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The application of the superhydrophobic coating is expected to be an effective method to further improve the pollution flashover voltage of insulators. However, so far, the relationship between electric field strength, droplet volume, and sliding angle in strong electric fields is not clear. This is not conducive to the evaluation of the practical application effect of superhydrophobic insulators. In this paper, the self-cleaning property of superhydrophobic coating and the critical motion condition of droplets in the electric field were analyzed theoretically. Then an experimental platform was set up to observe the movement of the droplet driven by the electric field, and the critical electric field strength for droplet motion was measured. Experimental and theoretical analysis results show that the critical electric field strength for positive droplet motion is less than that for the negative droplet. The droplet driven by the electric field can also remove water-insoluble pollution particles. And the maximum pollution concentration that droplets can remove by means of self-cleaning performance is calculated theoretically. The theoretical calculation method of the sliding angle of superhydrophobic coating in uniform DC electric field is obtained, which is in good agreement with the experimental results. This paper provides theoretical support for evaluating the practical performance of the superhydrophobic insulator in strong electric fields.
Shuai Ren; Shengwu Wang; Zhenqiu Dong; Junwu Chen; Lee Li. Dynamic Behaviors and Self-cleaning Property of Droplet on Superhydrophobic Coating in Uniform DC Electric Field. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2021, 626, 127056 .
AMA StyleShuai Ren, Shengwu Wang, Zhenqiu Dong, Junwu Chen, Lee Li. Dynamic Behaviors and Self-cleaning Property of Droplet on Superhydrophobic Coating in Uniform DC Electric Field. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2021; 626 ():127056.
Chicago/Turabian StyleShuai Ren; Shengwu Wang; Zhenqiu Dong; Junwu Chen; Lee Li. 2021. "Dynamic Behaviors and Self-cleaning Property of Droplet on Superhydrophobic Coating in Uniform DC Electric Field." Colloids and Surfaces A: Physicochemical and Engineering Aspects 626, no. : 127056.
As the widely implemented electrode material, graphite has the characteristic of sublimation by the thermal shock of the switching arc, and the produced carbon vapor is easy to condense into carbon powders and deposit in the switch. The impact of the type of dilution gas in a mixture of 20% oxygen and 80% dilution gas on the sublimation and oxidation characteristics of the graphite electrode is investigated. It is found that when nitrogen dilution gas was replaced by argon, the heat flux to the electrodes decreased, which led to a 63% reduction of graphite sublimation. At the same time, the cooling rate of the arc was slower in argon, which promotes oxidation of the carbon vapor. The residual solid carbon can be reduced by 70%‒¬¬85% by using argon as the dilution gas. Consequently, it is demonstrated that the stability and working life of the switch could be increased by appropriate selection of the dilution gas.
Hongyu Dai; Lee Li; Shuai Ren; Jingrun Guo; Xin Gong; Anthony Bruce Murphy. Effect of dilution gas composition on the evolution of graphite electrode characteristics in the spark gap switch. Plasma Science and Technology 2021, 23, 064009 .
AMA StyleHongyu Dai, Lee Li, Shuai Ren, Jingrun Guo, Xin Gong, Anthony Bruce Murphy. Effect of dilution gas composition on the evolution of graphite electrode characteristics in the spark gap switch. Plasma Science and Technology. 2021; 23 (6):064009.
Chicago/Turabian StyleHongyu Dai; Lee Li; Shuai Ren; Jingrun Guo; Xin Gong; Anthony Bruce Murphy. 2021. "Effect of dilution gas composition on the evolution of graphite electrode characteristics in the spark gap switch." Plasma Science and Technology 23, no. 6: 064009.
Understanding the mechanism of coalescence-induced self-propelled jumping behavior provides distinct insights in designing and optimizing functional coatings with self-cleaning and anti-icing properties. However, to date self-propelled jumping phenomenon has only been observed and studied on superhydrophobic surfaces, other than those hydrophobic surfaces with weaker but fairish water-repellency, for instance, RTV coatings. In this work, from the perspective of thermodynamic-based energy balance aspect, the reason that self-propelled jumping phenomenon does not happen on RTV coatings is studied. The apparent contact angles of droplets on RTV coatings can be less than the theoretical critical values therefore cannot promise energy surplus for the coalesced droplets onside. Besides, on RTV and superhydrophobic surfaces, the droplet-size dependent variation characteristics of the energy leftover from coalescence process are opposite. For the droplets coalescing on RTV coatings, the magnitudes of energy dissipations are more sensitive to the increase in droplet size, compared to that of released surface energy. While for superhydrophobic coatings, the energy generated during coalescence process can be more sensitive than the dissipations to the change in droplet size.
Sheng-Wu Wang; Lu Peng; Jun-Wu Chen; Lee Li. A comparative study of the self-propelled jumping capabilities of coalesced droplets on RTV surfaces and superhydrophobic surfaces. Chinese Physics B 2021, 30, 046501 .
AMA StyleSheng-Wu Wang, Lu Peng, Jun-Wu Chen, Lee Li. A comparative study of the self-propelled jumping capabilities of coalesced droplets on RTV surfaces and superhydrophobic surfaces. Chinese Physics B. 2021; 30 (4):046501.
Chicago/Turabian StyleSheng-Wu Wang; Lu Peng; Jun-Wu Chen; Lee Li. 2021. "A comparative study of the self-propelled jumping capabilities of coalesced droplets on RTV surfaces and superhydrophobic surfaces." Chinese Physics B 30, no. 4: 046501.
The droplet rolling angle is one of the important indicators to measure the coating’s hydrophobic performance, but the specific factors affecting the droplet rolling angle on the micro-nanostructured superhydrophobic coating surface are not yet known. Based on the rolling mechanism of droplets on rough surfaces, and from the perspective of coating microscopic energy conservation, this paper points out that the micron-scale morphology and the nanoscale morphology can comprehensively affect the droplet rolling angle. From the above perspective, a mathematical model of the droplet rolling angle on the micro-nanostructure superhydrophobic coating surface was established. The model shows that the droplet rolling angle is positively correlated with the ratio of nano-sized pillar width to spacing, the ratio of micron-sized papilla radius to spacing, and the liquid–gas interfacial tension, and is negatively correlated to the droplet intrinsic contact angle, droplet volume and droplet density. The droplet rolling angle calculated by the presented model is in good agreement with the experimentally tested results. This model can provide good accuracy in predicting the droplet rolling angle on the micro-nanostructured superhydrophobic coating surface.
Jinyu Chen; Junwu Chen; Lee Li; Shengwu Wang; Yi Xie. Droplet rolling angle model of micro-nanostructure superhydrophobic coating surface. The European Physical Journal E 2021, 44, 1 -11.
AMA StyleJinyu Chen, Junwu Chen, Lee Li, Shengwu Wang, Yi Xie. Droplet rolling angle model of micro-nanostructure superhydrophobic coating surface. The European Physical Journal E. 2021; 44 (2):1-11.
Chicago/Turabian StyleJinyu Chen; Junwu Chen; Lee Li; Shengwu Wang; Yi Xie. 2021. "Droplet rolling angle model of micro-nanostructure superhydrophobic coating surface." The European Physical Journal E 44, no. 2: 1-11.
In order to study the adaptation of the semiconductors for the special power supply application, a capacitive pulsed power supply is designed by using the pulse thyristors. The modular integrated method is adopted to redesign the main circuit of the power supply. The synchronous triggering of multiple sets of thyristors enables high current output of the pulsed power supply, which can avoid excessive current passing through the thyristors and eliminate current-sharing measures of the thyristors. Applying the fast switching MOSFET and magnetic induction of pulse transformer, a set of high gate trigger system is developed to control the synchronous conduction of the thyristors of each module. The simulation and experimental results show that most of the faults occurring during the operation of the pulsed power supply can be limited by protection devices. Practical operation indicates that the pulse power supply can provide specific required pulse current and energy for the pulsed xenon lamp. The design method of the pulsed power supply can provide a reference for the design of the pulsed power supply, and lay a foundation for the higher capacitive energy storage application.
Bin Yu; Yuan Pan; Lee Li; Jiaming Xiong; Hongyu Dai; Haibo Wu. Design and characteristics of a modular integrated power supply for the system of flashlamp-pumped in inertial confinement fusion. Fusion Engineering and Design 2020, 163, 112153 .
AMA StyleBin Yu, Yuan Pan, Lee Li, Jiaming Xiong, Hongyu Dai, Haibo Wu. Design and characteristics of a modular integrated power supply for the system of flashlamp-pumped in inertial confinement fusion. Fusion Engineering and Design. 2020; 163 ():112153.
Chicago/Turabian StyleBin Yu; Yuan Pan; Lee Li; Jiaming Xiong; Hongyu Dai; Haibo Wu. 2020. "Design and characteristics of a modular integrated power supply for the system of flashlamp-pumped in inertial confinement fusion." Fusion Engineering and Design 163, no. : 112153.
If the apparent contact angle (ACA) of superhydrophobic materials could be significantly affected by drop volume, it would not be reliable to use ACA as an important index to evaluate the wettability of superhydrophobic materials. In order to explore the effect of drop volume on the ACA of hierarchical structured superhydrophobic surfaces, two kinds of hierarchical structured superhydrophobic surfaces, natural lotus leaf surface and superhydrophobic coating, were used for experimental analysis. In addition, a physical model of ACA considering drop volume was established. And the relationship curve between drop volume and ACA was calculated. The experiment and simulation results show that for each kind of drop, the volume has no significant effect on the ACA of hierarchical structured superhydrophobic surfaces. And the ACA can reflect the wettability of the superhydrophobic material effectively
Shuai Ren; Junwu Chen; Miao Jiang; Shengwu Wang; Zhiyu Wan; Yi Xie; Lee Li. The effect of drop volume on the apparent contact angle of hierarchical structured superhydrophobic surfaces. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2020, 611, 125849 .
AMA StyleShuai Ren, Junwu Chen, Miao Jiang, Shengwu Wang, Zhiyu Wan, Yi Xie, Lee Li. The effect of drop volume on the apparent contact angle of hierarchical structured superhydrophobic surfaces. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2020; 611 ():125849.
Chicago/Turabian StyleShuai Ren; Junwu Chen; Miao Jiang; Shengwu Wang; Zhiyu Wan; Yi Xie; Lee Li. 2020. "The effect of drop volume on the apparent contact angle of hierarchical structured superhydrophobic surfaces." Colloids and Surfaces A: Physicochemical and Engineering Aspects 611, no. : 125849.
Dust particles suspended in the atmosphere have been a big headache for electric power transmission industry in China. As transmission lines pass through dusty or air-polluted areas, dust contaminants are likely to deposit and accumulate on line insulators, which is one of the greatest causes of flashover and failure of power transmission. To study the statistical characteristics of this type of contamination, dust samples were collected and measured, and a physical model was set up to explain the deposition and accumulation mechanism of the particles. The trajectories of particles were tracked using fluid mechanics and contact mechanics, and an adhesion criterion was proposed. Simulation software was then applied to validate the model; further different environmental factors were studied that would affect the particle size distribution. The results show that under natural contamination conditions, the particle size distribution on the surface of the insulator shows a certain concentration at size ranges 1~100 μm and basically obeys a log-normal distribution. In addition, relative humidity, air velocity, and the charge accumulated on the surface all have significant influences on particle size distribution characteristics, while the effect of the electric field is mainly reflected in the difference in the number concentration of particle adhesion.
Miao Jiang; Jingrun Guo; Yunpeng Jiang; Lee Li; Ming Lu. Dust contamination on surface of transmission line insulators in air-polluted regions in China: statistical characteristics, adhesion mechanism, and environmental impact factors. Environmental Science and Pollution Research 2020, 27, 23643 -23654.
AMA StyleMiao Jiang, Jingrun Guo, Yunpeng Jiang, Lee Li, Ming Lu. Dust contamination on surface of transmission line insulators in air-polluted regions in China: statistical characteristics, adhesion mechanism, and environmental impact factors. Environmental Science and Pollution Research. 2020; 27 (19):23643-23654.
Chicago/Turabian StyleMiao Jiang; Jingrun Guo; Yunpeng Jiang; Lee Li; Ming Lu. 2020. "Dust contamination on surface of transmission line insulators in air-polluted regions in China: statistical characteristics, adhesion mechanism, and environmental impact factors." Environmental Science and Pollution Research 27, no. 19: 23643-23654.
In this study, glass fiber (GF)/phenol formaldehyde resin (PF)/epoxy resin (EP) three-phase electrical insulating composites were fabricated by selective laser sintering (SLS) additive manufacturing technology and subsequent infiltration. In the three-phase composites, glass fibers modified by a silane coupling agent (KH-550) were used as reinforcements, phenol formaldehyde resin acted as the binder and matrix, and infiltrated epoxy resin was the filler. Mechanical and electrical properties such as tensile strength, bending strength, dielectric constant, electrical conductivity, and electric breakdown strength of the GF/PF/EP three-phase composite parts were investigated. The results indicated that after being infiltrated with EP, the bending strength and tensile strength of the GF/PF/EP composites increased by 30% and 42.8%, respectively. Moreover, the flexural strength and tensile strength of the GF/PF/EP composite increased with the increase of the glass fiber content. More importantly, the three-phase composites showed high electrical properties. Significant improvement in the dielectric constant, electric breakdown strength, and resistivity with the increase in the content of glass fiber was observed. This enables the prepared GF/PF/EP composites to form complex structural electrical insulation devices by SLS, which expands the materials and applications of additive manufacturing technology.
Zhaoqing Li; Wangbing Zhou; Lei Yang; Peng Chen; Chunze Yan; Chao Cai; Hua Li; Lee Li; Yusheng Shi. Glass Fiber-Reinforced Phenol Formaldehyde Resin-Based Electrical Insulating Composites Fabricated by Selective Laser Sintering. Polymers 2019, 11, 135 .
AMA StyleZhaoqing Li, Wangbing Zhou, Lei Yang, Peng Chen, Chunze Yan, Chao Cai, Hua Li, Lee Li, Yusheng Shi. Glass Fiber-Reinforced Phenol Formaldehyde Resin-Based Electrical Insulating Composites Fabricated by Selective Laser Sintering. Polymers. 2019; 11 (1):135.
Chicago/Turabian StyleZhaoqing Li; Wangbing Zhou; Lei Yang; Peng Chen; Chunze Yan; Chao Cai; Hua Li; Lee Li; Yusheng Shi. 2019. "Glass Fiber-Reinforced Phenol Formaldehyde Resin-Based Electrical Insulating Composites Fabricated by Selective Laser Sintering." Polymers 11, no. 1: 135.
The characteristics of contamination on the insulation medium surface play an important role in the surface flashover, especially size distribution of contaminated particles. After measuring the size of contaminated particles on the porcelain insulator surface, obvious size distribution characteristics of particles were found. To study the reason for these statistical characteristics, the movement of particles was analyzed in detail combining with fluid mechanics and collision dynamics. Furthermore, an adhesion model was established in this paper. In addition, the influences of different factors on the adhesion were studied. The results showed that the size of adhered particles on the porcelain insulator surface was easy to focus on a specific range, and the influences of relative humidity and wind speed were remarkable. However, the influences of electric field type, electric field strength, and aerodynamic shape were relatively weak. This research was significant and valuable to the study of artificial contamination simulation experiments, and the influence of particles size distribution on pollution flashover.
Ming Zhang; Rumeng Wang; Lee Li; Yunpeng Jiang. Size Distribution of Contamination Particulate on Porcelain Insulators. Coatings 2018, 8, 339 .
AMA StyleMing Zhang, Rumeng Wang, Lee Li, Yunpeng Jiang. Size Distribution of Contamination Particulate on Porcelain Insulators. Coatings. 2018; 8 (10):339.
Chicago/Turabian StyleMing Zhang; Rumeng Wang; Lee Li; Yunpeng Jiang. 2018. "Size Distribution of Contamination Particulate on Porcelain Insulators." Coatings 8, no. 10: 339.
Surface modification of fiber fabric sometimes needs a large volume of cold plasma to improve its efficiency. This experimental study is based on the treatment of polyamide 66 (PA66) fabrics using large contact-area glow-like plasma, which are produced in the atmospheric air without any dielectric barriers. The atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) are adopted, respectively, to detect the surface changes in physical microstructure and the variations in the type and quantity of chemical functional groups. The results show that the PA66 fabric surface will be etched remarkably by the glow-like plasma, and the surface roughness and the surface energy are augmented. On the surface of the processed PA66 fabrics, the oxygen-containing functional groups’ content rises together with the decrease on the total primary C–C and C–N bonds. After 30 seconds of sterilization by the glow-like plasmas, most of the bacterial colonies on the fabric vanish. The effectiveness of this kind of plasma treatment could last for three days in a sealed environment.
Mingyang Peng; Lee Li; Jiaming Xiong; Kui Hua; Shufan Wang; Tao Shao. Study on Surface Properties of Polyamide 66 Using Atmospheric Glow-Like Discharge Plasma Treatment. Coatings 2017, 7, 123 .
AMA StyleMingyang Peng, Lee Li, Jiaming Xiong, Kui Hua, Shufan Wang, Tao Shao. Study on Surface Properties of Polyamide 66 Using Atmospheric Glow-Like Discharge Plasma Treatment. Coatings. 2017; 7 (8):123.
Chicago/Turabian StyleMingyang Peng; Lee Li; Jiaming Xiong; Kui Hua; Shufan Wang; Tao Shao. 2017. "Study on Surface Properties of Polyamide 66 Using Atmospheric Glow-Like Discharge Plasma Treatment." Coatings 7, no. 8: 123.
The impact of the wire length on the large-scale diffuse discharge is investigated. The images and electrical measurements show that for a nanosecond pulse with a long tail, the decrease of the wire length can result in the transition from a diffuse mode to a spark discharge.
Yu Bin; Lee Li; Yun-Long Liu; Ya-Feng Ge; Lun Liu; Ning Ma; Yang Le; Fu-Chang Lin. Impact of Wire Electrode Length on Nanosecond-Pulse Diffuse Discharge in Atmospheric Pressure Air. IEEE Transactions on Plasma Science 2014, 42, 2492 -2493.
AMA StyleYu Bin, Lee Li, Yun-Long Liu, Ya-Feng Ge, Lun Liu, Ning Ma, Yang Le, Fu-Chang Lin. Impact of Wire Electrode Length on Nanosecond-Pulse Diffuse Discharge in Atmospheric Pressure Air. IEEE Transactions on Plasma Science. 2014; 42 (10):2492-2493.
Chicago/Turabian StyleYu Bin; Lee Li; Yun-Long Liu; Ya-Feng Ge; Lun Liu; Ning Ma; Yang Le; Fu-Chang Lin. 2014. "Impact of Wire Electrode Length on Nanosecond-Pulse Diffuse Discharge in Atmospheric Pressure Air." IEEE Transactions on Plasma Science 42, no. 10: 2492-2493.
This paper illustrates an observation of largescale cold plasma generated by repetitive nanosecond pulses and barrier-free wire electrodes in atmospheric air. The length of plasma tape achieved 110.0 cm and can be further lengthened. The applied repetitive nanosecond pulses are with ~30-ns rise time, negative ~70-kV peak, and ~750-ns width at the 500-Hz repetition frequency. The discharge images indicate that the large-scale homogeneous nonthermal plasma in open air can be stably formed with appropriate conditions.
Yun-Long Liu; Lee Li; Bin Yu; Ya-Feng Ge; Yang Le; Hu Wen; Ma Ning; Fu-Chang Lin. Large-Scale Nonthermal Plasma Generated by Repetitive Nanosecond Pulses and Barrier-Free Wire electrodes in Atmospheric Pressure Air. IEEE Transactions on Plasma Science 2014, 42, 2356 -2357.
AMA StyleYun-Long Liu, Lee Li, Bin Yu, Ya-Feng Ge, Yang Le, Hu Wen, Ma Ning, Fu-Chang Lin. Large-Scale Nonthermal Plasma Generated by Repetitive Nanosecond Pulses and Barrier-Free Wire electrodes in Atmospheric Pressure Air. IEEE Transactions on Plasma Science. 2014; 42 (10):2356-2357.
Chicago/Turabian StyleYun-Long Liu; Lee Li; Bin Yu; Ya-Feng Ge; Yang Le; Hu Wen; Ma Ning; Fu-Chang Lin. 2014. "Large-Scale Nonthermal Plasma Generated by Repetitive Nanosecond Pulses and Barrier-Free Wire electrodes in Atmospheric Pressure Air." IEEE Transactions on Plasma Science 42, no. 10: 2356-2357.
Gang Liu; Fuchang Lin; Yi Liu; Hua Li; Lee Li; Han Zeng; Liu Gang; Liu Yi; Lin Fuchang; Li Lee; Zeng Han. Study of a Magnetic Switch for the SG-III Energy Module. Journal of the Korean Physical Society 2011, 59, 3608 -3613.
AMA StyleGang Liu, Fuchang Lin, Yi Liu, Hua Li, Lee Li, Han Zeng, Liu Gang, Liu Yi, Lin Fuchang, Li Lee, Zeng Han. Study of a Magnetic Switch for the SG-III Energy Module. Journal of the Korean Physical Society. 2011; 59 (6(1)):3608-3613.
Chicago/Turabian StyleGang Liu; Fuchang Lin; Yi Liu; Hua Li; Lee Li; Han Zeng; Liu Gang; Liu Yi; Lin Fuchang; Li Lee; Zeng Han. 2011. "Study of a Magnetic Switch for the SG-III Energy Module." Journal of the Korean Physical Society 59, no. 6(1): 3608-3613.