Carbon black / PTFE composite hydrophobic gas diffusion layers for a water-absorbing porous electrolyte electrolysis cell

The characteristics of a water-absorbing porous electrolyte electrolysis cell, in which pressurized water is injected directly into the electrolyte layer, are investigated. High water support force is required for the gas diffusion layer (GDL) in this novel cell design, and therefore here we report a new type of hydrophobic GDL comprising an acetylene black (AB) and poly(tetrafluoroethylene) (PTFE) composite film. The method of preparation of the AB/PTFE slurry, film formation methods, and the AB/PTFE weight ratio were investigated and optimized. The ball-milling and transfer method were suitable for preparing uniform AB/PTFE slurry and successfully covering AB/PTFE film without any cracks on micro-porous layer coated carbon paper, respectively. An investigation about different PTFE weight ratios against AB from 0.1 to 6 showed a serious trade-off character between electrical resistance R, gas permeability V′, and water support force P_lim. The 1/2.5 of AB/PTFE weight ratio was most optimal, which showed to have most equivalent R (2.5 Ω cm^?2), V′(136 mL atm^?1 cm^?2 min^?1), and P_lim (0.25 MPa). We also confirmed that fabricated GDL with optimal condition was worked as the blocking layer against water injected through electrolyte layer and pressurized by nitrogen gas, and as gas-permeation layer for generated hydrogen gas in water electrolysis test.     

轧制电工钢板的可逆轧机

随着中国国内电工钢板需求量的急速增长,热轧电工钢逐渐向能耗低的冷轧电工钢发展,并且对于高牌号电工钢的需求增加。三菱日立制铁机械株式会社既制造生产电工钢板的连续TCM及PL-TCM轧机成套设备,满足大批量生产中低牌号的电工钢板,又制造可满足生产高牌号电工钢板的HZ-轧机,本文主要介绍最近提供给用户的最新型分体牌坊式HZ-轧机及UCM-轧机。     

Transmission electron microscope analysis of epitaxial growth processes in the sputtered β-FeSi2/Si(001) films

The crystallographic orientation relationships and the formation process of β-FeSi₂/Si(001) films were investigated by transmission electron microscopy. A film produced by sputtering pure iron onto a silicon substrate at 600 °C consists of α- and β-FeSi₂ particles. The crystallographic relationships obtained are: (112)_α‖(111)_Si and (101)_β‖(111)_Si or (110)_β‖(111)_Si. The grains of α- and β-FeSi₂ grown inside the substrate adopt the epitaxy to Si(111), irrespective of the surface orientation of the substrate. At 500 °C, on the contrary, there are few α-FeSi₂ grains and some grains of β-FeSi₂ with (100)_β‖(001)_Si [010]_β‖[110]_Si. These results demonstrate that the lower temperature and the higher Fe concentration suppress the formation of α-FeSi₂ and promote the formation of β-FeSi₂ on/below the substrate surface.     

Cloning and molecular characterization of plant aldehyde oxidase

Primary structural information of a plant aldehyde oxidase (AO), which was purified from maize coleoptiles using indole-3-acetaldehyde as a substrate, was obtained by sequencing a series of cleavage peptides, permitting the cloning of the corresponding cDNA (zmAO-1). The complete nucleotide sequence was determined; the deduced amino acid sequence encodes a protein of 1358 amino acid residues of Mr 146,681, which is consistent with the size of the AO monomeric subunit. There is a significant similarity with AO from mammals and xanthine dehydrogenases from various sources. The maize AO polypeptide contains consensus sequences for iron-sulfur centers and a putative molybdopterin cofactor-binding domain. In addition, another cDNA (zmAO-2), highly homologous to zmAO-1 at both the nucleotide and amino acid sequence levels, was cloned. zmAO-2 would encode a protein of 1349 amino acid residues of Mr 145,173 and has molecular characteristics similar to those of zmAO-1. zmAO-1 was expressed at a high level in roots, which was closely correlated with immunoblotting results using antiserum raised against the purified maize AO protein, whereas zmAO-2 was expressed at a higher level in coleoptiles than in roots. We propose each zmAO may have a unique function during plant development.     

Improvements in time resolution and signal-to-noise ratio in a compact pico-second pulse radiolysis system

A compact pico-second pulse radiolysis system has been developing at Waseda University for studying primary processes in radiation chemistry. The system is composed of a photo-injector system and a pico-second all-solid-state laser system. An infrared (IR) and an ultraviolet (UV) laser pulses are obtained from mode-locked Nd:YLF laser system and used for generation of the white light continuum as a probe light and the irradiation to the Cu cathode of a photo-cathode RF-gun, respectively. To improve signal-to-noise (S/N) ratio and time resolution of this pulse radiolysis system, we optimized both probe light and pump electron beam. As a result, our pico-second pulse radiolysis system has been enough to study the primary processes of radiation chemistry. The experimental results and the improvements of our system are described in this paper.     

A Simple Colorimetric Assay of Bleomycin-Mediated DNA Cleavage Utilizing Double-Stranded DNA-Modified Gold Nanoparticles

A colorimetric assay of DNA cleavage by bleomycin (BLM) derivatives was developed utilizing high colloidal stability on double-stranded (ds) DNA-modified gold nanoparticles (dsDNA-AuNPs) possessing a cleavage site. The assay was performed using dsDNA-AuNPs treated with inactive BLM or activated BLM (Fe(II)⋅BLM). A 10-min exposure in dsDNA-AuNPs with inactive BLM treatment resulted in a rapid color change from red to purple because of salt-induced non-crosslinking aggregation of dsDNA-AuNPs. In contrast, the addition of active Fe(II)⋅BLM retained the red color, probably because of the formation of protruding structures at the outermost phase of dsDNA-AuNPs caused by BLM-mediated DNA cleavage. Furthermore, the results of our model experiments indicate that oxidative base release and DNA-cleavage pathways could be visually distinguished with color change. The present methodology was also applicable to model screening assays using several drugs with different mechanisms related to antitumor activity. These results strongly suggest that this assay with a rapid color change could lead to simple and efficient screening of potent antitumor agents.