某含铁铅锌尾矿中铁分离试验研究

以某含铁铅锌尾矿为研究对象,通过对铅锌尾矿磁化焙烧时碳粉用量、温度、时间以及磁场强度最佳条件的研究,提出从铅锌尾矿中分离铁元素的合理方案,探讨铅锌尾矿中铁元素二次利用的可能性。试验结果表明,磁化焙烧时最佳碳粉用量为20%、焙烧温度为750℃、焙烧时间为80 min、磁场强度为256 kA/m,在此条件下所得精矿的铁品位为58. 44%,回收率为16. 98%。     

An overview of analytical methods for determining the geographical origin of food products

There is an increasing interest by consumers for high quality food products with a clear geographical origin. These products are encouraged and suitable analytical techniques are needed for the quality control. This overview concerns an investigation of the current analytical techniques that are being used for the determination of the geographical origin of food products. The analytical approaches have been subdivided into four groups; mass spectrometry techniques, spectroscopic techniques, separation techniques, and other techniques. The principles of the techniques together with their advantages and drawbacks, and reported applications concerning geographical authenticity are discussed. A combination of methods analysing different types of food compounds seems to be the most promising approach to establish the geographical origin. Chemometric analysis of the data provided by the analytical instruments is needed for such a multifactorial approach.     

某型旋流池分离效果的数值模拟研究

采用FLUENT软件对某型旋流池的固液分离效率与积泥问题进行了数值模拟,分析了 旋流池内的沉淀特征,得出了分离效率曲线,明确了该型旋流池在吸水井区域产生积泥的原因,据此 可优化该型旋流池的设计参数,减少吸水井积泥。     

干法变性温度对淀粉糊化及混合浆相分离的影响

通过比较不同温度处理过的淀粉试与原淀粉的Brabender粘度曲线,探讨了变性淀粉浆料干法生产过程中反应温度与淀粉糊化特性之间的联系,然后以初显分离时间和沉降率为量化指标,定量评估了该温度对淀粉与PVA－1799及VPA－1788混合浆液相分离的影响,实验结果表明,提高变性淀粉浆料干法生产过程中的反应温度,有助于降低淀粉的糊化温度和浆液粘度,并能减小淀粉与PVA混合浆液的初始相分离速度。     

麦草浆黑液中LCC组分及黑液热解处理研究

从麦草浆黑液中分离并鉴别LCC组分,指出麦草浆黑液LCC含量要比马尾松浆黑液高5.35倍,证实LCC是麦草浆黑液高粘度和低燃烧膨胀性的主要原因之一。采用原料高温蒸煮和黑液高温裂解的热处理工艺,可以使麦草浆黑液LCC含量降到拉近马尾松浆黑液的含量,粘度降低40%左右,VIE值提高3倍左右,但仍明显差于马尾松浆黑液。本文还比较了两种处理工艺的优劣。     

声场对糖浆气浮分离作用的研究

本文分别研究了声场及声场与ＰＡＭ协同对糖浆气浮分离作用的影响。结果表明：在不加ＰＡＭ的情况下，声场空化作用对气－固结合有负面影响；在ＰＡＭ存在下，声场空化表现了声场凝聚效应，显著提高糖浆气浮清净效率，同时减少絮凝剂用量。     

电泳沉积预涂晶种制备NaY分子筛膜及其分离性能

通过电泳沉积方法预涂晶种二次生长法制备出Y型分子筛膜。采用Y型分子筛合成的导向剂作为预涂晶种。考察了导向剂的陈化时间,电泳电压和电泳沉积时间对晶种质量以及分子筛膜的影响。结果表明,在电泳的作用下,导向剂作为晶种能够均匀地沉积在载体表面。二次合成后的载体的XRD表征显示,纯的Y型分子筛膜成功地生长在载体表面。SEM电镜表明,经过二次合成后的载体表面被高度孪生的分子筛晶体所覆盖。分子筛膜在不同渗透温度条件的分离性能用CO2/N2混合物进行评价。此外,考察了不同浓度的异丙醇水溶液在分子筛膜上的渗透汽化脱水性能。合成的Y型分子筛膜展现出较好的脱水性能和渗透通量.     

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我国煤层气资源十分丰富,但其利用率极低,这主要是因为抽放煤层气中的有效成分甲烷浓度低。因此对煤层气中甲烷的分离提纯极为重要。混合气中各组分在共同吸附时具有竞争性,在这变压吸附过程中直接影响到混合气中各组分的吸附和解吸。文章通过模拟煤层气（CH4／N2）的吸附过程,从理论上分析了混合气体吸附过程中各组分在游离相和吸附相的浓度变化特征及其对吸附分离的影响。最后讨论了抽放煤层气中其他组分对所要提纯组分CH4的影响。     

Separation and structure analysis of trisaccharide isomers produced from lactose by Lactobacillus bulgaricus L3 β-galactosidase

Using lactose as the substrate, galacto-oligosaccharides containing β-d-galactose residues were synthesised with β-galactosidase from Lactobacillus bulgaricus L3. The reaction mixture was fermented by yeast cells to consume the monosaccharides and disaccharides, and then it was fully acetylated in the presence of acetic anhydride under I₂ catalysis. Column chromatography of the resulting products, using ethyl acetate: petroleum ether as the eluent, generated two isomers of trisaccharide derivatives (I and II) in gram scale for the first time. Their structure characteristics were investigated by ESI-MS and NMR spectra. They were identified as (2,3,4,6-tetra-O-acetyl-d-galactopyranosyl)-β-(1 → 6)-(2,3,4-tri-O-acetyl-d-galactopyranosyl)-β-(1 → 4)-1,2,3,6-tetra-O-acetyl-α-d-glucopyranose (I) and (2,3,4,6-tetra-O-acetyl-d-galactopyranosyl)-β-(1 → 3)-(2,4,6-tri-O-acetyl-d-galactopyranosyl)-β-(1 → 4)-1,2,3,6-tetra-O-acetyl-α-d-glucopyranose (II), respectively. ESI-MS analysis of both deacetylated products of the two trisaccharide derivatives I and II revealed molecular ion peaks of free trisaccharides, which were structurally identified as Gal-β-(1 → 6)-Gal-β-(1 → 4)-Glc and Gal-β-(1 → 3)-Gal-β-(1 → 4)-Glc, respectively.     

维生素C生产技术

介绍了维生素C的性质、功能和用途。综述了维生素C生产技术的演变过程和发展趋势。着重探讨了微生物发酵法的生产工艺进展。介绍了二步发酵法与葡萄糖直接发酵法的研发现状，探讨了2—酮基—L—古龙酸的分离提取工艺。展望了我国维生素C生产技术的前景。指出，我国的维生素C生产应当重视工程菌的选育与发酵工艺的优化。