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Search Results: 1 - 10 of 104292 matches for " Guozhong Zhang "
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The Design and Analysis of Electromagnetic Tracking System  [PDF]
Zhanlei Zhang, Guozhong Liu
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2013, DOI: 10.4236/jemaa.2013.52014
Abstract:

With the development of optics and microelectronics technology, the portable 3D scanner which is regarded as combination of laser technology, computer science and artificial intelligence have been applied widely in the three-dimensional measuring field, the built-in electromagnetic tracking technology has played an important role in the portable scanner. Combined with the coordinate conversion formula and equipment we can get, using experimental method, we designed the built-in electromagnetic tracking system, using experimental tests, our system can work normally and we accomplished the design and analysis work. This paper is the introduction of this part.

Electrophoretic Deposition of Titanium Oxide Nanoparticle Films for Dye-Sensitized Solar Cell Applications  [PDF]
Jason Bandy, Qifeng Zhang, Guozhong Cao
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.210193
Abstract: Films of titanium oxide nanocrystalline particles (P25) were deposited using an electrophoretic deposition. The film’s characteristics were tuned for applications in dye-sensitized solar cells. Electrophoretic deposition allows control of film characteristics such as porosity and thickness by changing deposition parameters, such as the electric field and deposition time. To increase the efficiency of the dye-sensitized solar cells with films created using electrophoretic deposition, the problem of an electrolyte contamination in the film, which occurred during deposition, was addressed. With the proper chemical post treatment, efficiency of 2.93% with fill factor of 0.55 was obtained when the films were annealed at 450℃. A low annealing temperature of 150℃ resulted in efficiencys of 1.99% with fill factor of 0.68. When the P25 was replaced by hydrothermally fabricated titanium oxide nanocrystalline particles, efficiency of 4.91% with fill factor of 0.55 was obtained.
Electrokinetic Phenomena of Modified Polytetrafluoroethylene Membranes in the Oily Sewage from Oil Field  [PDF]
Aiguo LIN, Yihua YAO, Gang LIU, Guozhong ZHANG, Xiufeng LIN
Journal of Water Resource and Protection (JWARP) , 2009, DOI: 10.4236/jwarp.2009.12012
Abstract: Experimental investigations of electrokinetic phenomena of modified polytetrafluoroethylene membranes in the oily sewage from oil field were performed by using the streaming potential method. The zeta potentials of the membranes in the oily waste water are estimated on the basis of Helmholtz—Smoluchowski equation. The experiment and calculation results show that the membranes are charged negatively, whose zeta poten-tials maintain at around -20mV. And the aperture of membranes, the temperature and the filtration flux have little influence on the streaming potentials and the zeta potentials of the membranes.Also the suspended particulates in the oily sewage are charged negatively. The membranes have strong ability to withhold the suspended substance and powerful antipollution competence because of the role of the charges on the mem-branes.
An Identified Study on the Active Network of a Thermoacoustic Regenerator  [PDF]
Guozhong Ding, Feng Wu, Gang Zhou, Xiaoqing Zhang, Jiuyang Yu
Engineering (ENG) , 2009, DOI: 10.4236/eng.2009.11003
Abstract: An active thermo-acoustic network model of regenerator which is a key component to accomplish the con-version between thermal-and acoustic power in thermo-acoustic system has been established in this paper. The experiment was carried out to quantify the network. A method called least square is employed in order to identify the H matrix describing the system. The results obtained here show that the active thermo-acoustic network can reliably depict the characteristics of a thermo-acoustic system.
The Role of Oxide Thin Layer in Inverted Structure Polymer Solar Cells  [PDF]
Orawan Wiranwetchayan, Zhiqiang Liang, Qifeng Zhang, Guozhong Cao, Pisith Singjai
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.212226
Abstract: The role of wide band gap oxide thin layer in inverted structure polymer solar cells was investigated by employing oxide films of TiO2 and Nb2O5approximately 10 nm in thickness deposited onto FTO substrates. The experimental results demonstrated that the thin oxide layer serving to separate the electron collecting electrode and the photoactive film of a blend of poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) was necessary to promote the formation of continuous uniform PCBM film to block holes in P3HT from being recombined with electrons in collecting electrode. A use of TiO2 buffer layer leads to power conversion efficiency as high as 2.8%. As for Nb2O5, in spite the fact that its conduction band is higher than the LUMO level of PCBM polymer acting as electron transport material, a power conversion of 2.7%, which was only slightly different from the 2.8% achieved for the cell employing TiO2. These experimental results suggest a tunneling mechanism for the electrons to transport from the PCBM to collecting electrode over the oxide film, instead of a diffusion through the oxide film arising from either energy or concentration difference of the photogenerated electrons.
Alumina and Hafnia ALD Layers for a Niobium-Doped Titanium Oxide Photoanode
Naji Al Dahoudi,Qifeng Zhang,Guozhong Cao
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/401393
Abstract:
Low-Temperature Processing of Titanium Oxide Nanoparticles Photoanodes for Dye-Sensitized Solar Cells
Naji Al Dahoudi,Qifeng Zhang,Guozhong Cao
Journal of Renewable Energy , 2013, DOI: 10.1155/2013/545212
Abstract:
Low-Temperature Processing of Titanium Oxide Nanoparticles Photoanodes for Dye-Sensitized Solar Cells
Naji Al Dahoudi,Qifeng Zhang,Guozhong Cao
Journal of Renewable Energy , 2013, DOI: 10.1155/2013/545212
Abstract: Using the low-temperature processing of different organofunctional silanes like TEOS, GPTS, and MPTS to incorporate within TiO2 network, dye-sensitized solar cells (DSCs) processed at low temperatures were obtained. The UV-cured MPTS-modified layer exhibited better performance over the TEOS and GPTS, where better mechanical stable layer is achieved in addition to better interconnection between the TiO2 nanoparticles. The J-V characteristics of the DSC composed of silane-based layer showed that the improved cell performance was due to the high photocurrent density accompanied with more dye adsorption and higher charge injection from TiO2 to FTO substrate resulting from the formation of an ohmic contact with the substrate. The highest conversion efficiency attained for MPTS-TiO2 layer cured with UV and followed by heating at 300°C was %, which is 2.8 times better than the GPTS-based layer. 1. Introduction The increasing global demands of clean energy is becoming one of the major scientific challenges for scientists, economists, and politicians [1], as the combustion of fossil foils has produced widespread environmental damage [2]. Therefore, the Sun as an abundant source of energy represents the ideal source of clean energy, which has a solar flux deposited on the surface of the earth within one hour as much as the global power usage. However, the high production cost compared with the fossil foils has retarded the widespread commercialization of this alternative energy. There have been intensive investigations for higher efficiency and cost effective conversion of solar radiation to electricity. Silicon-based solar cell technologies are currently the widely used commercial photovoltaic technology; however, the nonsilicon photovoltaic thin films are a major competitor with less cost and more flexibility than traditional solar cells [3]. One of the most promising technologies is the dye-sensitized solar cells (DSCs), which have attracted much attention as they offer the possibility of extremely inexpensive and efficient solar energy conversion with flexible routes of production. The maximum reported efficiency since the first report published by O’Regan and Gr?tzel in 1991 [4], is with a current record of ~11–13% [5–12]. DSC is a mimic of the photosynthesis and a physical separation between photon absorption and charge percolation process. The light is absorbed by a molecular dye, that is attached to the surface of semiconducting thick layer (10–15?μm) deposited on transparent conducting oxide (TCO) electrode. The excited dye rapidly injects an electron
Alumina and Hafnia ALD Layers for a Niobium-Doped Titanium Oxide Photoanode
Naji Al Dahoudi,Qifeng Zhang,Guozhong Cao
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/401393
Abstract: Niobium-doped titanium dioxide (TiO2) nanoparticles were used as a photoanode in dye-sensitized solar cells (DSCs). They showed a high photocurrent density due to their higher conductivity; however, a low open-circuit voltage was exhibited due to the back-reaction of photogenerated electrons. Atomic layer deposition is a useful technique to form a conformal ultrathin layer of Al2O3 and HfO, which act as an energy barrier to suppress the back electrons from reaching the redox medium. This resulted in an increase of the open-circuit voltage and therefore led to higher performance. HfO showed an improvement of the light-to-current conversion efficiency by 74%, higher than the 21% enhancement obtained by utilizing Al2O3 layers. 1. Introduction The world is in urgent quest of seeking alternative renewable energy resources. Because of their low-cost materials and their simple elaboration of manufacturing, dye-sensitized solar cells [1–5] are considered as a promising candidate to replace the commercial silicon solar cells [6–8]. Titanium oxide is one of the extremely favorable materials [9] for the working electrode (photoanode) of DSCs. The control of their morphological properties, structure, and the kinetic transport of the charge carriers have a significant impact of their performance in the DSSCs. Using metal ions as dopants has a significant effect on the electrical properties of TiO2. This doping leads to significant changes of electrical conductivity, shifting of Fermi level potential, particle aggregation, charge transfer kinetics, and dye absorption characteristics of TiO2 [10]. Ko et al. [11] have found remarkable enhancement by doping the TiO2 with aluminum and tungsten. However, many reports have suggested that the performance of DSCs at the optimized level of metal ions doping into TiO2 relates mainly the tuning of the flat band of TiO2. Lü et al. [12] synthesized a well-crystalline niobium (Nb) doped anatase TiO2 (Nb?:?TiO2) and investigated its effect on the performance of DSSCs. It was revealed that Nb doping had positive effect on the short-circuit current with positive shift of the flat band potential. Doping of titanium oxide by metal ions may elevate the electron hole pair production, however, may create more trapping sites that affect the performance of dye-sensitized solar cells. Charge recombination occurs at the interface between the working electrode and the dye/electrolyte interfaces, where photogenerated electrons in the porous electrode tend to recombine with either the oxidized dye or the oxidized species in electrolyte, thereby
Application of Optical Motion Capture Technology in Power Safety Entitative Simulation Training System  [PDF]
Huimeng Zhang, Lanxiang Wang, Shenghui Chu, Shuo Chen, Hao Meng, Guozhong Liu
Optics and Photonics Journal (OPJ) , 2016, DOI: 10.4236/opj.2016.68B026
Abstract:
The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In this paper, an optical motion capture system based on the virtual reality technology is proposed to meet the requirements of the power enterprise for the qualified business ability. Electric power equipment, power equipment model entitative operating environment and the human model are established by electric power simulation unit, ZigBee technology and OpenGL graphics library. The problem of missing feature points is solved by applying the human model driven algorithm and the Kalman filtering algorithm. The experimental results show that it is more accurate to use Kalman filtering algorithm to extract the feature point in tracking process of actual motion capture and real-time animation display. The average absolute error of 3D coordinates is 1.61 mm and the average relative error is 2.23%. The system can improve trainees’ sense of experience and immersion.
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