In this study, we used classical and simple Sonogashira couplings to construct three 1,3,4-oxadiazole-linked conjugated microporous polymers (OXD-CMPs) through the reaction of 2,5-bis(4-bromophenyl)-1,3,4-oxadiazole (OXD-Br2) as a common partner with the structurally diverse units of ethynyl triphenylamine, tetraphenylethene, and pyrene, respectively. We used several methods, both spectroscopic and microscopic, to characterize the three OXD-CMPs. Each OXD-CMP displayed a high thermal stability. The Py-OXD-CMP possessed pores having sizes in the range 1.20–2.25 nm and a high surface area (298 m2 g–1). These OXD-CMPs interacted with singled-walled carbon nanotubes (CNTs), stabilized through noncovalent π–π interactions, to afford OXD-CMP/CNT composites that were suitable for supercapacitor devices. Among our OXD-CMP/CNT composites, the Py-OXD-CMP/CNT composite offered a specific capacitance of 504 F g–1 and a superior capacitance retention (91.1%) over 2000 cycles.
Conductive and porous nitrogen-rich materials have great potential as supercapacitor electrode materials. The exceptional efficiency of such compounds, however, is dependent on their larger surface area and the level of nitrogen doping. To address these issues, we synthesized a porous covalent triazine framework (An-CTFs) based on 9,10-dicyanoanthracene (An-CN) units through an ionothermal reaction in the presence of different molar ratios of molten zinc chloride (ZnCl2) at 400 and 500 °C, yielding An-CTF-10-400, An-CTF-20-400, An-CTF-10-500, and An-CTF-20-500 microporous materials. According to N2 adsorption–desorption analyses (BET), these An-CTFs produced exceptionally high specific surface areas ranging from 406–751 m2·g−1. Furthermore, An-CTF-10-500 had a capacitance of 589 F·g−1, remarkable cycle stability up to 5000 cycles, up to 95% capacity retention, and strong CO2 adsorption capacity up to 5.65 mmol·g−1 at 273 K. As a result, our An-CTFs are a good alternative for both electrochemical energy storage and CO2 uptake.
A rapid, efficient, and one-pot protocol has been developed for the synthesis of cyclized 2,6-dimethyl-5-substituted-thiazolo[3,2-b]-s-triazoles (3a–c) through the interaction of 5-methyl-1H-s-triazole-3-thiol (1) with aliphatic ketones (2a–d) in refluxing acetic acid in the presence of a catalytic amount of sulfuric acid (AcOH/H+) while with aromatic ketones (5a–d), a mixture of uncyclized 3-methyl-s-triazolylthioacetophenone derivatives (6a–d) and cyclized 6-aryl-2-methyl-thiazolo[3,2-b]-s-triazoles (7a–d) has been produced. With this catalytic system, inexpensive sulfuric acid was utilized as a catalyst, which prevented the production of poisonous and irritating halo carbonyl compounds. On the other hand, the interaction of s-triazole 1 with cyano compounds (9a,b) afforded the corresponding 6-amino-2-methyl-5-substituted-thiazolo[3,2-b]-s-triazoles (10a,b). Similarly, treatment of 4-amino-3-methyl-s-triazole-5-thiol (12) with aliphatic and aromatic ketones (2c and 5a–e) afforded directly 3-methyl-7H-s-triazolo[3,4-b]-1,3,4-thiadiazines (13a and 14a–e). Further, reaction of 12 with cyano compounds (9a,b) under the same reaction conditions yielded the corresponding 3-methyl-s-triazolo[3,4-b]-1,3,4-thiadiazole derivatives (15a,b). The reaction mechanism was studied, and the structures of all novel compounds were verified using spectroscopy and elemental analysis. Moreover, the potential application of the synthesized compounds toward heavy metal ions and inorganic anion removal from aqueous solution has been investigated. The removal effectiveness for metal ions reached up to 76.29%, while for inorganic anions it reached up to 100%, indicating that such synthesized compounds are promising adsorbents for water remediation.
In this paper, we obtain sufficient conditions for the existence of fixed points for a sequence of L-fuzzy mappings in a non-Archimedean ordered modified intuitionistic fuzzy metric space. We use contractive conditions of implicit relation. Further, as an application, we also generalize our usual contractive conditions into integral contractive conditions.
We report here a comparative study of the effects of La substituted Ca on (Bi, Pb):2212 and (Bi, Pb):2223 superconductors with various La content (0.00 ≤ x ≤ 0.30). Regardless of the effects of La, it is evident that superconducting volume fraction, excess of oxygen, critical concentration for quenching superconductivity, Vickers hardness, anisotropy, interlayer coupling, critical magnetic fields, and critical current are higher for the 2212 series than the 2223. In contrast, orthorhombic distortion, c-parameter, crystallite diameter, doping distance , distance between two Cu-atoms, hole carrier/Cu ion, melting temperature Tm, critical temperature Tc, onset of diamagnetic TcM , surface energy, elastic component, resistance pressure, and c-axis coherence length are higher for the 2223 series than the 2212. An inverse linear relationship between Tm and Tc is estimated for both series, and for RT BSCCO superconductors, the required Tm values should be 1048.03 oC for the 2223 series and 784.48 oC for the 2212. Surprisingly, the difference in temperature between zero resistivity and diamagnetic onset |TcM-TcR| for La = 0.30 samples is 30 K. In the critical field region (CFR) , the exponents of order parameters (OPD) are 2D, but their values are higher for the 2212 series than the 2223. Further, they became 3D as La increased to 0.30, due to the reduced effective length in highly substituted samples. Our results are discussed with the help of the differences in the physical parameters between the considered series. These findings reveal that the 2212 series is more suitable for applications that need higher hardness, and critical fields and currents. In contrast, the 2223 series is more suitable for research for higher Tc and altering plastic deformation. To our knowledge, the present systematic investigation may never have been reported elsewhere, which highlights the present work.
In this paper, an intrinsic decoherence model is solved analytically for a Λ-type qutrit interacting with a coherent field through intensity-dependent coupling. The effects of the qutrit-cavity interaction, the intrinsic decoherence and the initial coherent field intensity are examined on some quantum phenomena as: atom population inversion, mixedness, entanglement as well as total correlation. It is found that the increase of the physical parameters, the regular oscillatory behavior of the qutrit-population collapses and revivals are changed remarkably. The interaction between the three-level atom and the coherent cavity field generates a strong mixture, negativity entanglement and total correlation (classical + quantum). The growth, the regularity and the stability of these quantum effects depend on the decoherence and the initial coherent cavity intensity.
An approximation space plays a vital role in the accuracy of approximations of a subset of the universal set. The main goal of this paper is to develop new kinds of soft rough sets models by using the concept of near open sets, where the accuracy of approximations is enhanced significantly. Firstly, the concepts of near soft rough approximations, denoted by
“JSR-approximations” for each J ∈ {P, S, γ, α, β} are proposed as a generalization some previously introduced notions.
Then, their properties and relationships are disclosed. Comparisons among the proposed methods and the previous one are obtained. An algorithm has been given for decision-making problems. The proposed algorithm is tested on hypothetical data for the purpose of comparison with already existing methods.
