35 research outputs found

    Distinctly Improved Photocurrent and Stability in TiO<sub>2</sub> Nanotube Arrays by Ladder Band Structure

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    Introducing a ternary interlayer into binary heterostructures to construct a ladder band structure provides a promising way for photoelectrochemical water splitting. Here, we design and fabricate a sandwich structure on TiO<sub>2</sub> nanotubes using CdS<sub><i>x</i></sub>Se<sub>1–<i>x</i></sub> as the interlayer to obtain a matching band alignment. The photoelectrochemical (PEC) properties of composite photoanodes are optimized by the order of sensitization and elements ratio, wherein the TiO<sub>2</sub>/CdS/CdS<sub>0.5</sub>Se<sub>0.5</sub>/CdSe photoanode shows a significantly enhanced photocurrent of 14.78 mA cm<sup>–2</sup> at −0.2 V vs SCE, exhibiting a nearly 15-fold enhancement, over 1 order of magnitude. The quantum efficiency apparently increases to 40% at a range of 400–520 nm, resulting from the fact that a sensitizing layer with a matching band alignment can facilitate the separation of photogenerated electron–hole pairs and also extend the absorption range to the visible region due to its narrow bandgaps. Furthermore, its stability was distinctly improved by coating MoS<sub>2</sub> on the surface of the TiO<sub>2</sub>/CdS/CdS<sub>0.5</sub>Se<sub>0.5</sub>/CdSe photoanode. Our findings provide a novel route toward developing a highly efficient photoelectrode for water splitting

    Festuca loliacea

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    Three new <i>ent</i>-eudesmane sesquiterpenoids, arundinols A–C (<b>1</b>–<b>3</b>), one isochroman-1-one, arundinone A (<b>4</b>), and a polyoxygenated benzofuran-3­(2<i>H</i>)-one dimer, arundinone B (<b>5</b>), were isolated from the extract of a plant endophytic fungus, <i>Microsphaeropsis arundinis</i>. Their structures were elucidated primarily by NMR experiments, and <b>1</b> was confirmed by X-ray crystallography. The absolute configuration of <b>1</b> was assigned by X-ray crystallography using Cu Kα radiation, whereas those of the C-11 tertiary alcohols in <b>2</b> and <b>3</b> were deduced via the circular dichroism data of the in situ formed [Rh<sub>2</sub>(OCOCF<sub>3</sub>)<sub>4</sub>] complexes. Arundinone B (<b>5</b>) represents the first dimeric benzofuran-3­(2<i>H</i>)-one, showing cytotoxicity against T24 and A549 cells. The co-isolated known compound <b>6</b> showed a modest inhibitory effect against <i>Staphylococcus aureus</i>

    Table1_Effects of extreme cyclic loading on the cushioning performance of human heel pads under engineering test condition.xlsx

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    Human heel pads commonly undergo cyclic loading during daily activities. Low cyclic loadings such as daily human walking tend to have less effect on the mechanical properties of heel pads. However, the impact of cyclic loading on cushion performance, a vital biomechanical property of heel pads, under engineering test condition remains unexplored. Herein, dynamic mechanical measurements and finite element (FE) simulations were employed to explore this phenomenon. It was found that the wavy collagen fibers in the heel pad will be straightened under cycle compression loading, which resulted in increased stiffness of the heel pad. The stiffness of the heel pads demonstrated an inclination to escalate over a span of 50,000 loading cycles, consequently resulting in a corresponding increase in peak impact force over the same loading cycles. Sustained cyclic loading has the potential to result in the fracturing of the straightened collagen fibers, this collagen breakage may diminish the stiffness of the heel pad, leading to a reduction in peak impact force. This work enhances understanding of the biomechanical functions of human heel pad and may provide potential inspirations for the innovative development of healthcare devices for foot complex.</p

    Neonectrolide A, a New Oxaphenalenone Spiroketal from the Fungus <i>Neonectria</i> sp.

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    Neonectrolide A (<b>1</b>), an oxaphenalenone spiroketal with the previously undescribed (5,8′-dimethyl-5′-oxo-3a′,4,5,5′-tetrahydro-3<i>H</i>,3′<i>H</i>-spiro[furan-2,2′-isochromeno[3,4,5-<i>def</i>]chromene]-3′-yl)but-3-enoic acid skeleton, was isolated from cultures of the fungus <i>Neonectria</i> sp. Its absolute configuration was assigned by electronic circular dichroism (ECD) calculations. The skeleton of an oxaphenalenone fused with a 1,6-dioxaspiro[4.5]decane moiety in <b>1</b> could be derived from the coisolated putative precursors, corymbiferan lactone E (<b>2</b>) and 3-dehydroxy-4-<i>O</i>-acetylcephalosporolide C (<b>3</b>)

    Flower-visiting insects at different stages of anthesis.

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    <p>(A) Aggregation of <i>Bibio</i> sp. on the surface of a swollen bud during the pre-pistillate stage. (B) <i>Epuraea</i> sp. foraging for pollen when the anthers were dehisced. (C) <i>Polistes chinensis</i> in a floral chamber at the staminate stage. (D) Brown lacewing (Hemerobiidae, Neuroptera) (left) and <i>Epuraea</i> sp. (right) crawling on the inner petals during the staminate stage. (E) <i>Apis cerana</i> foraging for pollen at the post-staminate stage.</p

    A new <i>β</i>-diketonate Dy(III) single‒ion magnet featuring multiple magnetic relaxation processes

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    <p>A <i>β</i>-diketonate mononuclear dysprosium compound, [Dy(TFNB)<sub>3</sub>(bpy)] (<b>1</b>) (TFNB = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione, bpy = 2,2′-bipyridine), has been prepared and structurally and magnetically characterized. X-ray crystallographic analysis reveals that <b>1</b> contains two crystallographically equivalent Dy(III) ions of which the eight-coordinate geometries uniformly behave as distorted square antiprismatic configurations (<i>D</i><sub>4d</sub>). Magnetic investigations demonstrate that <b>1</b> displays dual relaxation processes of SMMs behavior with the effective barrier (Δ<i>E</i>/<i>k</i><sub>B</sub>) of 23.44 K under 1200 Oe DC field, corresponding to the coexistence of two metal centers in the structure of the compound. The comparative studies of some Dy(III)-based SIMs with TFNB ligand have been conducted as well. <i>Ab initio</i> studies demonstrate that the Kramers doublet ground state is predominantly axial with the <i>g</i><sub>z</sub> tensors of two Dy(III) fragments matching the Ising-limit factor (20) anticipated for the pure <i>M</i><sub>J</sub> = ±15/2 state.</p
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