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Comparison between Cooling Rate Dependence of Macroscopic and Microscopic Quantities in Simulated Aluminium Glass

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Chinese Physics Letters 2000年第11期17卷 821-823页

作者： LIU Chang-Song zhu zhen-gang Laboratory of Internal Friction and Defects in Solids Institute of Solid State PhysicsChinese Academy of SciencesHefei 230031

Constant-pressure molecular dynamics simulations and an analysis of the local atomic structures have been performed to study the cooling rate dependence of some macroscopic and microscopic quantities in aluminium *** quantities,enthalpy and density,see an observable but small dependence on the cooling *** ordering units exhibit strong cooling rate dependence,which is responsible for the dependence of the enthalpy and the density on the cooling rate;while the almost independence of some microstructural units such as the 1541,1431 and 1421 pairs of the cooling rate may lead to a small dependence of the enthalpy and the density on the cooling rate.

关键词： quantities independence enthalpy

Molecular Dynamics Simulations of Liquid Phosphorus at High Temperature and Pressure

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Communications in Theoretical Physics 2008年第5期49卷 1323-1332页

作者： WU Yan-Ning ZHAO gang LIU Chang-Song zhu zhen-gang Department of Physics Fuyang Teachers College Fuyang 236041 China Key Laboratory of Material Physics Institute of Solid State Physics Chinese Academy of Sciences PO Box 1129 Hefei 230031 China

By performing ab initio molecular dynamics simulations, we have investigated the microstructure, dynamical and electronic properties of liquid phosphorus （P） under high temperature and pressure. In our simulations, the calculated coordination number （CN） changes discontinuously with density, and seems to increase rapidly after liquid P is compressed to 2.5 g/cm3. Under compression, liquid P shows the first-order liquid-liquid phase transition from the molecular liquid composed of the tetrahedral P4 molecules to complex polymeric form with three-dimensional network structure, accompanied by the nonmetal to metal transition of the electronic structure. The order parameters Q6 and Q4 are sensitive to the microstructural change of liquid P. By calculating diffusion coefficients, we show the dynamical anomaly of liquid P by compression. At lower temperatures, a maximum exists at the diffusion coefficients as a function of density; at higher temperatures, the anomalous behavior is weakened. The excess entropy shows the same phenomena as the diffusion coefficients. By analysis of the angle distribution functions and angular limited triplet correlation functions, we can clearly find that the Peierls distortion in polymeric form of liquid P is reduced by further compression.

关键词： liquid structure ab initio molecular dynamics Peierls distortion

Final Structures of Crystallization of Liquid Copper Studied by Molecular Dynamics Simulation

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Chinese Physics Letters 1999年第11期16卷 850-852页

作者： XIA Jun-chao zhu zhen-gang LIU Chang-song Laboratory of Internal Friction and Defects in Solids Institute of Solid State PhysicsChinese Academy of SciencesHefei 230031

Molecular dynamics simulation is performed to study the cooling rate effects on the resulting crystallization microstructure of bulk liquid copper(homogeneous nucleation).Our studies reveal that mixtures of the metastable hcp phase and most-stable fcc phase,in all sorts of proportion and in various forms such as layering and phase separation,can be obtained by controlling the cooling *** have also found that,below the glass forming critical cooling rate,the ratio of the number of fcc-type polyhedra to the number of hcp-type polyhedra at 0K decreases with increase of the cooling rate.

关键词： microstructure Molecular Copper

Nonlinear Internal Friction Character of Foamed Aluminum

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Chinese Physics Letters 1998年第1期15卷 52-53页

作者： HAN Fu-sheng zhu zhen-gang WANG Shan-ying LIU Chang-song Institute of Solid State Physics Chinese Academy of SciencesHefei 230031

An experiment has been carried out to investigate the damping behavior of foamed *** was found that foamed aluminum has a significant nonlinear internal friction character,i.e.,its damping capacity is amplitude-depend... 详细信息

关键词： aluminum friction character

Turing Patterns in a Reaction-Diffusion System

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Communications in Theoretical Physics 2006年第4期45卷 761-764页

作者： WU Yan-Ning WANG Ping-Jian HOU Chun-Ju LIU Chang-Song zhu zhen-gang Key Laboratory of Material Physics Institute of Solid State Physics the Chinese Academy of Sciences P.O. Box 1129 Hefei 230031 China

We have further investigated Turing patterns in a reaction-diffusion system by theoretical analysis and numerical simulations. Simple Turing patterns and complex superlattice structures are observed. We find that the shape and type of Turing patterns depend on dynamical parameters and external periodic forcing, and is independent of effective diffusivity rate σ in the Lengyel Epstein model Our numerical results provide additional insight into understanding the mechanism of development of Turing patterns and predicting new pattern formations.

关键词： Turing pattern Lengyel-Epstein (LE) model

Diflferent Cooling Rate Dependences of Different Microstructure Units in Aluminium Glass by Molecular Dynamics Simulation

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Chinese Physics Letters 2000年第1期17卷 34-36页

作者： LIU Chang-Song zhu zhen-gang XIA Jun-Chao SUN De-Yan Laboratory of Internal Friction and Defects in Solids Institute of Solid State PhysicsChinese Academy of SciencesHefei 230031

Constant-pressure molecular dynamics simulation and the pair analysis technique have been performed to study the microstructural evolution of aluminium during rapid *** microstructure characteristics of icosahedral ordering increase with decrease of the cooling rate,whereas the microstructure unit characteristics of hep crystalline structure *** are two kinds of microstructure units which are similar to those in the fee crystal containing *** two kinds of microscopic units are nearly independent of the cooling *** microscopic structural unit characteristics of fee crystalline structure do not depend on the cooling rate *** results may help us understand the microstructure of glass and its stability.

关键词： stability. crystalline Microstructure

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不同一级相变材料的内耗峰形成机制

上海交通大学学报 2010年第5期44卷 650-654页

作者：杨开巍水嘉鹏朱震刚中南大学物理科学与技术学院长沙410083 中国科学院固体物理研究所合肥230031

试验研究了3种一级相变材料的相变过程,即非晶PdNiCuP的晶化与无序和有序型相变、形状记忆合金Cu-11.9Al-2.5Mn的无扩散位移型相变以及共析合金Zn-22Al的共析相变,设计并测量了3种材料的电阻和内耗,并采用插值法获得不同温度下内耗与频... 详细信息

试验研究了3种一级相变材料的相变过程,即非晶PdNiCuP的晶化与无序和有序型相变、形状记忆合金Cu-11.9Al-2.5Mn的无扩散位移型相变以及共析合金Zn-22Al的共析相变,设计并测量了3种材料的电阻和内耗,并采用插值法获得不同温度下内耗与频率的关系曲线.结果表明,3种材料的相变内耗峰不是弛豫型内耗峰,而是弛豫参数发生突变的结果,相变内耗峰高度与频率的关系是弛豫的表现.在低温区域,观测到其相变内耗峰的结构弛豫现象,并可用结构失稳和结构弛豫的概念定性解释升温速率对相变内耗峰高度的影响.

关键词：内耗约化电阻率一级固态相变

越婢加半夏汤对老年社区获得性肺炎痰热壅肺证及对炎性标志物预后的影响

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中国实验方剂学杂志 2020年第22期26卷 59-64页

作者：狄冠麟朱振刚郑延龙天津中医药大学第一附属医院天津300380

目的:观察越婢加半夏汤加减治疗痰热壅肺型老年社区获得性肺炎(CAP)的疗效及对炎性标志物和预后的影响。方法:采用随机按数字表法,以1∶1将120例符合要求的患者分为对照组和观察组60例;除脱落、失访和剔除,对照组和观察组最终均完成55... 详细信息

目的:观察越婢加半夏汤加减治疗痰热壅肺型老年社区获得性肺炎(CAP)的疗效及对炎性标志物和预后的影响。方法:采用随机按数字表法,以1∶1将120例符合要求的患者分为对照组和观察组60例;除脱落、失访和剔除,对照组和观察组最终均完成55例观察。两组均给予抗感染等综合治疗。对照组口服肺力咳合剂,20 mL/次,3次/d;观察组采用越婢加半夏汤加减内服,每天1剂;两组疗程均为10 d。记录退热时间和第5天的退热率,记录咳嗽、咯痰和肺部啰音缓解时间;进行临床肺部感染评分(CPSI)评分,记录CPSI<6分的时间,即停用抗生素时间;进行治疗前后痰热壅肺证评分;记录初始治疗失败情况;检测降钙素原(PCT)hs-CRP,红细胞体积分布宽度(RDW),D-二聚体(D-D)和合肽素水平等预后标志物,检测肿瘤坏死因子-α(TNF-α),白细胞介素-1β(IL-1β),IL-6和超敏C反应蛋白(hs-CRP)等炎性标志物水平;记录胸片复常率;进行安全性评价。结果:观察组患者主要症状、体征病程(退热,咳嗽缓解、咯痰缓解及肺部啰音缓解)时间均短于对照组(P<0.01);观察组第5天退热率为85.45%(47/55),停用抗生素率为94.55%(52/55),胸片复常率为90.91%(50/55),分别高于对照组的65.45%(36/55),81.82%(45/55),74.55%(45/55),组间差异均有统计学意义(P<0.05);观察组和对照组的初始治疗失败率分别为5.54%(3/55),20.00%(11/55),观察组低于对照组(P<0.05);观察组CPSI和痰热壅肺证评分均低于对照组(P<0.01);观察组PCT,RDW,D-D和合肽素水平均低于对照组(P<0.01);观察组患者hs-CRP,TNF-α,IL-1β和IL-6水平均低于对照组(P<0.01);观察组中医证候疗效总有效率为96.36%(53/55),高于对照组的83.64%(46/55)(χ2=4.949,P<0.05);该研究未发现与服用中药相关不良反应。结论:在抗感染等综合治疗的基础上,给予越婢加半夏汤加减内服治疗痰热壅肺型CAP患者,减轻了临床症状,改善了肺部感染和病情程度,控制了炎症反应,改善了预后,中医证候疗效显著,且临床使用安全。

关键词：社区获得性肺炎老年痰热壅肺证越婢加半夏汤炎性标志物预后

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Zn-Al二元合金熔化过程的低频内耗研究

物理学报 2002年第3期51卷 625-628页

作者：陈刚朱震刚江苏理工大学材料科学与工程学院中国科学院固体物理研究所内耗与固体缺陷开放研究实验室合肥230031 中国科学院固体物理研究所内耗与固体缺陷开放研究实验室

利用强迫振动扭摆方法对Zn Al二元合金熔化过程的低频内耗进行了研究 .结果表明 ,Zn Al二元合金熔化过程的内耗峰与其固态相变内耗峰的特征有较大差异 .结合该合金熔化过程的微观结构变化 ,初步分析了内耗峰的形成机理 .

关键词： Zn-Al合金低频内耗熔化锌铝二元合金内耗峰微观结构