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Synthesis and luminescence properties of Eu3+-doped a novel double perovskite Sr2YTaO6 phosphor
摘要： A novel Sr2Y1?xTaO6:xEu3+ (x = 0.04–0.20) red-emitting phosphor was synthesized by using the conventional solid-state reaction method. The crystal structure, photoluminescence properties, thermal stability and decay lifetimes were investigated in detail. Upon near UV light excitation, this sample exhibited a strong red emission peak centered at 612?nm due to 5D0 → 7F2, which indicated that Eu3+ occupies low symmetry sites within the Sr2YTaO6 host lattice. The optimized doping concentration of Eu3+ ion is about 12?mol%. The excellent thermal stability of Sr2YTaO6:Eu3+ phosphor was tested according to the temperature dependent emission spectra. In addition, the Sr2Y1?xEuxTaO6 phosphors exhibited good color coordinate (0.6076, 0.3879) and high color purity about 84.55%. All results indicated that the Sr2Y1?xTaO6:xEu3+ phosphors can serve as an efficient red phosphor in the white light emitting diodes.
关键词： Sr2YTaO6:Eu3+,phosphor,luminescence,thermal stability,white light emitting diodes
更新于2025-09-04 15:30:14
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Lumière derrière, lumière devant
摘要： The paper discusses the philosophical and artistic perspectives on light, painting, and the human condition, drawing on the works of Eugène Leroy and Geneviève Asse. It explores the themes of illusion, the fragility of appearance, and the interplay between light and matter in art. The text also delves into the biblical and philosophical interpretations of light, vision, and the senses, contrasting Greek and biblical views on perception and existence. Furthermore, it examines the concept of time, the phenomenology of life and death, and the role of medicine and science in understanding human existence. The paper concludes with a reflection on the importance of integrating philosophy and medicine to better comprehend the human condition.
关键词： philosophy,perception,light,phenomenology,time,human condition,medicine,painting,art,biblical interpretation
更新于2025-09-04 15:30:14
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Enhanced Temperature-Tunable Narrow-Band Photoluminescence from Resonant Perovskite Nanograting
摘要： Tunable light-emitting nanostructures are prospective for reconfigurable compact optoelectronic devices. In this regard, halide perovskites are one of the most efficient class of materials, because of their outstanding electronic and optical properties as well as low cost of fabrication and nanostructuring. Here, we study the temperature-tunable reconfiguration of photonic modes in periodically nanostructured perovskite (MAPbI3) film probed by enhanced photoluminescence. We achieved the quality factors of resonances around 500 at wavelengths 750–760 nm. The experimental results are in well agreement with theoretical simulations. Our study reveals the origin of the emission enhancement from such kind of perovskite nanostructures and paves the way to highly directional, efficient, and tunable narrowband emission from optoelectronic devices.
关键词： Optoelectronic devices,Photoluminescence,Tunable light-emitting nanostructures,Halide perovskites,Nanogratings
更新于2025-09-04 15:30:14
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High Performance Thermally Activated Delayed Fluorescence Sensitized Organic Light‐Emitting Diodes
摘要： Recently, organic light-emitting diodes (OLEDs) employing thermally activated delayed fluorescence (TADF) materials have aroused huge attention in both academia and industry. Compared with fluorescent and phosphorescent materials, TADF materials can theoretically capture 100 % excitons without incorporating noble metals, making them effective emitters and hosts for OLEDs simultaneously. Here, in this review, our recent works on mechanisms and materials of high performance TADF-sensitized phosphorescent (TSP) OLEDs, TADF-sensitized fluorescent (TSF) OLEDs and TADF-sensitized TADF (TST) OLEDs are summarized. Finally, we propose the outlook for the further development and application of TADF-sensitized OLEDs.
关键词： bipolar host,Dexter energy transfer,organic light-emitting diodes,F?rster energy transfer,thermally activated delayed fluorescence
更新于2025-09-04 15:30:14
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Molecular motors with high quantum efficiency and visible-light responsiveness: Meeting two challenges in one design
摘要： The development of light-driven rotary molecular motors is guided by a number of key goals regarding performance and applicability. While a variety of approaches to achieve high quantum yields for small UV-driven motors have been discovered, such as incorporating a protonated or alkylated nitrogen Schiff base, less progress has been made toward the goal to power molecular motors with nondestructive visible light, which will facilitate their future usage in radiation-sensitive environments. Here, we present non-adiabatic molecular dynamics simulations based on multiconfigurational quantum chemistry to demonstrate that Schiff-base motors can maintain high quantum yields also when their conjugated systems are sufficiently large for them to rather be driven by visible light. In particular, we show that a visible-light responsive Schiff-base motor featuring dihydropyridinium and cyclopentenylidene motifs achieves quantum yields of almost 70% for each of the two photoisomerizations that underlie its rotary motion.
关键词： Molecular devices,Quantum yield,Rotary motion,Molecular dynamics,Visible light
更新于2025-09-04 15:30:14
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Novel microreactors of polyacrylamide (PAM) CdS microgels for admirable photocatalytic H2 production under visible light
摘要： Cadmium sul?de, with its narrow band gap, can be used as a photocatalyst in the visible light region for the splitting of water, but its limited number of active sites and tendency to agglomerate are problematic for producing high yields of hydrogen. Therefore, an inverse emulsion polymerization method was used to fabricate polyacrylamide (PAM) microgels as a substrate to immobilize CdS nanoparticles (PAM-CdS). The PAM microgels not only immobilized the CdS nanoparticles, but also prevented aggregation. NeCd bonds in the PAM-CdS microgels facilitated electron transfer from the PAM to the CdS resulting in more electrons participating in the H2 production process. The electrostatic interactions between the PAM and CdS also hindered the recombination of electron-hole pairs. These PAM-CdS microgels exhibit admirable photocatalytic H2 production performance with a H2 production rate of up to 5.21 mmol h?1 g?1.
关键词： Visible-light water splitting,PAM microgels,CdS,Photocatalytic H2 production
更新于2025-09-04 15:30:14
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Characterization of neurite dystrophy after trauma by high speed structured illumination microscopy and lattice light sheet microscopy
摘要： Background: Unbiased screening studies have repeatedly identified actin-related proteins as one of the families of proteins most influenced by neurotrauma. Nevertheless, the status quo model of cytoskeletal reorganization after neurotrauma excludes actin and incorporates only changes in microtubules and intermediate filaments. Actin is excluded in part because it is difficult to image with conventional techniques. However, recent innovations in fluorescent microscopy provide an opportunity to image the actin cytoskeleton at super-resolution resolution in living cells. This study applied these innovations to an in vitro model of neurotrauma. New method: New methods are introduced for traumatizing neurons before imaging them with high speed structured illumination microscopy or lattice light sheet microscopy. Also, methods for analyzing structured illumination microscopy images to quantify post-traumatic neurite dystrophy are presented. Results: Human induced pluripotent stem cell-derived neurons exhibited actin organization typical of immature neurons. Neurite dystrophy increased after trauma but was not influenced by jasplakinolide treatment. The F-actin content of dystrophies varied greatly from one dystrophy to another. Comparison with existing methods: In contrast to fixation dependent methods, these methods capture the evolution of the actin cytoskeleton over time in a living cell. In contrast to prior methods based on counting dystrophies, this quantification scheme parameterizes the severity of a given dystrophy as it evolves from a local swelling to an almost-perfect spheroid that threatens to transect the neurite. Conclusions: These methods can be used to investigate genetic factors and therapeutic interventions that modulate the course of neurite dystrophy after trauma.
关键词： Traumatic brain injury,Dystrophy,Structured illumination microscopy,Human induced pluripotent stem cell derived neurons,Lattice light sheet microscopy
更新于2025-09-04 15:30:14
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A photoresponsive molecularly imprinted polymer with rapid visible-light-induced photoswitching for 4-ethylphenol in red wine
摘要： The trans to cis isomerization of the azobenzene chromophore in most azobenzene-based photoresponsive molecularly imprinted polymers (MIPs) is initiated by UV irradiation. This limits the application of these materials in cases where UV light toxicity is an issue, such as in biological systems, food monitoring, and drug delivery. Herein we report a tetra-ortho-methyl substituted azobenzene, (4-[(4-methacryloyloxy)-2,6-dimethyl phenylazo]-3,5-dimethyl benzenesulfonic acid (MADPADSA). The photoswitching of MADPADSA could be induced by visible-light in 4-hydroxyethylpiperazineethanesulfonic acid (HEPES) buffer-ethanol (4:1, v/v) at pH 7.0, however, the photo-isomerization was slow. With the use of MADPADSA as a functional monomer, NaYF4:Yb3+,Er3+ as a substrate, 4-ethylphenol (4-EP) as a template, a novel photoresponsive surface molecularly imprinted polymer NaYF4:Yb3+,Er3+@MIP was obtained. The NaYF4:Yb3+,Er3+@MIP displayed rapid visible-light-induced photoswitching. The NaYF4:Yb3+,Er3+ substrate could efficiently increase the trans to cis isomerization rate of the photoresponsive MIP on its surface, which was faster than that of the corresponding azobenzene monomer MADPADSA. Possible reasons for this effect were investigated by fluorescence spectroscopy. NaYF4:Yb3+,Er3+@MIP displayed good specificity toward 4-EP with a specific binding constant (Kd) of 3.67 × 10?6 mol L?1 and an apparent maximum adsorption capacity (Qmax) of 10.73 μmol g?1, respectively. NaYF4:Yb3+,Er3+@MIP was applied to determine the concentration of 4-EP in red wine with good efficiency and a limit of detection lower than the value that could cause an unpleasant off-flavor.
关键词： Molecularly imprinted polymer,Visible-light-induced photoswitching,4-Ethylphenol,Red wine,Azobenzene
更新于2025-09-04 15:30:14
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O12:Ce scintillator
摘要： The light yield (LY) and decay kinetics of a single crystal scintillator of Gd3Al2Ga3O12(GAGG):Ce were measured for 0.662 MeV ??- and 5.48 MeV ??-rays between ?100 ?C and room temperature. As the temperature decreased, the LY increased by 20% for ??-rays, reaching its maximum at around ?70 ?C, and increased monotonously by 50% for ??-rays. Both the rise and decay times increased gradually. Furthermore, the results indicate that pulse shape discrimination is most effective at room temperature.
关键词： Pulse shape discrimination,Light yield,Temperature dependence,Scintillator,Gd3Al2Ga3O12(GAGG):Ce,Particle detector,Decay time
更新于2025-09-04 15:30:14
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Dynamically evolving surface patterns through light-triggered wrinkling erasure
摘要： For many applications, it is an imperative that changes in polymer surface topography, especially periodic patterns, can be triggered on command by a well-defined remote signal. In this contribution, we report a light-induced cascade of changes in wrinkling wavelengths on thin polymer layers supported by an elastomeric substrate under tensile stress. Through the applied supramolecular design, the effect of varying the ratio of light active and light passive components can be easily assessed, and it is shown that both the cascade type as well as the rate of the progress of the dynamic light-induced changes can be tuned by this ratio, as well as by the light intensity. Furthermore, for the reported phenomena to occur, nominally only every 20th polymer repeat unit needs to be occupied by a chromophore, which makes the conversion of the sub-nm photoisomerization reaction into 10 μm - scale changes of periodic surface patterns extremely efficient.
关键词： light-triggered wrinkling erasure,polymer surface topography,photoisomerization,supramolecular design,elastomeric substrate
更新于2025-09-04 15:30:14