Journal of South China University of Technology(Natural Science Edition)

Acquirement of Welding Seam Information Based on Fractal Theory

Zhu Ruolei, Huang Shisheng, Zhang Hongbing, et al

2004, 32(6): 1-4.

Asbtract ( 147 )

PDF (590KB) ( 160 )

Related Articles | Metrics

In the weld seam-tracking system based on machine vision, the welding seam images acquired in the welding process are mixed with strong noises because of the effect of welding conditions. This makes it difficult to get precise seam situation. In this paper, a new edge extraction algorithm based on the fractal theory was introduced to seek welding edge's position in the seam images with noises. In this algorithm, seam images are analyzed depending on the fractional Brownian field model, and the fractal dimension of some pixels and their neighborhood in seam images are calculated by selecting the scaleless range properly, thus distinguishing the seam edge area. The proposed algorithm was then applied to process the images with noises in natural light and arc light (mixed gas shielded welding). The result shows that this algorithm can be used to Correctly extract the position information of welding seam even with strong interference, with the central position error of welding seam less than 0.3mm.

Simulation of an 802.11-based Power Control Protocol

Li Ning Xu Yan Xie Shengli

2004, 32(6): 5-9.

Asbtract ( 102 )

PDF (383KB) ( 136 )

Related Articles | Metrics

Decoupled Model and Simulation of Three-phase Voltage Source PWM Rectifier Based on Feedback Linearization Theory

Zhang Bo Lu Zhi-feng Deng Wei-hua

2004, 32(6): 10-13,17.

Asbtract ( 113 )

PDF (309KB) ( 186 )

Related Articles | Metrics

Contorllability and Reachability of a Class of Linear Switched Systems with the Same Input Matrix

Hu Zong-bo Zhang Bo Deng Wei-hua

2004, 32(6): 14-17.

Asbtract ( 120 )

PDF (255KB) ( 424 )

Related Articles | Metrics

The sufficient and necessary condition for the controllability and reachability of a class of linear switched systems with different systematic matrixes and the same input matrix was presented and the sufficient and necessary condition for the controllability and reachability of the systems with different input matrixes and the same systematic matrix was also given. It is pointed out that the sufficient and necessary conditions for the controllability and reachability of the two classes of linear switched systems are dual in nature. Each of the two classes of linear switched systems was illustrated with an example and their controllability and reachability were fully analyzed and discussed.

Wed Browsers for Information Appliances

Liu Fa-gui Zhang Hui

2004, 32(6): 18-22.

Asbtract ( 109 )

PDF (393KB) ( 395 )

Related Articles | Metrics

By analyzing the software and hardware characteristics of information appliance (IA) platforms, the restrictions and requirements of the software of Web browser on IA platform were defined, with the aspects of code-weight, run-time memory requirement and implementation cost. The structure and design of the embedded and modularized Web browser software with free function configuration were proposed, and a Web browser applicable to embedded information apparatuses was obtained, that is, GDBrowser. The structure and design scheme of this browser are of extensive applications in the user interactive interface, the function configuration interface and the presentation procedure of the system service information in Electronical-government, VOD and digital television, etc.

Preloading Optimization of Large Net-shape Deployable Antennas

Di Jie-jian Duan Bao-yan Luo Ying Qiu Yuan-ying Yang Dong-wu

2004, 32(6): 23-26.

Asbtract ( 120 )

PDF (298KB) ( 431 )

Related Articles | Metrics

A mathematical model to optimize the preloading of large net-shape deployable antennas was established , with the magnitude of the preloading on vertical cables as the design variable, the root mean square on the net-shape reflective surface as the objective function, and the stress and the frequency as constraints. Optimization using Genetic Algorithm was then performed. As a result, the proposed method can effectively provide a group of preloading, thus obtaining high surface accuracy of the initial shape of the net-shape antenna. The experimental results may serve as a good reference for engineering designers.

Fitting of the Sensitivity-temperature Curves of Nanosized Gas Sensor

Liu Hai-yan Jian Qi-fei

2004, 32(6): 27-30,35.

Asbtract ( 147 )

PDF (300KB) ( 445 )

Related Articles | Metrics

The variation of the sensitivity of nanosized benzene-mixed gas sensor with temperature was measured by experiments. The sensitivity-temperature characteristic curves of the sensor were then simulated on the basis of the experimental data and by using Matlab software. Theoretical analysis and comparison of the characteristics of the two methods, namely, the polynomial fitting method and the spline-polynomial fitting in least square method, was carried out. It is found that the fitting accuracies of the two methods are all 10-3. The relative error of polynomial fitting is ±1.5%, and there are break points in the section connections of the fitting curve, while the relative error of spline-polynomial fitting is only ±0.5% , and the fitting curve is smooth without any break point in the connections.

Structure and Chromic Properties of the Photoelectrochromic Devices with Heat Treatment

Chen Ming-jie Shen Hui

2004, 32(6): 31-35.

Asbtract ( 106 )

PDF (699KB) ( 404 )

Related Articles | Metrics

In this paper, stable WO3 sol and TiO2 sol with well-dispersed granules and narrow dimension distribution were prepared by the sol-gel method. Thin films were obtained by dip-coating and spin-coating methods and they were then assembled into a photoelectrochromic device. The variation of the transmittance with heating temperature of the photoelectrochromic device was investigated. The results show that the transmittance of the device decreases from 70% (bleached state) to 20% (colored state) under the illumination by 1000W tungsten-iodine lamp for 10min, thus achieving the purpose of adjusting the visible lights.

Preparation of Non-uniform Lead-doped TiO₂ Thin Film by Sol-gel Methed

Yu Shu-ping Gu Guo-bang Li Xin-jun

2004, 32(6): 36-40.

Asbtract ( 131 )

PDF (462KB) ( 377 )

Related Articles | Metrics

The non-uniform lead-doped TiO2 thin films deposited on glass substrates were prepared by the sol-gel method. The surface features of the photo-catalytic composite films were investigated by means of AFM, XRD and UV-Vis. The photo-catalytic activity of the films was then characterized by using the model reaction of the photo-catalytic degradation of methyl orange. The results show that, for the non-uniform lead-doped TiO2 thin film (PbDx) and the uniform lead-doped TiO2 thin film (PbTx), the optimum doping mole ratios of Pb/Ti are all 0.005. It is also shown that the maximum apparent degradation rate constant of PbD0.005, that is, 7.37×10-3 min-1, is 2.52 times that of the pure TiO2 thin film, while that of PbT0.005 is 5. 95×10-3 min-1. The doping mechanism was discussed based on the separation efficiency theory of charge carrier.

Influence of Doping Metal Ions on the UV-Vis Light Absorption Properties of ZnO Nanopowders

Li Ling, Bai Jian-shuang, Jin Zhi-chen, et al

2004, 32(6): 41-44.

Asbtract ( 162 )

PDF (477KB) ( 192 )

Related Articles | Metrics

ZnO nanopowder doped with Fe, Mg and Cu were synthesized. The TEM photographs show that the shapes, diameters and diameter distributions of the doped ZnO nanopowders vary little with the metal ions, and the diameters of the particles with doping or without doping are all 30 - 80 nm, with the same statistic average diameter of 50 nm. By comparing and analyzing the UV-Vis absorption spectra of nanosized ZnO doped with different metal ions, it is found that the doping changes the absorption wavelength and transmission of ZnO nanopowder and causes obvious blue immigration or red immigration. Fe doping has the greatest influence on the blue immigration, the absorption wavelength of the nanosized ZnO doped with Fe changes from 400 nm to 315nm and the transmission at 315 -700nm increases from 0.256% to 4. 872% . ZnO doped with Mg shows a red immigration and its absorption wavelength changes from 400nm to 500nm, while the transmission at 500 -700nm increases from 0.221% to 3.816%. ZnO doped with Cu shows a blue immigration of only 20nm, and the transmission at 380 - 700 nm increases from 0.080% to 1. 471 %.

Preparation of Water-borne Hydroxyacrylate Resin Grafted by Organic Siloxane

Pan Li-sha, Wen Xiu-fang, Cheng Jiang, et al

2004, 32(6): 45-48,54.

Asbtract ( 95 )

PDF (363KB) ( 165 )

Related Articles | Metrics

Organic siloxane was added in the synthesis prescription of water-borne hydroxyacrylate resin to improve the performances of water-borne two-component acrylate-polyurethane coating, such as the resistance to water and solvent. The effects of various factors on the consistency of the two components as well as the performance of drying and coating were investigated. These factors include such parameters as the acrylate monomer type, the organic siloxane monomer type, the acid value of the resin, the hydroxy content, the temperature of glass transformation and neutralization degree, etc. The results show that, by choosing high-activity hydroxide acrylate monomer and interruptive vinyltriisopropoxysilane momomer and by controlling the acid value at 35 -50mg/g(calculated in the KOH content) with the hydroxy content set at 3. 5% , the glass transformation temperature set at 25℃ and the neutralization degree at 60% , excellent resin can be synthesized, from which wood coating with excellent resistance to water and solvent can be confected. The drying time and gelling time of the coating meet the construction needs well.

Influence of the Polar Components Produced in Oil on Food Quality During Deep-frying

Deng Yun, Yang Ming-duo, Li Jian, et al

2004, 32(6): 49-54.

Asbtract ( 173 )

PDF (567KB) ( 264 )

Related Articles | Metrics

The polar components produced in oil during deep-frying were analyzed and their effects on the quality of the special fried food were discussed. The experimental results show that some polar components will be produced during deep-frying, and that with the increase of frying time, the types and contents of the polar components in the oil increase; the water content of the food, however, is not clearly influenced; the thickness of the food crust and the oil uptake show a slight increase, while the oil uptake of the food fried in waste oil decreases. The experimental results also show that the oiliness and hardness observed by sensory evaluation have no obvious relation with the quality change of oil, but the crispness and cohesiveness tend to decrease with the degree of oil degradation.

Biodegradability of Modified Cornstarches with High-content Amylose

Qiu Li-ping Wen Qi-biao

2004, 32(6): 55-58.

Asbtract ( 165 )

PDF (292KB) ( 419 )

Related Articles | Metrics

By using the simulated physical digestion method of decomposing the substrates by micropopulation in half-vivo model, the biodegradabilities of cornstarches with different amylose contents and those of their modified starches were studied. The results indicate that the biodegradabilities of cornstarches and their modified starches are related to the amylose content, that the high-content amylose starch containing 50% amylose is most difficult to biodegrade, while the ordinary cornstarch (with the amylose content of 26% ) is most easy to biodegrade, and the biodegradability of the cornstarch containing 70% amylose is medium. The experimental results also indicate that the biodegradabilities of ordinary cornstarches and the cornstarches with high-content amylose decrease by cross-linking but increase by carboxyl-methvlation.

Enhancement of the Cytotoxicity of Carboplatin to Mouse Hepatoma Cell Line by Chymopapain

Cai Xiao-ling, Guo Yong, Wang Jie, et al

2004, 32(6): 59-62.

Asbtract ( 122 )

PDF (288KB) ( 365 )

Related Articles | Metrics

Chymopapain, carboplatin(CBP)and chymopapain +CBP with different concentrations were added in the liquid culture medium of mouse hepatoma cell line hepa-6 under different culture time. The cytotoxicity to hepa-6 was then measured by the MTT method. The results indicate that chymopapain shows cytotoxicivity to hepa-6 with the IC50 of 1 200μg/mL and the inhibition caused by chymopapain increases with chymopapain concentration. Chymopapain with different concentrations can all enhance the cytotoxicity of CBP to heap-6 cells. The enhancement continues with chymopapain added for the second time after 48-hour culture.

Treatment of Slightly Contaminated Industrial Source Water by Using Biological Aerated Filter

Huang Rui-min, Wang Xin, Lin De-xian, et al

2004, 32(6): 63-66. doi:1000-565X(2004)06-0063-04

Asbtract ( 122 )

PDF (288KB) ( 218 )

Related Articles | Metrics

Two processes for treating slightly contaminated source water, namely, the combinative process by flocculation and biological aerated filter and the single flocculation process, were experimentally compared. The results show that, when the CODCr of the source water, the mass concentration of NH3-N and the turbidity are respectively 20 -28mg/L, 5.2 -6.7mg/L and 8 -18NTU, with 1.5 -3.5 million algae in per liter source water, the combinative process can help decrease the corresponding values of the effluent by less than 10mg/L, 0. 6 mg/L and 2 NTU and that the efficiency of the combinative process to remove the contamination (especially the algae) is much better than that of the single flocculation process, and that the combinative process can remove 90% algae and save 45% flocculant.

Multi-phase Fuzzy Control of Intersections Based on Neural Network

Xu Lun-hui Zhong Lu-sheng Xu Jian-min

2004, 32(6): 67-70,79. doi:1000-565X(2004)06-0067-04

Asbtract ( 129 )

PDF (358KB) ( 468 )

Related Articles | Metrics

According to the features of traffic flow in urban intersections, a multi-phase self-adaptive control algorithm was proposed. Multi-layer BP neural network was used to realize the multi-phase fuzzy control in road intersections by taking the queue length on contiguous phase lanes into account. Simulation results show that, as a new method of the intelligent control of traffic system, the proposed fuzzy neural network controller can decrease the average vehicle delay in single intersections and it possesses excellent learning and generating abilities.

Selection of Distribution Center's Location Based on Genetic Algorithm