Methanol synthesis from carbon dioxide at atmospheric pressure over Cu/ZnO catalyst. Role of methoxide species formed on ZnO support

Methanol synthesis from CO₂ and H₂ was carried out over a Cu/ZnO catalyst (Cu/Zn = 3/7) at atmospheric pressure, and the surface species formed were analyzed by diffuse reflectance FT-IR spectroscopy and temperature programmed desorption method. Two types of formate species and zinc methoxide were formed in the course of the reaction. Zinc methoxide was readily hydrolyzed to methanol. H₂O formed through the reverse water gas shift reaction was suggested to be involved in the hydrolysis of zinc methoxide.     

Many-Body Analysis of the Hess-Fairbank Effect in One-Dimensional Bose-Einstein Condensates with Attractive Interactions

No Heading In terms of the many-body energy spectrum obtained by a diagonalization of Hamiltonian, we discuss the Hess-Fiarbank effect in an attractive Bose-Einstein condensate on a one-dimensional ring. Depending on the strength of interaction and the rotational frequency of the container, there exist two characteristic features in the spectrum. We argue that the existence of a regime of a huge number of low-lying levels causes the smearing of the plateau of the quantized circulation in contrast to conventional superfluids with repulsive interaction.PACS numbers: 03.75.Hh, 03.75Lm     

Electron spin resonance study of defects in CVD-grown 3C-SiC irradiated with 2MeV protons

Electron spin resonance (ESR) was used to study defects induced by 2MeV-proton irradiation in cubic silicon carbide (3C-SiC) epitaxially grown on Si substrates by chemical vapor deposition. A new ESR signal labeled T5 was observed at temperatures lower than ≈100 K in Al doped, p-type 3C-SiC epilayers irradiated. The T5 signal has anisotropic g-values of g₁ = 2.0020 ± 0.0001, g₂ = 2.0007 ± 0.0001,and g₃ = 1.9951 ± 0.0001. The principal axes of the g-tensor were found to be along the 〈100〉 directions, indicating that the T5 center has D₂ symmetry. Isochronal annealing of the irradiated epilayers showed that the T5 center was annealed at temperatures around 150° C. A tentative model is discussed for the T5 center.     

Equilibrium state and crystal growth of (BEDT-TTF)2I3

The equilibrium state and crystal growth of (BEDT-TTF)₂I₃ were investigated. Measurements of the temperature dependence of solubility and analyses of the components in the solution were carried out. The analysis of the solution showed that the crystals decompose into neutral BEDT-TTF and I₂ molecules. As to the polymorphism, it was clarified that the -form is more stable than the -form in the temperature region between 0 and 50 °C. Using these information, we succeed in growing single crystals form BEDT-TTF and I₂ and in control of the crystallizing polymorph. The polymorphic behavior was explained in terms of supersaturation as a driving force of crystal growth.     

Theoretical conformational analysis of tetrapeptide Ac-Cys-Pro-Gly-Cys-NHMe with disulfide linkage

Theoretical conformational analysis was carried out for the acyclic and cyclic tetrapeptides Ac-Cys-Pro-Gly-Cys-NHMe using ECEPP and optimization procedure for investigating the conformational preference of peptides having disulfide linkage. Calculated results indicate that cyclic Ac-Cys-Pro-Gly-Cys-NHMe forms compactly fold conformations with type II β-bend at the Pro-Gly portion, and also show fairly good agreement with experimental results of the NMR spectroscopy for the tetrapeptides having Cys-Pro-Gly-Cys sequence. Received: 26 August 1996/Revised version: 18 September 1996/Accepted: 23 September 1996     

Theoretical conformational analysis of tetrapeptide Ac-Cys-Pro-D-Ala-Cys-NHMe with Disulfide Linkage

Summary. Theoretical conformational analysis was carried out for the acyclic and cyclic tetrapeptides Ac-Cys-Pro-d-Ala-Cys-NHMe using ECEPP and optimization procedure for investigating the conformational preference of peptides having disulfide linkage. Calculated results indicate that cyclic Ac-Cys-Pro-d-Ala-Cys-NHMe forms compactly fold conformations with type II β-bend at the Pro-d-Ala protion, and also show fairly good agreement with experimental results of the NMR spectroscopy for the tetrapeptides having Cys-Pro-d-Ala-Cys sequence. Received: 23 March 1997/Revised: 25 June 1997/Accepted: 4 July 1997     

Dynamics of track/wheel systems on high-speed vehicles

For high speed railway vehicles, we consider a vibiation of flexible track/wheel system It is very important to deal with the complex phenomena of high-speed vehicles that can be occurred in the vertical vibration of the system From a viewpoint of multibody dynamics, this kind of problem needs accurate analysis because the system includes mutual dynamic behaviors of rigid body and flexible body The simulation technique for the complex problems is also discussed We consider the high-speed translation, rail elasticity, elastic supports under the rail and contact rigidity Eigen value analysis is also completed to verify the mechanism of the coupled vertical vibration of the system     

Striking effects of cobalt (III) nuclearity in fused salphen complexes on their electroconductivity and thin film transistor activity

Dinuclear and trinuclear cobalt (III) complexes were prepared using fused salphen ligands that have the same number of benzene rings along the major axis of the molecules. The two compounds were used as organic thin film formed on a glass or a SiO₂/n-Si substrate for investigating electronic conductivity and transistor characteristics, respectively. The conductivity of di- and trinuclear complexes were 8.5 × 10⁻⁵ and 5.8 × 10⁻³ S cm⁻¹, meaning that the increment of the nuclearity from two to three resulted in multiplication of 70 times. The thin film of the trinuclear complex showed a faint transistor activity, where the thin film act as n-type semiconductor. In contrast, the dinuclear complex did not afford a detectable response to the gate voltage.     

Transmission analysis of electromagnetic induction RFID system

The transmission characteristics of the electromagnetic induction RFID systems are greatly influenced by the distance between the primary and secondary antenna coils and by the materials used in their design. In this paper the induced current of the secondary antenna coil is calculated by the 3D finite element method when both the primary and secondary antenna coils are operated in resonant circuits. The influences of the analyzed parameters on the transmission characteristics are demonstrated. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(4): 38–45, 2010; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21019