An approach for phosphate removal with quartz sand, ceramsite, blast furnace slag and steel slag as seed crystal

The phosphate removal abilities and crystallization performance of quartz sand, ceramsite, blast furnace slag and steel slag were investigated. The residual phosphate concentrations in the reaction solutions were not changed by addition of the ceramsite, quartz sand and blast furnace slag. The steel slag could provide alkalinity and Ca(2+) to the reaction solution due to its hydration activity, and performed a better phosphate removal performance than the other three. Under the conditions of Ca/P 2.0, pH 8.5 and 10 mg P/L, the phosphate crystallization occurred during 12 h. The quartz sand and ceramsite did not improve the phosphate crystallization, but steel slag was an effective seed crystal. The phosphate concentration decreased drastically after 12 h after addition of steel slag, and near complete removal was achieved after 48 h. The XRD analysis showed that the main crystallization products were hydroxyapatite (HAP) and the crystallinity increased with the reaction time. Phosphate was successfully recovered from low phosphate concentration wastewater using steel slag as seed material.     

饮料中咖啡因含量的测定

采用HPLC法,以水为溶剂,0.02mol/L醋酸铵溶液—甲醇(7525)为流动相,在254nm波长下,测定饮料中咖啡因含量。回收率>97%,与按国家标准GB/T16344—1996测定值比较,两种方法的相对偏差<2%。方法简便,有实用价值。     

SRMC—I型打浆度自动在线检测仪

本文介绍了SRMC-I型纸浆打浆度自动在线检测仪的组成、原理、性能指标、功能和使用。实际应用表明,该检测仪工作稳定可靠,使用方便,提高了打浆度检测的实时性,可在造纸厂推广使用。     

金属离子对马尾松硫酸盐浆碱性过氧化氢漂白的影响

进行添加几种金属离子的H2O2漂白试验,表明在碱性条件下,金属离子对过氧化氢分解作用比在酸性条件下大。各种金属离子中,Cu^2 、Mn^2 、Co^2 对H2O2催化分解最为严重。在有浆条件下,Co^2 对漂浆的粘度、白度损害最大,漂白的选择性最差。添加适当Mg^2 ,有明显的稳定H2O2、提高H2O2漂浆白度和粘度的作用,选择性最好。     

Determination of sphinganine, sphingosine and Sa/So ratio in urine of humans exposed to dietary fumonisin B1

Fumonisin B₁ (FB₁) is an inhibitor of sphinganine N-acyltransferase and the increase in the sphinganine/sphingosine (Sa/So) ratio in urine or serum has been proposed as a biomarker to evaluate exposure to fumonisins. The objectives of this study were to (1) develop a liquid chromatographic method sufficiently sensitive to determine the low concentration of free Sa in male human urine, and (2) analyse So and Sa in human urine and monitor the Sa/So ratio in urine of humans exposed to FB₁ in corn diets over 1 month. The liquid chromatographic method involved isolation from human urine of exfoliated cells followed by an extraction of free sphingoid bases and their separation and quantification by high performance liquid chromatography. The detection limits for So and Sa were 0.15ng/ml in female urine (2ml used) and 0.005ng/ml in male urine (60ml used). Twenty-eight healthy adult volunteers consumed for 1 month a normal diet containing their homegrown corn potentially contaminated with FB₁. Immediately preceding the start of the test, morning urine samples for the determination of So and Sa were collected from each person, and the corn samples used in cooking were obtained from each family for the determination of FB₁. At the end of the test period, morning-urine samples were collected from each person and analysed again. The daily FB₁ intakes were estimated and used to assess the relationship between them and the urinary Sa/So ratios in humans exposed to dietary FB₁ over 1 month. All the home grown corn samples contained FB₁ ranging from 0.08 to 41.1mg/kg, and the estimated daily FB₁     

锌-铝-稀土合金镀层中稀土含量的测定

介绍用偶氮氯膦—mA分光光度法测定锌 -铝 -稀土合金镀层中的稀土量。该测定法稀土量在 0～ 1mg L范围内符合比尔定律 ,相对误差小于 2 .4 % ,加标回收率可达 97.6 %～ 99.4 % ,用于锌 -铝 -稀土合金镀层中稀土的测定 ,有良好的准确性和重现性。     

浅谈牛津布之开发及生产

本文介绍了三大类型的牛津布系列产品之开发和生产工艺，并对织物组织结构及外观风格进行了分析叙述。     

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。     

Using the curve moment and the PSO-SVM method to diagnose downhole conditions of a sucker rod pumping unit

Downhole working conditions of sucker rod pumping wells are automatically identified on a computer from the analysis of dynamometer cards. In this process, extraction of feature parameters and pattern classification are two key steps. The dynamometer card is firstly divided into four parts which include different production information according to the "four point method" used in actual oilfield production, and then the moment invariants for pattern recognition are extracted. An improved support vector machine (SVM) method is used for pattern classification whose error penalty parameter C and kernel function parameter g are optimally chosen by the particle swarm optimization (PSO) algorithm. The simulation results show the method proposed in this paper has good classification results.     

漠河冻土区天然气水合物科学钻探MK 2孔地层岩性的测井识别

岩性识别是天然气水合物储层测井评价的基础,准确的岩性识别结果可以为天然气水合物的勘探提供可靠的依据,在寻找天然气水合物和评估天然气水合物储量方面发挥着巨大的作用。针对漠河冻土区天然气水合物科学钻探 2孔（MK 2孔）的钻探情况,利用已钻井段地层的岩心资料和常规测井资料,分别采用交会图法和支持向量机法对研究区的地层开展了岩性识别研究。结果表明：研究区内有砂岩、泥岩、石灰岩、糜棱岩和泥质板岩５种岩石,其不同岩性的测井响应差异能够定性识别岩性;自然电位与电阻率测井参数的交会,能够有效的、定量识别研究区地层的岩性;支持向量机法所建立的岩性识别模型,对研究区地层的岩性识别率可达96.67%。所建立的测井识别方法较好地解决了该区地层岩性识别问题,也为类似地区的天然气水合物地层测井评价提供了一种重要的手段。