A new species of gall wasp, Andricus wugangensis Zeng, Liu, & Zhu sp. nov. is described and illustrated herein from Hunan Province, China.
View Article and Find Full Text PDFOwing to sluggish reaction kinetics and high potential, oxygen evolution reaction (OER) electrocatalysts face a trade-off between activity and stability. Herein, an innovative topological strategy is presented for preparing 2D multimetallic (oxy)hydroxide, including ternary CoFeZn, quaternary CoFeMnZn, and high-entropy CoFeMnCuZn. The key to the synthesis lies in using Ca-rich brownmillerite oxide as a precursor, which possesses inherent structural flexibility enabling tailored elemental adjustments and topologically transforms from a point-shared structure of metal-oxygen octahedrons into an edge-shared structure under alkaline conditions.
View Article and Find Full Text PDFA new species of gall inquiline, , is described from Hubei Province, China. Morphological descriptions, photographs and biological information are provided. Mitochondrial cytochrome oxidase (COI) sequences of the new species were newly obtained and a molecular species delimitation analysis of 12 species of performed using the ASAP method recovered 16 molecular operational taxonomic units, providing support for recognition of the new species.
View Article and Find Full Text PDFThe oxygen evolution reaction (OER) plays a vital role in renewable energy technologies, including in fuel cells, metal-air batteries, and water splitting; however, the currently available catalysts still suffer from unsatisfactory performance due to the sluggish OER kinetics. Herein, we developed a new catalyst with high efficiency in which the dynamic exchange mechanism of active Fe sites in the OER was regulated by crystal plane engineering and pore structure design. High-density nanoholes were created on cobalt hydroxide as the catalyst host, and then Fe species were filled inside the nanoholes.
View Article and Find Full Text PDFObjective: To understand the relationship between deliberate rumination and post-traumatic growth and the mechanisms affecting this relationship, we constructed an adjustment model to test the impact of deliberate rumination on the post-traumatic growth of college students and the moderating role of self-efficacy during the 2019 COVID-19 pandemic.
Study Design And Setting: A total of 881 college students from a university of science and technology in Guangdong Province, China, completed a questionnaire that measured deliberate rumination, post-traumatic growth, and self-efficacy. SPSS (version 26) and the PROCESS plug-in (version 4.
In the past few decades, 2D layer materials have gradually become a central focus in materials science owing to their uniquely layered structural qualities and good optoelectronic properties. However, in the development of 2D materials, several disadvantages, such as limited types of materials and the inability to synthesize large-scale materials, severely confine their application. Therefore, further exploration of new materials and preparation methods is necessary to meet technological developmental needs.
View Article and Find Full Text PDFThe highly efficient bifunctional catalyst for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) is the key to achieving high-performance rechargeable Zn-air batteries. Non-precious-metal single-atom catalysts (SACs) have attracted intense interest due to their low cost and very high metal atomic utilization; however, high-activity bifunctional non-precious-metal SACs are still rare. Herein, we develop a new nanospace-confined sulfur-enamine copolymerization strategy to prepare a new type of bifunctional Mo SACs with O/S co-coordination (Mo-OS-C) supported on the multilayered, hierarchically porous hollow tubes.
View Article and Find Full Text PDFThe oxygen evolution reaction (OER) is a key reaction in water splitting and metal-air batteries, and transition metal hydroxides have demonstrated the most electrocatalytic efficiency. Making the hydroxides thinner for more surface commonly fails to increase the active site number, because the real active sites are the edges. Up to now, the overpotentials of most state-of-the-art OER electrocatalysts at a current density of 10 mA cm (η ) are still larger than 200 mV.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2021
Owing to the scarcity of Pt, low-cost, stable, and efficient nonprecious metal-based electrocatalysts that can be applied in a wide pH range for the hydrogen evolution reaction (HER) are urgently required. Herein, a highly efficient and robust HER catalyst that is applicable at all pH values is fabricated, containing isolated Co-single atomic sites anchored in the self-supported WO arrays grown on Cu foam. At a current density of 10 mA cm, the HER overpotentials are 117, 105, and 149 mV at pH values of 0, 7, and 14, respectively, which are significantly lower than those of the undoped WO, suggesting superior electrocatalytic H-evolution activity at all pH values.
View Article and Find Full Text PDFPotassium-ion batteries are potential alternatives to lithium-ion batteries for large-scale energy storage considering the low cost and high abundance of potassium. However, it is challenging to obtain stable electrode materials capable of undergoing long-term potassiation/depotassiation due to the high accumulated stress associated with the huge volume variation of the electrode. Here, we simulate the von Mises stress distributions of four different carbon three-dimensional models under an isotropic initial stress by the finite element method and reveal the critical role of the structure of a hollow multihole bowl on the strain-relaxation behavior.
View Article and Find Full Text PDFSilver/polymer nanocomposites have made inroads into the fields of electronic devices, thermally conductive materials, antimicrobial agents and sensors. Here, we present the hydrothermal synthesis of a novel three-dimensional self-standing silver/crosslinked-poly(vinyl alcohol) (Ag/crosslinked-PVA) hybrid network constructed by linking three different subunits, namely, microfibers, nanowires and nanoparticles. One-dimensional crosslinked-PVA-based microfibers act as the skeleton of the sponge.
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