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Beam breakup simulation study for a high energy ERL

CHEN Si , M.Shimada , N.Nakamura , HUANG Sen-Lin , LIU Ke-Xin , CHEN Jia-Er

中国物理C doi:10.1088/1674-1137/39/1/017006

关键词:

Chen系统的状态变量周期性反馈控制

李开明 , 李亚洲 , 冯维贵 , 林长

量子电子学报 doi:10.3969/j.issn.1007-5461.2007.05.014

采用非线性反馈控制,用附加了带参数的正弦项对Chen系统进行了有效的控制.随着参数k的逐渐增大,系统的动力学行为呈现出一系列的变化.数值研究结果表明:随控制参数的增大,驱动信号的强度渐大,混沌系统由混沌运动到周期轨道,最终到一相点.

关键词: 混沌 , Chen系统 , 不动点 , Lyapunov指数 , 反馈控制

ER Smart Fluids: Properties and Applications

Yanju LIU , Jinsong LENG and Dianfu WANG(Research Lab. of Composite Materials , Harbin Institute of Technology , Harbin 150001 , China)

材料科学技术（英文）

ER fluid is one of the popular materials used in smart materials and structures (SMS). In thispaper, several ER fluids were synthesized. The static and dynamic mechanic characteristics weremeasured and discussed. The application of ER fluid on a sandwich beam featuring ER fluidapplied to vibration control was investigated.

关键词:

Luminescence and Thermal Properties of Er:GSGG and Yb,Er:GSGG Laser Crystals

Chinese Physics Letters

Er3+-doped and Yb3+/Er3+ co-doped Gd3Sc2Ga3O12 (abbreviated as Er:GSGG and Yb,Er:GSGG, respectively) laser crystals are investigated by using a combination of spectroscopic measurements and thermal characterizations. An absorption peak of Yb, Er: GSGG crystal shifts to 970 nm and its absorption band broadens obviously, which makes the crystal suitable for pumping by a 970 nm laser diode (LD). This crystal also exhibits a shorter lifetime of a lower laser level, a larger emission cross section and higher thermal conductivity than those of Er: GSGG. All these factors suggest that Yb3+/Er3+ co-doping has a positive effect on improving the spectroscopic and thermal performances in GSGG based laser crystals, and imply that double-doped Yb, Er: GSGG crystal is a potential candidate as an excellent LD pumped 2.79 mu m laser material.

关键词: mu-m;energy-transfer;gsgg laser;er3+;yag;irradiation;absorption;spectra;ysgg;yb3+

REINVESTIGATION OF THE ER-CO BINARY-SYSTEM

Zeitschrift Fur Metallkunde

A systematic reexamination of the Er - Co system was carried out by differential thermal analysis, optical microscopy, X-ray diffraction and EPMA techniques. A revised Er - Co binary phase diagram is proposed. This binary system consists of four peritectic reactions, three reactions of congruent melting and a eutectoidal reaction. The four peritectic reactions result in the formation of Er3Co, ErCo2, Er2Co7 and ErCo5, respectively. The three congruent reactions involve the formation of almost-equal-to Er16Co9, ErCo3 and Er2Co17. The eutectoidal reaction involves the decomposition of ErCo5 into Er2Co7 and Er2Co17. There are also four eutectic reactions in this system. The solid solubility of Er in Co is extremely small.

关键词: intermetallic compounds

Al-Zn-Mg-Cu-Li-Er合金时效组织中Er相的TEM观察

赵中魁 , 周铁涛 , 刘培英 , 陈昌麒

稀有金属材料与工程

采用TEM对5.6%Zn,1.9%Mg,1.6%Cu,1.0%Li,0.3%Er(质量分数)合金中的Er相进行研究,发现Er在合金中主要以AEr形式存在,Al3Er在合金中的形状为块状、点状、片状或蠕虫状,部分Al3Er与铝合金基体共格.细小的Al3Er可作为η相异质形核的核心.Er在合金的晶界有很大的偏析,而且晶界处Al3Er的存在,使该处晶界析出物不连续.

关键词: Er , AEr , 晶界

An effect of Si nanoparticles on enhancing Er3+ electroluminescence in Si-rich SiO2 : Er films

Solid State Communications

Er-doped Si-rich SiO2 (SRSO:Er) films have been deposited on n(+)-Si substrates by the magnetron sputtering technique, and both photoluminescence (PL) and electroluminescence (EL) at 1.54 mum have been observed from the films at room temperature. Dependence of pi, and EL intensities on the excess-Si content and annealing temperature has been studied. It is found that proper Si content and annealing temperature can evidently enhance EL intensity. An SRSO:Er film with 20% excess Si (area ratio of the Si target to the whole target) had more intense EL than a SiO2:Er film without excess Si, both annealed at 800 degreesC, by a factor of 5. This fact clearly demonstrates that energy coupling between Si nanometer particles and Er3+ ions also exists in the EL process as well as in the PL process. Experimental results also indicate that crystallization is not a prerequisite for NSPs enhancing luminescence in SRSO:Er films. The PL and EL spectra of the SRSO:Er films have much broader full widths at half maximum (FWHM, similar to 60 nm) than those of the other Er-doped materials reported. This wide FWHM can perhaps be used in wavelength division multiplexing in optical communication in future. (C) 2001 Elsevier Science Ltd. All rights reserved.

关键词: thin films;nanostructures;recombination and trapping;luminescence;molecular-beam epitaxy;oxygen-doped silicon;erbium;nanocrystals;light;oxide

Al-Er合金中Al3Er相的形成及演化

朱世旦 , 黄晖 , 聂祚仁 , 文胜平 , 张志军

稀有金属 doi:10.3969/j.issn.0258-7076.2009.02.006

采用金属型水冷模铸造制备了不同含铒量的Al-Er二元合金,通过对铸态及均匀化处理后实验合金的金相观察、电子探针(EPMA)以及透射电镜分析,研究了对不同含量的Er在AI-Er合金中的存在形式及固溶Er在纯铝中的固溶度.结果表明,在本实验条件下铒元素以过饱和固溶体形式存在于α-Al中和以Al3Er化合物的形式分布在晶界上,另外Er在铝基体的最大固溶度为O.1%(质量分数).

关键词: 铝铒合金 , 固溶度 , EPMA , Al3Er相

Al-5Mg-Er合金中Al3Er相的析出及其热力学计算分析

余胜文 , 王为 , 杨军军 , 邹景霞 , 聂祚仁

中国稀土学报

通过应用Miedema热力学模型方法对添加了微量Er的Al-5Mg合金中的Er的存在形式进行了初步的分析,并结合XRD,TEM试验进行了验证.微量Er在Al-5Mg合金中主要是以Al3Er的形式存在,并且不会出现元素Mg与Er之间的金属间化合物;同时通过XRD和TEM分析证实,含微量Er(0.1%～0.7%)的Al-5Mg合金中Er是以Al3Er相存在并且弥散分布,讨论了Al3Er相与Al基体之间的取向关系,分析了Al3Er相的存在能够改善Al-5Mg合金材料的机械性能.

关键词: Er , Al3Er , Al-Mg合金 , 热力学计算 , 稀土