BIHARMONIC GREEN FUNCTION AND BISUPERMEDIAN ON INFINITE NETWORKS

In this article, we have discussed Biharmonic Green function on an infinite network and bimedian functions. We have proved some standard results in terms of supermedian and bimedian. Also, we have proved the Discrete Riquier problem in the setting of bimedian functions

Maximizing analytical precision: exploring the advantages of ratiometric strategy in fluorescence, Raman, electrochemical, and mass spectrometry detection

Ratiometric strategy are an invaluable method that helps to detect and quantify analytes. This approach relies on measuring changes in the ratio of two or more signals to improve the accuracy and sensitivity of the results. Ratiometric strategies are widely used in a variety of fields including biomedical, environmental monitoring and food safety. It is particularly popular when traditional single-signal based detection methods are not feasible, especially when interfering substances severely affect the detection. In addition, ratiometric methods have the potential to improve the accuracy and reliability of analyte detection, leading to better results in a variety of complex environments. The article provides a comprehensive review of ratiometric strategy, focusing on ratiometric fluorescent nanoprobes for the visual detection of analytes. This paper also discusses the design of ratiometric two-photon fluorescent probes for biomedical imaging, the synthesis of ratiometric surface-enhanced Raman scattering nanoprobes for the imaging of intracellular analytes, the development of ratiometric molecularly imprinted electrochemical sensors for detection of electroactive species, and the use of isotopically-labeled internal standards in matrix-assisted laser desorption/ionization for ratiometric analysis. The article not only discusses each technique in detail, including its principles, advantages, potential applications, and limitations, but also highlights recent advances in each method and possible future directions

Synthesis and characterization of cation-doped BiFeO₃ materials for photocatalytic applications

131-139A sol-gel method was applied to synthesize Bi1-xMxFeO3 (M = Mg, Al, Y) ceramic materials. Subsequently, these materials were structurally characterized by applying Rietveld refinement techniques. The magnetic properties of the synthesized materials were determined by SQUID measurements and their optical properties (band-gap) were determined by applying diffused reflectance (DR) techniques. The low band-gap nature of these materials enabled to them exhibit photocatalytic activity and accordingly 2% Y doped BiFeO3 samples exhibited higher photocatalytic effect (18% compared to 14% for undoped). Under identical conditions, TiO2 standard exhibited only 7% degradation indicating superior properties of cation-doped bismuth ferrites

Optimization and Characterization of Lithium Ion Cathode Materials in the System (1 – x – y)LiNi0.8Co0.2O2 • xLi2MnO3 • yLiCoO2

There is ongoing effort to identify novel materials that have performance better than LiCoO2. The objective of this work is to explore materials in the system (1 – x – y) LiNi0.8Co0.2O2 • xLi2MnO3 • yLiCoO2. A ternary composition diagram was used to identify sample points, and compositions for testing were initially chosen. Detailed characterization of the synthesized materials was done, including Rietveld Refinement of XRD data, XPS analysis for valence state of transition-metals, SEM for microstructure details, and TGA for thermal stability of the materials. Electrochemical performance showed that discharge capacities on the order of 230 mAh/g were obtained. Preliminary results showed that these materials exhibit good cycling capabilities thereby positioning these materials as promising for Li-ion battery applications

Construction of Fluorescent Conjugated Polytriazole Containing Double-Decker Silsesquioxane: Click Polymerization and Thermal Stability

This study synthesized two azide-functionalized monomers through p-dichloro xylene and double-decker silsesquioxane (DDSQ) units with NaN3 to form DB-N3 and DDSQ-N3 monomers, respectively. In addition, five different propargyl-functionalized monomers were also prepared from hydroquinone, bisphenol A, bis(4-hydroxyphenyl)methanone, 2,4-dihydroxybenzaldehyde (then reacted with hydrazine hydrate solution) and 1,2-bis(4-hydroxyphenyl)-1,2-diphenylethene with propargyl bromide to form P-B, P-BPA, P-CO, P-NP, and P-TPE monomers, respectively. As a result, various DDSQ-based main chain copolymers could be synthesized using Cu(I)-catalyzed click polymerization through DDSQ-N3 with different propargyl-functionalized monomers, of which the chemical structure and molecular weight could be confirmed by using Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC) analyses. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscope (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy analyses also could characterize the thermal stability, morphology, and optical behaviors of these DDSQ-based copolymers. All results indicate that the incorporation of an inorganic DDSQ cage could improve the thermal stability such as thermal decomposition temperature and char yield, because of the DDSQ dispersion homogeneously in the copolymer matrix, and this would then affect the optical properties of NP and TPE units in this work

Shape memory effect, temperature distribution and mechanical properties of friction stir welded nitinol

Welding of shape memory alloys without deterioration of shape memory effect could vastly extend their applications. To retain shape memory behavior, a solid-state welding technique called friction stir welding was employed in this study. Austenitic NiTi alloy sheets of thickness 1.2 mm were joined at tool rotational speeds of 800,1000, and 1200 rpm. Due to dynamic recrystallization, the grain refinement has occurred in the weld region. The tensile testing has shown superelastic plateau for the welds at 800 and 1000 rpm. The phase transformation behavior of different weld regions was studied in detail using differential scanning calorimeter. A marginal drift in transformation temperatures was observed in the weld. To understand the drift in phase transformation temperatures, finite element analysis was carried out with focus on temperature distribution during welding. Finally, time-dependent shape recovery of a FSW welded joint was studied and it was found that the original position was completely recovered after 27 s at a temperature of 65 degrees C. (C) 2018 Elsevier B.V. All rights reserved

Microstructure, mechanical properties and shape memory behaviour of friction stir welded nitinol

For the first time, NiTi shape memory alloy was successfully joined by Friction Stir Welding (FSW). The weld showed significant grain refinement without formation of detrimental phases. The yield strength of the weld joint increased by 17% as compared to the base metal without substantial change in shape memory behaviour

Construction of Ultrastable Conjugated Microporous Polymers Containing Thiophene and Fluorene for Metal Ion Sensing and Energy Storage

In this study, we have used the one-pot polycondensation method to prepare novel 2D conjugated microporous polymers (Th-F-CMP) containing thiophene (Th) and fluorene (Fl) moieties through the Suzuki cross-coupling reaction. The thermogravimetric analysis (TGA) data revealed that Th-F-CMP (Td10 = 418 °C, char yield: 53 wt%). Based on BET analyses, the Th-F-CMP sample displayed a BET specific surface area of 30 m2 g−1, and the pore size was 2.61 nm. Next, to show the effectiveness of our study, we utilized Th-F-CMP as a fluorescence probe for the selective detection of Fe3+ ions at neutral pH with a linear range from 2.0 to 25.0 nM (R2 = 0.9349). Furthermore, the electrochemical experimental studies showed that the Th-F-CMP framework had a superior specific capacity of 84.7 F g−1 at a current density of 0.5 A g−1 and outstanding capacitance retention (88%) over 2000 cycles