Point-Free Version of Kakutani Duality

There are many results proved using the Axiom of Choice. Using point-free topology, we can prove some of these results without using this axiom. B. Banaschewski in [Pointfree Topology and the Spectra of f-rings, Ordered algebraic structures (Curacoa, 1995), Kluwer, Dordrecht, 123–148], studying the spectra of f-rings, describes the point-free version of the classical Gelfand duality without using the Axiom of Choice In this paper, referring to [Ebrahimi, M. M., Karimi Feizabadi, A. and Mahmoudi, M.: Pointfree Spectra of Riesz Space, Appl. Categ. Struct. 12 (2004), 397–409; Ebrahimi, M. M. and Karimi Feizabadi, A.: Pointfree Spectra of ℓ-Modules, To appear in J. Pure Appl. Algebra], we describe a point-free version of the classical Kakutani duality. For this, using one of the spectra given in [Ebrahimi, M. M., Karimi Feizabadi, A. and Mahmoudi, M.: Pointfree Spectra of Riesz Space, Appl. Categ. Struct. 12 (2004), 397–409; Ebrahimi, M. M. and Karimi Feizabadi, A.: Pointfree Spectra of l-Modules, To appear in J. Pure Appl. Algebra], we find an adjunction between the category of compact completely regular frames with frame maps and the category of Archimedean bounded Riesz spaces with continuous Riesz maps.     

Novel thin film nanocomposite membranes incorporated with polyoxovanadate nanocluster for high water flux and antibacterial properties

Using interfacial polymerization (IP) of m-phenylenediamine aqueous solution containing polyoxovanadate nanoclusters (POV) and trimesoyl chloride (TMC) in organic solution, we fabricated a novel polyamide (PA)- polyoxovanadate nanocluster (POV) nanocomposite membranes (PA-POV TFN). The chemical structures and morphologies of the synthesized membranes were characterized by Fourier transform infrared (FTIR) spectroscopy, atomic force microscope (AFM), scanning electron microscopy (SEM) and water contact angle measurements. Experimental results showed that the performances of PA-POV TFN membranes are remarkably dependent on POV incorporation in the membranes, which could be controlled by using different amounts of POV particles. Moreover, the PA-POV TFN membranes illustrated outstanding antibacterial properties against Gram-negative E. coli. On the other hand, the incorporation of various amounts of POV in the membranes improved the membrane separation performances (water flux and salt rejection) as well as the antibacterial activity in FO process as compared to the original thin-film composite (TFC) polyamide membrane.     

无溶剂条件下铜磷酸锆催化醇类和酚类化合物乙酰化(英文)

Copper zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetyla-tion of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent-free conditions. The steric and electronic properties of the different substrates had a signif-icant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively-coupled plasma optical emission spectroscopy,energy dispersive spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 8.0  when Cu2+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several key advantages, including mild and environmentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.     

On Pure Subgroups of the Baer–Specker Group and Weak Crawley Groups

In this work we show how endomorphisms of certain pure subgroups of the Baer–Specker group can be extended to endomorphisms of the whole group. This allows us to establish the existence of a large family of essentially indecomposable slender groups with prescribed endomorphism rings. The extension technique is then applied to show that the Baer–Specker group is a countably-free weak Crawley group which is not a Crawley group.     

Application of a 1‐benzyl‐4‐ferrocenyl‐1H‐[1,2,3]‐triazole/carbon nanotube modified glassy carbon electrode for voltammetric determination of hydrazine in water samples

The electrochemical behaviour of hydrazine at a 1‐benzyl‐4‐ferrocenyl‐1H‐[1,2,3]‐triazole‐triazole/carbon nanotube modified glassy carbon electrode has been studied. The modified electrode shows an excellent electrocatalytic activity for the oxidation of hydrazine and accelerates electron transfer rate. The electrocatalytic current increases linearly with hydrazine concentration in the range 0.5–700.0 μm and the detection limit for hydrazine was 33.0 ± 2.0 nm . The diffusion coefficient (D = 2.5 ± 0.1 × 10^?5 cm² s^?1) and kinetic parameters such as the electron transfer coefficient, (α = 0.52) and the heterogeneous rate constant (k′ = 5.5 ± 0.1 × 10^?3 cm s^?1) for hydrazine were determined using electrochemical approaches. Finally, the method was employed for the determination of hydrazine in water samples. Copyright © 2013 John Wiley & Sons, Ltd.     

Encapsulation of Pd(II) into superparamagnetic nanoparticles grafted with EDTA and their catalytic activity towards reduction of nitroarenes and Suzuki–Miyaura coupling

A robust, safe and magnetically recoverable palladium catalyst was synthesized by anchoring Pd(II) onto ethylenediaminetetraacetic acid‐coated Fe₃O₄ (Fe₃O₄@EDTA) magnetic nanoparticles. The Fe₃O₄ magnetic nanoparticle‐supported Pd(II)–EDTA complex catalyst thus obtained was characterized using scanning and transmission electron microscopies, thermogravimetric analysis, vibrating sample magnetometry, X‐ray diffraction, and inductively coupled plasma atomic emission and Fourier transform infrared spectroscopies. Fe₃O₄@EDTA–Pd(II) was screened for the Suzuki reaction and reduction of nitro compounds in water. The Pd content of the catalyst was measured to be 0.28 mmol Pd g^?1. In addition, the Fe₃O₄@EDTA–Pd catalyst can be easily separated and recovered with an external permanent magnet. The anchored solid catalyst can be recycled efficiently and reused five times with only a very slight loss of catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.     

Cobalt nanoparticles supported on ionic liquid‐functionalized multiwall carbon nanotubes as an efficient and recyclable catalyst for Heck reaction

A novel and environmentally friendly cobalt nanoparticle catalyst supported on ionic liquid‐functionalized multiwall carbon nanotubes was successfully prepared and evaluated as a heterogeneous catalyst for the Mizoroki–Heck reaction. Several reaction parameters, including type and amount of solvent and base, were evaluated. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.