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441.
大蒜多糖具有众多的生理功能,有很高的经济价值。以大蒜为原料,采用超声辅助酶解法提取大蒜多糖,具有高速、高效、节能、环保等优点。在单因素试验的基础上,通过正交试验进一步优化提取工艺条件,确定影响提取率的主次因素分别为超声酶解时间、料液比、提取温度和提取时间。结果表明,先期酶解条件为温度50℃、pH5.O、酶用量5.0%,最佳提取条件为超声波酶解时间40min、料液比(m/V)1:3、提取温度85℃、提取时间50min,多糖提取率达72.64%。 相似文献
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介绍了液位检测仪表,并阐述在污泥处理站中采用超声波液位计和液位调节器实现液位自动控制的方法。 相似文献
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Effect of ultrasonic pretreatment on sludge dewaterability was determined and the fate of extracellular polymeric substances (EPS) matrix in mesophilic anaerobic digestion after ultrasonic pretreatment was studied. Characteristics of proteins (PN), polysaccharides (PS), excitation-emission matrix (EEM) fluorescence spectroscopy and molecular weight (MW) distribution of dissolved organic matters (DOM) in different EPS fractions were evaluated. The results showed that after ultrasonic pretreatment, the normalized capillary suction time (CST) decreased from 44.4 to 11.1 (sec·L)/g total suspended solids (TSS) during anaerobic digestion, indicating that sludge dewaterability was greatly improved. The normalized CST was significantly correlated with PN concentration (R2 = 0.92, p 0.01) and the PN/PS ratio (R2 = 0.84, p 0.01) in the loosely bound EPS (LB-EPS) fraction. Meanwhile, the average MW of DOM in the LB- EPS and tightly bound EPS (TB-EPS) fractions also had a good correlation with the normalized CST (R2 0.66, p 0.01). According to EEM fluorescence spectroscopy, tryptophan-like substances intensities in the slime, LB-EPS and TB-EPS fractions were correlated with the normalized CST. The organic matters in the EPS matrix played an important role in influencing sludge dewaterability. 相似文献
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目前.螺旋焊缝越来越多地应用于简体和管道生产中,尤其是螺旋焊压力管道的应用日趋广泛,然而在压力管道安装过程的监督检验中.对环焊缝的射线底片抽查中经常发现与环焊缝一起曝光的螺旋焊缝中。存在比较严重的超标缺陷,以未熔合居多,这可能与螺旋焊钢管的生产工艺有关。而且,螺旋焊缝的内部质量检测都是利用工业电视,其灵敏度比X射线低,且对未熔合之类的面积性缺陷不敏感。 相似文献
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In order to reduce the operation time and improve the extraction efficiency, ultrasonic energy by means of ultrasonic bath was used to the modified Tessier sequential extraction for speciation analysis of heavy metals in soil. Extractable contents of Cu, Fe, Mn, Ni,Pb and Zn were measured by atomic absorption spectroscopy(hAS). The merit of the ultrasonic extraction (UE) applied to the modified Tessier method is not only that the operation time for the first 4 fractions was reduced from ca. 18 h to 8 h, comparing with conventional extraction(CE), but also the extraction efficiency was higher. The results for both of UE and CE were consistent. The extractable Cu, Ni and Zn in the sample No. 1 were mainly associated with the third fraction (Fe-Mn oxides fraction), and fourth fraction (organic matter fraction) in the sample No.2. The extractable Fe and Mn were all mainly associated with the third fraction, and Pb the fourth fraction in both of the samples. The effects of concentration of hydroxylamine chloride on the capability for the extraction of studied metals were also studied. 相似文献