43 results match your criteria: "National Taiwan University Taipei 10617 Taiwan.[Affiliation]"

By strategic design and synthesis of a new series of phosphonium salts (compounds 1-7[OTf]), where [OTf] stands for the trifluoromethanesulfonate anion, we performed comprehensive spectroscopic and dynamic studies on the photoinduced anion migration in toluene. Our aim is to probe if the anion migration is associated with an intrinsic barrier or is barrier-free. After the occurrence of excited-state intramolecular charge transfer (ESICT) in 1-7, the charge redistribution of the cation triggers the translocation of the counter anion [OTf], resulting in emission spectral temporal evolution.

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A terbium-based metal-organic framework (MOF) with exceptional water stability for highly selective detection of pesticide thiamethoxam (TMX) in aqueous solution is reported. To date, most reported lanthanide metal-organic frameworks (Ln-MOFs) still exhibit poor water stability, which may limit their practical applications in bio-sensing and detecting pollutants in environmental water samples. In this work, a Tb-MOF [Tb(BDC)(DEF)·0.

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Electrospun nanofibers made from chitosan are promising materials for surgical wound dressings due to their non-toxicity and biocompatibility. However, the antibacterial activity of chitosan is limited by its poor water solubility under physiological conditions. This study addresses this issue by producing electrospun nanofibers mainly from natural compounds, including chitosan and quaternized chitosan, which enhance both its solubility for electrospinning and the antibacterial activity of the resulting electrospun nanofibers.

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Fano enhancement of SERS for rapid early diagnosis of colorectal cancer.

Nanoscale Adv

September 2024

Laboratory of Digestive Surgery, State Key Laboratory of Biotherapy and Cancer Center, Department of Gastro-intestinal Surgery, West China Hospital, West China School of Medicine, Sichuan University China

Patients benefit greatly from early detection of colorectal cancer, but present diagnostic procedures have high costs, low sensitivity, and low specificity. However, it is still difficult to develop a strategy that can effectively detect cancer early using high-throughput blood analysis. Fano resonance-boosted SERS platform label-free serum creates an effective diagnostic system at the point of care.

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Metal-halide perovskites are recognized as cutting-edge solar energy technology, boasting remarkable absorption capabilities, minimal environmental impact, and cost-effectiveness. This study delves into the structural stability, mechanical stability, and optoelectronic properties of lead-free halide perovskites, specifically XMgI (X = Li/Na), by utilizing the CASTEP and WIEN2k software along with the GGA-PBE and Tran-Blaha modified Becke-Johnson (TB-mBJ) exchange-correlation functions to compare their electronic properties. The structural and mechanical stabilities were confirmed by assessing their tolerance factor and formation energy and by evaluating their elastic constants, respectively.

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Mixed-matrix membranes (MMMs) have been reported to have considerable scope in gas separation applications because of their merged inherent strength of a durable polymer matrix and the exceptional performance capabilities of inorganic fillers. The selection of comparatively suitable polymers with fillers that can match each other and boost interfacial compatibility while ensuring uniform dispersion of filler within the polymer is still intensively demanding and is challenging at the experimental scale. Ionic liquids (ILs) are effective in promoting better dispersion and compatibility, leading to improved separation performance.

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High-order layered self-assembled multicavity metal--organic capsules and anti-cooperative host-multi-guest chemistry.

Chem Sci

June 2024

Department of Organic and Polymer Chemistry, Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University Changsha Hunan-410083 China.

Article Synopsis
  • - The rapid advancement in constructing metal-organic cages with internal cavities faces challenges in synthesizing complex capsules with multiple cavities and understanding how they recognize and interact with multiple guests.
  • - Researchers developed high-order layered metal-organic architectures (G1 to G4) by using specific ligands and metal ions, which function like LEGO blocks to create structures with various compartment sizes.
  • - Experiments showed these structures can encapsulate up to four C molecules and exhibit negative cooperation behavior during multi-guest recognition, offering new insights into interactions in supramolecular chemistry.
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Photocatalytic reactions and their magnetic-field enhancement present significant potential for practical applications in green chemistry. This work presents the mutual enhancement of plasmonic photocatalytic reaction by externally applied magnetic field and plasmonic enhancement in a micro optofluidic chip reactor. The tiny gold (Au) nanoparticles of only a few atoms fixed on the surface of titanium dioxide (TiO) nanoparticles lead to mutually boosted enhancement photocatalytic reactions under an external magnetic field and plasmonic effects.

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Perovskite quantum dots (QDs) are considered as promising materials for numerous optoelectronic applications due to their narrow emission spectra, high color purity, high photoluminescence quantum yields (PLQYs), and cost-effectiveness. Herein, we synthesized various types of perovskite QDs and incorporated Au nanoparticles (NPs) to systematically investigate the impact of plasmonic effects on the photoluminescence performance of perovskite QDs. The PLQYs of the QDs are enhanced effectively upon the inclusion of Au NPs in the solutions, with an impressive PLQY approaching 99% achieved.

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Co-integration of gallium nitride (GaN) power devices with Si logic ICs provides a way of applying high power and high efficiency circuits on a single chip. In order to co-integrate GaN devices with Si ICs, an ohmic contact for GaN devices has to be Si compatible and durable at the same or higher temperature of the back-end process in the conventional complementary metal oxide semiconductor (CMOS) industry. In this work, an Au-free ohmic junction with high thermal stability for AlGaN/GaN high electron mobility transistors (HEMTs) was presented.

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Solvent (, water)-catalyzed proton transfer (SCPT) the relay of hydrogen (H)-bonds plays a key role in proton migration. In this study, a new class of 1-pyrrolo[3,2-]quinolines (PyrQs) and their derivatives were synthesized, with sufficient separation of the pyrrolic proton donating and pyridinic proton accepting sites to probe excited-state SCPT. There was dual fluorescence for all PyrQs in methanol, , normal (PyrQ) and tautomer 8-pyrrolo[3,2]quinoline (8H-PyrQ) emissions.

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Water electrolysis is the most promising method for the production of large scalable hydrogen (H), which can fulfill the global energy demand of modern society. H-based fuel cell transportation has been operating with zero greenhouse emission to improve both indoor and outdoor air quality, in addition to the development of economically viable sustainable green energy for widespread electrochemical applications. Many countries have been eagerly focusing on the development of renewable as well as H-based energy storage infrastructure to fulfill their growing energy demands and sustainable goals.

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This paper presents an integrated and scalable precision health service for health promotion and chronic disease prevention. Continuous real-time monitoring of lifestyle and environmental factors is implemented by integrating wearable devices, open environmental data, indoor air quality sensing devices, a location-based smartphone app, and an AI-assisted telecare platform. The AI-assisted telecare platform provided comprehensive insight into patients' clinical, lifestyle, and environmental data, and generated reliable predictions of future acute exacerbation events.

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Catalysts for the oxygen evolution reaction (OER) are receiving great interest since OER remains the bottleneck of water electrolyzers for hydrogen production. Especially, OER in acidic solutions is crucial since it produces high current densities and avoids precipitation of carbonates. However, even the acid stable iridates undergo severe dissolution during the OER.

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The straightforward preparation of N-coordinated ruthenium triazolato complexes by [3 + 2] cycloaddition reactions of a ruthenium azido complex [Ru]-N (1, [Ru] = (η-CH)(dppe)Ru, dppe = PhPCHCHPPh) with a series of terminal phenylacetylenes is reported. The reaction products, N(2)-bound ruthenium 4-aryl-1,2,3-triazolato complexes such as [Ru]NCH(4-CHCN) (2), [Ru]NCH(4-CHCHO) (3), [Ru]NCH(4-CHF) (4), [Ru]NCH(Ph) (5) and [Ru]NCH(4-CHCH) (6) were produced from 4-ethynylbenzonitrile, 4-ethynylbenzaldehyde, 1-ethynyl-4-fluorobenzene, phenylacetylene and 4-ethynyltoluene, respectively, at 80 °C or above under an atmosphere of air. To the best of our knowledge, this is the first example of the preparation of N-coordinated ruthenium aryl-substituted 1,2,3-triazolato complexes by the [3 + 2] cycloaddition of a metal-coordinated azido ligand and a terminal aryl acetylene, less electron-deficient terminal aryl alkynes.

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In this study, we synthesized gradient MoS films with a home-made suspended mask and characterized them by transmission electron microscopy (TEM) and Raman spectroscopy. The advantage of using gradient films is to simultaneously produce numerous samples under the same growth condition but with different thicknesses. The cross-sectional TEM images and their Fourier transform spectra revealed the thickness dependency of the grain orientations for synthetic MoS films.

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Over the past few years, thermally-assisted-occupation density functional theory (TAO-DFT) [J.-D. Chai, , 2012, , 154104] has been proved to be an efficient electronic structure method for investigating the ground-state properties of large electronic systems with strong static correlation effects.

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The electrochemical sensing applications of a series of water-stable 2D metal-organic framework (MOF)-modified screen-printed carbon electrodes (SPCEs) are reported. The MOF materials in this study are [M(bipy)(CO)(HO)]·3HO, in which bipy = 4,4'-bipyridine and M = Mn, Fe, Co and Zn. The MOF materials are characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), showing that the MOFs have a layer-by-layer rod structure with a smooth surface.

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Developing a colloidal quantum-dot light-emitting device (QDLED) with high efficiency and good reliability is necessarily preliminary for the next-generation high-quality display application. Most QDLED reports are focused on efficiency improvement, but the device operational lifetime issue is less addressed and also the relevant degradation mechanisms. This study achieved a 1.

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An asymmetric 2,3-fluoranthene imide building block for regioregular semiconductors with aggregation-induced emission properties.

Chem Sci

January 2022

Key Laboratory for Material Chemistry of Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology Wuhan 430074 China

For organic semiconductors, the development of electron-deficient building blocks has lagged far behind that of the electron-rich ones. Moreover, it remains a significant challenge to design organic molecules with efficient charge transport and strong solid-state emission simultaneously. Herein, we describe a facile synthetic route toward a new π-acceptor imide building block, namely 2,3-fluoranthene imide, based on which four regioregular small molecules (F1-F4) are synthesized by tuning the imide orientations and the central linkage bridges.

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A tunable bandgap without doping is highly desirable for applications in optoelectronic devices. Herein, we develop a new method which can tune the bandgap without any doping. In the present research, the bandgap of FeO nanostructured films is simply tuned by changing the synthesis temperature.

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Article Synopsis
  • Recent advancements in organometallic 2D nanosheets have captured attention in optoelectronics, particularly for their ability to be processed in solution, yet their application is limited by the stability of organic components.
  • A new air-stable 2D nanosheet, bis(dithiolene)iron(II) (FeBHT), has been developed using a special polymerization method that protects sensitive sulfur groups, enhancing durability against oxidation.
  • The FeBHT exhibits impressive photoresponse characteristics and maintains over 94% of its original performance even after 60 days in air, suggesting strong potential for practical applications in optoelectronic devices.
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A novel quinoidal thienoisoindigo (TII)-containing small molecule family with dicyanomethylene end-capping units and various alkyl chains is synthesized as n-type organic small molecules for solution-processable organic field effect transistors (OFETs). The molecular structure of the 2-hexyldecyl substituted derivative, , is determined via single-crystal X-ray diffraction and shows that the core is planar and exhibits molecular layers stacked in a "face-to-face" arrangement with short core intermolecular distances of 3.28 Å.

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Based on an integrated study of magnetic susceptibility, specific heat, and thermal expansion of single-crystal LaCoO free from cobalt and oxygen vacancies, two narrow spin gaps are identified before and after the phonon softening of gap size Δ ∼ 0.5 meV in a CoO-octahedral crystal electric field (CEF) and the thermally activated spin gap ∼ 25 meV, respectively. Significant excitation of Co spins from a low-spin (LS) to a high-spin (HS) state is confirmed by the thermal activation behavior of spin susceptibility of energy gap ∼ 25 meV, which follows a two-level Boltzmann distribution to saturate at a level of 50% LS/50% HS statistically above ∼200 K, without the inclusion of a postulated intermediate spin (IS) state.

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Article Synopsis
  • - The linewidth of the field emission resonance (FER) on MoS surfaces can change significantly, by up to ten times, as the electric field increases.
  • - This variation is explained by a concept called quantum trapping, where an electron becomes temporarily trapped in a potential well because of its wave properties after relaxation from a resonance state.
  • - The Pauli exclusion principle plays a role in lengthening the lifetimes of resonant electrons, allowing them to coexist with relaxed electrons and leading to a notably reduced linewidth of about 12 meV.
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