红毛菜多糖的分离、纯化及纯度鉴定

将红毛菜经过脱脂后用热水抽提可溶性多糖,经脱蛋白后得粗多糖,用DEAE-32纤维素和SephadaxG-100对粗多糖进行柱层析分离提纯,得组分PY1和PY2;利用紫外光谱和红外光谱,对组分进行鉴定纯度。     

Improved Sample Preparation for Real-Time PCR Detection of Listeria monocytogenes in Hot-Smoked Salmon using Filtering and Immunomagnetic Separation Techniques

This work evaluated the application of filtration and immunomagnetic separation (IMS) as sample pretreatments for use in combination with real-time polymerase chain reaction (PCR) to detect and quantify Listeria monocytogenes in hot-smoked salmon. Salmon was artificially inoculated with L. monocytogenes at levels ranging from 8 × 10⁰ to 8 × 10⁵ cfu/g of sample, and homogenates obtained from these samples were filtered to recover bacterial cells without a pre-enrichment step. High recovery of bacterial cells was achieved using standard coffee filters. IMS significantly reduced the co-extraction of PCR inhibitors present in the samples to increase the assay sensitivity with regression line parameters applicable for quantification. The limit of detection and quantification were equal to 2 × 10¹–4 × 10¹ and 2 × 10² cfu/g of sample, respectively. The entire detection procedure could be completed within 3.5 h. This study demonstrated that coupling filtration and IMS with real-time PCR has contributed to improve the sensitivity of L. monocytogenes detection from hot-smoked salmon.     

硼矿石中镁资源的综合利用研究

采用高温结晶法处理硼矿石硫酸法制硼酸后的母液,进行硫酸镁和硼酸的分离。结晶实验在ＦＸＹ－０．５Ａ 高压釜中进行。在１８０℃温度下,ＭｇＳＯ４－Ｈ３ＢＯ３－Ｈ２Ｏ 体系结晶生成固相ＭｇＳＯ４·Ｈ２Ｏ。研究了硫酸镁浓度、硼酸浓度、结晶时间对ＭｇＳＯ４·Ｈ２Ｏ 结晶产率的影响,最后确定母液中ＭｇＳＯ４ 结晶生成固相ＭｇＳＯ４·Ｈ２Ｏ 的最佳工艺条件为：溶液中硫酸镁的浓度为２５％ —２８％ ,硼酸的浓度小于４％ ,结晶时间４ｈ,结晶温度１８０℃,一水硫酸镁产率为５７．６％ 。     

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.     

基于概念和语义相似度的文本聚类算法

提出一种基于概念和语义相似度的聚类算法TCBCSS（Text Clustering Based on Concept and Semantic Similarity）,TCBCSS算法基于WordNet对文档概念进行抽取和归并,形成语义网络,利用小世界理论和网络的几何特性对其进行分析并构建概念列表来表示文档,不仅有效解决了“表达差异”问题也有利于文档相似度的计算。TCBCSS算法利用两个概念列表的语义相似度作为文档间相近程度的度量,以图为基础进行聚类分析,避免了有些聚类算法对聚簇形状的限制,试验证明TCBCSS算法提高了聚类质量。     

山东某低品位铜钼矿石选矿试验

山东某斑岩型铜钼矿石铜钼品位较低,硫化铜、硫化钼占总铜、总钼量的90%以上。对该矿石进行了铜钼回收工艺技术条件研究。结果表明,在磨矿细度为-0.074 mm占65%的条件下进行铜钼混合浮选预抛尾,铜钼混合精矿再磨至-0.043 mm占80%的情况下进行铜钼分离浮选,最终获得了铜品位为20.34%、回收率为90.23%的铜精矿,钼品位为50.33%、回收率为87.53%的钼精矿。     

某铜锌硫化矿浮选分离试验研究

在对福建某多金属铜锌硫化矿进行工艺矿物学研究的基础上,按常用的抑锌浮铜原则流程进行了系统的铜、锌分离回收试验。试验研究表明,采用1粗1扫2精浮铜、1粗2扫3精浮锌、中矿顺序返回的工艺流程处理该铜锌多金属硫化矿,可得到铜品位24.23%、铜回收率89.92%、含锌2.02%的铜精矿,以及锌品位53.55%、锌回收率81.87%、含铜1.33%的锌精矿。     

气相色谱法浓缩氘的研究

采用气相色谱技术建立了一套含氚重水氘浓缩的演示实验装置,用氘-氢（D-H）体系进行实验,结果表明,装置实现了长期、连续、安全的运行。D浓度为O．1％的样品经装置浓缩后得到D浓度为30％的产品,贫化部分D浓度小于10^-5;D浓度为10％的样品经装置浓缩后得到D浓度大于90％的产品。装置对D-H体系的处理容量达到40m%3/d。     

Influence of separated vortex on aerodynamic noise of an airfoil blade

In order to clarify the mechanism by which aerodynamic noise is generated from separated flow around an airfoil blade, the relation between the attack angle and the aerodynamic noise of the blade was analyzed using a wind tunnel experiment and a CFD code. In the case of rear surface separation, the separated vortex which has a large-scale structure in the direction of the blade chord is transformed into a structure that concentrates at the trailing edge with an increase in the attack angle. The aerodynamic noise level then becomes small according to the vortex scale in the blade chord. When the flow is separated at the leading edge, a separated vortex of low pressure is formed at the vicinity of the trailing edge. The pressure fluctuations on the blade surface at the vicinity of the trailing edge become large due to the vortex in the wake. It is considered that the aerodynamic noise level increases when the flow is separated at the leading edge because the separated vortex is causing the fluctuations due to wake vortex shedding.     

磷矿石分选工艺的研究

本文对现有磷矿石分选工艺进行了分析总结,同时对磷矿分选工艺的发展进行了展望。最后提出了磷矿重介质选矿-浮选工艺流程。