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Effects of Re, Ta, and W in [110] (001) dislocation core of γ/γ' interface to Ni-based superalloys: First-principles study 被引量:1
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作者 Chuanxi Zhu Tao Yu 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第9期390-396,共7页
The strengthening effects of alloying elements Re,Ta,and W in the[110](001)dislocation core of theγ/γ'interface are studied by first-principles calculations.From the level of energy the substitution formation en... The strengthening effects of alloying elements Re,Ta,and W in the[110](001)dislocation core of theγ/γ'interface are studied by first-principles calculations.From the level of energy the substitution formation energies and the migration energies of alloying elements are computed and from the level of electron the differential charge density(DCD)and the partial density of states(PDOSs)are computed.Alloying elements above are found to tend to substitute for Al sitesγ'phase by analyzing the substitution formation energy.The calculation results for the migration energies of alloying elements indicate that the stability of the[110](001)dislocation core is enhanced by adding Ta,W,and Re and the strengthening effect of Re is the strongest.Our results agree with the relevant experiments.The electronic structure analysis indicates that the electronic interaction between Re-nearest neighbor(NN)Ni is the strongest.The reason why the doped atoms have different strengthening effects in the[110](001)dislocation core is explained at the level of electron. 展开更多
关键词 Ni-based superalloys dislocation structure electronic structure first-principles calculations
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Molecular dynamics simulation of kink in 〈100〉 edge dislocation in body centred cubic iron 被引量:5
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作者 CHEN LiQun1,2,WANG ChongYu2,3,4 & YU Tao2 1 College of Sciences,Central South University of Forestry & Technology,Changsha 410004,China 2 Central Iron and Steel Research Institute,Beijing 100081,China +1 位作者 3 Department of Physics,Tsinghua University,Beijing 100084,China 4 International Center for Materials Physics,Chinese Academy of Sciences,Shenyang 110016,China 《Chinese Science Bulletin》 SCIE EI CAS 2007年第16期2291-2296,共6页
Using the molecular dynamics method,we have constructed two kink models corresponding to the 〈100〉{010} and 〈100〉{011} edge dislocations (EDs) in body centred cubic (bcc) Fe. It is found that the geometric structu... Using the molecular dynamics method,we have constructed two kink models corresponding to the 〈100〉{010} and 〈100〉{011} edge dislocations (EDs) in body centred cubic (bcc) Fe. It is found that the geometric structure of a kink depends on the type of edge dislocation and the structural energies of the atoms sites in the dislocation core region. The formation energies,migration energies and widths of the kinks in different types of EDs are calculated. The results show that formation and migration of the kink in the 〈100〉{010} edge dislocation are difficult. The 〈100〉{011} edge dislocation moves primarily through kink nucleation,rather than kink migration. 展开更多
关键词 分子动力学 边缘位移 纽结结构
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Identifying the crystal structure of T 1 precipitates in Al-Li-Cu alloys by ab initio calculations and HAADF-STEM imaging 被引量:5
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作者 Shuo Wang Xianghai Yang +2 位作者 Junsheng Wang Chi Zhang Chengpeng Xue 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第2期41-57,共17页
Controversial experimental reports on the crystal structure of T 1 precipitates in Al-Li-Cu alloys have ex-isted for a long time,and all of them can be classified into five models.To clarify its ground-state atomic st... Controversial experimental reports on the crystal structure of T 1 precipitates in Al-Li-Cu alloys have ex-isted for a long time,and all of them can be classified into five models.To clarify its ground-state atomic structure,herein,we have combined high-throughput first-principles calculations and CALPHAD,as well as aberration-corrected HAADF-STEM experiments.Employing the special quasi-random structure(SQS)and supercell approximation(SPA)methods to simulate the local disorder on Al-Cu sub-lattices,we find that none of the present models can satisfy the phase stability in Al-Li-Cu ternary system based on temperature-dependent convex hull analysis.Using the cluster expansion(CE)formulas,structural predic-tions derived from the five-frame models were performed.Subsequently,by introducing the vibrational contribution to the free energy at aging temperatures,we proposed a novel ground-state T 1 structure that maintains a coherent relationship with Al-matrix at the<112>Al orientation.The underlying phase transition between the variants of T 1 precipitates was further discussed.By means of ab initio molecular dynamics(AIMD)simulations,we resolved the controversy regarding the number of atomic layers con-stituting the T 1 phase and acknowledged the existence of Al-Li corrugated layers.The root cause of this structural distortion is triggered by atomic forces and bondings.Our work can have an positive impact on the novel fourth generation of Al-Cu-Li alloy designs by engineering the T 1 strengthening phase. 展开更多
关键词 Al-Cu-Li alloys T 1 precipitates Cluster expansion first-principle calculations ab initio molecular dynamics HAADF-STEM
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Atomistic simulation of kink structure on edge dislocation in bcc iron
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作者 陈丽群 王崇愚 于涛 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第2期662-668,共7页
Based on the general theory of dislocation and kink, we have constructed the three kink models corresponding to the 1/2 (111){011} and 1/2 (111){112} edge dislocations (EDs) in bcc Fe using the molecular dynamic... Based on the general theory of dislocation and kink, we have constructed the three kink models corresponding to the 1/2 (111){011} and 1/2 (111){112} edge dislocations (EDs) in bcc Fe using the molecular dynamics method. We found that the geometric structure of a kink depends on the type of ED and the structural energies of the atom sites in the dislocation core region, as well as the geometric symmetry of the dislocation core and the characteristic of the stacking sequence of atomic plane along the dislocation line. The formation energies and widths of the kinks on the 1/2 (111){011} and 1/2 (111){112} EDs are calculated, the formation energies are 0.05eV and 0.04eV, and widths are 6.02b and 6.51b, respectively (b is the magnitude of the Burgers vector). The small formation energies indicate that the formation of kink in the edge dislocation is very easy in bcc Fe. 展开更多
关键词 molecular dynamics edge dislocation kink structure bcc iron
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Atomistic simulation of thermal effects and defect structures during nanomachining of copper 被引量:5
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作者 郭永博 梁迎春 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第11期2762-2770,共9页
Molecular dynamics (MD) simulations of monocrystalline copper (100) surface during nanomachining process were performed based on a new 3D simulation model. The material removal mechanism and system temperature dis... Molecular dynamics (MD) simulations of monocrystalline copper (100) surface during nanomachining process were performed based on a new 3D simulation model. The material removal mechanism and system temperature distribution were discussed. The simulation results indicate that the system temperature distribution presents a roughly concentric shape, a steep temperature gradient is observed in diamond cutting tool, and the highest temperature is located in chip. Centrosymmetry parameter method was used to monitor defect structures. Dislocations and vacancies are the two principal types of defect structures. Residual defect structures impose a major change on the workpiece physical properties and machined surface quality. The defect structures in workpiece are temperature dependent. As the temperature increases, the dislocations are mainly mediated from the workpiece surface, while the others are dissociated into point defects. The relatively high cutting speed used in nanomachining results in less defect structures, beneficial to obtain highly machined surface quality. 展开更多
关键词 monocrystalline copper atomistic simulation thermal effects molecular dynamics simulation nanomachining temperature distribution defect structures dislocations VACANCIES
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First-principles study of the growth and diffusion of B and N atoms on the sapphire surface with h-BN as the buffer layer 被引量:1
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作者 Jianyun Zhao Xu Li +2 位作者 Ting Liu Yong Lu Jicai Zhang 《Journal of Semiconductors》 EI CAS CSCD 2021年第8期66-72,共7页
Currently,the preparation of large-size and high-quality hexagonal boron nitride is still an urgent problem.In this study,we investigated the growth and diffusion of boron and nitrogen atoms on the sapphire/h-BN buffe... Currently,the preparation of large-size and high-quality hexagonal boron nitride is still an urgent problem.In this study,we investigated the growth and diffusion of boron and nitrogen atoms on the sapphire/h-BN buffer layer by first-principles calculations based on density functional theory.The surface of the single buffer layer provides several metastable adsorption sites for free B and N atoms due to exothermic reaction.The adsorption sites at the ideal growth point for B atoms have the lowest adsorption energy,but the N atoms are easily trapped by the N atoms on the surface to form N-N bonds.With the increasing buffer layers,the adsorption process of free atoms on the surface changes from exothermic to endothermic.The diffusion rate of B atoms is much higher than that of the N atoms thus the B atoms play a major role in the formation of B-N bonds.The introduction of buffer layers can effectively shield the negative effect of sapphire on the formation of B-N bonds.This makes the crystal growth on the buffer layer tends to two-dimensional growth,beneficial to the uniform distribution of B and N atoms.These findings provide an effective reference for the h-BN growth. 展开更多
关键词 hexagonal boron nitride buffer layer first-principles calculations molecular dynamics
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Multiscale energy density algorithm and application to surface structure of Ni matrix of superalloy
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作者 Min Sun Chong-Yu Wang Ji-Ping Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第9期482-488,共7页
Multiscale materials modeling as a new technique could offer more accurate predictive capabilities. The most active area of research for multiscale modeling focuses on the concurrent coupling by considering models on ... Multiscale materials modeling as a new technique could offer more accurate predictive capabilities. The most active area of research for multiscale modeling focuses on the concurrent coupling by considering models on disparate scales simultaneously. In this paper, we present a new concurrent multiscale approach, the energy density method(EDM), which couples the quantum mechanical(QM) and the molecular dynamics(MD) simulations simultaneously. The coupling crossing different scales is achieved by introducing a transition region between the QM and MD domains. In order to construct the energy formalism of the entire system, concept of site energy and weight parameters of disparate scales are introduced.The EDM is applied to the study of the multilayer relaxation of the Ni(001) surface structure and is validated against the periodic density functional theory(DFT) calculations. The results show that the concurrent EDM could combine the accuracy of the DFT description with the low computational cost of the MD simulation and is suitable to the study of the local defects subjected to the influence of the long-range environment. 展开更多
关键词 first-principles calculation molecular dynamics surface relaxation NICKEL
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Dislocation mechanism of Ni_(47)Co_(53) alloy during rapid solidification
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作者 刘云春 梁永超 +5 位作者 陈茜 张利 马家君 王蓓 高廷红 谢泉 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期410-419,共10页
Dislocations and other atomic-level defects play a crucial role in determining the macroscopic properties of crystalline materials,but it is extremely difficult to observe the evolution of dislocations due to the limi... Dislocations and other atomic-level defects play a crucial role in determining the macroscopic properties of crystalline materials,but it is extremely difficult to observe the evolution of dislocations due to the limitations of the most advanced experimental techniques.Therefore,in this work,the rapid solidification processes of Ni_(47)Co_(53) alloy at five cooling rates are studied by molecular dynamics simulation,and the evolutions of their microstructures and dislocations are investigated as well.The results show that face-centered cubic(FCC) structures are formed at the low cooling rate,and the crystalline and amorphous mixture appear at the critical cooling rate,and the amorphous are generated at the high cooling rate.The crystallization temperature and crystallinity decrease with cooling rate increasing.Dislocations are few at the cooling rates of 1×10^(11) K/s,5×10^(12) K/s,and 1×10^(13) K/s,and they are most abundant at the cooling rates of 5×10^(11) K/s and1 × 10^(12) K/s,in which their dislocation line lengths are both almost identical.There appear a large number of dislocation reactions at both cooling rates,in which the interconversion between perfect and partial dislocations is primary.The dislocation reactions are more intense at the cooling rate of 5×10^(11) K/s,and the slip of some dislocations leads to the interconversion between FCC structure and hexagonal close packed(HCP) structure,which causes the twin boundaries(TBs) to disappear.The FCC and HCP are in the same atomic layer,and dislocations are formed at the junction due to the existence of TBs at the cooling rate of 1 ×10^(12) K/s.The present research is important in understanding the dislocation mechanism and its influence on crystal structure at atomic scales. 展开更多
关键词 molecular dynamics simulation rapid solidification crystal structure dislocation interaction
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Multiscale simulations in face-centered cubic metals:A method coupling quantum mechanics and molecular mechanics 被引量:1
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作者 于潇翔 王崇愚 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期395-400,共6页
An effective multiscale simulation which concurrently couples the quantum-mechanical and molecular-mechanical calculations based on the position continuity of atoms is presented.By an iterative procedure,the structure... An effective multiscale simulation which concurrently couples the quantum-mechanical and molecular-mechanical calculations based on the position continuity of atoms is presented.By an iterative procedure,the structure of the dislocation core in face-centered cubic metal is obtained by first-principles calculation and the long-range stress is released by molecular dynamics relaxation.Compared to earlier multiscale methods,the present work couples the long-range strain to the local displacements of the dislocation core in a simpler way with the same accuracy. 展开更多
关键词 first-principles calculation molecular dynamics dislocation structure
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Atomistic simulation study of the diffusion and growth mechanisms of Ti thin films on Si(100)surfaces for betavoltaic cell
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作者 Han-Zi Zhang Kai-Hong Long +3 位作者 Yun-Ze Han Chuan-Kai Shen Meng-He Tu Bao-Liang Zhang 《Nuclear Science and Techniques》 2025年第9期75-87,共13页
The nucleation and growth behaviors of Ti thin films on Si(100)surfaces at 500 K were investigated via molecular dynamics and Monte Carlo methods.This study focuses on the nucleation characteristics,growth mode,crysta... The nucleation and growth behaviors of Ti thin films on Si(100)surfaces at 500 K were investigated via molecular dynamics and Monte Carlo methods.This study focuses on the nucleation characteristics,growth mode,crystal structure,and surface structure of Ti thin films for use in betavoltaic cells.The results demonstrate that at the initial stage of deposition,the Ti film mixes with the Si substrate at the interface.The surface roughness of the Ti film is influenced by the deposition atomic rate,which is associated with the crystal structure transition in the film,and the stable hexagonal close-packed(HCP)grains in the film are frequently accompanied by the presence of dislocations with an face-centered cubic(FCC)laminated structure.As the deposition rate increases,the growth behavior of the Ti film transitions from random growth orientation to selective growth orientation.Furthermore,the adsorption energies of Ti at different sites on the Si(100)p(2×2)surface were calculated.This was performed to identify the optimal diffusion path of the Ti atoms on the Si(100)surface,which was then found via the transition state search method. 展开更多
关键词 DEPOSITION SI(100) TI first-principles calculation molecular dynamics
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成分相关的单晶Cr-Co-Ni合金形变机制的分子动力学模拟研究
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作者 耿长建 杨怡斌 +2 位作者 由宝财 董会苁 马海坤 《材料导报》 北大核心 2025年第2期234-238,共5页
近年来,Co-Cr-Ni中熵合金因其杰出的性能在材料领域引起广泛关注。然而,在单晶Co-Cr-Ni中熵合金中,随着化学成分的变化,其内部微观结构对材料的塑性和硬度等力学性能的影响仍然需要详细研究。本工作借助分子动力学模拟,对包括等原子比例... 近年来,Co-Cr-Ni中熵合金因其杰出的性能在材料领域引起广泛关注。然而,在单晶Co-Cr-Ni中熵合金中,随着化学成分的变化,其内部微观结构对材料的塑性和硬度等力学性能的影响仍然需要详细研究。本工作借助分子动力学模拟,对包括等原子比例的CoCrNi和非等原子比例的Co_(10)(CrNi)_(90)、Cr_(10)(CoNi)_(90)以及Ni_(10)(CoCr)_(90)在内的不同成分的单晶Co-Cr-Ni中熵合金进行了深入探讨。研究结果揭示了不同成分下材料力学性能的显著差异,包括屈服应力、杨氏模量和流变应力。同时,分析了Lomer-Cottrell锁结构、层错四面体和显微组织的演化,以及这些因素对材料的强化作用。 展开更多
关键词 中熵合金 分子动力学模拟 Shockley不全位错 Lomer-Cottrell锁结构 层错四面体
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Influence of Ni on Cu precipitation in Fe Cu Ni ternary alloy by an atomic study 被引量:3
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作者 朱露珊 赵世金 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第6期193-198,共6页
The early aging Cu precipitations in Fe-3%Cu and Fe-3%Cu-4%Ni ternary alloys are investigated by molecular dynamics (MD) simulations. The results show that the average size of Cu clusters in Fe-3%Cu-4%Ni alloy is la... The early aging Cu precipitations in Fe-3%Cu and Fe-3%Cu-4%Ni ternary alloys are investigated by molecular dynamics (MD) simulations. The results show that the average size of Cu clusters in Fe-3%Cu-4%Ni alloy is larger than that in Fe-3%Cu alloy. The diffusion of Cu is accelerated by Ni according to the mean square displacement (MSD). Furthermore, the whole formation process of Cu-rich clusters is analyzed in detail, and it is found that the presence of Ni promotes small Cu-rich clusters to be combined into big ones. Ni atoms prefer to stay at the combination positions of small clusters energetically due to a large number of the first nearest neighbor Cu-Ni interactions, which is verified by first-principles calculations based on density functional theory (DFT). 展开更多
关键词 Cu precipitation Fe-Cu-Ni ternary alloy molecular dynamics first-principles calculations
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Multiscale simulations of surface adsorption characteristics of amino acids on zinc metal anode
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作者 Yufan Xia Zijian Hong +6 位作者 Linming Zhou Shuang Chen Zhen Luo Shoutong Jin Yuhui Huang Yinzhu Jiang Yongjun Wu 《Journal of Energy Chemistry》 SCIE EI CSCD 2023年第12期153-161,I0006,共10页
Aqueous zinc-ion batteries(ZIBs) are considered promising power sources for grid storage,but they face several issues,including dendrite growth,corrosion,hydrogen evolution,etc.,which are related to the Zn metal/liqui... Aqueous zinc-ion batteries(ZIBs) are considered promising power sources for grid storage,but they face several issues,including dendrite growth,corrosion,hydrogen evolution,etc.,which are related to the Zn metal/liquid electrolyte interface.To address these challenges,many researchers have focused on modifying the Zn anode with surface adsorption.However,the underlying mechanism between the Zn surface and adsorbed/protective molecules has not been thoroughly explored.In this study,we built a multiscale simulation platform that integrates state-of-art simulation methods to comprehensively investigate the adsorption process of amino acids on the Zn metal surface.Our major finding is that adsorption sites,adsorbate–surface angle,and average distance are critical parameters for the stability and strength of surface adsorption.Additionally,ab initio molecular dynamics reveal the kinetics of the surface adsorption and molecule reorientation processes.Specifically,it can be discovered that the amino acids prefer to align parallel to the Zn metal surface,leading to better surface protection against corrosion and preventing dendrite growth.These findings pave the way for an in-depth understanding of the surface adsorption process,as well as providing concrete design principles for stable Zn metal anodes. 展开更多
关键词 Zn-ion battery first-principles calculations Surface adsorption Ab initio molecular dynamics
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二恶英物质的结构性质分析 被引量:3
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作者 李欣 王郁萍 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2004年第4期513-514,519,共3页
利用商业化的分子模拟软件,在分子力学计算的基础上,对二恶英分子的最稳定构型、最高占据轨道、电荷密度分布图和溶剂可及表面等进行了研究,并给出了二恶英的VRML分子模型,计算出分子的物理化学性质.对二恶英分子物质结构性质的分析将... 利用商业化的分子模拟软件,在分子力学计算的基础上,对二恶英分子的最稳定构型、最高占据轨道、电荷密度分布图和溶剂可及表面等进行了研究,并给出了二恶英的VRML分子模型,计算出分子的物理化学性质.对二恶英分子物质结构性质的分析将有助于从理论上寻找控制与治理二恶英污染的技术手段和方法. 展开更多
关键词 二恶英物质 结构性质分析 分子力学计算 VRML分子模型 最高占据轨道 电荷密度分布图
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氮化镓小团簇结构的理论研究 被引量:2
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作者 宋斌 凌俐 曹培林 《浙江大学学报(理学版)》 CAS CSCD 2004年第3期270-275,共6页
用局域密度泛函近似下的全势能线性Muffin-Tin轨道组合分子动力学方法对氮化镓小团簇GanNn(n=2~6)的结构和能量进行了计算,并和已有的报道进行了比较.除Ga2N2外,获得了所有上述团簇的新的最稳定结构.最稳定结构中存在着N2单元或N3单元... 用局域密度泛函近似下的全势能线性Muffin-Tin轨道组合分子动力学方法对氮化镓小团簇GanNn(n=2~6)的结构和能量进行了计算,并和已有的报道进行了比较.除Ga2N2外,获得了所有上述团簇的新的最稳定结构.最稳定结构中存在着N2单元或N3单元或两者兼有,表明N—N键在GanNn(n=2~6)团簇的形成中起着决定性的作用.同时,对上述团簇的HOMO-LUMO能量间隔进行了计算.HOMO-LUMO能量间隔为1.601~2.667eV,表明上述团簇将显示像半导体一样的性质. 展开更多
关键词 氮化镓 小团簇结构 分子动力学计算 微观结构 半导体材料
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疏水蛋白在云母表面的吸附 被引量:2
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作者 何佳 冯喜增 +1 位作者 邵学广 蔡文生 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2015年第1期110-115,共6页
采用分子动力学模拟方法研究了疏水蛋白(HFBI)在亲水云母表面的吸附过程.通过6组平行的分子动力学模拟得到了2种不同的稳定吸附结构,即通过N端和通过亲水的α螺旋与表面吸附,得到了5种吸附残基.进一步用自适应偏置力方法计算了所有吸附... 采用分子动力学模拟方法研究了疏水蛋白(HFBI)在亲水云母表面的吸附过程.通过6组平行的分子动力学模拟得到了2种不同的稳定吸附结构,即通过N端和通过亲水的α螺旋与表面吸附,得到了5种吸附残基.进一步用自适应偏置力方法计算了所有吸附残基与表面的结合自由能.结果表明,残基Lys是吸附过程的关键残基,即当HFBI通过含有Lys残基的α螺旋与云母表面作用时,其吸附构象最稳定.静电作用是吸附过程的主要驱动力.在该吸附结构中,HFBI的疏水面暴露在溶液中,有效降低了云母表面的润湿性. 展开更多
关键词 疏水蛋白 云母 分子动力学模拟 自由能计算 吸附构象 自适应偏置力方法
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盐酸介质中咪唑离子液体对碳钢缓蚀作用的机理研究 被引量:1
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作者 田国才 袁楷涛 《昆明理工大学学报(自然科学版)》 CAS 北大核心 2018年第4期9-19,共11页
采用量子化学方法研究了三种离子液体1-丁基-3-甲基咪唑硝酸盐([BMIM]NO3),1-丁基-3-甲基-咪唑四氟化硼酸盐([BMIM]BF4)和1-丁基-2,3-二甲基咪唑四氟化硼酸盐([BDMIM]BF4)的局部和全局活性.研究表明其缓释效率顺序为[BMIM]NO3>[BMIM]... 采用量子化学方法研究了三种离子液体1-丁基-3-甲基咪唑硝酸盐([BMIM]NO3),1-丁基-3-甲基-咪唑四氟化硼酸盐([BMIM]BF4)和1-丁基-2,3-二甲基咪唑四氟化硼酸盐([BDMIM]BF4)的局部和全局活性.研究表明其缓释效率顺序为[BMIM]NO3>[BMIM]BF4>[BDMIM]BF4,这与电化学和失重方法测试的实验结果一致.建立了离子液体的量子化学参数与其缓蚀效率之间的定量构效关系,计算结果与实验符合很好.采用分子动力学模拟方法研究了1 mol/L的盐酸溶液中三种离子液体在碳钢表面的吸附行为和缓释机理,发现三种离子液体的阳离子中的咪唑环都平行地吸附在铁表面上,阴离子NO-3与铁表面的相互作用比BF-4与铁表面相互作用强.研究结果可为今后设计和筛选绿色离子液体缓蚀剂提供理论指导. 展开更多
关键词 离子液体 缓蚀剂 量子化学计算 动力学模拟 缓蚀机理 定量构效关系
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温度对单晶镁拉伸性能影响的分子动力学研究 被引量:8
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作者 薛春 杨千华 +4 位作者 楚志兵 桂海莲 拓雷锋 高虹 沈卫强 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2021年第5期1812-1816,共5页
本研究主要运用分子动力学的模拟方法,研究了拉伸速率为10^(10)s^(-1)下温度对于单晶镁性能的影响,并对结果进行应力应变分析,势能应变分析,共近邻分析,位错密度分析等。结果表明:随着温度的升高,单晶镁的抗拉强度峰值降低,各峰值点对... 本研究主要运用分子动力学的模拟方法,研究了拉伸速率为10^(10)s^(-1)下温度对于单晶镁性能的影响,并对结果进行应力应变分析,势能应变分析,共近邻分析,位错密度分析等。结果表明:随着温度的升高,单晶镁的抗拉强度峰值降低,各峰值点对应的应变值随着温度的升高逐渐减小;在应力峰值出现前hcp首先转化成Other结构且没有位错产生,在应力峰值过后fcc,bcc结构出现,同时产生位错,其中位错主要为1/3<1100>位错和未知结构位错,对应的晶体结构的转化与位错的产生大约滞后应力峰值点0.5%的应变值,并且温度对于滞后值的影响不大,晶体结构的转化和位错的产生也随着温度的升高提前发生。 展开更多
关键词 单晶镁 分子动力学 温度 晶体结构 位错密度
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Al2O3-SiO2-CaO-FeO四元体系煤灰结构及流动性关系的实验和理论研究 被引量:10
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作者 代鑫 白进 +4 位作者 李东涛 袁苹 颜婷珪 孔令学 李文 《燃料化学学报》 EI CAS CSCD 北大核心 2019年第6期641-648,共8页
将分子动力学、热力学计算与实验结合研究了Al2O3-SiO2-CaO-FeO四元体系灰渣黏度变化机理。在Al2O3-SiO2-CaO-FeO四元体系中,钙铁质量比(简称钙铁比,下同)增加,黏度下降,黏温曲线类型由结晶渣转变为玻璃渣,钙铁比为2时为黏温特性转变的... 将分子动力学、热力学计算与实验结合研究了Al2O3-SiO2-CaO-FeO四元体系灰渣黏度变化机理。在Al2O3-SiO2-CaO-FeO四元体系中,钙铁质量比(简称钙铁比,下同)增加,黏度下降,黏温曲线类型由结晶渣转变为玻璃渣,钙铁比为2时为黏温特性转变的拐点。钙铁比小于2时,体系中的矿物质主要是结晶矿物质,体系中降温过程中生成晶体矿物较多,当钙铁比大于2时,体系以无定形矿物质为主;从微观角度分析,钙铁比增加导致体系中Al由六配位([AlO6]9-)转变为四配位([AlO4]5-),钙铁两种原子对体系中六配位铝的影响存在竞争作用。体系中的桥氧含量降低,体系的聚合程度降低,稳定性降低。通过四元体系的氧键为桥梁,建立了碱性组分含量与黏度的函数关系。 展开更多
关键词 分子动力学 热力学计算 煤灰结构 氧键类型 钙铁比
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Materials Studio软件在计算化学和计算材料学课程教学中的应用 被引量:12
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作者 许真铭 刘庆生 陈江安 《大学化学》 CAS 2024年第1期332-339,共8页
将Materials Studio软件使用引入计算化学和计算材料学等课程教学,采取“计算理论方法讲解+计算软件实践操作科研案例”模式进行高效课程教学,实现科研反哺高质量教学。让学生在软件实践操作中运用、巩固理论知识概念,实现理论方法水平... 将Materials Studio软件使用引入计算化学和计算材料学等课程教学,采取“计算理论方法讲解+计算软件实践操作科研案例”模式进行高效课程教学,实现科研反哺高质量教学。让学生在软件实践操作中运用、巩固理论知识概念,实现理论方法水平和软件操作技能的双重提升。同时使课程教学内容变得形象具体,激发学生对计算化学和计算材料学课程的学习兴趣,培养学生的科研思维和探索能力,实现教学支撑高水平科研。 展开更多
关键词 计算模拟软件 结构建模 量子化学计算 第一性原理计算 分子动力学模拟 蒙特卡洛模拟
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