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This study investigated the inhibition effect of nanoscale silver–copper particle (20 nm) against Coriolus versicolor and Gloeophyllumtrabeum. Poplar wood samples (Populus L.) were vacuum-impregnated using aqueous nano-AgCu solutions at concentrations of 0.01 %, 0.02 %, 0.03 %, 0.05 %, 0.075 %, and 0.1 %. Alkaline copper quaternary (ACQ, 0.1 %), boric acid (0.2 %) and untreated control group (CK) were employed for comparisons. Decay resistance and leachability were studied. The anti-fungi effects were compared between nano-AgCu, nano-Ag, Ag+ (silver nitrate), Cu2+ (copper nitrate), and a composite of Ag+–Cu2+. Nano-AgCu particle exhibited effective resistance to fungi after 12 weeks of exposure. The threshold retention of the nano-AgCu against C. versicolor and G. trabeum on poplar wood was 0.19 kg m−3 and 0.62 kg m−3, respectively. The silver–copper nanoparticles demonstrated excellent leach resistance, and the inhibition effect was retained after leaching. The nano-AgCu particle provided better antifungal effects than single ions or metal nanoparticles. This study illustrates the potential of using nano-AgCu particle as an efficient wood preservative compared to commercial water-soluble preservatives. [ABSTRACT FROM AUTHOR]

Nano inorganic antibacterial materials (such as nano silver and nano copper) are popular in preventing the spread of bacteria on wood and protecting human health. However, their antibacterial activity and cost are always difficult to balance, and their leachability during the applied procedure impedes service life. Herein, a low-cost nano AgCu alloy with high antibacterial activity is synthesized by a liquid reduction method and further physically mixed with waterborne paint to fabricate the composite paint. The obtained nano AgCu alloy is demonstrated to possess superior antibacterial performance against Escherichia coli and Staphylococcus aureus with a low concentration (10 ppm), a short time (1 min), and a 100% antibacterial rate, due to the synergistic effect between Ag and Cu, and the promoted release of Ag ion. Meanwhile, the composite coating containing nano AgCu alloy could endow the effective migration of Ag ions and further facilitate the high durability and maintain the lasting antibacterial effect on the wood surface by reducing the leaching rate of nano alloy particles from 1.58% to 0.62%. This work provides a reference for future research and development on antibacterial coatings of wood surfaces. [ABSTRACT FROM AUTHOR]

Nucleophilic high molecular-weight organic compounds (HMWOCs) are sensitive to protons (H+) in Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis. A comprehensive evaluation of the diurnal evolution of nucleophilic HMWOCs was performed. HMWOCs aged significantly in daily cycles, accompanied by functionality shifts, particularly oxygenated and reduced nitrogen (CHON and CHN) as well as oxygenated organics. The intensities of high molecular-weight (HMW) oxygenated compounds increased during both daytime and nighttime. The daytime evolution produced more nitrogen-containing compounds with carboxylic group (–COOH) homologues with molecular weights greater than 300, while the nighttime evolution produced mostly small CHON compounds (molecular weights < 300). During evolution, nighttime CHON removals were observed; meanwhile, carboxylation was also identified in CHON groups. The daytime evolution produced significantly more reduced-nitrogen-containing compounds; a day- and nighttime increase in CHN compounds with five members was also observed. This study can provide insights into the aging of less polar organic aerosols. [ABSTRACT FROM AUTHOR]

The activation of large ancient rock landslides caused by reservoir operation is a primary threat to the TGR. Understanding the deformation characteristics and failure mechanisms of these landslides can be helpful for stability assessment and long-term landslide prediction. The primary aim of this study is to research the motion characteristics of ancient rock landslides and their relationships with engineering activities and natural factors. The Tanjiahe landslide, a large reactivated landslide in the TGR region, is used as an example. Long-term professional monitoring data collected since 2006 show that the landslide is experiencing creep deformation. By combining 15 years of meteorological, hydrological and manual GNSS monitoring information, 5 years of displacement measurements from open fractures and deep boreholes, automatic GNSS measurements, and macroscopic inspection results, the deformation mechanisms of landslides are studied in detail. The study shows that landslide deformation is affected by the reservoir water level and that rainfall promotes landslide deformation. Specifically, from November to May, during the high reservoir water level stage and subsequent declining water level stage, the landslide exhibits a very distinct movement pattern with high deformation, lasting nearly 7 months. As the water level rises, the deformation subsides until almost no deformation exists. Landslide displacement continues to increase each year, indicating likely slope instability. However, the deformation rate of the Tanjiahe landslide is gradually decreasing, and the probability of large-scale sliding is low; still, the monitoring system must be strengthened, and additional research must be performed on the corresponding deformation mechanism. [ABSTRACT FROM AUTHOR]