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In our previous studies on the relationships between lignin structure and hemicellulose composition in a wide range of hardwood species, we showed that the higher the syringyl ratio, the higher the xylan/mannan ratio. In this study, the relationship of the syringyl ratio and xylan/mannan ratio was further studied using fractions obtained by stepwise extraction of finely milled beech wood by use of aqueous dioxane and subsequent dimethyl sulfoxide (DMSO)/LiCl solvents with increasing LiCl concentration. Each soluble fraction obtained with a different LiCl concentration was compared with the corresponding insoluble residue, and it was shown that both the syringyl ratio and xylan/mannan ratio were always higher in the insoluble fraction. To analyze polysaccharides closely located with lignin, milled wood lignin (MWL), and cellulolytic enzyme lignin (CEL) obtained by enzyme treatment after DMSO/LiCl swelling were investigated. Although the xylan/mannan ratio of MWL was higher, that of CEL with more than 80% lignin yield was lower. [ABSTRACT FROM AUTHOR]

The composition and absolute amount of neutral sugars were determined for 48 hardwood species (including 17 hardwoods of generaAcacia, 14 hardwoods of generaEucalyptus, and 17 hardwoods of other genera) and 14 softwood species by alditol-acetate method, and their relationships to the syringyl ratio (syringyl/(syringyl+guaiacyl)) of lignin, which was determined by nitrobenzene oxidation, was investigated. In the hardwood species, an increase in the syringy ratio of lignin correlated with a tendency toward increased xylose/glucose, rhamnose/glucose, and arabinose/glucose ratios. However, the absolute amount of glucose in hardwood was maintained in a small range (0.4–0.5 g in 1 g sample), independent of changes in the syringyl ratio. In the softwood species, with increasing lignin content, the mannose/glucose ratio decreased, but the absolute amount of glucose remained almost constant. In both hardwood and softwood species, a strong correlation was suggested between lignin, indicated by higher syringy ratio, and hemicellulose, indicated by higher xylan/mannan ratio. [ABSTRACT FROM AUTHOR]

Abstract: The electrochemical corrosion behaviors of Fe41Co7Cr15Mo14C15B6Y2 bulk metallic glasses (BMGs) were investigated by immersion tests and potentiodynamic polarization experiments. The results of immersion test in 1N HCl, 1N HNO3, 1N NaOH and 3.5% NaCl solutions show that the corrosion rate of Fe41Co7Cr15Mo14C15B6Y2 metallic glasses is very low in all kinds of solutions, particularly in 3.5% NaCl solution. It indicates that the corrosion resistance in NaCl solution is superior to the other three solutions. The corrosion rate in 3.5% NaCl solution is much lower than those of other Fe-based amorphous alloys. Moreover, Fe41Co7Cr15Mo14C15B6Y2 metallic glass has excellent corrosion resistance in different concentrations of NaCl solutions through the further polarization experiments. [Copyright &y& Elsevier]