Voltammetric study of sodium hypochlorite using dendrimer-stabilized gold nanoparticles

Electrochemical activity of dendrimer-stabilized gold nanoparticles on a glassy carbon electrode (GCE) was studied by means of cyclic voltammetry of sodium hypochlorite. Dendrimer-stabilized gold nanoparticles were deposited onto a glassy carbon surface by electrophoresis and the deposition was observed by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Both anodic and cathodic peak currents were found to increase after the deposition of dendrimer-stabilized gold nanoparticles. In the case of dendrimers deposited onto the GCE surface, the magnitude of the current was smaller than for dendrimer-stabilized-gold-nanoparticle-modified GCE. This indicates the enhancement in the rate of electrolysis due to gold nanoparticles.     

Fluorine-containing seven-membered benzoheterocycles derived from hexafluoropropene oligomers

4-Fluoro-2-($\text{F}$-ethyl)-3-($\text{F}$-methyl)-1, 5-benzoxazepine was prepared by reaction of $\text{F}$-2-methyl-2-pentene with 2-aminophenol in the presence of triethylamine in diethyl ether. The reaction of $\text{F}$-2,4-dimethyl-3-heptene with 2-aminophenol in dimethylformamide gave 7-($\text{F}$-1-methylethyl)-8- ($\text{F}$-ethyl)-9,14-benzoxazepino[4,3-b]1,6-benzoxazepine. Several ortho-bifunctional benzenes reacted similarly with $\text{F}$-2-methyl-2-pentene and $\text{F}$-2,4-dimethyl-3-heptene to give the corresponding seven-membered benzoheterocycles.     

Catalytic properties of Hf?Eu oxide fine crystalline powders. Isomerization of n-butenes

Catalytic properties of a series of HfO₂–Eu₂O₃ fine crystalline powders were examined by the isomerization of n-butenes. HfO₂ pretreated at 873 K showed a high activity. It decreased with the addition of the Eu component. The product distributions are discussed on the basis of the acid-base properties.

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HfO₂–Eu₂O₃ -. HfO₂, 873 K, . Eu. - .

     

Effects of vinyl series polymers on the formation of hematite particles in a forced hydrolysis reaction

The influence of polymers on the formation of hematite particles from forced hydrolysis of acidic FeCl(3) solution was investigated using vinyl series polymers with different functional groups. The disk-like hematite particles were produced from forced hydrolysis of acidic FeCl(3) solution in the presence of polyvinyl alcohol (PVA: 0-1 wt%). On the other hand, spherical particles were produced by addition of very small amounts of polyacrylamide (PAAm: 0-0.004 wt%). The size of spherical particles was slightly decreased with increase in the concentration of PAAm. The ellipsoidal particles were precipitated by addition of a very low concentration of polyacrylic acid (PAAc: 0-0.004 wt%). The effect of polymers on the hematite particle formation was expressed in the order of PVA相似文献   

Inclusive Λ, Λ and Σ±(1385) production in 405 GeV/c pp interactions

We have investigated inclusive Λ, $\text{Λ}$ and Σ^±(1385) productions in 405 GeV/c pp interactions. The observed cross sections are σ(Λ)=4.05±0.39 mb, $\text{σ(}\text{Λ}\text{=0.63±0.17}$ mb, σ(Σ⁺(1385))=0.74±0.17 mb and σ(Λ^?(1385))=0.56±0.17 mb. $\text{Λ}$ production is dominant in a central region of ∣x∣≤0.4. The $\text{Λ/}\text{Λ}$ production ratio at ∣x∣≈0 is found to be 1.2±0.5. The excess, about 0.2 mb, of σ(Λ⁺(1385)) over σ(Λ^?(1385)) is most likely attributed to proton fragmentations (∣x∣≥0.4), and gives an evidence for scaling.     

Formation of a symmetric vortex configuration in a pure electron plasma trapped with a penning trap

In the formation of vortical crystal structures of electrons, the distribution of background electrons works as a “cooler” of randomly moving, intense vortices. We examine the supporting effect of background electrons to forming crystal structures from the perspective of a reduction of the vortices’ random motion.     

Oxidation process of Mg films by using high-concentration ozone for magnetic tunnel junctions

Ozone oxidization process of metal Mg film for the barrier formation in magnetic tunnel junctions (MTJs) is investigated. Ozone exposure method is expected to oxidize ultra-thin metal films more mildly than with the plasma oxidization method, since the energy level of atomic oxygen is ∼2 eV lower in the ozone method than in the plasma method. The main results were as follows: (1) In the case of ozone oxidation, the diffusion coefficient of oxygen in the insulator is much smaller than that in plasma oxidation. (2) Mg–O film thickness, which is formed by reaction immediately on the metal Mg surface, is thicker as compared with the Al case. (3) In the ozone oxidation method of metal films with the thickness of more than the film thickness formed by reaction, the oxidation is spontaneously stopped at the interface to the bottom Co–Fe. As a result, we succeeded in inducing a TMR ratio of 25% at room temperature in MTJs with Mg(1.3 nm)–O barrier with wider exposure range than in the plasma case.     

Composite bonded magnets with controlled anisotropy directions prepared by viscous deformation technique

When a radially anisotropic rare earth bonded magnet for a rotor with a high (BH)_max value is magnetized multi-polarly, its flux distributes rectangularly and increases a cogging torque. In order to overcome this difficulty, we newly developed highly dense Sm₂Fe₁₇N₃ and Nd₂Fe₁₄B-based composite bonded magnets with continuously controlled anisotropy directions by using a viscous deformation technique.