Search

Carbon dot-based room-temperature phosphorescence materials have emerged as a shining new star in the carbon nanomaterial family in recent years due to their excellent optical properties. However, there still exists a significant challenge in obtaining carbon dots (CDs) with ultra-long phosphorescence lifetimes. In this study, tetraethyl orthosilicate (TEOS) was used to achieve in situ growth and encapsulation of CDs in a 3D SiO2 network using a one-pot hydrothermal method. It was demonstrated that Na+ is the key factor to achieve ultra-long afterglow lifetimes of CDs in dense SiO2 matrices, and the introduction of Na+ has a significant effect on extending the afterglow lifetime of various CDs. The designed Na/CDs@SiO2 nanomaterial exhibited an ultra-long afterglow lifetime of 6.69 s, which surpassed most reported CD-based afterglow lifetimes. This work provides a design principle and general strategy for achieving ultra-long afterglow lifetimes of CDs in dense SiO2 matrices. Due to the stable photoluminescence (PL) properties, low biotoxicity, and ultra-long afterglow lifetime of the Na/CDs@SiO2 nanomaterial, it was successfully applied in HeLa cell imaging. [ABSTRACT FROM AUTHOR]

Clostridium perfringens causes necrotic enteritis (NE) after proliferation in the intestine of poultry, resulting in considerable losses to the poultry industry. This study aimed to investigate the impact of tannic acid on the antioxidant, immunity, and gut health of broilers with NE. In the experiment, 630 one-day-old Cobb500 male chicks were randomly divided into six treatment groups, with seven replicate cages and with fifteen birds in each cage. The treatment groups were as follows: control group (NC), challenged group (PC), and challenged NE chickens treated with 250, 500, 750, and 1000 mg/kg tannic acid (PTA1, PTA2, PTA3, and PTA4, respectively). To induce NE, coccidia vaccine and Clostridium perfringens were administered on day 19 and days 22–28, respectively. Indexes related to antioxidant, immune, and intestinal health were measured on days 28 and 35. During the infection period, we observed significant increases in fecal water content, D-LA, TNF-α, and malondialdehyde concentrations (p < 0.05). Conversely, significant decreases were noted in chyme pH and in T-AOC, IL-4, and IL-10 concentrations (p < 0.05). The addition of tannic acid exhibited a linear decrease in fecal water content and TNF-α concentration (p < 0.05). Furthermore, tannic acid supplementation resulted in a quadratic curve decrease in D-LA concentration and linear increases in T-AOC, IL-4, and IL-10 (p < 0.05). Cecal microbiological analysis revealed that Ruminococcaceae and Butyricimona were dominant in PTA3. In conclusion, the dietary addition of tannic acid may reduce the negative effects of NE by increasing antioxidant and anti-inflammatory capacity, improving the intestinal barrier, and regulating the intestinal flora. [ABSTRACT FROM AUTHOR]

Aiming at the problems that the analysis of track circuit dynamic detection data is insufficient and the evaluation of the actual operation state of track circuit is difficult, the comprehensive evaluation method of the track circuit dynamic operation quality based on feature index extraction is improved. Track circuit Evaluation Index of Dynamic operation quality (TEI) is obtained by synthetically weighting the scores of seven characteristic indexes. For the problem of the unreasonable allocation of index weight, a weight allocation model based on mixed integer linear programming (MILP) is proposed to optimize the index weight allocation, and the track circuit evaluation index of dynamic operation quality ( TEI) is obtained. Combined with the actual dynamic inspection data, the application of proposed evaluation method of track circuit in the analysis of section evaluation and the analysis of influencing factors is discussed. Analysis results show that: ( 1) Compared with the existing evaluation method, the TEI obtained by the improved method is more reasonable and has sufficient differentiation; (2) Sections in tunnel are more likely to sustain interference from neighboring sections, which leads to the lower dynamic operation quality than that of sections on bridge; (3) It is likely for ballasted sections to sustain the invasion of interference signal from neighboring sections, which leads to lower dynamic operation quality than ballastless sections; (4) The best dynamic operating quality of the track circuit is achieved in the sections with mechanically insulated joint at the transmitting end and electrically insulated joint at the receiving end. [ABSTRACT FROM AUTHOR]

Ru-Fe bimetallic alloy nanoparticle catalyst (Ru-Fe/GO) was prepared by chemical reduction method on graphene oxide prepared using Hummers modified method. The structure and morphology of both GO and Ru-Fe/GO were analyzed using X-ray diffraction (XRD), Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS).The effect of catalyst components on hydrogen generation rate for NaBH4 methanolysis was investigated. When Ru:Fe is 6:1, the catalytic activity is the highest, and the average rate is about 473 mL·min−1·g−1. The effect of temperature, Sodium hydroxide concentration, and sodium borohydride concentration on reaction rate is also discussed, and the activation energy for the methanolysis of sodium borohydride is 59.33 kJ·mol−1 based on the data. [ABSTRACT FROM AUTHOR]