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881.
研究黏弹性材料中激光激发的Rayleigh波的传播特征. 考虑到黏弹性材料的黏性特征,在频域内建立黏弹性材料中激光激发Rayleigh波的有限元数值模型. 在验证有限元频域数值模型正确性的基础上,模拟脉冲激光作用在黏弹性材料上激发出Rayleigh波,进而讨论激光激发的黏弹Rayleigh波的传播特征,并比较黏弹性材料与弹性材料中激光激发的Rayleigh波差异,同时分析了材料的黏性劲度参量变化对Rayleigh波特征的影响.
关键词:
表面波
激光超声
有限元方法
黏弹性 相似文献
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在课堂教学中,要注重训练学生的逆向思维、发散思维、直观思维、简化思维、辩证思维和逻辑思维,培养数学思维的开阔性、独创性、深刻性、逻辑性和严谨性,逐步提升学生的数学思维能力和核心素养. 相似文献
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Influence of reducing anneal on the ferromagnetism in single crystalline Co-doped ZnO thin films 下载免费PDF全文
This paper reports that the high-quality Co-doped ZnO
single crystalline films have been grown on $a$-plane sapphire
substrates by using molecular-beam epitaxy. The as-grown films show
high resistivity and non-ferromagnetism at room temperature, while
they become good conductive and ferromagnetic after annealing in the
reducing atmosphere either in the presence or absence of Zn vapour.
The x-ray absorption studies indicate that all Co ions in these
samples actually substituted into the ZnO lattice without formatting
any detectable secondary phase. Compared with weak ferromagnetism
(0.16~$\mu _{\rm B}$/Co$^{2 + })$ in the Zn6110M, 7550P, 7280E, 7870D http://cpb.iphy.ac.cn/CN/10.1088/1674-1056/19/5/056101 https://cpb.iphy.ac.cn/CN/article/downloadArticleFile.do?attachType=PDF&id=111756 Co-doped ZnO, diluted magnetic semiconductors, x-ray
absorption fine structure, single crystalline thin films Project partially supported by
National Science Foundation of China (Grant No.~10804017), National
Science Foundation of Jiangsu Province of China (Grant
No.~BK2007118), Research Fund for the Doctoral Program of Higher
Education of China (Grant No.~20070286037), Cyanine-Project
Foundation of Jiangsu Province of China (Grant No.~1107020060),
Foundation for Climax Talents Plan in Six-Big Fields of Jiangsu
Province of China (Grant No.~1107020070) and New Century Excellent
Talents in University (NCET-05-0452). This paper reports that the high-quality Co-doped ZnO
single crystalline films have been grown on $a$-plane sapphire
substrates by using molecular-beam epitaxy. The as-grown films show
high resistivity and non-ferromagnetism at room temperature, while
they become good conductive and ferromagnetic after annealing in the
reducing atmosphere either in the presence or absence of Zn vapour.
The x-ray absorption studies indicate that all Co ions in these
samples actually substituted into the ZnO lattice without formatting
any detectable secondary phase. Compared with weak ferromagnetism
(0.16~$\mu _{\rm B}$/Co$^{2 + })$ in the Zn$_{0.95}$Co$_{0.05}$O
single crystalline film with reducing annealing in the absence of Zn
vapour, the films annealed in the reducing atmosphere with Zn vapour
are found to have much stronger ferromagnetism (0.65~$\mu _{\rm
B}$/Co$^{2 + })$ at room temperature. This experimental studies
clearly indicate that Zn interstitials are more effective than
oxygen vacancies to activate the high-temperature ferromagnetism in
Co-doped ZnO films, and the corresponding ferromagnetic mechanism is
discussed. Co-doped;ZnO;diluted;magnetic;semiconductors;x-ray;absorption;fine;structure;single;crystalline;thin;films This paper reports that the high-quality Co-doped ZnO single crystalline films have been grown on a-plane sapphire substrates by using molecular-beam epitaxy.The as-grown films show high resistivity and non-ferromagnetism at room temperature,while they become more conductive and ferromagnetic after annealing in the reducing atmosphere either in the presence or absence of Zn vapour.The x-ray absorption studies indicate that all Co ions in these samples actually substituted into the ZnO lattice without formatting any detectable secondary phase.Compared with weak ferromagnetism(0.16 μB/Co2+) in the Zn0.95Co0.05O single crystalline film with reducing annealing in the absence of Zn vapour,the films annealed in the reducing atmosphere with Zn vapour are found to have much stronger ferromagnetism(0.65 μB/Co2+) at room temperature.This experimental studies clearly indicate that Zn interstitials are more effective than oxygen vacancies to activate the high-temperature ferromagnetism in Co-doped ZnO films,and the corresponding ferromagnetic mechanism is discussed. 相似文献
889.
Using the measure of interference defined in this paper, we investigate the quantum phase transition of one-dimensional Ising chains. We find that thermal fluctuations affect the interference more strongly at the critical point. We also show that the derivative of the interference with respect to the coupling parameter, A, can be depressed by the thermal fluctuation. Finally, we find that this suppression is due to multi-particle excitations. 相似文献
890.
A new differential absorption lidar for NO_2 measurements using Raman-shifted technique 总被引:3,自引:0,他引:3
Based on Raman-shifted wavelengths of D2 and CH4 pumped by third harmonic of Nd:YAG laser, a differential absorption lidar was presented in this paper and had been constructed for probing environmental NO2 concentration. NO2 experimental measurements were carried out at Anhui Institute of Optics and Fine Mechanics in Hefei. Some NO2 measurement results were given and discussed. 相似文献