A series of Na0.5Bi0.5TiO3-based catalysts were synthesized by using the solvothermal route. The successful synthesis of catalysts was confirmed by various measurements. The influence of Y3+ doping on the band gap was revealed by the UV–visible absorbance spectra. Their photocatalytic, piezocatalytic, and piezo-photocatalytic activities were investigated by degrading methylene blue. The results show that the Y3+ doping can enhance the catalytic activity of Na0.5Bi0.5TiO3 due to the more efficient harvesting of light, and the catalytic activity can be further enhanced by the support of polyacrylonitrile nanofibers on account of the existence of more active sites. The reaction constants of Na0.5Bi0.485Y0.015TiO3 and Na0.5Bi0.485Y0.015TiO3@PAN in photocatalysis processes are 0.0075 and 0.0112 min–1, which is 1.23 and 1.84 times as many as that of Na0.5Bi0.5TiO3. In addition, the catalysts show higher catalytic activities when the catalysis is carried out at the operating condition including both simulated sunlight irradiation and ultrasonic vibration. The reaction constant of Na0.5Bi0.485Y0.015TiO3@PAN in piezo-photocatalysis is 0.0381 min–1, which is 3.09 and 6.77 times of photocatalysis and piezocatalysis. The enhanced activity results from suppression of charge carrier recombination. The radicals of •O2– and h+ play actual roles in the catalytic processes.
Abstract To acquire a material with simultaneous oil–water emulsion demulsification and oil‐absorbing performance, SiO 2 nanoparticles were introduced into the acrylate polymerization system to prepare oil absorbent SiO 2 /P (SMA‐ co ‐MMA‐ co ‐BA) (PSA‐SiO 2 ). PSA‐SiO 2 was synthesized from monomers and functional materials, including methyl methacrylate (MMA), butyl acrylate (BA), octadecyl methacrylate (SMA) and SiO 2 hydrophobically modified by vinyltrimethoxysilane. The molecular structure of PSA‐SiO 2 was characterized by FT‐IR, and its morphology was observed using scanning electron microscopy. In addition, the optimal synthesis conditions for the polymerization system, such as the monomer ratio, the amount of crosslinker and stabilizer and then the particle size and dose of SiO 2 , were discussed in detail. PSA‐SiO 2 had a decent oil absorbency for pure halogenated and aromatic hydrocarbons (49.10, 56.41, 47.32, 43.45, 36.22, and 30.14 g/g for CH 2 Cl 2 , CHCl 3 , CCl 4 , C 2 Cl 4 , toluene and styrene, respectively). Furthermore, SiO 2, as a functional material, makes composites that possess excellent demulsification properties for oil‐in‐water emulsions. The oil removal efficiency of CHCl 3 in Tween 80‐stabilized and CTAB‐stabilized emulsions were 94.88% and 98.11%, respectively. All results indicated that PSA‐SiO 2 had valuable potential for oil removal and emulsion treatment. Highlights An organic–inorganic composite was synthesized by suspension polymerization. The composite was applied for absorbing pure oil or removing oil form water. By modification, the composite acquired the demulsification ability. The composite accomplished one‐step demulsification and emulsion treatment. The oil absorption and emulsion treatment could achieve at room temperature.
Smoke from wildland fires is one of the sources of atmospheric anthropogenic aerosols. it can dramatically affect regional and global radiative balance. Ross et al. (1998) estimated a direct radiative forcing of nearly -20 ~ m ' for the 1995 Amazonian smoke season (August and September). Penner et al. (1992) indicated that the magnitude of the smoke global radiative forcing is comparable to that of anthropogenic aerosols.
The water contamination from pharmaceuticals and personal care products (PPCPs) has attracted worldwide attention in recent years because of its threat to public health. Berberine is a typical anti-inflammatory medicine and berberine wastewater is difficult to be treated due to its high toxicity, poor biodegradability, and high acidity. Metal-organic frameworks would be a good choice to remove berberine from wastewater due to its advantages of high specific surface area, ultrahigh porosity, and structural and functional tunability. In this study, MIL-101(Fe) was synthesized and used for the removal of berberine from water. Experimental results indicated that MIL-101(Fe) showed promising characteristics when berberine was adsorbed in acidic wastewater. The high concentration of chloride in berberine wastewater could promote the adsorption of berberine by MIL-101(Fe). Fitting of batch equilibrium data showed that MIL-101(Fe) had a maximum adsorption capacity of 163.93 mg/g for berberine removal at pH 7, and the berberine sorption on MIL-101(Fe) followed the pseudo-second-order model. Furthermore, the associate mechanism for berberine removal was proposed by characterizing the material and theoretical calculation. The X-ray power diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis showed that no chemical reaction occurred during the adsorption of berberine by MIL-101(Fe). Also, the theoretical calculation results indicated that π-π interactions may play the main role in the adsorption of berberine onto MIL-101(Fe). The findings of this study suggest that MIL-101(Fe) is a promising sorbent for berberine removal from wastewater.
Wildfires can lead to severe environmental consequences by releasing large amounts of particulate matter (PM) and precursors of ozone (Sandberg et al., 1999; Riebau and Fox, 2001). The Southeast has the most burned area among various U.S. regions (Stanturf et al., 2002) and has regionally some of the highest levels of PM and ozone in the nation. Fires have been found to be an important contributor (Zheng et al. 2002). On the other hand, smoke particles from wildfires are one of the atmospheric anthropogenic aerosol sources. They can affect global and regional radiation and climate (e.g., Penner et al. 1992, Liu 2005a).
Flavonoids have a major contribution to the fruit quality in cultivated strawberries and are regulated by MYB, bHLH and WD40 transcriptional factors. We reported here the identification of the FaMYB5, an R2R3-MYB transcription factor, which positively regulated the accumulation of anthocyanins and proanthocyanidins through the trans-activation of the F3'H and LAR. The strawberry FaEGL3 and FaLWD1/FaLWD1-like interact with the R2R3-FaMYB5 to form an MYB-bHLH-WD40 complex (MBW), enhancing the regulatory efficiency. The R2R3-FaMYB5 was constitutively expressed in various tissues and in fruits of different developmental stages, which was strikingly contrasting to the fruit-specific expression patterns of FaMYB10. Meanwhile, R2R3-FaMYB5 failed to promote a stable accumulation of anthocyanin glycosides in the mature fruits of the myb10 mutant, mainly due to the suppressed expression of TT19. The R2R3-FaMYB5 was regulated by an antisense long noncoding RNA lncRNA-myb5. Additionally, the R2R3-FaMYB5 protein could interact with FaBT2 and was degraded through the ubiquitin/26 S proteasome pathway. Transcriptome and metabolome data showed that R2R3-FaMYB5 enhanced the gene expression and the metabolite accumulation involved in the flavonoid, phenylpropanoid and lignin biosynthesis pathways. Collectively, we conclude that the FaMYB5 is an R2R3-MYB activator involved in the composition of MBW, which positively regulates the biosynthesis of anthocyanin and proanthocyanidin. These findings provided new insights into the molecular mechanisms that regulate flavonoids in strawberry fruits.
The dune density is an important parameter for representing the characteristics of desert geomorphology, providing a precise depiction of the undulating topography of the desert. Owing to the limitations of estimation methods and data availability, accurately quantifying dune density has posed a significant challenge; in response to this issue, we propose an innovative model to estimate dune density using a dune vertex search combined with four-directional orographic spectral decomposition. This study reveals several key insights: (1) Taklimakan Desert distributes approximately 5.31 × 107 dunes, with a linear regression fit R2 of 0.79 between the estimated and observed values. The average absolute error and root mean square error are calculated as 25.61 n/km2 and 30.48 n/km2, respectively. (2) The distribution of dune density across the eastern, northeastern, southern, and western parts of the Taklimakan Desert is relatively lower, while there is higher dune density in the central and northern areas. (3) The observation data constructed using the improved YOLOv8s algorithm and remote sensing imagery effectively validate the estimation results of dune density. The new algorithm demonstrates a high level of accuracy in estimating sand dune density, thereby providing crucial parameters for sub-grid orographic parameterization in desert regions. Additionally, its application potential in dust modeling appears promising.
Fe and Cr are regarded as two of the most important friction components in Cu-based composites (Cu–BCs). In this study, the microstructural detection and micro- and macro-tribology evaluation of Cu–BCs containing Fe and Cr were performed. The results indicated that both Fe and Cr formed diffusion interfaces with the copper matrix. Because of the generation of a defect interface layer, the Cr/Cu interface exhibited a low bonding strength. Owing to the excellent binding interface between Fe and Cu, the high coefficient of friction (COF) of Fe, and the formation of a mechanical mixing layer promoted by Fe, the Cu–BCs containing Fe presented better friction performance under all braking energy per unit area (BEPUA) values. The main wear mechanism of Cu–BCs containing Fe and Cr changed from abrasion to delamination with an increase in BEPUA, and the delamination of Cu–BCs containing Fe was induced by breaks in the mechanical mixed layer (MML).
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