Nagoya Institute of Technology

About: Nagoya Institute of Technology is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Thin film & Turbulence. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

Temperature dependence on the piezoelectric property of (1 − x)(Na0.5K0.5)NbO3–xLiNbO3 ceramics

Abstract: Lead-free (1 − x)(Na0.5K0.5)NbO3–xLiNbO3 ((1 − x)NKN−xLN) piezoelectric ceramics have been synthesized by solid state sintering between x = 0.040 and 0.080. The effects of temperature on the dielectric, ferroelectric and piezoelectric properties were investigated. For all the samples measured, the remanent polarization (Pr) and coercive field (Ec) showed a tendency of reduction with increasing temperature, but a planer-mode electromechanical coupling coefficient (kp) and frequency constant (Np) varied in non-linearity as a function of temperature. The temperature dependence of the piezoelectric properties of (1 − x)NKN–xLN ceramics was strongly affected by the lithium content, too. The kp values enhanced at the tetragonal–orthorhombic phase transition temperature for all the specimens with different Li contents due to the MPB effects. Especially for the x = 0.055 and 0.060 sample, the variation of elastic compliance also affected their piezoelectric property.

Effects of heat treatment and poly(vinylpyrrolidone) (PVP) polymer on electrocatalytic activity of polyhedral Pt nanoparticles towards their methanol oxidation

Abstract: In this paper, the polyhedral Pt nanoparticles under control were prepared by polyol method using AgNO3 and poly(vinylpyrrolidone) (PVP) in the reduction of H2PtCl6 with ethylene glycol (EG). Transmission electron microscopy (TEM) and high resolution (HR) TEM measurements were used to investigate their characterization. In the case of the previous removal of PVP by washing and heating at 300°C, the specific morphologies of polyhedral Pt nanoparticles were still observed. However, the removal of PVP only by heat treatment at 300°C without washing causes the significant variation of their morphology. The large Pt particles were observed in the self-aggregation and assembly of the as-prepared polyhedral Pt nanoparticles. The pure Pt nanoparticles by washing and heat treatment showed the electrocatalytic property better than PVP-Pt nanoparticles by heat treatment due to the incomplete removal of PVP and by-products from AgNO3. Therefore, the removal modes of PVP without changing their characterization are required to obtain the good catalytic performance.

Organocatalytic Enantioselective Aza‐Friedel–Crafts Reaction of Cyclic Ketimines with Pyrroles using Imidazolinephosphoric Acid Catalysts

Abstract: Organocatalytic enantioselective aza-Friedel-Crafts reactions of cyclic ketimines with pyrroles or indoles were catalyzed by imidazoline/phosphoric acid catalysts. The reaction was applied to various 3H-indol-3-ones to afford products in excellent yields and enantioselectivities. The chiral catalysts can be recovered by a single separation step using column chromatography and are reusable without further purification. Based on the experimental investigations, a possible transition state has been proposed to explain the origin of the asymmetric induction.