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61.
Yayun Ye Xiaodong YuanXia Xiang Wei DaiMeng Chen Xinxiang MiaoHaibing Lv Haijun WangWanguo Zheng 《Optics and Lasers in Engineering》2011,49(4):536-541
A Nd:YAG laser (1064 nm) induces optical breakdown of the airborne above the gold-coated K9 glass surface and the created shockwave removes the SiO2 particles contaminated on the gold films. The laser cleaning efficiency has been characterized by optical microscopy, dark field imaging, ultraviolet-visible-near infrared spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and the Image-pro software. The relationships between removal ratio and particle position and laser gap distance have been studied in the case of single pulse laser cleaning. The results show that the 1064 nm laser induced plasma shockwave can effectively remove the SiO2 particles. The removal ratio can reach above 90%. The effects of particle position and laser gap distance on the cleaning efficiency are simulated for the single pulse laser cleaning. The simulated results are consistent with the experimental ones. 相似文献
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Wei-Xin Lv Rui Zhang Ting-Liang Xia Hong-Mei Bi Ke-Ying Shi 《Journal of nanoparticle research》2011,13(6):2351-2360
Nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs) have been prepared by pyrolysis of pyridine and iron phthalocyanine over an iron catalyst at 850 °C at various ammonia gas (NH3) flow rates. X-ray photoelectron spectroscopy results reveal that the pyridine-like nitrogen (N) content can be controlled by changing the flow rate of NH3, and that pyridine-like N plays an important role: it can increase the electrocatalytic activity and the rate of nitric oxide (NO) electrooxidation and decrease the activation energy of NO electrooxidation. Cyclic voltammetry results demonstrate that the N-MWCNTs sample grown with 200 mL/min NH3 flow has the maximum N content of 3.22 atomic %, and its content of pyridine-like N that is chemically active is also the highest among all the N-MWCNTs samples. Electrochemical impedance spectroscopy results indicate that two-step electron transfer process occurs at the N-MWCNT-modified electrode, and the control step is different in various potential regions. The stability of NO electrooxidation at the N-MWCNT-modified electrode is examined, and the reaction mechanism is discussed. 相似文献
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采用沉淀法与异相共沸蒸馏技术相结合制备了ZnO纳米粉体,并利用X射线粉末衍射、扫描电镜、透射电镜和液氮吸-脱附等技术对制备的样品进行了分析与表征.考察了Pt的负载量、煅烧温度以及牺牲试剂的种类和浓度对制备的纳米ZnO的光催化产氢效率的影响.结果表明:与其他温度下煅烧获得的产物相比,400 oC煅烧产物表现出最佳的光催化产氢效率,且以甲醇为牺牲试剂时纳米ZnO悬浮体系的光催化产氢效率远高于以三乙醇胺为牺牲试剂时的产氢效率.其原因在于光催化过程中甲醇氧化也对体系的产氢有贡献.此外,探讨了基于实验结果对含甲醇的 相似文献
66.
Jianguo Lv Kai Huang Xuemei Chen Jianbo Zhu Lijun Wang Xueping Song Zhaoqi Sun 《Superlattices and Microstructures》2011
The chemical composition, crystalline structure, surface morphology and photoluminescence spectra of Na-doped ZnO thin films with different heat treatment process were investigated by X-ray photoelectron spectroscopy, X-ray diffraction, atomic force microscopy and a fluorescence spectrometer. The results show that preferred orientation, residual stress, average crystal size and surface morphology of the thin films are strongly determined by the preheating temperature. The effects of preheating temperature on microstructure and surface morphology have been discussed in detail. The photoluminescence spectra show that there are strong violet & UV emission, blue emission and green emission bands. The violet & UV emission is ascribed to the electron transition from the localized level below the conduction band to the valence band. The blue emission is attributed to the electron transition from the shallow donor level of oxygen vacancies to the valence band, and the electron transition from the shallow donor level of interstitial zinc to the valence band. The green emission is assigned to the electron transition from the level of ionized oxygen vacancies to the valence band. 相似文献
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Synthesis of hexagonal monocrystal AlN microtubes and nanowires at low temperature 总被引:1,自引:0,他引:1 下载免费PDF全文
This paper reports that pure hexagonal aluminium nitride microtubes
and nanowires growing along the [0001] direction have been
successfully synthesized by directly reacting AlClh-AlN, microtubes, nanowires, h-AlN, microtubes, nanowires Project supported by the
National Natural Science Foundation of China (Grant No 10474078)
and the Science Foundation of the Education Office of Shanxi
Province, China. 2006-11-23 This paper reports that pure hexagonal aluminium nitride microtubes and nanowires growing along the [0001] direction have been successfully synthesized by directly reacting AlCl3 with NaN3 at low temperature (450℃) under condition of non-solvent system. The grey-white powder of reacting product was characterized by high-resolution transmission electron microscope (HRTEM), which shows that the powder is long straight-wire morphology with outer diameter from 40nm to 300 nm and length up to several micrometres. The results of both electron diffraction (ED) and x-ray diffraction (XRD) indicate that the AlN microtubes have a pure hexagonal monocrystal tubular structure with the combination of the curled AlN nanobelts. Room-temperature photoluminescence spectrum of the synthesized sample showed an emission peak, which is closely related to the small size of the microtubes. 相似文献
70.
In this paper, we aim to answer the question proposed by Magdziarz (Stoch. Proc. Appl. 119:3238?C3252, 2009), i.e. we investigate the solution of an anomalous diffusion equation with time and space dependent force and diffusion coefficient. First, we try to find the stochastic representation of this equation, which means the PDF of this stochastic process is rightly the solution of the equation we aim to solve. Then, we also simulate the sample paths of the stochastic process. At last, taking advantage of the stochastic representation method, we employed Monte Carlo method to approximate the solution of the mentioned equation. 相似文献