45 research outputs found

    Transparent Wood Film Incorporating Carbon Dots as Encapsulating Material for White Light-Emitting Diodes

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    Epoxy resins are the main encapsulation materials for light-emitting diodes (LEDs) due to their high transparency, appropriate mechanical strength, and excellent thermal stability. However, environmentally benign materials needed to be developed with improving performances. Transparent wood and its nanocomposites prepared from natural biomass are potential alternative materials to them. Green preparation of transparent wood incorporating with trichromatic systems is an attractive topic, especially for white LEDs (W-LEDs). Here, multiple-color-emission carbon dots (CDs), serving as trichromatic systems in W-LEDs, were synthesized by tuning the extent of graphitization and surface function of the nanoparticles using citric acid and urea as feedstocks. Then, a green, facile, and energy-efficient method for the preparation of carbon dots/transparent wood (CDs-TW) composites was raised by the ultrafast removing of lignin from wood using deep eutectic solvent (DES, oxalic acid and choline chloride) under microwave-assisted treatment, and then, CDs and poly­(acrylic acid) (PAA) were filled into the delignified wood through an in situ polymerization. The transparent wood film embedding multicolor CDs was fabricated, which showed white light emission under ultraviolet light excitation and enhanced mechanical tensile strength (60.92 MPa). Simultaneously, the as-prepared film can be used as an encapsulation film for white LEDs, which exhibited excellent color characteristics with the Commission Internationale Eclairage (CIE) color coordinates, a correlated color temperature (CCT), and a color rendering index (CRI) of (0.33, 0.32), 5237 K, and 83, respectively. This provides a simple route to prepare metal-free wood-based encapsulating materials for W-LEDs

    Smoothing Surface Trapping States in 3D Coral-Like CoOOH-Wrapped-BiVO<sub>4</sub> for Efficient Photoelectrochemical Water Oxidation

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    Highly efficient oxygen evolution driven by abundant sunlight is a key to realize overall water splitting for large-scale conversion of renewable energy. Here, we report a strategy for the interfacial atomic and electronic coupling of layered CoOOH and BiVO<sub>4</sub> to deactivate the surface trapping states and suppress the charge-carrier recombination for high photoelectrochemical (PEC) water oxidation activity. The successful synthesis of a 3D ultrathin-CoOOH-overlayer-coated coral-like BiVO<sub>4</sub> photoanode effectively tailors the migration route of photocarriers on the semiconductor/liquid interface to realize a great increase of ∼200% in the photovoltage relative to bare BiVO<sub>4</sub>, consequently decreasing the corresponding onset potential of PEC water splitting from 0.60 to 0.20 V<sub>RHE</sub>. As a result, the unique CoOOH/BiVO<sub>4</sub> photoanode could efficiently perform PEC water oxidation in a neutral aqueous solution (pH = 7) with a high photocurrent density of 4.0 mA/cm<sup>2</sup> at 1.23 V<sub>RHE</sub> and a prominent quantum efficiency of 65% at 450 nm. Electronic structural characterizations and theoretical calculations reveal that the combination of layered CoOOH and BiVO<sub>4</sub> forming interfacial oxo-bridge bonding could greatly eliminate surface trapping states and promote the direct transfer of photogenerated holes from the valence band to the surface water redox potential for water oxidation

    Meta-analysis of the <i>IL10</i> −1082G/A polymorphism and SLE.

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    <p>OR: odds ratio; CI: confidence interval; SLE: systemic lupus erythematosus.</p>*<p>exclude the studies deviating from Hardy-Weinberg equilibrium.</p>#<p>exclude the study by Shen (2003).</p

    Taming Dinitramide Anions within an Energetic Metal–Organic Framework: A New Strategy for Synthesis and Tunable Properties of High Energy Materials

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    Energetic polynitro anions, such as dinitramide ion [N­(NO<sub>2</sub>)<sub>2</sub><sup>–</sup>], have attracted significant interest in the field of energetic materials due to their high densities and rich oxygen contents; however, most of them usually suffer from low stability. Conveniently stabilizing energetic polynitro anions to develop new high energy materials as well as tuning their energetic properties still represent significant challenges. To address these challenges, we herein propose a novel strategy that energetic polynitro anions are encapsulated within energetic cationic metal–organic frameworks (MOFs). We present N­(NO<sub>2</sub>)<sub>2</sub><sup>–</sup> encapsulated within a three-dimensional (3D) energetic cationic MOF through simple anion exchange. The resultant inclusion complex exhibits a remarkable thermal stability with the onset decomposition temperature of 221 °C, which is, to our knowledge, the highest value known for all dinitramide-based compounds. In addition, it possesses good energetic properties, which can be conveniently tuned by changing the mole ratio of the starting materials. The encapsulated anion can also be released in a controlled fashion without disrupting the framework. This work may shed new insights into the stabilization, storage, and release of labile energetic anions under ambient conditions, while providing a simple and convenient approach for the preparation of new energetic MOFs and the modulation of their energetic properties

    Regions of decreased grey matter volume at baseline in antipsychotic-naïve patients with schizophrenia compared to healthy controls. <i>P</i><0.001, uncorrected, threshold = 50.

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    <p>Regions of decreased grey matter volume at baseline in antipsychotic-naïve patients with schizophrenia compared to healthy controls. <i>P</i><0.001, uncorrected, threshold = 50.</p

    Characteristics of included studies in this meta-analysis.

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    <p>ASO: allele-specific oligonucleotid hybridization; RFLP: restriction fragment length polymorphism; PCR-SSP: polymerase chain reaction sequence specific primer; HPLC: high-performance liquid chromatography; MS: mass spectrometry; PLACE-SSCP post-PCR fluorescent labeling and automated capillary electrophoresis under single-strand conformation polymorphism conditions; SNPs: single nucleotide polymorphisms.</p>#<p>no polymorphisms.</p

    Activating Cobalt Nanoparticles via the Mott–Schottky Effect in Nitrogen-Rich Carbon Shells for Base-Free Aerobic Oxidation of Alcohols to Esters

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    Heterogeneous catalysts of inexpensive and reusable transition-metal are attractive alternatives to homogeneous catalysts; the relatively low activity of transition-metal nanoparticles has become the main hurdle for their practical applications. Here, the <i>de novo</i> design of a Mott–Schottky-type heterogeneous catalyst is reported to boost the activity of a transition-metal nanocatalyst through electron transfer at the metal/nitrogen-doped carbon interface. The Mott–Schottky catalyst of nitrogen-rich carbon-coated cobalt nanoparticles (Co@NC) was prepared through direct polycondensation of simple organic molecules and inorganic metal salts in the presence of g-C<sub>3</sub>N<sub>4</sub> powder. The Co@NC with controllable nitrogen content and thus tunable Fermi energy and catalytic activity exhibited a high turnover frequency (TOF) value (8.12 mol methyl benzoate mol<sup>–1</sup> Co h<sup>–1</sup>) for the direct, base-free, aerobic oxidation of benzyl alcohols to methyl benzoate; this TOF is 30-fold higher than those of the state-of-the-art transition-metal-based nanocatalysts reported in the literature. The presented efficient Mott–Schottky catalyst can trigger the synthesis of a series of alkyl esters and even diesters in high yields
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