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The paper proposes a diagnosis technique for transformer faults and a technological process for hidden peril management based on vibration analysis by analyzing pluses and minuses of conventional fault test methods for transformers. Through vibration spectrum， the cause of a slight increase in acetylene content of a UHV reactor is analyzed and the fault source is fitted， analyzed and located based on the amplitude trend distribution； through on-site modal testing， the inherent frequencies of structural components are obtained to diagnose and precisely control structural resonance faults of the main transformer cooler of a converter station； through vibration monitoring， the impact on the surrounding transformers when the ±800 kV Fulong-Fengxian DC system is put into operation and in the case of single and double pole operation is analyzed to provide data support for the safe and stable operation of equipment. The transformer fault diagnosis and hidden peril management of transformer based on vibration analysis enable fault diagnosis in the early stage and rids equipment of damages from grid disturbance.

The bioactivity of tea polysaccharides (TPs) has been widely reported, but studies to date have focused on green tea. Some human health investigations have implied that black tea may possess potential antidiabetic effects, but less is known about their potential role and related antidiabetic mechanism. The present study was, therefore, conducted to investigate the chemical properties and antidiabetic activity of TPs from black tea. Monosaccharide composition revealed that Alduronic acid (77.8 mol%) considerably predominated in the fraction. TP conformation analysis indicated that three components in TPs were all typical of high-branching structures. Oral administration of TPs could effectively alleviate fasting blood glucose in type 2 diabetes mellitus (T2D) mice, with the values 23.6 ± 1.42, 19.6 ± 2.25, and 16.4 ± 2.07 mmol/L in the 200, 400, and 800 mg/kg·BW groups, respectively. Among these TPs groups, the 800 mg/kg·BW groups significantly decreased by 37.88% when compared with the T2D+water group (p < 0.05). Further studies demonstrated that TP treatment upregulated the expression of p-Akt/p-PI3K (p < 0.001). Additionally, TP treatment significantly promoted glucose transporter protein 2 (GLUT2) translocation in the liver (p < 0.001). These findings suggest that TPs from black tea protect against T2D by activating PI3K/Akt/GLUT2 signaling and might serve as a novel therapeutic candidate for T2D. [ABSTRACT FROM AUTHOR]

SUMMARY: Dendrobium officinale is edible and has medicinal and ornamental functions. Polysaccharides and flavonoids, including anthocyanins, are important components of D. officinale that largely determine the nutritional quality and consumer appeal. There is a need to study the molecular mechanisms regulating anthocyanin and polysaccharide biosynthesis to enhance D. officinale quality and its market value. Here, we report that high light (HL) induced the accumulation of polysaccharides, particularly mannose, as well as anthocyanin accumulation, resulting in red stems. Metabolome and transcriptome analyses revealed that most of the flavonoids showed large changes in abundance, and flavonoid and polysaccharide biosynthesis was significantly activated under HL treatment. Interestingly, DoHY5 expression was also highly induced. Biochemical analyses demonstrated that DoHY5 directly binds to the promoters of DoF3H1 (involved in anthocyanin biosynthesis), DoGMPP2, and DoPMT28 (involved in polysaccharide biosynthesis) to activate their expression, thereby promoting anthocyanin and polysaccharide accumulation in D. officinale stems. DoHY5 silencing decreased flavonoid‐ and polysaccharide‐related gene expression and reduced anthocyanin and polysaccharide accumulation, whereas DoHY5 overexpression had the opposite effects. Notably, naturally occurring red‐stemmed D. officinale plants similarly have high levels of anthocyanin and polysaccharide accumulation and biosynthesis gene expression. Our results reveal a previously undiscovered role of DoHY5 in co‐regulating anthocyanin and polysaccharide biosynthesis under HL conditions, improving our understanding of the mechanisms regulating stem color and determining nutritional quality in D. officinale. Collectively, our results propose a robust and simple strategy for significantly increasing anthocyanin and polysaccharide levels and subsequently improving the nutritional quality of D. officinale. Significance Statement: Dendrobium officinale is edible and has medicinal and ornamental functions. Polysaccharides and flavonoids are the predominant bioactive compounds produced by D. officinale. However, the relationship between anthocyanin biosynthesis and polysaccharide biosynthesis is unclear. Our study revealed a mechanism underlying the high‐light‐induced co‐regulation of anthocyanin biosynthesis and polysaccharide biosynthesis in D. officinale, improving our understanding of how plants coordinate anthocyanin and polysaccharide biosynthesis. [ABSTRACT FROM AUTHOR]

The distribution of vanadium (V) in aerosols is commonly used to track ship exhaust emissions, yet the atmospheric abundance of V has been greatly reduced due to the implementation of a clean fuel policy. Recent research mainly discussed the chemical compositions of ship-related particles during specific events, yet few studies focus on the long-term changes of V in the atmosphere. In this study, a single-particle aerosol mass spectrometer was used to measure V-containing particles from 2020 to 2021 in Huangpu Port in Guangzhou, China. The long-term trend of the particle counts of V-containing particles declined annually, but the relative abundance of V-containing particles in the total single particles increased in summer due to the influence of ship emissions. Positive matrix factorization revealed that in June and July 2020, 35.7% of the V-containing particles were from ship emissions, followed by dust and industrial emissions. Furthermore, more than 80% of the V-containing particles were found mixing with sulfate and 60% of the V-containing particles were found mixing with nitrate, suggesting that the majority of the V-containing particles were secondary particles processed during the transport of ship emissions to urban areas. Compared with the small changes in the relative abundance of sulfate in the V-containing particles, the relative abundance of nitrate exhibited clear seasonal variations, with a high abundance in winter. This may have been due to the increased production of nitrate from high concentrations of precursors and a suitable chemical environment. For the first time, the long-term trends of V-containing particles in two years are investigated to demonstrate changes in their mixing states and sources after the clean fuel policy, and to suggest the cautious application of V as an indicator of ship emissions. [ABSTRACT FROM AUTHOR]

Based on the continuous strain data recorded in Xinjiang since 1985, we discuss the mechanisms of Tianshan’s uplift and Tarim basin’s clockwise rotation. The results indicate; 1) The principal – compression directions in Tianshan are nearly NS, and their intersection angles with regional structures and mountains are nearly perpendicular, which is in accordance with Tianshan’s uplift and crustal shortening. 2) The principal compressions around Tarim basin tend to facilitate the regional faults’ left-lateral strike-slip movements and the basin’s clockwise rotation. These phenomena of uplift/shortening and rotation are fundamentally the results of India plate’s northward push on Euro-Asia plate, and the associated Pamir arc’s rapid northward movement and regional blocks’ interaction.

This note deals with the robust Hurwitz stability of a class of linear systems with uncertain commensurate time delays, which is formulated as the robust Hurwitz stability of a nonpolytopic family of quasi-polynomials, a NP-hard problem from the viewpoint of computational complexity. On the basis of the "Edge Theorem" and Sylvester resultant elimination, a necessary and sufficient condition is developed for the robust stability of the whole family, and it yields an effective testing procedure. An illustrative example is given to show the effectiveness of the method. Index Terms--Nonpolytope, quasi-polynomial, resultant elimination, robust stability, time delay.

The output of an accelerometer often has coupled components of displacement and acceleration, and is rarely used individually for balancing tasks. In order to balance a wheeled inverted pendulum like the Segway, the conventional control usually requires gyroscopes or a combination of accelerometers and gyroscopes. In this paper, we prove that even in the presence of time delay, a wheeled inverted pendulum can be well stabilized with only one accelerometer as the sensor when the mechanical structure is slightly modified. The key idea is the introduction of an additional damper that does not have a physical connection with the wheels. Moreover, we show that balancing can be achieved with an appropriately selected accelerometer position over a range of time delays. [ABSTRACT FROM AUTHOR]

To identify the four typical faults of dry-type transformer winding insulations, looseness, deformation and eccentricity, this study establishes the electric magnetic force multi-physical field simulation model of a dry-type transformer winding under the four typical faults with COMSOL software, based on the vibration mechanism of an SCB10-1000/10 dry-type transformer. Through the multi-physical field coupling calculation, the comparative relationship between the vibration acceleration of the winding under the four kinds of faults and the normal working state is obtained. The results show that the amplitude growth rate of the fundamental frequency or harmonic frequency of the acceleration signal under four kinds of faults is different from that under normal conditions. Therefore, the threshold value of the fundamental frequency or harmonic increment of the acceleration signal is introduced to describe the growth rate of the acceleration signal relative to normal conditions. Finally, four typical faults are identified with different threshold ranges of acceleration increment under faults, laying a foundation for the fault diagnosis of transformer winding vibrations. [ABSTRACT FROM AUTHOR]