Construction of 3D Arrays of Cylindrically Hierarchical Structures with ZnO Nanorods Hydrothermally Synthesized on Optical Fiber Cores

With ZnO nanorods hydrothermally synthesized on manually assembled arrays of optical fiber cores, 3D arrays of ZnO nanorod-based cylindrically hierarchical structures with nominal pitch 250 μm or 375 μm were constructed. Based on micrographs of scanning electron microscopy and image processing operators of MATLAB software, the 3D arrays of cylindrically hierarchical structures were quantitatively characterized. The values of the actual diameters, the actual pitches, and the parallelism errors suggest that the process capability of the manual assembling is sufficient and the quality of the 3D arrays of cylindrically hierarchical structures is acceptable. The values of the characteristic parameters such as roughness, skewness, kurtosis, correlation length, and power spectrum density show that the surface morphologies of the cylindrically hierarchical structures not only were affected significantly by Zn2+concentration of the growth solution but also were anisotropic due to different curvature radii of the optical fiber core at side and front view.

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Effects of the geometries of micro-scale substrates on the surface morphologies of ZnO nanorod-based hierarchical structures

Applied Surface Science ◽

10.1016/j.apsusc.2015.07.116 ◽

2015 ◽

Vol 355 ◽

pp. 403-410 ◽

Cited By ~ 5

Author(s):

Weixuan Jing ◽

Han Qi ◽

Jiafan Shi ◽

Zhuangde Jiang ◽

Fan Zhou ◽

...

Keyword(s):

Hierarchical Structures ◽

Zno Nanorod ◽

Micro Scale ◽

Surface Morphologies

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Effects of pH on the Growth of ZnO Nanorod Arrays in Aqueous Solution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.418-420.1507 ◽

2011 ◽

Vol 418-420 ◽

pp. 1507-1510

Author(s):

Chun Mei Zhang ◽

Tao Meng ◽

Yan Ping Hao ◽

Qiang Chen

Keyword(s):

Aqueous Solution ◽

Ph Value ◽

Zno Nanorods ◽

Nanorod Array ◽

Zno Nanorod ◽

Nanorod Arrays ◽

Zno Nanorod Arrays ◽

Effects Of Ph ◽

Xrd Patterns

Well-aligned crystalline ZnO nanorod arrays were synthesized on the glass substrate via an aqueous solution route, and the effect of the pH value on structural properties and morphology of ZnO nanorod arrays was investigated using XRD and FESEM. FESEM micrographs show the formation of ZnO nanorod arrays at different pH values. XRD patterns confirm that the ZnO nanorods were wurtzite structure preferentially oriented in c-axis direction and the highest quality of nanorod array was formed at high pH value.

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STRUCTURAL HEALTH MONITORING ON SPANS USING THE RESONANCE REGIONS OF THE POWER SPECTRUM DENSITY (RR-PSD)

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/57/6a/14038 ◽

2020 ◽

Vol 57 (6A) ◽

pp. 141

Author(s):

Thanh Quang Nguyen

Keyword(s):

Structural Health Monitoring ◽

Power Spectrum ◽

Damage Detection ◽

Health Monitoring ◽

Power Spectrum Density ◽

New Method ◽

Mechanical Responses ◽

Spectrum Density ◽

Over Time

This article proposes a new method which can be used to evaluate the mechanical responses of damage detection in spans. This method can monitor the stiffness degradation of spans over time. This monitoring processes will be conducted at different measuring points on spans, on different spans at the same or different measuring periods. The obtained results show that the change of acreage in the resonance regions of the power spectrum density has brought many positive preliminary outcomes in evaluating the quality of projects during their operational period. The study also shows that the change of acreage in the resonance regions allows us to identify the dangerous points on different spans of a bridge.

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Orientation holes positioning of printed board based on LS-Power spectrum density algorithm

Traitement du signal ◽

10.3166/ts.35.277-288 ◽

2018 ◽

Vol 35 (3-4) ◽

pp. 277-288

Author(s):

Xiaxia ZENG ◽

Zhenhua SONG ◽

Wenzhong LIN ◽

Haibo LUO

Keyword(s):

Power Spectrum ◽

Power Spectrum Density ◽

Spectrum Density

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Facile Synthesis of a Porous ZnO Nanorod Array with Enhanced Photocatalysis for Photoelectrochemical Water Splitting Application

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.17411 ◽

2020 ◽

Vol 20 (6) ◽

pp. 3512-3518

Author(s):

Saleh Khan ◽

Xiao-He Liu ◽

Xi Jiang ◽

Qing-Yun Chen

Keyword(s):

Annealing Temperature ◽

Zno Nanorods ◽

Nanorod Array ◽

Photocurrent Density ◽

Zno Nanorod ◽

Nanorod Arrays ◽

Zno Nanorod Arrays ◽

Irradiation Intensity ◽

Heat Treated ◽

Positive Effect

Highly efficient and effective porous ZnO nanorod arrays were fabricated by annealing ZnO nanorod arrays grown on a substrate using a simple hydrothermal method. The annealing had a positive effect on the nanorod morphology, structure and optical properties. The porosity was closely related to the annealing temperature. After heating at 450 °C, pores appeared on the nanorods. It was demonstrated that the porosity could be exploited to improve the visible light absorption of ZnO and reduce the bandgap from 3.11 eV to 2.99 eV. A combination of improved charge separation and transport of the heat-treated ZnO thus led to an increase in the photoelectrochemical properties. At an irradiation intensity of 100 mW/cm−2, the photocurrent density of the porous nanorod array was approximately 1.3 mA cm−2 at 1.2 V versus Ag/AgCl, which was five times higher than that of the ZnO nanorods. These results revealed the synthesis of promising porous ZnO nanorods for photoelectrochemical applications.

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Random Response Analysis of a Large-Size Cooling Tower Subjected to the Stationary Earthquake Motion

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.423-426.1589 ◽

2013 ◽

Vol 423-426 ◽

pp. 1589-1593

Author(s):

Jia Ning Zhu ◽

Ya Zhou Xu ◽

Guo Liang Bai ◽

Rui Wen Li

Keyword(s):

Power Spectrum ◽

Random Vibration ◽

Cooling Tower ◽

Response Spectrum ◽

Power Spectrum Density ◽

Random Response ◽

Large Size ◽

Earthquake Motion ◽

Spectrum Density ◽

Random Vibration Theory

The response of a large-size cooling tower with 250m high subjected to the seismic action are investigated by both random vibration theory and response spectrum method. Shell element is taken to model the tower body, and beam element is used for the circular foundation and supporting columns. The earthquake motion input is a colored filtered white noise model and mode superposition method is adopted to analyze the random response of the large-size cooling tower. The paper presents the power spectrum density functions (PDF) and standard deviation of the displacement of the top and characteristic node, and the analysis results indicate that the results of the stationary random vibration theory and the response spectrum method are the same order of magnitude. The power spectrum density function of the bottom node stress is obviously bigger than the one at the top and the throat, and the random response of meridonal stress is dominated at the top. In addition, the peak frequency position of the power spectrum density function is different from the corresponding stress.

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Quantitative Study on the Effect of Extrusion Process of AZ80 Magnesium Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.129-131.1191 ◽

2010 ◽

Vol 129-131 ◽

pp. 1191-1195

Author(s):

Yan Lou

Keyword(s):

Set Theory ◽

Rough Set ◽

Rough Set Theory ◽

Extrusion Process ◽

Average Weight ◽

Characteristic Parameters ◽

Billet Temperature ◽

Az80 Magnesium Alloy ◽

Ram Speed

By data mining from 3DFEM simulation and Rough Set Theory (RST), it was performed that the extrusion process and die structures effect on the quality of AZ80 magnesium extrudate. The weights of the effect can be obtained. The results show that the effect of the billet temperature on the product quality is dominate, and its average weight is 0.27. The second important parameter is the ram speed and its average weight is 0.22. In addition, it was also found that the effect of the die characteristic parameters on the extrudate is insignificant.

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