In this paper, a computational scheme in conjunction with the moving element method has been proposed to investigate the dynamic response of a high-speed rail system in which the discrete sleepers on the subgrade support the railway track. The track foundation is modeled as a beam supported by uniformly spaced discrete spring-damper units. The highspeed train is modeled as a moving sprung-mass system that travels over the track. The effect of the stiffness of the discrete supports, train speed, and railhead roughness on the dynamic behavior of the train-track system has been investigated. As a comparison, the response of a continuously supported high-speed rail system that uses a foundation stiffness equivalent to that of a discretely supported track has been obtained. The difference in results between the ''equivalent'' continuously supported and the discretely supported high-speed rails has been compared and discussed. In general, the study found that a high-speed train that travels over a discretely supported track produces more severe vibrations than that travels over a continuously supported track of equivalent foundation stiffness.

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In this study, a desirable and versatile Lactobacillus plantarum strain possessing great ability of L-malic acid consumption, biogenic amine degradation and resistance to wine harsh environment was obtained through successive screenings. Malolactic fermentation (MLF) in contaminated grape wine and cherry wine (supplemented with histamine, tyramine and cadaverine) conducted by this strain was finished within 24 and 18 days, respectively, and the concentration of histamine, tyramine and cadaverine was decreased by over 57% following MLF. The enzyme from L. plantarum responsible for the amine degradation was purified to homogeneity by four steps including cell disruption, ammonium sulphate fractionation, an anion chromatography and a gel filtration chromatography. Such enzyme was identified as glyceraldehyde-3-phosphate dehydrogenase (GAPDH) after N-terminal sequence analysis and protein Blast, a tetramer enzyme with a subunit molecular weight of 36 kDa. The optimum values of pH and temperature of this enzyme were at pH 7.5 and 40°C, and stable between pH 5.5-8.5 and 30-50°C.

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