Although employing nanocarriers for gene/drug delivery shows great potential in agricultural fields, the biotoxicity of nanocarriers is a major concern for largescale applications. Herein, we synthesized a cationic star polymer (SPc) as a pesticide nanocarrier/adjuvant to evaluate its safety against a widely used predatory ladybird (Harmonia axyridis). The application of SPc at extremely high concentrations nearly did not influence the hatching of ladybird eggs but it led to the death of ladybird larvae at lethal concentration 50 (LC 50 ) values of 43.96 and 19.85 mg/mL through the soaking and feeding methods, respectively. The oral feeding of SPc downregulated many membrane protein genes and lysosome genes significantly, and the cell membrane and nucleus in gut tissues were remarkably damaged by SPc application, revealing that the lethal mechanism might be SPc-mediated membrane damage. Furthermore, the oral feeding of SPc increased the relative abundance of Serratia bacteria in ladybird guts to result in bacterial infection. Coapplication of ladybird and SPc-loaded thiamethoxam/matrine achieved desired control efficacies of more than 80% against green peach aphids, revealing that the coapplication could overcome the slow-acting property of ladybirds. To our knowledge, this is the first attempt to investigate the polymer-mediated lethal mechanism toward natural enemies and explore the possibility of coapplying SPc-loaded pesticides and natural enemies for pest management.

Main observation and conclusion As a common electrocatalytic system, Au‐Pt alloy particles are often prepared as Au‐core‐Pt‐shell (Au@Pt) to make full use of platinum. However, Au has a strong tendency to segregate to the outer surface, leading to the redistribution of the active sites. Unfortunately, the mechanism of such reconstruction and its effect on the electrocatalytic activity have not been thoroughly discussed, largely owing to the complexity of in‐situ characterization and computational modeling. Herein, by taking the 55‐atom Au13Pt42 core‐shell nanocluster as an example, we utilized the neural network potential at density functional theory (DFT) level and the genetic algorithm to search the complex global configurational space. It turns out that it is thermodynamically favorable when all gold atoms are segregated to the surface and the shape of the cluster tends to change from icosahedron to a distorted amorphous structure (at a reduced core, DRC) with a unique gold distribution. Towards understanding the dynamic activity variation of oxygen reduction reaction (ORR) on this bimetallic Au@Pt system, oxygen adsorption energy calculations show that this reconstruction could not only increase the number of adsorption sites but also dramatically improve the ORR catalytic activity of each site, thus enhance the overall ORR reactivity.

Developing renewable energies, especially ocean wave energy, is very significant for solving the energy and environmental crisis. The emergence of triboelectric nanogenerators (TENGs) provides new possibilities for harvesting the abundant clean ocean wave energy on earth. In this work, the magnets assisted triboelectric nanogenerator (MA‐TENG) is designed to harvest low frequency ocean wave energy. The integration of electromagnetic generators (EMGs) and TENGs in the MA‐TENG can accomplish their complementary strengths. Additionally, the MA‐TENG system features four output units and a contact separation structure to further improve its output performance while avoiding friction loss. Driven by the linear motor and simulated water waves, the MA‐TENG system can achieve a maximum power density of 79 and 26.2 W m‐3, respectively. This research not only demonstrates a new design idea for TENGs, but also provides a cost‐efficient way for wave energy harvesting.

Understanding how the composition and structure of heterogeneous catalysts change during in situ reaction is of critical importance but greatly challenging because of the complexity of multiple time–space scale. Herein, we propose a self-adaptive simulation strategy driven by the first-principles microkinetic modeling and genetic-algorithm-based global structural search accelerated by machine learning that allows the interplay of surface reaction and catalyst evolution, and uncover the structural/compositional evolution of a Pd(111) single-crystal catalyst under the reaction conditions for CO oxidation, which is a classic open problem lasting for decades. The possible active phases at the kinetically steady state are identified and their common nature is unraveled. We show that, in the presence of CO/O2 reaction mixtures, a dynamically stable partially oxidized nonstoichiometric palladium oxide (PdO0.44 layer) grown on Pd(111) is formed with the O adatoms inserted into the Pd(111) sublayer that drives the formation of the surface oxide. Remarkably, the first-principles microkinetic analyses demonstrate that this self-evolved PdO0.44 surface at the steady state exhibits higher catalytic activity for CO oxidation as compared with Pd(111) and overoxidized PdO catalyst, which may explain the long-standing puzzle of the “PdO x ” active phase for Pd catalyst during CO oxidation.

Current research work focuses on the tribological and thermal properties of epoxy resin matrix composites, which were modified by polyaryletherketone (PAEK-C). The results of the infrared spectra and morphologies of fracture surfaces experiments corroborate the successful synthesis of the materials. From the tribological experiments, it can be known that when the mass fraction of PAEK-C was 10 phr., the corresponding composite exhibited the outstanding wear performances, which could be ascribed to the higher H/E ratio. Based on the results of tribological experiments, it could be obtained that the main wear mechanism is governed by combination of the plastic deformation, creation of vertical cracks in the sliding track, separation of debris, and material waves due to adhesions. In addition, the glass transition temperatures ( Tg) and heat-resistance index ( THRI) of the PAEK-C/epoxy resin higher than those of pure epoxy resin matrix, respectively. Furthermore, when the mass fraction of PAEK-C increased, the heat resistance index ( THRI) of the corresponding composite is 196.3°C, which is higher than that of neat epoxy resin (180.9°C). Also, according to the results of thermogravimetric analysis experiments, it could conclude that the activation energy of the curing process is situated in the range of 150–160 kJ mol−1 depending on the mass fraction of epoxy resins.

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