characterizing the band gaps of two-dimensional perfect, randomly disordered and quasi-periodic phononic crystals. Band structures of the phononic crystals can be tuned by different random disorder or changing quasi-periodic parameters. The quasi phononic crystals exhibit more band gaps with narrower width than the ordered and randomly disordered systems.

关键词： phononic crystal quasi phononic crystal disorder localization factors plane-wavebased transfer-matrix method periodic average structure

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木材分子考古研究进展

林业科学 2024年第2期60卷 118-127页

作者：焦立超陆杨郭雨殷亚方中国林业科学研究院木材工业研究所、中国林业科学研究院木材标本馆、国家林业和草原局木材标本资源库CITES全球野生动植物鉴定实验室北京100091

木材考古学研究是推动木质文物自然和历史信息挖掘、保护和修复的重要基础。近年来,随着古DNA捕获和测序技术的快速发展,从木质遗存中可获取古DNA信息,在木材解剖学基础上,创新开展以古DNA为核心的木材分子考古研究已成为木材考古学的... 详细信息

木材考古学研究是推动木质文物自然和历史信息挖掘、保护和修复的重要基础。近年来,随着古DNA捕获和测序技术的快速发展,从木质遗存中可获取古DNA信息,在木材解剖学基础上,创新开展以古DNA为核心的木材分子考古研究已成为木材考古学的前沿热点。本文首先对木材分子考古研究进行概述,从古DNA的保存和降解、获取以及数据处理和序列分析3方面归纳木材古DNA的研究进展,并指出古DNA因高度降解、含量极低和化学损伤特征导致其难于提取和信息解译的难题。然后总结木材分子考古在解读先民认知与利用森林资源方式、复原历史时期地域性森林植被类型和物种多样性以及重建古代树木应对气候和生境变化的微进化反应等方面的主要应用。最后提出该研究领域未来应优先开展的工作:1)建立考古木材标本库及其DNA信息数据库;2)研究不同时空维度下木材古DNA损伤及变化规律;3)构建稳定高效的木材古DNA提取及序列信息解译技术体系。通过进一步加强木材分子考古等多学科交叉研究,推动新理论、新方法、新技术在木材学和考古学领域的应用,为木质文物的用材树种识别、保护利用以及重建历史时期森林植被、环境气候与人类活动的耦合关系提供重要科学依据。

关键词：木质遗存古DNA 树种 DNA提取 DNA损伤分子考古

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数码电子雷管深水起爆性能试验研究

爆破器材 2022年第4期51卷 47-50页

作者：李春军崔广强陈士海郭雅芳长江重庆航道工程局重庆400011 华侨大学土木工程学院福建厦门361021

采用密封压力罐中注入一定量的水,然后施加不同气压的方法模拟数码电子雷管在一定水深下的工况,通过系列试验研究模拟相应工况下的起爆能力。试验结果证明:所用数码电子雷管在40 m水深处放置48 h,其抗水性、起爆能力、延期精度均不会受... 详细信息

采用密封压力罐中注入一定量的水,然后施加不同气压的方法模拟数码电子雷管在一定水深下的工况,通过系列试验研究模拟相应工况下的起爆能力。试验结果证明:所用数码电子雷管在40 m水深处放置48 h,其抗水性、起爆能力、延期精度均不会受水深的影响,可满足工程需要。通过系列试验,弥补了现有工程资料数据的不足,为类似工程提供了必要的试验数据和依据。

关键词：数码电子雷管深水模拟起爆能力延期时间

Molecular dynamics simulations of mechanical properties of epoxy-amine:Cross-linker type and degree of conversion effects

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Chinese Physics B 2022年第6期31卷 396-402页

作者：张永钦杨华孙亚光郑香蕊郭雅芳 Department of Mechanics School of Civil EngineeringBeijing Jiaotong UniversityBeijing 100044China School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027China

Molecular dynamics(MD)simulations are conducted to study the thermo-mechanical properties of a family of thermosetting *** crosslinked epoxy resin EPON862 with a series of cross-linkers is built and simulated under the polymer consistent force field(PCFF).Three types of curing agents(rigidity1,3-phenylenediamine(1,3-P),4,4-diaminodiphenylmethane(DDM),and phenol-formaldehyde-ethylenediamine(PFE))with different numbers of active sites are selected in the *** focus on the effects of the cross-linkers on thermo-mechanical properties such as density,glass transition temperature(T_(g)),elastic constants,and *** simulations show a significant increase in the Tg,Young’s modulus and yield stress with the increase in the degree of *** simulation results reveal that the mechanical properties of thermosetting polymers are strongly dependent on the molecular structures of the cross-linker and network topological properties,such as end-to-end distance,crosslinking density and degree of conversion.

关键词： polymer molecular dynamic simulation mechanical properties thermodynamics