ESCA and FT-IR studies on boundary-phase structure between blend polymers and polyamide substrate

Electron spectroscopy for chemical analysis (ESCA) and Fourier-transform infrared (FT-IR) attenuated total reflection (ATR) studies have been made on the film of blend polymers consisting of poly(hydroxypropyl ether) of bisphenol A (P) and poly(ethylene oxide) (E) or P and poly(ethylene adipate) (A) formed on nylon-6 (Ny) substrate to investigate the boundary-phase structure between the substrate and the polymer blends. For the case of P/A blend, A is enriched to the depths probed by both ESCA (below ca. 60 Å) and FT-IR-ATR (below ca. 0.7 μm) from the nylon-6 surface. For the P/E blend, though P is enriched to the depth probed by ESCA from the Ny surface, the enrichment of neither of the blend components can be found to the depth probed by FT-IR-ATR. These results indicate the different susceptibility between P/A and P/E blends to the influence from the Ny substrate.     

Computational characterization on mechanical behavior of polymer electrolyte membrane based on nonaffine molecular chain network model

This paper investigates the mechanical behavior of polymer electrolyte membrane based on a nonaffine molecular chain network model (nonaffine model), which may account for the change in the entanglement situation for the physical linkages of the molecular chain during the deformation process. After the identification of the parameters used in the nonaffine model with the experimental data of the fresh membrane, a computational model is proposed for the degraded membrane, in which the swelling parts of the degraded membrane are replaced with voids. Employing the extended 2D homogenization method, the effect of the change in the entanglement situation for the physical linkages of the molecular chain and that of the macroscopic loading conditions on the mechanical behavior of the membrane with different volume fractions of voids are discussed. The results indicate that the dramatic increase in the average number of segments in a single chain, which occurs inside the microscopic sharp shear band, leads to a great strain softening after the macroscopic yield. Moreover, such strain softening tends to appear at early deformation stage for the membrane with high volume fraction of voids under high macroscopic triaxiality loading condition.     

Fluorescent SiC and its application to white light-emitting diodes

Fluorescent-SiC(f-SiC),which contains donor and acceptor impurities with optimum concentrations, has high conversion efficiency from NUV to visible light caused by donor-acceptor-pair(DAP) recombination. This material can be used as a substrate for a near UV light-emitting diode(LED) stack,and leads to monolithic white LED device with suitable spectral property for general lighting applications.In this paper,we describe basic technologies of the white LED,such as optical properties of f-SiC substrate,and epitaxial growth of NUV stack on the f-SiC substrate.     

Characteristics of the mode converter of Gyrotron FU CW GII radiating Gaussian beams in both the fundamental and second harmonic frequency bands

Gyrotron FU CW GII, the second gyrotron of the Gyrotron FU CW G-series with an internal quasi-optical mode converter, was recently developed at the Research Center for Development of Far-Infrared Region, University of Fukui (FIR FU) [Y. Tatematsu et al., J. Infrared, Millimeter, Terahertz Waves 35, 169 (2014)]. The design oscillation mode of this gyrotron is TE_8,3 with a corresponding frequency of 393.4 GHz in the second harmonic cyclotron resonance. We observed oscillations of different modes including fundamental harmonic modes in the 200-GHz band upon varying the strength of the magnetic field in the cavity. Radiation patterns corresponding to these modes emitted from the window were Gaussian although the internal mode converter was designed for the TE_8,3 mode. The directions of the radiated Gaussian beams were found to depend on the oscillation modes with a relation similar to that obtained for another gyrotron that was also equipped with a mode converter. This relation is explained based on geometrical optics. Moreover, numerical calculation with the electromagnetic wave code developed in FIR FU confirmed the same relation. The observed features of the Gyrotron FU CW GII show that it can serve as a unique power source with two frequency bands at 200 and 400 GHz. This result provides a way of developing multiple-frequency gyrotrons.     

一种高铝喷涂料的开发

以铝矾土（3．35mm～0．425mm和≤150μm）为主要原料,铝酸钙水泥为结合剂,制备出了一种氧化铝含量在70％以上的喷涂料。将试样经110％干燥后,每隔100％设置一次烧结试验。测定试样经过不同热处理温度后的体积密度、线性变化率、抗折强度和耐压强度。结果表明,研制出的高铝喷涂料在高温下具有较优良的性能。     

Electron transport in Si nanochains/nanowires

Electronic transport properties of a bundle of Si nanochains/nanowires were investigated. Si nanochains and nanowires were grown via a self-organized vapor-liquid-solid process and located on a pair of electrodes with a gap of several hundred nanometers. Unstable and a variety of current-voltage (I-V) characteristics were observed and some of those were Coulomb staircase-like. In addition, fluctuations which were seemingly random but partly and partially reproducible were observed in I-V curves of a parallel junction of a nanochain and a nanowire.     

Interaction between the reinforcement and matrix in carbon-fiber-reinforced composite: Effect of forming the thin layer of polyimide resin on carbon fiber by in situ polymerization

For the purpose of enhancing the reinforcement–matrix interaction in carbon-fiber-reinforced polymer composite, mechanical and spectroscopic studies were made on the epoxy resin composite reinforced with the carbon fiber coated with thin Layer of polyimide resin. On the loss modulus and loss tangent vs. temperature curves, a subtransition appears at a temperature above the primary transition. The T-peel strength of a laminated specimen and the fiber efficiency factors for modulus and strength are larger than those of the composite reinforced with nonpolyimide treated fiber. These results show the increased interaction between the epoxy resin and the carbon fiber coated with polyimide resin. The occurrence of specific interaction between an epoxy resin and the polyimide resin are recognized on fourier transform infrared spectra.