Laser direct patterning induced the tunable optical properties of indium tin oxide micro-hole arrays films

Liao Jing,Liu Qingyou,Hong Ruijin,Tao Chunxian,Wang Qi,Lin Hui,Han Zhaoxia,Zhang Dawei 한국물리학회 2022 Current Applied Physics Vol.36 No.-

Here we introduce a facile method to fabricate patterned indium tin oxide (ITO) thin films via selective laser ablation at ambient conditions. By scanning the ITO thin films with focused Nd: YAG pulsed laser, the ITO thin films were selective ablated and patterned without using any conventional chemical etching or photolithography steps. Then we investigated the effects of scanning rate for the structure, morphology and optical properties of patterned ITO thin film. These results indicate that the epsilon-near-zero (ENZ) wavelength of ITO thin films can be tuned from 1100 nm to 1340 nm by adjusting the period of the micro-hole array in microstructure. The nonlinear absorption response of patterned ITO films was about 2.85 time than of the as-deposited ITO thin film. Additionally, the results of the Finite-Difference Time-Domain (FDTD) simulation are in good agreement with those of the experiments.

Photoluminescence properties of NaGd(WO_4)_2:Eu^3+ nanocrystalline prepared by hydrothermal method

Jinsheng Liao,Hangying You,Bao Qiu,He-Rui Wen,Ruijin Hong,Weixiong You,Zhipeng Xie 한국물리학회 2011 Current Applied Physics Vol.11 No.3

NaGd(WO_4)_2:Eu^3+ (hereafter NGW:Eu) red-phosphors were synthesized via a facile hydrothermal method at different pH value. X-ray power diffraction (XRD), transmission electron microscope (TEM),energy dispersive X-ray spectra (EDS), photoluminescence excitation and emission spectra and decay curve were used to characterize the NGW:Eu phosphors. It was found that the pH value has a crucial effect on synthesis of the scheelite structure NGW:Eu. The intense red emission is obtained by exciting into the 5^L_6 state with 395 nm, which corresponds to the popular emission line from near-UV LED chips. The values of Ω2,4 experimental intensity parameters (14.9 × 10^-20 and 5.6 × 10^-20 cm^2) are determined. The high emission quantum efficiency and suitable color coordination of the NGW:Eu phosphor suggest the material could be a promising red phosphor for generating white light in phosphor-converted white light emitting diodes (WLEDs).

Study on Influences and Elimination of Test Temperature on PDC Characteristic Spectroscopy of Oil-Paper Insulation System

Xiao Liu,Ruijin Liao,Yandong Lv,Jiefeng Liu,Jun Gao,Jian Hao 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Test temperature is an important factor affecting the measurement results of dielectric response of field power transformers. In order to better apply the polarization and depolarization current (PDC) to the condition monitoring of oil-paper insulation system in power transformers, the influences and elimination method of test temperature on PDC characteristic spectroscopy (PDC-CS) were investigated. Firstly, the experimental winding sample was measured by PDC method at different test temperatures, then the PDC-CS was obtained from the measurement results and its changing rules were discussed, which show that the PDC-CS appears a horizontal mobility with the rise of temperature. Based on the rules, the “time temperature shift technique” was introduced to eliminate the influence of test temperature. It is shown that the PDC-CS at different test temperatures can be converted to the same reference temperature coincident with each other.

Study on Influences and Elimination of Test Temperature on PDC Characteristic Spectroscopy of Oil-Paper Insulation System

Liu, Xiao,Liao, Ruijin,Lv, Yandong,Liu, Jiefeng,Gao, Jun,Hao, Jian The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Test temperature is an important factor affecting the measurement results of dielectric response of field power transformers. In order to better apply the polarization and depolarization current (PDC) to the condition monitoring of oil-paper insulation system in power transformers, the influences and elimination method of test temperature on PDC characteristic spectroscopy (PDC-CS) were investigated. Firstly, the experimental winding sample was measured by PDC method at different test temperatures, then the PDC-CS was obtained from the measurement results and its changing rules were discussed, which show that the PDC-CS appears a horizontal mobility with the rise of temperature. Based on the rules, the “time temperature shift technique” was introduced to eliminate the influence of test temperature. It is shown that the PDC-CS at different test temperatures can be converted to the same reference temperature coincident with each other.

A New Support Vector Machine Model Based on Improved Imperialist Competitive Algorithm for Fault Diagnosis of Oil-immersed Transformers

Yiyi Zhang,Hua Wei,Ruijin Liao,Youyuan Wang,Lijun Yang,Chunyu Yan 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

Support vector machine (SVM) is introduced as an effective fault diagnosis technique based on dissolved gases analysis (DGA) for oil-immersed transformers with maximum generalization ability; however, the applicability of the SVM is highly affected due to the difficulty of selecting the SVM parameters appropriately. Therefore, a novel approach combing SVM with improved imperialist competitive algorithm (IICA) for fault diagnosis of oil-immersed transformers was proposed in the paper. The improved ICA, which is proved to be an effective optimization approach, is employed to optimize the parameters of SVM. Cross validation and normalizations were applied in the training processes of SVM and the trained SVM model with the optimized parameters was established for fault diagnosis of oil-immersed transformers. Three classification benchmark sets were studied based on particle swarm optimization SVM (PSOSVM) and IICASVM with four multiple classification schemes to select the best scheme for transformer fault diagnosis. The results show that the proposed model can obtain higher diagnosis accuracy than other methods. The comparisons confirm that the proposed model is an effective approach for classification problems.

Investigation on Oil-paper Degradation Subjected to Partial Discharge Using Chaos Theory

Jun Gao,Youyuan Wang,Ruijin Liao,Ke Wang,Lei Yuan,Yiyi Zhang 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.5

In this paper, oil-paper samples composed of transformer windings were used to investigate the insulation degradation process subjected to partial discharge (PD), with artificial defects inside to simulate the PD induced insulation degradation. To determine appropriate test voltages, the breakdown time obtained through a group of accelerated electrical degradation tests under high voltages was firstly fitted by two-parameter Weibull model to acquire the average breakdown time, which was then applied to establish the inverse power law life model to choose advisable test voltages. During the electrical degradation process, PD signals were synchronously detected by an ultra-high frequency (UHF) sensor from inception to breakdown. For PD analysis, the whole degradation process was divided into ten stages, and chaos theory was introduced to analyze the variation of three chaotic parameters with the development of electrical degradation, namely the largest Lyapunov exponent, correlation dimension and Komogorov entropy of PD amplitude time series. It is shown that deterministic chaos of PD is confirmed during the oil-paper degradation process, and the obtained results provide a new effective tool for the diagnosis of degradation of oil-paper insulation subjected to PD.

Investigation on Oil-paper Degradation Subjected to Partial Discharge Using Chaos Theory

Gao, Jun,Wang, Youyuan,Liao, Ruijin,Wang, Ke,Yuan, Lei,Zhang, Yiyi The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.5

In this paper, oil-paper samples composed of transformer windings were used to investigate the insulation degradation process subjected to partial discharge (PD), with artificial defects inside to simulate the PD induced insulation degradation. To determine appropriate test voltages, the breakdown time obtained through a group of accelerated electrical degradation tests under high voltages was firstly fitted by two-parameter Weibull model to acquire the average breakdown time, which was then applied to establish the inverse power law life model to choose advisable test voltages. During the electrical degradation process, PD signals were synchronously detected by an ultra-high frequency (UHF) sensor from inception to breakdown. For PD analysis, the whole degradation process was divided into ten stages, and chaos theory was introduced to analyze the variation of three chaotic parameters with the development of electrical degradation, namely the largest Lyapunov exponent, correlation dimension and Komogorov entropy of PD amplitude time series. It is shown that deterministic chaos of PD is confirmed during the oil-paper degradation process, and the obtained results provide a new effective tool for the diagnosis of degradation of oil-paper insulation subjected to PD.

A New Support Vector Machine Model Based on Improved Imperialist Competitive Algorithm for Fault Diagnosis of Oil-immersed Transformers

Zhang, Yiyi,Wei, Hua,Liao, Ruijin,Wang, Youyuan,Yang, Lijun,Yan, Chunyu The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

Support vector machine (SVM) is introduced as an effective fault diagnosis technique based on dissolved gases analysis (DGA) for oil-immersed transformers with maximum generalization ability; however, the applicability of the SVM is highly affected due to the difficulty of selecting the SVM parameters appropriately. Therefore, a novel approach combing SVM with improved imperialist competitive algorithm (IICA) for fault diagnosis of oil-immersed transformers was proposed in the paper. The improved ICA, which is proved to be an effective optimization approach, is employed to optimize the parameters of SVM. Cross validation and normalizations were applied in the training processes of SVM and the trained SVM model with the optimized parameters was established for fault diagnosis of oil-immersed transformers. Three classification benchmark sets were studied based on particle swarm optimization SVM (PSOSVM) and IICASVM with four multiple classification schemes to select the best scheme for transformer fault diagnosis. The results show that the proposed model can obtain higher diagnosis accuracy than other methods. The comparisons confirm that the proposed model is an effective approach for classification problems.

Deviation Calculation and Analysis of Tooth Surfaces of Conjugate-Curve Gear Drive

Dong Liang,Bingkui Chen,Shuai Peng,Chengli Hua,Ruijin Liao 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.5

Conjugate-curve gears are point contact gears and the locus curves of contact points are conjugate curves. For conjugate-curve gear drive, the application of rack cutters may result in geometrical deviation between the theoretical tooth profiles and the generated tooth profiles. To discuss the deviation conditions between two tooth surfaces, generation of theoretical tooth profiles is described and the tooth profiles generated by the rack cutters are derived. General calculation method for the deviation is provided and the analysis of tooth surfaces is also carried out. Numerical examples utilizing the circular-arc curve and parabolic curve are performed, respectively. The obtained results are discussed and the influences of design parameters including the design parameter, helix angle and the radius of pitch circle on the deviation are shown. The summarized contents of this paper are finally present.

A novel slippery liquid infused porous aluminum conductor with excellent corrosion resistance in simulated marine atmosphere

Tao Zhu,Yuan Yuan,Qi Yu,Huiying Xiang,Xu Dai,Guoyong Liu,Ruijin Liao 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.127 No.-

The overhead aluminum conductors are prone to corrosion, especially in areas with marine climates,which interferes with the safe operation of the power system. Herein, slippery liquid infused porous surface(SLIPS) conductors were successfully prepared on pure aluminum (Bare) conductors by anodizingand infusion of silicone oil. The corrosion resistance of the conductors during 30 days of salt spray corrosionand 7 days of energized conditions was studied. The results indicated that the corrosion of theBare and anodic aluminum oxide (AAO) conductors was more severe under energized (alternating current(AC) and direct current (DC)) conditions. The exacerbation of corrosion by DC energization wasremarkably higher than that of AC energization. The AAO conductor showed better corrosion resistancethan the Bare conductor, which was attributed to the porous alumina retarding the medium intrusion. Due to the barrier effect provided by the lubricant layer, the SLIPS conductor always presented excellentcorrosion resistance than the Bare and AAO conductors. In addition, the mechanical and electrical propertiesof the SLIPS conductor were comparable to the Bare conductor and could satisfy the basic requirementsfor practical applications. The prepared SLIPS conductors offer great application prospects for thecorrosion protection of aluminum conductors.