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关键词： Thermal barrier coating (TBC)   Bond coat   Composition   Oxidation   Microstructure  

摘要： Thermal barrier coatings (TBCs) are vital to the safety of industrial components operating at high temperatures; however, microstructural changes in TBC-coated specimens over prolonged periods high-temperature exposure remain unclear. Hence, this study investigated the long-term high-temperature isothermal oxidation behavior of TBCs incorporating three different commercially available NiCoCrAlY-based bonds deposited by vacuum plasma spray on CM247 superalloy substrates. Coated specimens were oxidized in atmospheric air at 1000 °C for up to 15,000 h, and the evolution of microstructural features was analyzed in detail with emphasis on the thermally grown oxide (TGO), Al-rich phase depletion zone (ADZ), and interdiffusion zone (IDZ). A quantitative analysis of the compositional details revealed that minor additions of Hf and Si accelerated Al depletion in the bond coat, resulting in increased oxidation rates beyond 11,000 h and the formation of Cr-rich oxides at the bond coat-oxide interface. However, Hf and Si additions suppressed the formation of α-Cr in the IDZ, thus maintaining a more uniform composition. A bond coat containing Hf, Si, Ta, and Re exhibited a dual-layer TGO composed of a Ta-rich oxide and a PEG-like structure. The presence of Ta and Re helped effectively reduce interdiffusion within the bond coat, resulting in slower TGO growth and enhanced microstructural stability. Moreover, the chemical composition of the IDZ remained closer to that of the substrate, thus preserving a stable dual-phase microstructure. The findings are expected to contribute to our understanding of the microstructural features of TBCs employed in high-temperature applications.

关键词： Bisphenol A   Mechanism   Mesoporous HKUST-1   Molecularly imprinted polymer   Selective removal  

摘要： Metal–organic frameworks (MOFs) with high surface area and tunable pore structures have been widely used as molecularly imprinted polymer (MIP) supports. However, conventional microporous MOF structures restrict imprinting layer formation on their internal surfaces, thus limiting accessible imprinting sites. In this study, mesoporous HKUST-1 (Me-HKUST-1) was prepared using sodium dodecyl sulfate (SDS) as a soft template, employed as a support to construct a double-imprinted polymer composite (Me-HKUST-1@MIP). Introduction of mesopores increased support accessibility and promoted formation of additional imprinting sites, enabling rapid and highly selective bisphenol A (BPA) adsorption. The results showed that the most probable Me-HKUST-1 pore size reached 24.34 nm, and Me-HKUST-1@MIP exhibited an adsorption capacity of 187.83 mg g⁻¹ toward BPA within 60 min, 1.45-fold that of traditional microporous HKUST-1@MIP (129.28 mg g⁻¹). The adsorption behavior was well fitted by the Elovich kinetic model and Freundlich isotherm, indicating heterogeneous adsorption. Me-HKUST-1@MIP exhibited superior selectivity, with a 2.22-fold higher recognition ability than HKUST-1@MIP in a mixed system containing BPA, bisphenol B (BPB), 2,4-dinitrophenol (2,4-NP), chloramphenicol (CAP), and sulfadiazine (SD). Mechanistic analysis combined with two-dimensional correlation infrared spectroscopy (2D-COS IR) suggested the sequential evolution of cavity-related responses, hydrogen bond-associated interactions, and subsequent guest accumulation during adsorption. In actual matrix-spiked samples, Me-HKUST-1@MIP achieved 81.63–109.74% recovery for BPA with relative standard deviations (RSDs) < 6.74% and could be reused for 15 cycles. These results indicate that increasing porous crystalline support pore size is an effective strategy for improving MIP adsorption performance and practical applicability toward organic pollutants.

关键词： Exact solution   Frustrated spin chain   Magnons  

摘要： This paper considers an N-site spin-1/2 J₁-J₂ ring with $N=6$ and 8. With the help of a set of exact few-magnon Bloch states, we obtain the block-diagonalized Hamiltonian consisting of block matrices of at most four dimensions. Partial of the eigenstates are analytically solved. For the six-site anisotropic ring, we reveal a subset of eigenstates that are simultaneous eigenstates of the Hamiltonian and the total angular momentum operator, even though the latter is not conserved. For both the six- and eight-site isotropic rings, we achieve momentum-space manifestations of several important states, including the famous Majumdar-Ghosh (MG) ground states and the Hamada-Kane-Nakagawa-Natsume (HKNN) ground state. The equivalence of these states with their real-space counterparts is explicitly shown for $N=6$. The structure of the HKNN ground state for small rings suggests that for any even number N this state might behave like a “bound state” with N/2 successive down spins binding together.

关键词： GLP-1 receptor agonists   Idiopathic intracranial hypertension   Neuroendocrine therapy   Systematic review   meta-analysis  

关键词： Ferrocene   1,2,3-triazole   Cholinesterase inhibition   α-amylase inhibition   Antioxidant activity  

摘要：

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  New compounds containing ferrocene groups, 1,2,3-triazole, oxime and hydrazide groups in a single structure were synthesized.
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  All the compounds exhibited measurable AChE (IC₅₀ = 6.67–32.87 µM), BChE (IC₅₀ = 3.07–9.84 µM) and α-amylase (IC₅₀ = 5.41–12.45 µM) inhibition.
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  The antioaxidant properties of these hybrid compounds were investigated.
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  The antioxidant properties of the compounds showed higher radical scavenging activity compared to the reference antioxidants ascorbic acid and butylated hydroxytoluene.
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  The addition of a hydrazide group to the structure significantly increased its antioxidant capacity.

关键词： Ferroelectric thin films   KBNNO   Photovoltaic output   Flexoelectric effect  

摘要：

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  In-situ poling & flexoelectricity enable reversible tuning of Pb-free ferroelectric film photovoltaics, boosting photocurrent.
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  KBNNO device delivers 50% higher short-circuit current via synergy, featuring narrow bandgap & broad UV-NIR absorption as a promising photoactive layer.
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  Generalizable band-modulation mechanism with all-inorganic flexible structure enables broad use in next-gen flexible optoelectronics.

关键词： Palm oil fuel ash   KCC-1   copper   photocatalysts   methylene Blue  

摘要： A waste-to-wealth strategy is reported for the fabrication of a copper-functionalized fibrous nanosilica (Cu/KCC-1) photocatalyst derived from palm oil fuel ash (POFA an abundant silica-rich agricultural residue. The Cu/KCC-1 nanocomposite retains the characteristic dendritic fibrous architecture and high surface area of KCC-1, while incorporating catalytically active Cu species within the amorphous silica framework, as confirmed by FESEM, XRD, BET, FTIR, and UV-Vis DRS analyses. The resulting catalyst exhibits outstanding photocatalytic activity toward methylene blue degradation, achieving 94.30% efficiency under UV irradiation at pH 8 with a catalyst dosage of 3 g/L and an initial dye concentration of 10 mg/L. Reaction temperature strongly influenced performance, with optimal degradation at 50 degrees C, beyond which charge-carrier recombination and partial deactivation limited the catalytic efficiency. The superior activity is attributed to enhanced light absorption, increased density of accessible active sites, and improved charge separation induced by Cu incorporation within the fibrous silica matrix. Alkaline conditions further promoted degradation by facilitating reactive oxygen species generation. A mechanism involving surface adsorption followed by center dot OH- and O2 center dot- driven oxidative mineralization is proposed. This study demonstrates the viability of POFA-derived Cu/KCC-1 as a high-performance, low-cost, and sustainable photocatalyst for advanced wastewater remediation.

关键词： In situ Raman scattering   iPB-1 II-I crystal transition   Role of amorphous region  

摘要： Raman spectroscopy is indispensable for studying polymeric materials due to its non-destructive nature, sensitivity to molecular vibrations, and ability to reveal chemical composition, structure, and crystallinity. As the number of atoms in a polymer increases, the potential for greater entropic contributions to order or disorder also rises. The kinetics of order-disorder transition is determined by the chain dynamics with entropic change. Rac-ethylenebis(indenyl)zirconium chloride (rac-Et(Ind)₂ZrCl₂) and methylaluminoxane (MAO) were used as catalysts to copolymerize 1-butene with allyltrimethylsilane (TMAS) as copolymers PB-TMAS for blending with isotactic polybutene-1(iPB-1) to understand the role of amorphous phase in II-I crystal transition. The iPB-1 was blended with various contents of the synthesized PB-TMAS (no more than 1.0 wt%) for investigating the II-I crystal transition of iPB-1 by in-situ Raman spectra. The melting of form I during heating and the formation of form II during cooling in highly isotactic polybutene-1(HIPB) together with the II-I crystal transition of iPB-1 in HIPB and iPB-1/PB-TMAS blends were characterized. Raman spectra after differentiation indicates that the form I and form II do not interfere with each other during II-I transition, and their characteristic vibration modes remain constant. The results show that the transition of form II to form I is retarded by the copolymer PB-TMAS in all blends with formation of form I initiating first followed by a reduction of form II. It is convinced that the amorphous region plays key roles not only in the formation of form II from melt but also in the form II to form I transition, which is necessary to understand the II-I transition process and the applications of iPB-1.