913 research outputs found

    Improved reversibility in lithium-oxygen battery: Understanding elementary reactions and surface charge engineering of metal alloy catalyst

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    Most Li-O-2 batteries suffer from sluggish kinetics during oxygen evolution reactions (OERs). To overcome this drawback, we take the lesson from other catalysis researches that showed improved catalytic activities by employing metal alloy catalysts. Such research effort has led us to find Pt3Co nanoparticles as an effective OER catalyst in Li-O-2 batteries. The superior catalytic activity was reflected in the substantially decreased overpotentials and improved cycling/rate performance compared to those of other catalysts. Density functional theory calculations suggested that the low OER overpotentials are associated with the reduced adsorption strength of LiO2 on the outermost Pt catalytic sites. Also, the alloy catalyst generates amorphous Li2O2 conformally coated around the catalyst and thus facilitates easier decomposition and higher reversibility. This investigation conveys an important message that understanding elementary reactions and surface charge engineering of air-catalysts are one of the most effective approaches in resolving the chronic sluggish charging kinetics in Li-O-2 batteries.

    Storage of Yellow Croaker Larimichthys polyactis Semen

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    Abstract Storage of semen is useful for genetic studies and artificial breeding of fish. The aims of the present study were to find the best extender, dilution ratio, temperature, and antibiotic for cold storage of yellow croaker Larimichthys polyactis semen

    Barrier protection via Toll-like receptor 2 signaling in porcine intestinal epithelial cells damaged by deoxynivalnol

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    Additional file 2. IPEC-J2 cells pretreated with TLR2 ligand maintained the expression of MCP-1, GM-CSF and TLR2 against DON exposure. IPEC-J2 cells pretreated with or without TLR2 ligand for 24Ā h were exposed to DON. (A) The bar graph showed the mRNA levels of porcine mcp-1, gm-csf measured using real time-PCR at 1 and 6Ā h after DON exposure (nĀ =Ā 3). (B) The mRNA levels of porcine tlr2 were measured using real-time quantitative PCR analysis at 6Ā h. NT represents no treatment. Expression of each mRNA was presented relative to the expression of housekeeping gene, gapdh (nĀ =Ā 3). *PĀ <Ā 0.05; **PĀ <Ā 0.01; ***PĀ <Ā 0.001, determined by one-way ANOVA with Tukeyā€™s posttest
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