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[1] Forty-five unconnected upward leaders (UULs) occurred in 19 downward negative flashes are analyzed. Each observed UUL is initiated by a downward stepped leader before a new strike point is struck. For each UUL, several parameters are determined when possible mainly by using high-speed images: inception height, inception time prior to return stroke (RS), horizontal distance from the flash's strike point, two-dimensional (2D) distance between the nearest downward leader branch tip and the UUL's inception point at its inception time, 2D length, and 2D average propagation velocity.

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Gardenoside is one of the most important effective extractions of a herb for its hepatoprotective properties. The aim of this study was to address the mechanism of Gardenoside on HepG2 cellular steatosis induced by free fatty acids (FFAs). The model of HepG2 steatosis was duplicated by oleic and palmitic acid at the proportion of 2:1 (FFAs mixture) for 24 h, then lipid toxicity was induced. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) were used to detect cell viability and Oil Red O staining method was used to judge the lipid accumulation respectively. Inflammatory cytokines TNF-α, IL-1β, IL-6 and intracellular NFκB were measured after 24 h. The steatosis was significantly decreased after Gardenoside treatment without cytotoxicity. TNF-α, IL-1β, IL-6 were modulated to HepG2 cells by treatment of Gardenoside. In the meantime, the activation of NFκB was inhibited by Gardenoside. Gardenoside has a protective effect on FFA-induced cellular steatosis in HepG2 cells which indicates that Gardenoside might be a potential therapeutic herb against NASH by suppressed supernatant inflammatory cytokine production and intracellular NFkB activity.

Performance evaluation for the lightning location system (LLS) of the power grid in Guangdong Province, China, was conducted based on observation data of the triggered lightning flashes obtained in Conghua, Guangzhou, during 2007-11 and natural lightning flashes to tall structures obtained in Guangzhou during 2009-11. The results show that the flash detection efficiency and stroke detection efficiency were about 94% (58/62) and 60% (97/162), respectively. The arithmetic mean and median values for location error were estimated to be about 710 and 489 m, respectively, when more than two reporting sensors were involved in the location retrieval (based on 87 samples). After eliminating one obviously abnormal sample, the absolute percentage errors of peak current estimation were within 0.4%^2%, with arithmetic mean and median values of about 16.3% and 19.1%, respectively (based on 21 samples).

SummaryIn this paper, an adaptive integral sliding mode control (ISMC) scheme is developed for a class of uncertain multi‐input and multi‐output nonlinear systems with unknown external disturbance, system uncertainty, and dead‐zone. The research is motivated by the fact that the ISMC scheme against unknown external disturbance and system uncertainty is very important for multi‐input and multi‐output nonlinear systems. The system uncertainty, the unknown external disturbance, and the effect of dead‐zone are integrated as a compounded disturbance, which is well estimated using a sliding mode disturbance observer (SMDO). Then, the adaptive ISMC based on the designed SMDO is presented to guarantee the satisfactory tracking performance in the presence of system uncertainty, external disturbance, and dead‐zone. Finally, the designed adaptive ISMC strategy based on SMDO is applied to the attitude control of the near space vehicle, and simulation results are presented to illustrate the effectiveness of the proposed adaptive ISMC scheme using the SMDO. Copyright © 2016 John Wiley & Sons, Ltd.