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Vacancies and Antisites in B2 FeAl and DO_3 Fe_3Al with a Modified Analytic EAM Model

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Journal of materials Science & Technology 2001年第6期17卷 601-604页

作者： Xiaolin SHU, Wan gyu HU, Hanning XIAO and Huiqiu DENG College of materials Science and Engineering, Hunan University, Changsha 410082, china Ban gwei ZHANG international centre of materials physics, Chinese Academy of Sciences, S Hunan Univ Coll Mat Sci & Engn Changsha 410082 Peoples R China Chinese Acad Sci Int Ctr Mat Phys Shenyang 110016 Peoples R China

A simple modified analytic EAM model for bcc Fe and fcc Al was used to calculate the lattice constant and elastic constants of B2 FeAl and DO3 Fe3Al alloys. The formation energies of ... 详细信息

A simple modified analytic EAM model for bcc Fe and fcc Al was used to calculate the lattice constant and elastic constants of B2 FeAl and DO3 Fe3Al alloys. The formation energies of vacancy and antisite were also calculated. The present calculations are in agreement with the experimental data and the theoretical results obtained by other authors.

关键词： Al DO Fe Vacancies and Antisites in B2 FeAl and DO3 Fe3Al with a Modified Analytic EAM Model EAM

金属中晶界的原子密度分布与其正电子湮没寿命谱特征

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高能物理与核物理 1989年第10期13卷 879-885页

作者：谌季强龙期威周瑾汪克林中国科学技术大学基础物理中心中国科学院金属研究所

在一简单晶界模型的基础之上,求解纯A1晶界的正电子捕获态和计算相应的寿命谱,由此讨论了晶界原子密度分布与寿命谱之间的关联,并尝试对已有的实验结果进行理论上的解释.

关键词：金属晶界原子密度正电子湮没

Gasflow style level posture sensor and angular velocity gyroscope assembled inertial sensor

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Progress in Natural Science:materials international 2007年第8期17卷 971-978页

作者： Zhang Fuxue~(**) Mao Xu (research centre of Sensor Technology,Beijing Information Technology institute,Beijing 100101,china) [a]research centre of Sensor Technology Beijing Information Technology Institute Beijing China

The compensational loop consisting of a gasflow style angular velocity gyroscope and gasflow level posture sensor is pro- posed to improve the signal of gasflow style *** compensational loop could remove acceleration interfere from the signal of *** assembled gasflow type inertial sensor not only measures static state angular,but also restrains the acceleration which interferes the output signal of level posture sensor in dynamic ***,the precision of outputs signal increases ***,the output sig- nal includes the angle velocity signal.

关键词： gasflow style inertia sensor

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电磁场曝露对生物组织电磁特性的影响

生物化学与生物物理进展 2011年第7期38卷 604-610页

作者：李滚庞小峰电子科技大学生命科学与技术学院生物物理与生物电子学实验室成都610054 中国科学院国际材料物理中心沈阳110015

电磁辐射严重影响着人体的健康.电磁场生物效应的发生机制与电磁场本身的特性相关,同时也与生物组织在电磁场作用下电磁特性的改变密切相关.生物体内的信号分子、自由基以及磁颗粒等处于外加电磁场中时其电磁特性会发生变化,尤其是不同... 详细信息

电磁辐射严重影响着人体的健康.电磁场生物效应的发生机制与电磁场本身的特性相关,同时也与生物组织在电磁场作用下电磁特性的改变密切相关.生物体内的信号分子、自由基以及磁颗粒等处于外加电磁场中时其电磁特性会发生变化,尤其是不同频率电磁场曝露作用下生物组织的导电、介电以及磁学等特性会有非常显著的区别.明确不同频率电磁场作用下生物组织电磁特性的变化规律是研究电磁场生物效应发生机制以及预防问题的关键.综述了近年来电磁场对于生物组织电磁特性影响的研究成果,并对未来的研究方向做了展望.

关键词：电磁辐射生物效应生物组织电磁特性

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液滴和液面碰撞

力学学报 1989年第3期21卷 273-279页

作者：蔡一坤北京大学物理系

本文记述有关液滴向液面碰撞实验(速度范围是0至600cm/s)的三种现象:在碰撞速度为0至lOOcm/s范围内观察到两类现象,其共同的特点是水面几乎没有扰动,即没有溅起水花或明显凹坑,在本文中分别简称为“穿入”和“劈裂”。当碰撞速度增至lOO... 详细信息

本文记述有关液滴向液面碰撞实验(速度范围是0至600cm/s)的三种现象:在碰撞速度为0至lOOcm/s范围内观察到两类现象,其共同的特点是水面几乎没有扰动,即没有溅起水花或明显凹坑,在本文中分别简称为“穿入”和“劈裂”。当碰撞速度增至lOOcm/s时,出现了第三种现象(飞溅),我们测量了飞溅现象中产生凹坑直径、凹坑深度、形成最大凹坑的时间和中心柱开始回弹的时间,测量了这些量随落滴高度变化的实验曲线。

关键词：水滴液面碰撞液滴飞溅

Synthesis and characterization of nanocrystalline Ni produced by cryomilling in liquid nitrogen

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Rare metals 2007年第2期26卷 147-151页

作者： YANG Bin FAN Jianzhong HAO Bin TIAN Xiaofeng CHENG Junsheng ZHANG Jishan State Key Laboratory for Advanced metals and materials University of Science and Technology Beijing Beijing 100083 China international centre for materials physics Chinese Academy of Sciences Shenyang 110016 China National Engineering and Technology research Center for Nonferrous metals Composites General Research Institute for Nonferrous Metals Beijing 100088 China

NanocrystaUine Ni powders were successfully fabricated by mechanically milling at cryogenic temperature （cryomilling） with 1 wt.%Y2O3 particles. The experimental results have shown that the Ni grain size is reduced to 25 nm after 2 h of cryomilling in the presence of the Y2O3 particles. The cryomiUed Ni/Y2O3 powders can maintain their nanocrystalline structure up to 900℃, or 62% of the melting point of Ni. A bulk nanocrystalline Ni/Y2O3 material with a thermally stable grain size of approximately 100 nm was produced by cryomilling, cold isostatic pressing, followed by hot isostatic pressing. The microhardness of bulk nanocrystalline Ni/1wt.%Y2O3 is 315 DPH, which is two times as high as that of conventional Ni.

关键词： nanocrystalline mechanical milling nickel characterization

Genetic and logic networks with the signal-inhibitor-activator structure are dynamically robust

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Progress in Natural Science:materials international 2006年第12期16卷 1329-1336页

作者： LI Fangting** and TAN Ning(School of physics and centre for Theoretical Biology, Peking University, Beijing 100871, china) [a]School of physics and centre for Theoritical Biology Peking University Beijing China

The proteins, DNA and RNA interaction networks govern various biological functions in living cells, these networks should be dynamically robust in the intracellular and environmental fluctuations. Here, we use Boolean network to study the robust structure of both genetic and logic networks. First, SOS network in bacteria E. coli, which regulates cell survival and repair after DNA damage, is shown to be dynamically robust. Comparing with cell cycle network in budding yeast and flagella network in E. coli, we find the signal-inhibitor-activator (SIA) structure in transcription regulatory networks. Second, under the dynamical rule that inhibition is much stronger than activation, we have searched 3-node non-self-loop logical networks that are dynamically robust, and that if the attractive basin of a final attractor is as large as seven, and the final attractor has only one active node, then the active node acts as inhibitor, and the SIA and signal-inhibitor (SI) structures are fundamental architectures of robust networks. SIA and SI networks with dynamic robustness against environment uncertainties may be selected and maintained over the course of evolution, rather than blind trial-error testing and being an accidental consequence of particular evolutionary history. SIA network can perform a more complex process than SI network, and SIA might be used to design robust artificial genetic network. Our results provide dynamical support for why the inhibitors and SIA/SI structures are frequently employed in cellular regulatory networks.

关键词： genetic network signal-inhibitor-activator (SIA) structure Boolean network model dynamical robust.

First-principles study of the effects of Si doping on geometric and electronic structure of closed carbon nanotube

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Science Bulletin 2005年第17期 9-14页

作者： zhou Junzhe1 & WANG Chongyu1, 2 1. Department of physics, Tsinghua University, Beijing 100084, china 2. international centre for materials physics, Chinese Academy of Sci-ences, shenyang 110016, china

The effects of Si doping on geometric and elec-tronic structure of closed carbon nanotube (CNT) are stud-ied by, a first-principles method, DMol. It is found that the local density of states at the Fermi level (EF) increases due to the Si-doping and the non-occupied states above the EF go down toward the lower energy range under an external elec-tronic field. In addition, due to the doping of Si, a sub-tip on the CNT cap is formed, which consisted of the Si atom and its neighbor C atoms. From these results it is concluded that Si-doping is beneficial to the CNT field emission properties.

关键词： carbon nanotube doping electronic structure field emission.

Nonmetal-metal Transition in Solutions of metals in Molten Salts

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Journal of materials Science & Technology 1998年第1期14卷 1-8页

作者： M. P. Tosi(international centre for Theoretical physics, Strada Costiera 11, I-34014 Trieste, Italy) Int Ctr Theoret Phys I-34014 Trieste Italy Scuola Normale Super Pisa Ist Nazl Fis Mat & Classe Sci I-56126 Pisa Italy

Solutions of metals in molten salts present a rich phenomenology: localisatlon of electrons in disordered ionic media, activated electron transport increasing with metal concentration towards a nonmetal-metal (NM-M) transition, and liquid-liquid phase separation. A brief review of progress in the study of these systems is given in this article, with main focus on the NM-M transition. After recalling the known NM-M behaviour of the component elements in the case of expanded fluid alkali metals and mercury and of solid halogens under pressure, the article focuses on liquid metal-molten salt solutions and traces the different NM-M behaviours of the alkalis in their halides and of metals added to polyvalent metal halides.

关键词： Rev nm Nonmetal-metal Transition in Solutions of metals in Molten Salts Cl NaF