Arc extinction of DC side low-voltage breaker of charging device for battery pack in power plant based on insulated-gate bipolar transistor module series technology

The 110 V lead-acid battery pack is widely used as the DC power supply for the load control of power plants. If the low-voltage DC circuit breaker (LVDCCB) at the DC side of its charging device cannot operate in time when the fault current is flowing in charging loop, there will be of harmfulness to the safety and the durability of the battery pack. The plasma theory is applied to analyse the arc mechanism based on the voltage, the current and the power waveform of LVDCCB when it breaking. Then, an arc extinction is developed by assembling an additional device to LVDCCB. The device, connected to the contacts of LVDCCB, includes an insulated-gate bipolar transistor series branch, an energy-absorbing branch, a transfer switches branch, and a drive circuit. The test shows that the break time of LVDCCB, assembled with the additional device, is significantly shortened than that of the original

Iron(III)-Modified Tungstophosphoric Acid Supported on Titania Catalyst: Synthesis, Characterization, and Friedel–Craft Acylation of <i>m</i>‑Xylene

The Friedel–Craft acylation of <i>m</i>-xylene with benzoyl chloride over iron-modified tungstophosphoric acid supported on titania was investigated. It was found that FeTPA/TiO₂ catalyst displayed excellent catalytic performance for this reaction. Furthermore, a series of catalysts were prepared and characterized by FT-IR, XRD, BET, NH₃-TPD, and Py-IR. The results indicated that both the Lewis acidity and the textural properties presented significant influences on their catalytic performance. Moreover, the influence of catalyst calcination temperature to the above reaction was also studied. The reaction parameters, including reaction temperature, catalyst dose, and molar ratio of <i>m</i>-xylene to benzoyl chloride, were optimized, and a 95.1% yield of 2,4-dimethylbenzophenone was obtained under optimal conditions. Finally, the kinetics of the benzoylation of <i>m</i>-xylene over 30% FeTPA/TiO₂ was established

Herpes simplex virus type I glycoprotein L evades host antiviral innate immunity by abrogating the nuclear translocation of phosphorylated NF-κB sub-unit p65

Nuclear factor (NF)-κB plays an important role in the innate immune response by inducing antiviral genes’ expression. However, the herpes simplex virus 1 (HSV-1) virus has developed multiple ways to interfere with NF-κB activity to escape the host antiviral response. Here, we found that HSV-1 envelope glycoprotein L(gL) markedly inhibits interferon (IFN) production and its downstream antiviral genes. Our results showed that ectopic expression of gL inhibited IFN-β promoter activation, and decreased IFN-β production, the expression of IFN-stimulated genes (ISGs), and inhibited immunologic stimulant (poly I:C) induced activation of IFN signaling pathway. Depletion of gL by short interfering RNA (siRNA) significantly upregulated IFN-β and ISG production. Further study showed that the N-terminus of the gL bound to the Rel homology domain (RHD) of the p65 and concealed the nuclear localization signal of p65, thereby impeding the translocation of phosphorylated p65 to the nucleus. In summary, our findings indicated that the N-terminal of HSV-1 gL contributes to immune invasion by inhibiting the nuclear translocation of p65

Urea-formaldehyde resin room temperature phosphorescent material with ultra-long afterglow and adjustable phosphorescence performance

Abstract Organic room-temperature phosphorescence materials have attracted extensive attention, but their development is limited by the stability and processibility. Herein, based on the on-line derivatization strategy, we report the urea-formaldehyde room-temperature phosphorescence materials which are constructed by polycondensation of aromatic diamines with urea and formaldehyde. Excitingly, urea-formaldehyde room-temperature phosphorescence materials achieve phosphor lifetime up to 3326 ms. There may be two ways to enhance phosphorescence performance, one is that the polycondensation of aromatic diamine with urea and formaldehyde promotes spin-orbit coupling, and another is that the imidazole derivatives derived from the condensation of aromatic o-diamine with formaldehyde maintains low levels of energy level difference and spin-orbit coupling, thus achieving ultra-long afterglow. Surprisingly, urea-formaldehyde room-temperature phosphorescence materials exhibit tunable phosphorescence emission in electrostatic field. Accordingly, 1,4-phenylenediamine, urea, and formaldehyde are copolymerized and self-assembled into phosphorescence microspheres with different electrostatic potential strengths. By mixing 1 wt% 1,4-phenylenediamine polycondensation microspheres with 1,4-phenylenediamine free microspheres, phosphor lifetime of the composite could be regulated from 27 ms to 123 ms. Moreover, vulcanization process enables precise shaping of urea-formaldehyde room-temperature phosphorescence materials. This work not only demonstrates that urea-formaldehyde room-temperature phosphorescence materials are promising candidates for organic phosphors, but also exhibits the phenomenon of electrostatically regulated phosphorescence

(1R,2R)-(+)-(1,2)-DPEN-Bonded Sulfonic Acid Resin: A Trifunctional Heterogeneous Catalyst for Asymmetric Michael Additions of Acetone to Nitroolefins

<div><p></p><p>Based on (1R,2R)-(+)-(1,2)-DPEN skeleton, a series of primary amine–sulfamide bifunctional catalysts were synthesized, which exhibited excellent catalytic performance in the Michael addition of acetone to β-nitrostyrene. Therefore, a trifunctional heterogeneous catalyst was designed and prepared by simple N-sulfonyl reaction of (1R,2R)-(+)-(1,2)-DPEN and sulfonyl chloride resin. It was employed for the aforementioned addition without any additive and satisfactory results (80.5% conversion; 84.3% <i>ee</i>) were obtained. Meanwhile, the structural and textural properties of the catalyst were characterized by infrared spectroscopy (FT-IR), elemental analysis, SEM, and N₂ adsorption and desorption experiments. Finally, the generality of the catalyst was investigated.</p></div

Redressing the interactions between stem cells and immune system in tissue regeneration

Skeletal muscle has an extraordinary regenerative capacity reflecting the rapid activation and effective differentiation of muscle stem cells (MuSCs). In the course of muscle regeneration, MuSCs are reprogrammed by immune cells. In turn, MuSCs confer immune cells anti-inflammatory properties to resolve inflammation and facilitate tissue repair. Indeed, MuSCs can exert therapeutic effects on various degenerative and inflammatory disorders based on their immunoregulatory ability, including effects primed by interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha). At the molecular level, the tryptophan metabolites, kynurenine or kynurenic acid, produced by indoleamine 2,3-dioxygenase (IDO), augment the expression of TNF-stimulated gene 6 (TSG6) through the activation of the aryl hydrocarbon receptor (AHR). In addition, insulin growth factor 2 (IGF2) produced by MuSCs can endow maturing macrophages oxidative phosphorylation (OXPHOS)-dependent anti-inflammatory functions. Herein, we summarize the current understanding of the immunomodulatory characteristics of MuSCs and the issues related to their potential applications in pathological conditions, including COVID-19