细粒矿泥与钨矿物凝聚行为和对浮选分离影响的机理研究

在疏水体系下,计算所得的矿泥与钨矿物作用总EDLVO势能为负,说明矿泥与钨矿物会发生凝聚行为。矿物表面动电位理论计算和实测表明,矿泥中的主要矿物萤石表面呈正电,钨矿物表面均呈负电。由于静电力相互作用,萤石、白钨矿、黑钨矿矿物细粒间将发生互凝。显微照片证实了凝聚和互凝现象。该种现象说明,细粒矿泥对钨矿浮选分离有不利影响。因此,浮选新工艺提出在钨浮选前预先脱泥是合理的。     

Effect of fructooligosaccharide on nutritional parameters and mineral bioavailability in rats

The effect of fructooligosaccharide on protein digestibility and mineral absorption was studied in rats fed diets containing 5 g kg^?1 fructooligosaccharide, 5 g kg^?1 cellulose/fructooligosaccharide (1:1) or 5 g kg^?1 cellulose as a source of dietary fibre. Addition of cellulose/fructooligosaccharide or fructooligosaccharide to the diet did not significantly modify the daily food intake and food efficiency. However, the fructooligosaccharide‐fed group showed a significant decrease in body weight gain compared with cellulose‐fed groups. Faecal excretion was significantly lower when there was fructooligosaccharide intake, despite there being no significant differences in cellulose‐fed groups. Intake of fructooligosaccharide produced an increase in caecal content and an enlargement of the caecal wall. This trophic effect could be attributed to short‐chain fatty acids produced from the anaerobic fermentation of fructooligosaccharide by intestinal bacteria. Cellulose/fructooligosaccharide enhanced the apparent absorption and apparent retention of Ca, Mg, Zn and Fe. Fructooligosaccharide‐fed rats experienced an increase in apparent absorption and apparent retention of Mg compared with cellulose‐fed rats. Fructooligosaccharide intake at the lowest dose was enough to provide a desirable effect on mineral bioavailability in rats without any modification of nutritional parameters. © 2002 Society of Chemical Industry     

Mung Bean: Technological and Nutritional Potential

Mung bean (Vigna radiata (L.) R. Wilczek) has been intensively researched; scattered data are available on various properties. Data on physical, chemical, food processing, and nutritional properties were collected for whole mung bean grains and reviewed to assess the crop's potential as food and to set research priorities. Results show that mung bean is a rich source of protein (14.6–33.0 g/100 g) and iron (5.9–7.6 mg/100 g). Grain color is correlated with compounds like polyphenols and carotenoids, while grain hardness is associated with fiber content. Physical properties like grain dimensions, sphericity, porosity, bulk, and true density are related to moisture content. Anti-nutrients are phytic acid, tannins, hemagglutinins, and polyphenols. Reported nutrient contents vary greatly, the causes of which are not well understood. Grain size and color have been associated with different regions and were used by plant breeders for selection purposes. Analytical methods require more accuracy and precision to distinguish biological variation from analytical variation. Research on nutrient digestibility, food processing properties, and bioavailability is needed. Furthermore, the effects of storage and processing on nutrients and food processing properties are required to enable optimization of processing steps, for better mung bean food quality and process efficiency.     

高效液相色谱法测定保健食品-复合营养素补充剂中维生素B1含量

摘要：目的建立一种简单、高效、抗基质干扰能力强的样品前处理结合高效液相色谱法（high performance liquid chromatography, HPLC）测定保健食品-复合营养素补充剂中维生素B1(vitamin B1,VB1)含量的分析方法。方法选取基质复杂的多种维生素矿物质片作为代表样品,通过创新性的设计酸性饱和乙二胺四乙酸二钠盐（ethylenediaminetetraacetic acid disodium salt,EDTA）提取溶液结合超声提取前处理方法,充分络合各类矿物质元素并有效消除其他基质干扰,针对样品中的维生素B1进行高效率提取。提取液经滤膜过滤后,HPLC分离检测。结果此改进后的分析方法能够针对多种维生素矿物质片中维生素B1含量进行准确定量。维生素B1在浓度范围1.0237~204.7380 μg/mL内线性良好（r2=0.9999）;实际样品加标回收率达98.59%;相对标准偏差(relative standard deviation, RSD)为0.61%（n=6）;方法定量限(limits of quantification, LOQ)为0.05 μg/mL。结论本方法简单、高效、抗基质干扰能力强、重现性好,适用于多种维生素矿物质片中的维生素B1的含量测定,同时也为复杂基质的保健食品-复合营养素补充剂中维生素B1的含量检测提供新的途径。     

速冻蔬菜矿物质成分变化规律的研究

用原了吸收分光光度计法分析测定了菜椒、绿菜花、菠菜、芹菜等几种蔬菜在速冻加工与冷藏过程中营养元素的变化及变化规律。实验结果表明，在加工过程中的热烫处理使铁元素损失较大，钙、锌略有损失。在冷藏过程中这儿种元素均无明显变化。     

本溪市大连洲铁矿床地质及矿石特征浅析

介绍了大连洲铁矿矿区地质概况,阐述了该铁矿床的地质特征、矿石矿物的主要类型及特征。     

钢渣——脱硫灰基全固废胶凝材料及其砂浆界面过渡区的研究

为提高冶金行业伴生固废的资源化利用率,将钢渣粉与烧结烟气脱硫灰复配组成全固废胶凝材料,添加粉煤灰调整其硅铝矿相组成,取三异丙醇胺（Triisopropanolamine,TIPA）作为激发剂,首先对净浆的力学性能、水化产物组成、水化产物微形貌和孔结构以及水化放热表征分析,探究矿相调整与化学激发对钢渣—脱硫灰基全固废胶凝材料水化硬化过程的影响规律。然后采用铁尾矿砂与上述胶凝材料制备全固废砂浆,考察砂浆力学性能发展规律,并探究全固废胶凝材料与固废骨料之间界面过渡区的特征。结果表明:单掺20%的粉煤灰明显促进水化硅酸钙（C—S—H）生成,使净浆14 d抗压强度提升1.86倍,但粉煤灰掺量增大至50%则对3、7 d的强度不利;单独使用TIPA激发则可帮助净浆3 d抗压强度从0.52 MPa提升至11.44 MPa,借助TIPA对铁离子的络合作用,可促进高掺量（50%）粉煤灰的全固废胶凝材料的水化,3 d抗压强度可达3.69 MPa;钢渣—脱硫灰全固废砂浆界面过渡区内Ca（OH）₂生长在C—S—H骨架中而不与骨料直接接触,矿相调整后界面过渡区出现了垂直生长在骨料表面的钙矾石...     

硫化矿自燃的机械活化机理

为了揭示硫化矿发生自燃的本质原因,从典型金属矿山采集了具有代表性的矿样,在室内开展了硫化矿的机械活化实验.采用扫描电镜(SEM)、X射线衍射技术(XRD)、综合热分析技术(STA)表征了矿样在经历不同时间的机械活化作用后的表观形貌、微观结构和热行为等物理化学性质的差异.结果发现:硫化矿石经历机械活化作用后,比表面积增大,出现团聚效应,产生晶格畸变与晶格缺陷,初始放热点及最大反应速率所对应的温度值均有所下降.由此提出了一种新的解释硫化矿自燃的机械活化理论,认为在金属矿山开采中施加于矿体上的各种机械力使得硫化矿产生了机械活化效应,从而使化学反应活性得到相应提高,在一定的环境条件下更加容易产生氧化自热,最终引发自燃火灾.     

A novel method for synthesizing nano-crystalline MgTiO<Subscript>3</Subscript> geikielite

We report here for the first time a novel method of preparing nano-crystalline metatitanate, MgTiO₃ geikielite, with crystalline size varying from 20–40 nm. The preparation has been carried out by coprecipitation method involving titanium hydroxide and magnesium nitrate solution. The samples were characterized by using transmission electron microscopic, powder XRD and FT-IR spectroscopic studies. The sample annealed at 900 K for 2 h show ten X-ray diffraction peaks corresponding to the pure geikielite phase. FT-IR spectra of the nano-crystalline geikielite exhibit strong broad vibrational bands near 1000, 650 and 470 cm⁻¹ arising from normal vibrations of the TiO₃ group.     

Hydrothermal alteration in the Aluto-Langano geothermal field, Ethiopia

The hydrothermal mineral assemblages found in eight wells (with a depth range of 1320–2500 m) of the active geothermal field of Aluto-Langano (Ethiopia) indicate a complex evolution of water-rock interaction processes. The zone of upflow is characterized by high temperatures (up to 335°C) and the presence of a propylitic alteration (epidote, calcite, quartz and chlorite, as major phases) coexisting with calcite and clay minerals. The zone of lateral outflow is characterized by mixing of deep and shallow waters and the occurrence of a calcite-clay alteration that overprints a previous propylitic assemblage. Clay minerals have a mushroom-shaped zonal distribution consistent with the present thermal structure of the field. Microprobe analyses have been carried out on chlorite and illite in order to apply several geothermometers. Most of the chlorite is iron-rich chlorite. It is found that the temperatures calculated from the chlorite geothermometer (159–292°C) after Cathelineau and Nieva [Contrib. Mineral. Petrol. 91, 235–244 (1985)] are in good agreement with in-hole measured temperatures (155–300°C). In the upflow zone, temperatures calculated from this geothermometer (217–292°C), together with fluid inclusion data of Valori et al. [Eur. J. Mineral. 4, 907–919 (1992)], and computed saturation indices of alteration minerals, indicate thermal stability or slight heating. On the other hand, evidence of a significant cooling process (up to 171°C) in the outflow zone is provided by the comparison between fluid inclusion homogenization temperature (240–326°C) and in-hole temperature (155–250°C). The apparent salinities (0.8–2.3 wt% NaCl eq.) of the fluid inclusions are generally higher than the salinity of the present reservoir fluid (0.29–0.36 wt% NaCl eq.). Clay minerals (illite, smectite, Ill/S mixed layers, vermiculite and chloritic intergrades) generally occur at temperatures consistent with their stability fields.