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1、本科毕业设计（论文）外文翻译- 1 浙江师范大学生化学院本科毕业设计(论文 )外文翻译译文1 -Fe-Fe3B-Y2O3纳米复合材料在千兆赫范围内的电磁微波吸收性能刘九荣a、伊藤正博a、Ken-ichi Machidaaa大阪大学尖端科学技术合作研究中心吹田市 , 大阪 565-0871,日本接到于 2003 年 2 月 24 日， 2003 年 9 月 8 日录用摘要 :-Fe-Fe3B-Y2O3 纳米复合材料采用熔体纺技术研发，其电磁微波吸收性能在0.05-20.05 GHz 范围内。与-Fe/Y2O3复合物相比，-Fe-Fe3B-Y2O3的共振频率转移到一个较高的频率范围，这归因于四方
2、-Fe3B的大各向异性场HA（ 0.4 MA/m ） 。其相对介电常数（ rrrj）一直在低于 0.5-10 GHz 的地区，这表明复合粉体具有高电阻率（100m） 。含质量分数 80 %，厚度 6-3 mm 的-Fe-Fe3B-Y2O3粉末的树脂复合材料分别在2.7-6.5 GHz 频率范围内获得有效的电磁微波吸收（反射损耗99%） 中制备 Ba3Co1.8Fe23.6Cr0.6O41。 通过在乙烷中将 Ba3Co1.8Fe23.6Cr0.6O41（-20 dB） 。 r值在 0.1-18 GHz范围随着频率迅速从5.4 减少到 0.5。此外， r本科毕业设计（论文）外文翻译- 12 值也随
3、着频率从 1.5 减少到 0.3，其 0.1-18 GHz 内没有呈现铁磁共振峰（图2） ，虽然，相对介电常数（ rrrj）在 2-18 GHz范围保持几乎不变 （ r=17， r=1.5） 。 但是，-Fe/Ba3Co1.8Fe23.6Cr0.6O41树脂复合材料的一个铁磁共振峰在4-18GHz 范围被观察到（图 2（c） ） 。早期的结果表明，在Ba3Co1.8Fe23.6Cr0.6O41添加-Fe粉末形成纳米复合材料对减少涡流损耗具有显著影响。总之，通过将-Fe 和 Ba3Co1.8Fe23.6Cr0.6O41进行球磨，已经分别制备了-Fe/Ba3Co1.8Fe23.6Cr0.6O41（
4、38，70 或 85 vol%-Fe）纳 米复合 材 料，其中Ba3Co1.8Fe23.6Cr0.6O41具 有 磁 体 和 绝 缘 体 压 制 的 涡 流 损 耗 的 双 重 作 用 。-Fe/Ba3Co1.8Fe23.6Cr0.6O41纳米复合材料具有比-Fe 和 Ba3Co1.8Fe23.6Cr0.6O41更高的Hc值。与铁氧体相比，含70或85 vol%-Fe的-Fe/Ba3Co1.8Fe23.6Cr0.6O41纳米复合材料有希望在较低频率范围生产更薄、更轻的电磁波吸收材料。这项工作得到了日本教育、科学、体育、文化部门和从2003年的新能源和工业技术发展组织的研究奖助金的支持（NEDO
5、） 。卡号： 15205025 本科毕业设计（论文）外文翻译- 13 原文1 Electromagnetic wave absorption properties of a-Fe/Fe3B/Y2O3nanocomposites in gigahertz range Jiu Rong Liu, Masahiro Itoh, and Ken-ichi Machidaa)a Collaborative Research Center for Advanced Science and Technology Osaka University, 2-1 Yamadaoka, Suita, Osaka 56
6、5-0871, Japan (Received 24 February 2003; accepted 8 September 2003) Abstract: Nanocomposites a-Fe/Fe3B/Y2O3were prepared by a melt-spun technique, and the electromagneticwave absorption properties were measured in the 0.05 20.05 GHz range. Compared witha-Fe/Y2O3 composites, the resonance frequency
7、(fr) of a-Fe/Fe3B/Y2O3 shifted to a higher frequency range due to the large anisotropy ?eld ( HA) of tetragonal Fe3B (0.4 MA/m). The relative permittivity ( rrrj) was constantly low over the 0.5 10 GHz region, which indicates that the composite powders have a high resistivity (100m). The effective e
8、lectromagnetic wave absorption ( re?ection loss 99.9 % in purity) by means of induction melting in Ar. Amorphous Y5Fe77.5B17.5 alloy ribbons with 1.5 mm in width and about 30 mm in thickness were prepared by the single-roller melt-spun apparatus at a roll surface velocity of 20 m/s using the earlier
9、 ingots as the starting materials. After ball milling, the powders with particle sizes of 2-4 m were heated to 953 K in He with a heating rate of 40 K/min 本科毕业设计（论文）外文翻译- 15 for 10 min. Subsequent heating at 573 K for 2 h in O2stream gave the resultant powders which were characterized by x-ray diffr
10、action (XRD). The microstructures were observed on a high-resolution scanning electron microscope (HITACHI S-5000). 3. Results and discussion 3.1. Structure characteristics Epoxy resin composites were prepared by homogeneously mixing the composite powders with 20 wt% epoxy resin and pressing into cy
11、lindrical shaped compacts. These compacts were cured by heating at 453 K for 30 min, and then cut into toroidal shaped samples of 7.00 mm outer diameter and 3.04 mm inner diameter. The scattering parameters (S11, S21) of the toroidal shaped sample were measured using a Hewlett-packard 8720B network
12、analyzer. The relative permeability (r) and permittivity (r) values were determined from the scattering parameters as measured in the frequency range of 0.05-20.05 GHz. The re?ection loss(RL) curves were calculated from the relative permeability and permittivity at given frequency and absorber thick
13、ness with the following equations: 1/21/2 0(/)tanh (2/ )()inrrrrZZjfd c(2) 0020log | () /() |ininRLZZZZ(3) where f is the frequency of the electromagnetic wave, d is the thickness of an absorber, c is the velocity of light, Z0is the impedance of air, and Zinis the input impedance of absorber. FIG. 1
14、. The XRD pattern of Y5Fe77.5B17.5 powders: （a） as obtained, （b） after annealing at 953 K for 10 min in He gas, and（c） oxidation-disproportionating the sample （b）in O2 at 573 K for 2 h. 本科毕业设计（论文）外文翻译- 16 Figure 1 shows the typical x-ray diffraction patterns measured on the amorphous Y5Fe77.5B17.5 p
15、owder: (a) as obtained, （b）after annealing at 953 K for 10 min in He, and （c）after oxidation-disproportionating sample （b）at 573 K for 2 h in O2 . From Fig. 1（a）, it was found that the Y5Fe77.5B17.5 alloy powders prepared by using the melt-spun technique were amorphous. After annealing as shown in F
16、ig. 1（b）, the powders were composed of both the Fe3B and Y2Fe14B phases. After oxidation-disproportionation, the phase of Y2Fe14B disappeared. Comparing the XRD pattern in Fig.1 （b）with that of Fig. 1 （c） , we see that the intensity for the main peak of Fe3B（2=44.5 ）, which is just a main peak of a-Fe （110）, is much stronger after oxidation. This result indicates that a-Fe is formed because of the oxidation of Y2Fe14B into a-Fe, Fe3B and Y2O3 nanoparticles. But
