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Filter materials with structural stability and high-temperature resistance are urgently needed in the field of industrial exhaust gas filtration. Here, an Al₂O₃ porous ceramic with a biomass porous structure and thermal stability (above 1500 °C) was developed using a cost-effective and a readily available feedstock sacrificial biomass template method and subsequent calcination. Al₂O₃ porous ceramics from the sacrificial biomass template method exhibit better filtration capacity for air than general porous alumina ceramics; this can be attributed to the porous structure of Al₂O₃-PCBT, which increases the contact area and the number of contact points between the PM particles and the pores. In addition, the Al₂O₃-PCBT filter cartridge specimens showed high filtration efficiencies (up to 95.20%) and a low-pressure drop (down to 400 Pa) for the ultrafine CaCO₃ particles at an air velocity of 4.5-10 m.s-1. We envision that the Al₂O₃-PCBT filter will provide a solution for the removal of the particulate matter from industrial high-temperature exhaust gases.

The objective of this study was to produce hydrophobic porous wood ceramics as adsorbents for CO2 through the resin treatment of pine. The prepared samples underwent analysis using various methods to determine their structure and properties. An orthogonal experimental approach was employed to obtain adsorbents with optimal preparation process. The highest adsorption capacity was determined to be 1.36 mmol/g at a temperature of 30 ℃ and a CO2 concentration of 15 vol%. The effect of temperature on the microstructure of wood ceramics was studied by characterization. Increasing temperatures adversely affected the adsorption capacity. Nevertheless, the hydrophobic nature of wood ceramics resulted in little impact of humidity on CO2 absorption. The CO2 adsorption kinetics of wood ceramics were analyzed using kinetic studies, which demonstrated that the kinetics can be accurately fitted by both the pseudo-first-order and Avrami models. The findings of the adsorption isotherm analysis showed that the Langmuir model fit was optimal. Following 30 cycles of adsorption-desorption in the presence of simulated gas, the CO2 sorption capacity of the wood ceramics was maintained at over 90%. In terms of CO2/N2 selectivity, the wood ceramics showed a clear preference for CO2, especially at 30 °C, where the CO2/N2 selectivity ratio reached 24.50. [ABSTRACT FROM AUTHOR]

Nucleoside-derived supramolecular hydrogels based on G4-structures have been extensively developed in the biomedical sector and recognized for superior excellent biocompatibility and biodegradability. However, limited longevity and stability present a significant challenge. Chemical modifications in the molecular structure have been shown to enhance the longevity stability of G4-structure-based supramolecular hydrogels, but the precise way in which the molecular structure impacts the stability of the G4-structures and consequently affects the properties of the hydrogel remains to be elucidated. This issue represents a notable challenge in the field, which restricts their further applications to some extent. In this study, single crystals of Gd, αGd and αGd* were cultivated and compared with G. Notably, before this study, the single crystal structures of all natural nucleosides, with the exception of Gd, had been determined. The investigation into the molecular structure and supramolecular self-assembly properties of four guanosine analogs at the atomic scale revealed that the formation of G-quartets is critical for their ability to form hydrogels. The stability of the sugar ring geometry conformation (an intrinsic factor) and the disorder and strength of the hydration effect (extrinsic factors) are vital for maintaining the stability of the G4-structures. The rapid cooling changes the molecular geometry conformation, and the organic solvent changes the hydration effect, which can improve the longevity stability of G4-structure-based supramolecular hydrogels instead of chemical modifications. Consequently, the lifespan of the hydrogels was extended from 2 h to over one week. This advancement is expected to offer significant insights for future research in designing and developing G4-structure-based supramolecular hydrogels. [ABSTRACT FROM AUTHOR]

There are detrimental effects of vehicle exhaust pollutants such as particulate matter (PM) and nitrogen oxides (NOx) on the environment and human health. In order to enhance the performance of woody LaCo0.7Fe0.3O3 perovskite-type catalysts for purifying PM and NOx, non-thermal plasma (NTP) generated by dielectric barrier discharge (DBD) was used as an assisted preparation method in this paper. The physicochemical properties of LaCo0.7Fe0.3O3 perovskite-type catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), and N2 adsorption–desorption. The LaCo0.7Fe0.3O3 perovskite-type catalysts prepared with and without NTP assisted method were tested and compared by a simulated test bench. The experimental results indicate that the purification efficiency of LaCo0.7Fe0.3O3 perovskite-type catalysts for PM and NOx with NTP assisted method is significantly higher than LaCo0.7Fe0.3O3 perovskite-type catalysts without NTP assisted method. When the input voltage and frequency are 15 kV and 10 kHz, the precursor of the catalyst sample is pretreated for 90 min, and the woody LaCo0.7Fe0.3O3 perovskite-type catalyst obtained shows the highest PM and NOx purification efficiency, within the range of approximately 96% and 50%, respectively. The PM and NOx purification mechanisms were deduced based on the experimental findings. [ABSTRACT FROM AUTHOR]

In order to enhance the four‐way purification performance of PM, NOx, CO and HC emitted by automobile exhausts over woody La0.8Ce0.2Fe0.3Co0.7O3 perovskite‐type catalysts. First, the woody La0.8Ce0.2Fe0.3Co0.7O3 perovskite‐type catalysts were modified by nonthermal plasma (NTP). The physicochemical properties of the catalyst surface were characterized utilizing x‐ray diffractometer, Fourier‐transform infrared spectroscopy, x‐ray photoelectronic spectroscopy, scanning electron microscope and Brunauer–Emmett–Teller to analyze the effect of NTP on surface character of the catalyst samples. Second, NTP was combined with woody La0.8Ce0.2Fe0.3Co0.7O3 perovskite‐type catalysts to form in‐plasma catalysis purification (IPCP) systems. Finally, the four‐way purification performance of perovskite‐type catalysts were evaluated in the presence and absence of the plasma by simulation test bench. The results showed that NTP can enhance the four‐way purification performance for PM, NOx, CO and HC emitted by automobile exhausts over woody La0.8Ce0.2Fe0.3Co0.7O3 perovskite‐type catalysts. NTP can increase the specific surface area and porosity. When the input voltage, frequency and filling rate of IPCP systems are 15 kV, 15 Hz and 0.3, respectively, the maximum purification efficiency for PM, NOx, CO and HC are about 96%, 95%, 95%, and 84%. Moreover, four‐way purification mechanism of IPCP was deduced according to the experimental results. [ABSTRACT FROM AUTHOR]

This article explores a delayed stochastic epidemic model with double epidemic hypothesis and saturated incidence. First, we give some preliminaries of the epidemic system. Second, by building Lyapunov functions and utilizing inequalities, we study the asymptotic properties of the delayed stochastic system around each equilibrium point. Furthermore, we prove the persistence in mean of the epidemic system. In the end, several numerical simulations are presented to show that stochastic disturbance and time delay can impact the dynamics of the epidemic system. [ABSTRACT FROM AUTHOR]