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Nd_2Fe_(14)B/α-Fe纳米晶复合永磁材料的计算机模拟研究

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稀土 2002年第5期23卷 65-68页

作者：张静贤张同俊崔山昆华中科技大学模具技术国家实验室湖北武汉430074

采用计算机模拟的方法计算了 Nd2 Fe1 4B/α- Fe纳米晶复合永磁材料的磁性能 ,并对软磁相比例及不规则晶粒对磁性能的影响进行了研究。结果显示 ,当软磁相比例增加时 ,由于软磁相高的饱和磁极化强度以及软硬磁相间的交换耦合作用的影响 ... 详细信息

采用计算机模拟的方法计算了 Nd2 Fe1 4B/α- Fe纳米晶复合永磁材料的磁性能 ,并对软磁相比例及不规则晶粒对磁性能的影响进行了研究。结果显示 ,当软磁相比例增加时 ,由于软磁相高的饱和磁极化强度以及软硬磁相间的交换耦合作用的影响 ,剩磁逐渐增加 ,但矫顽力则随着软磁相的增加而逐渐下降。不规则晶粒对磁体的剩磁基本没有影响 ,但降低矫顽力。

关键词： Nd2Fe14B/α-Fe 纳米晶复合永磁材料计算机模拟剩磁增强矫顽力不规则晶粒模型钕铁硼铁

Modification of Fe_3O_4 magnetic Nanoparticles by L-dopa or Dopamine as an Enzyme Support

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Journal of Wuhan university of Technology(materials Science) 2008年第4期23卷 480-485页

作者： PENG Hong ZHANG Xiao HUANG Kaixun XU Huibi Department of Chemistry Huazhong University of Science and Technology Wuhan 430074 China

Fe3O4 magnetic nanoparticles were prepared by co-precipitation of Fe^2＋ and Fe^3＋ in an ammonia solution, and its size was about 36 nm measured by an atomic force microscope. Fe3O4 magnetic nanoparticles were modified by L-dopa or dopamine using sonication method. The analysis of FTIR clearly indicated the formation of Fe-O-C bond. Direct immobilization of trypsin （EC： 3.***.21.4） on Fe3O4 magnetic nanoparticles with L-dopa and dopamine spacer was investigated using glutaraldehyde as a coupling agent. No significant changes in the size and magnetic property of the three kinds of magnetic nanoparticles linked with or without trypsin were observed. The existence of the spacer molecule on magnetic nanoparticles could greatly improve the activity and the storage stability of bound trypsin through increasing the flexibility of enzyme and changing the microenvironment on nanoparticles surface compared to the naked magnetic nanoparticles.

关键词： Fe3O4 magnetic nanoparticles modification trypsin immobilization L-dopa dopamine

Optical and magnetic Properties of Fe_2O_3/SiO_2 Nano-composite Films

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Journal of Wuhan university of Technology(materials Science) 2010年第2期25卷 206-209页

作者：关飞飞姚兰芳 College of Science University of Shanghai for Science and Technology

Fe2O3/SiO2 nano-composite films were prepared by sol-gel technique combining heat treatment in the range of 100-900 ℃. The particle size was observed by FE-SEM. Optical properties of the films were investigated by UV-visible spectra. Structural and magnetic characteristics were investigated through FT-IR and VSM. The transparency of the Fe2O3/SiO2 nano-composite films decreased with the content of the Fe2O3. Water and organic solvent in the films were evaporated with heat treatment, so the transparency of the films was enhanced under high temperature. It is also found that the saturation magnetization （Ms） of the films increases with the temperature. As the content of the Fe2O3 increases, when the content of the Fe2O3 is around 30wt%, the Ms of the films has a maximum value.

关键词： sol-gel technique Fe2O3/SiO2 nano-composite films magnetism

Colossal magnetoresistance and spin-glass properties of La(1-x)TexMnO3(x=0.04,0.1)

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Chinese Science Bulletin 2003年第13期48卷 1321-1324页

作者： TAN Guotai, DUAN Peng, DAI Shouyu, CHEN Zhenghao, LU Huibin & ZHOU Yueliang laboratory of Optical Physics, Institute of Physics & Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, china Correspondence should be addressed to Chen Zhenghao (e-mail: zhchen @***) laboratory of Optical Physics Center for Condensed Matter Physics Chinese Academy of Sciences Beijing 100080 China

For the first time, a novel material of La1-x- TexMnO3 (x = 0.04, 0.1), in which the La ions are replaced by the nonmetal element Te in the Chalcogen, has been synthesized. The material has a rhombohedral lattice with the space group of R3c, and Te ions have a tetravalence state. The curves of the resistivity vs. temperature indicate that this material has the property of a metal-semiconductor transition and the colossal magnetoresistance (CMR) effect. The maximum magnetoreistance ratio MR=[(0)()]/(0)H? is about 51% at 4 T for x = 0.1. Besides, a spin-glass behavior at low magnetic fields is observed in this compound.

关键词：巨磁电阻 La1-xTexMnO3 镧碲物理性质

THE GRAIN SIZE EFFECT ON DIELECTRIC PROPERTIES OFBATIO3 BASED CERAMICS

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THE GRAIN SIZE EFFECT ON DIELECTRIC PROPERTIES OFBATIO3 BASE...

Preparation,structural and optical characterizations of Bi2O3-SiO2 based glasses

第8届国际材联电子材料国际研讨会

作者： Xiao-Hui Wang Ren-Zheng Chen Zhi-Lun Gui Long-Tu LiState key Lab of New Ceramic and Fine Processing Dept. of materials Sci. and Eng.Beijing 100084 P. R. china

＜正＞ Barium titanate as dielectric material for X7R-type service finds extensive use in electric equipment for data processing, military applications, automotive applications, telecommunications and other applications in which the materials is subjected to substantial changes in temperature, frequency and voltages. With the recent tendency in miniaturization of electronic equipment, electric components are required to have a high

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Preparation,structural and optical characterizations of Bi2O...

Giant Magneto-Impedance Effect in Fe_(96-x)B_4 (x=7 or 10) Nanocrystalline Ribbons

第十六届全国光散射学术会议

作者： Chen-Yang Wang,Guan-Qin Hu,Hao-Hong Chen,Jing-Tai Zhao~* (key laboratory of Transparent Opto-Functional Inorganic materials of Chinese Academy of Sciences,Shanghai Institute of Ceramics,1295 Ding Xi Road,Shanghai 200050)

＜正＞Bismuth silicate glasses have been prepared by modified melt-quench *** changes of the prepared Bi2O3-SiO2 glasses were studied by Raman spectroscopy at different temperatures and XRD. A broad but strong band centered at about 140 cm-1 are observed on all the Raman spectra recorded at -190℃and 600℃（Fig.1）,and these peaks can be assigned to the Bi-O-Bi vibration of[BiO6]octahedral *** weak band at 400 cm-1 can be assigned to vibration of heavy metal Bi3+ *** the

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Journal of materials Science & Technology 2000年第2期16卷 148-150页

作者： Zhichao LU and Wei HAN (National Amorphous and Nanocrystalline Alloy Engineering Research Center, Center Iron and Steel Research Institute, Beijing 100081, china) Deren LI (Department of Physics, Northeastern university, Shenyang 110006, china)

The total ribbon voltage of as-quenched and annealed Fe96-xZr_xB_4 (x=7 or 10) ribbons has been measured as a function of applied dc field and drive current frequency. The experimental results show that both samples exist the optimum annealing temperature and optimum frequency at which the relative change in ribbon voltage is strongest, and the sensitivity of the magnetic response of the annealed Fe_89Zr_7B_4 ribbon is two order of magnitude larger than that of the annealed Fe_86Zr_10 B4 ribbon. The effect of magnetic properties and structural characteristics on giant magneto-impedance was discussed.

关键词： Giant Magneto-Impedance Effect in Fe x=7 or 10 x)B4 x Nanocrystalline Ribbons GMI

La-Y对纳米级W-Ni-Fe复合粉末制备的影响

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中国稀土学报 2004年第4期22卷 463-466页

作者：马运柱黄伯云范景莲熊翔魏定池汪登龙中南大学粉末冶金国家重点实验室湖南长沙410083

以喷雾干燥法制备的(W,Ni,Fe)复合氧化物粉末为原料,采用700℃,保温90min的条件进行还原,研究了La-Y含量对还原制备纳米级W—Ni—Fe复合粉末特性的影响;采用XRD及高倍SEM分别对所制备的复合粉末进行了物相分析、晶粒尺寸测试和形貌观察... 详细信息

以喷雾干燥法制备的(W,Ni,Fe)复合氧化物粉末为原料,采用700℃,保温90min的条件进行还原,研究了La-Y含量对还原制备纳米级W—Ni—Fe复合粉末特性的影响;采用XRD及高倍SEM分别对所制备的复合粉末进行了物相分析、晶粒尺寸测试和形貌观察;并对所制得复合粉末的Fsss粒度、比表面进行了测定与分析。研究结果表明:不加La-Y时还原粉末由W和γ-(Ni,Fe)两相组成,添加一定量La—Y的还原粉末有W,γ-(Ni,Fe),Y(Ni0.75W0.25)O3和La(Ni0.75W0.25)O3四相组成;当La.Y的质量分数在0～0.8％范围时(占90W-7Ni-3Fe复合粉末的质量分数),随着La—Y含量的增加,粉末dBET粒度由96.6降到50.3 nm,粉末Fsss粒度由0.64降到0.33 μm,粉末晶粒尺寸由26.1降到22.2 nm;未添加La-Y时粉末颗粒为球形,添加一定量的La-Y,粉末颗粒变为近球形或多面体;添加一定量的La—Y不仅可以有效地抑制晶粒长大,还可以在一定程度上提高粉末的分散性。

关键词：材料学 W-Ni-Fe复合粉末纳米级粉末氢还原稀土

Study on Decay Resistance Performance of CuAz Preservative for Bamboo

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Chinese Forestry Science and Technology 2008年第4期7卷 28-32页

作者： WANG Yamei1 WANG Ximing1 LIU Junliang2 1. College of Material science and Art Design, Inner Mongolia Agricultural university, Huhehaote 010018,P.R.china 2. Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, P. R. china

Blocks of Moso bamboo were used as experimental materials to test the toxicity of CuAz preservative on decay fungi by the lab test in this paper. The result showed that the natural decay resistance of 4-year-old Mao bamboo is moderate, and the resistance to brown fungi is stronger than that to white fungi. The anti-fungi properties of CuAz preservative at the retention of 3.3 kg/m3 are equal to those of CCA-C and ACQ-B at the retention of about 4.0 kg/m3 , and obviously superior to those of organic acids preservatives.

关键词： Moso bamboo (Phyllostachys pubescens) CuAz decay resistance accelerated test fungus