Catalytic fluorination of 1,3-dicarbonyl compounds using iodoarene catalysts

Catalytic fluorination of 1,3-dicarbonyl compounds with aqueous hydrofluoric acid proceeded efficiently with the aid of iodoarene catalysts in the presence of m-CPBA as a terminal oxidant. o-Iodotoluene, o-iodoanisole, and o-ethyliodobenzene showed a high catalytic efficiency to give 2-fluoro-1,3-dicarbonyl compounds in good yields.     

Persistent photocatalysis of continuously flowing gas-phase nitric oxide using CaAl2O4:(Eu,Nd)/rutile phase TiO2−x N y composites

CaAl₂O₄:(Eu,Nd)/rutile phase TiO_2?x N _y composites were synthesized via a two-step method, i.e. a solvothermal reaction followed by a mechanochemical treatment. The photocatalytic deNO _x activity of the composites was evaluated under UV light (λ > 290 nm) irradiation and after turning off the UV light. It was confirmed that rutile phase TiO_2?x N _y nanoparticles could be uniformly dispersed on the surface of CaAl₂O₄:(Eu,Nd) after planetary ball milling treatment. The composites prepared by this two-step method had high photocatalytic activity and good prolonged catalysis time even after turning off the light.     

Grafting of Polymers from Carbon Fiber. Anionic Graft Polymerization of Vinyl Monomers Initiated by Metallized Aromatic Rings on Carbon Fiber

The anionic graft polymerization of vinyl monomers onto carbon fiber initiated by metallized carbon fiber was investigated. The metalation of polycondensed aromatic rings of the carbon fiber surface was achieved by the treatment of carbon fiber with n-butyl-lithium (BuLi) in N, N, N′, N′ -tetramethylethylenediamine (TMEDA) or hexamethylphosphorous triamide (HMPT) at 0°C. The anionic polymerization of methyl methacrylate (MMA) and styrene (St) was initiated by the metallized carbon fiber, and these polymers were grafted onto the surface. The conversion and the percentage of grafting increased with increasing amount of BuLi used for the metalation of carbon fiber. When 0.20 g carbon fiber was treated with 0.3 mmol BuLi in TMEDA, the percentage of grafting of PMMA and PSt reached a maximum value (PMMA, 34.5%; PSt, 37.1 %). Furthermore, the metalation of aromatic rings of carbon fiber also proceeds by the treatment with BuLi in HMPT. On the contrary, no grafting was observed when carbon fiber was treated with BuLi in tetrahydrofuran (THF) or toluene. This may be due to the fact that metalation of carbon fiber does not proceed in THF or toluene.     

Morphology control of TiO2 through hydrothermal synthesis method using protonic tetratitanate

Fibrous TiO₂ and plate-like TiO₂ were obtained through the hydrothermal synthesis method by using two kinds of protonic tetratitanate (H₂Ti₄O₉), prepared by ion exchange of K₂Ti₄O₉ and HCl, or milled K₂Ti₄O₉ and HCl, respectively. The product made by hydrothermal treatment of H₂Ti₄O₉ without milling in water consisted of anatase TiO₂ and retained the fibrous morphology of the precursor but with fine crystals attached on the surface, formed by the in?situ topotactic transformation reaction and dissolution and recrystallization. On the other hand, TiO₂ prepared with H₂Ti₄O₉ obtained through ion exchange of milled K₂Ti₄O₉ and HCl had plate-like shape, namely retaining the morphology of nanosheets of H₂Ti₄O₉ through an in?situ transformation process. Under ultraviolet irradiation, 70% methyl orange degradation by TiO₂ nanosheets was about 3.3 times higher than that by fibrous TiO₂. The higher surface area, higher pore volume, and smaller particle size led to the higher photocatalytic activity of the TiO₂ nanosheets.     

Single Folding Optical Potential for Elastic Scattering of Protons from <Superscript>14</Superscript>N and <Superscript>16</Superscript>O in a Wide Range of Energies

Available experimental data for protons elastically scattered from ¹⁴N and ¹⁶O target nuclei are reanalyzed within the framework of single folding optical potential (SFOP) model. In this model, the real part of the potential is derived on the basis of single folding potential. The renormalization factor N _r is extracted for the two aforementioned nuclear systems. Theoretical calculations fairly reproduce the experimental data in the whole angular range. Energy dependence of real and imaginary volume integrals as well as reaction cross sections are discussed.     

Structure of χ3-Borophene Studied by Total-Reflection High-Energy Positron Diffraction (TRHEPD)

We have investigated the structure of χ₃-borophene on Ag(111), a monolayer material of boron atoms, via total-reflection high-energy positron diffraction (TRHEPD). By comparing the experimental rocking-curves with ones for several structures calculated by using dynamical diffraction theory, we confirmed that the χ₃-borophene layer has a flat structure. The distance from the topmost layer of the metal crystal is 2.4 Å, which is consistent with results reported by X-ray standing wave-excited X-ray photoelectron spectroscopy. We also demonstrated that the in-plane structure of χ₃-borophene is compatible with the theoretical predictions. These structural properties indicate that χ₃-borophene belongs to a group of epitaxial monolayer sheets, such as graphene, which have weak interactions with the substrates.     

Chemical Composition and Anti-Urolithiatic Activity of Extracts from Argania spinosa (L.) Skeels Press-Cake and Acacia senegal (L.) Willd

Ethnobotanical studies have reported the traditional medicinal uses of Acacia senegal (L.) Willd. and Argania spinosa (L.) Skeels against kidney stone formation and other chronic kidney diseases. The present work is undertaken to study the litholytic activity and the inhibiting activity of calcium oxalate crystallization by bioactive compounds identified in Argania spinosa (L.) Skeels press-cake (residue of Argan oil) and in Acacia senegal (L.) Willd. The litholytic activity was studied in vitro on cystine and uric acid stones using a porous bag and an Erlenmeyer glass. The study of the inhibiting activity of calcium oxalate crystallization, was based on temporal measurements of the optical density, registered at a 620 nm wavelength for 30 min using an ultraviolet–visible spectrophotometer. The silylation method was performed to identify phytochemicals, followed by gas chromatography coupled with mass spectrophotometry (GC/MS) analysis. The results show significant litholytic activity of Argania Spinosa press-cake hydro-ethanolic extract on uric acid and cystine stones, respectively, with dissolution rates (DR) of 86.38% and 60.42% versus 3.23% and 9.48% for the hydro-ethanolic extract of Acacia senegal exudate. Furthermore, the percentages of nucleation inhibition are 83.78% and 43.77% (p ˂ 0.05) for Argania spinosa and Acacia senegal, respectively. The results point to the detection of 17 phytochemicals in Argania spinosa press-cake extract, the majority of which are phenolic acids and have potent anti-urolithiatic action.     

Bohr's inequality for holomorphic and pluriharmonic mappings with values in complex Hilbert spaces

Let ${\mathbb{B}}_H$ be the unit ball of a complex Hilbert space H. First, we give a Bohr's inequality for the holomorphic mappings with lacunary series with values in complex Hilbert balls. Next, we give several results on Bohr's inequality for pluriharmonic mappings with values in ℓ₂. Note that the Bohr phenomenons that we have obtained are completely different from those in the case with values in $\mathbb{C}$ and are sharp in the case with values in ℓ₂.