玻璃中Fe~(2+)/(Fe~(2+)+Fe~(3+))比值在浮法玻璃生产监控中的应用

通过连续测试某条浮法玻璃生产线玻璃中Fe2+/(Fe2++Fe3+)比值,分析Fe2+/(Fe2++Fe3+)比值与气泡个数的变化规律,确定稳定生产过程中Fe2+/(Fe2++Fe3+)的比值。在浮法玻璃生产中控制Fe2+/(Fe2++Fe3+)比值能控制微气泡的产生,提高玻璃质量。     

低铁玻璃的熔化成型与退火

我厂玻璃成份中含铁量是较低的.同兄弟厂硅质原料以及玻璃中的Fe_2O_3含量比较可见表1.在硅酸盐玻璃中,辐射吸收系数与波长有关,主要取决于玻璃中含铁量的多少以及Fe~(2+)和Fe~(3+)的比例.玻璃在熔化时吸收和透过红外辐射,冷却时向外辐射红外辐射,红外透过特性是关键的因素;昆明玻璃的红外透过率图如下:一、低铁玻璃的熔化1、铁含量对粘度和温度的影响以1%的氧化铁代替玻璃中1%SiO_2使玻璃粘度保持不变时温度值的变化℃,可看出Fe_2O_3代替SiO_2有助于熔化.2、配合料的熔融配合料进入熔窑在高温下剧烈反应.熔     

玻璃配合料中B2O3、Fe2O3检测方法的改进

玻璃配合料中B2O3和Fe2O3含量的稳定性是决定玻璃纤维生产稳定与否的关键因素,而现今使用的传统的配合料中B2O3、Fe2O3检测方法都较繁冗,不能快速准确地指导生产。本文介绍了配合料中B2O3、Fe2O3的新的检测方法,此检测方法具有简单、快捷、误差小的优点。     

矿物原料对SiO_2-Al_2O_3-MgO玻璃熔制的影响研究

目前SiO_2-Al_2O_3-MgO系统的S级高强玻璃纤维生产主要以石英砂、氧化铝、重质氧化镁等化工级原料分别引入玻璃组分中的各氧化物实现。这些化工原料纯度高,有助于提高产品成分和性能的稳定性,但这些原料在熔制过程中需要更高的熔制温度,具有能耗大、玻璃液的澄清及均化困难等缺点。为改善SiO_2-Al_2O_3-MgO系统S级高强玻璃的熔制工艺性能,开展了在玻璃原料中引入高岭土、滑石粉的熔制实验,研究矿物原料对高强玻璃熔制的影响规律。通过DSC分析了玻璃的特征温度点,利用XRD表征了熔制过程中配合料的物相变化情况,并在快速升温炉中进行了配合料的熔制实验观测,同时进行了新生态玻璃纤维的强度测试。研究表明:采用矿物原料能显著降低配合料的熔制温度,降低熔制能耗,改善特种玻璃熔制的工艺性能,形成玻璃的温度降低50℃以上;同时也发现矿物原料中的Fe~(2+)含量较大,增加了玻璃液的温度梯度,玻璃液表面温度低,不利于玻璃液的澄清,因此需要采取措施降低矿物原料中Fe~(2+)的含量,以改善玻璃液的澄清效果,避免玻璃纤维的性能受到影响。     

光伏太阳能减反射镀膜玻璃的制备

酸性条件下,以正硅酸乙酯为主要原材料,通过溶胶凝胶法引入不同长度桥联基团的有机硅氧烷调节SiO2粒子中的孔径大小和膜层脆性,利用氨基树脂与SiO2粒子交联形成立体网状结构,制备性能稳定的SiO2减反射镀膜液.再利用辊涂法将镀膜液涂覆于光伏玻璃表面,制成的光伏太阳能减反射镀膜玻璃的透过率最高可达94.52％,380～1100 nm波段平均透过率增益高达2.6％,硬度4H,具有较好的光学性能及优异的耐候性.     

太阳能光伏玻璃及其薄膜的开发与应用(一)

太阳能光伏玻璃是指应用于太阳能电池组件上对太阳光具有较普通玻璃更高透过率或能选择性透过的玻璃,它直接用于太阳能光伏发电和太阳能光热发电系统组件,起到传递和控制光线,或者具有导出电流作用。太阳能光伏玻璃是太阳能电池组件专用玻璃,也是重要组件之一。在太阳能电池玻璃中,高透过率特性的应用更为广泛,通常它们被用做具有保护作用的...     

V_2O_5-WO_3/TiO_2烟气脱硝催化剂失活前后元素的赋存特征

研究了火电厂烟气脱硝过程中新催化剂和运行35000 h后不可直接再生失活催化剂的元素分布规律和表面结合方式等特征.结果表明,在气体体积空速为30000 h-1、NH3/NO体积比为0.8及O_2体积含量为5%条件下,失活催化剂脱硝率在200℃仅为41%,在250~400℃比新催化剂下降8%.失活催化剂晶型仍为锐钛型Ti O_2,但整体蜂窝状结构塌陷,化学磨损导致晶体粒径降至37.2 nm.催化剂表面Fe,K,Al,As等杂质元素非均匀沉积,使孔容减小10.44%.对比新催化剂,失活催化剂中锐钛型Ti O_2载体呈现非均匀分布,且表面V/Ti原子比降低29.53%,V4+/(V4++V5+)价态比降低25.89%,使表层酸性位减少,导致催化剂低温活性明显降低.     

新疆和田玉的特征研究

重点阐述了新疆和田玉的矿物成分及其分类，并通过对和田玉的主要化学成分与透闪石理论值相比较以及由其化学成分计算Mg2+/(Mg2++Fe2+)的特征值，确定和田玉的主要成分是透闪石矿物，同时指出FeO含量的变化对玉石颜色及玉质的影响。     

控制原料Fe2O3含量提高浮法玻璃质量的实践

本文主要从分析玻璃硅质原料中的Fe2O3含量对生产优质浮法玻璃质量的影响出发，对原料的采选、配合料配制及熔制等几个工序进行剖析，提出了对硅质原料中Fe2O3含量的目标控制及策略。     

透远紫外玻璃中痕量铁对紫外透过率的影响

以透远紫外玻璃UVGM为基础,研究痕量铁对玻璃在远紫外区域透过率的影响。讨论了在相同铁含量基础上,氧化气氛和还原气氛对紫外透过率的影响,研究了还原气氛条件下,不同铁含量对紫外透过率的影响和产生的原因,以此为依据对UVGM玻璃生产过程可能出现的杂质铁污染的允许范围给出了定量的结论。     

双波长分光光度法测定自来水中Fe2+和Fe3+的含量

采用双波长分光光度法测定 Fe2 和 Fe3 的方法 ,结果表明 ,在 λ1 =4 0 0 nm,λ2 =5 4 2 nm处 ,显色时间在 6 0 min～ 80 min,p H =4～ 5时能联合测定水中 Fe2 和 Fe3 ,其结果具有较高的精密度和准确度。     

The effect of Co2+, Cu2+, Fe2+ and Fe3+ during electrowinning of nickel

The effects of the impurities Co²⁺, Cu²⁺, Fe²⁺, Fe³⁺ on the current efficiency, physical appearance, purity, crystallographic orientation and surface morphology of the deposit and on nickel deposition polarization behaviour during nickel electrowinning were determined. The current efficiency did not change significantly in the presence of these impurities over the concentration range studied, but certain changes in the purity and physical appearance of the deposit were observed. Based on the physical appearance of the electrodeposited nickel, the tolerance limits of the impurities in the electrolyte are reported. The tolerance limit of Co²⁺ was a maximum at 500 p.p.m. and a minimum at 5 p.p.m. in the case of Fe²⁺. No deviation of nickel structure from fcc was observed in the presence of any of these impurities but the peak height values for different orientations showed variations with all the impurities and the values also changed with increase in the impurity concentrations. The surface morphology of electrodeposited nickel also changed in the presence of the impurities. The potentiodynamic scan curves for electrodeposition of nickel showed deviations in the presence of all the impurities except Cu²⁺. Based on the results, an attempt is made to correlate the effects of the various factors investigated.     

Cu2+, Fe2+ and Fe3+ analysis of bioleaching solutions using chronoamperometry and BDD electrode

In this work, a boron-doped diamond (BDD) electrode was evaluated for the electroanalytical determination of millimolar concentrations of Cu²⁺, Fe²⁺ and Fe³⁺ using chronoamperometry. The interfering role that each ion plays on the quantitative determination of other metal ion concentrations was also assessed. No interference from other metal ions was observed when Fe³⁺ and Fe²⁺ were analysed. By contrast, reduction of Fe³⁺ took place at the same potential where [Cu²⁺] was measured causing a minor interference to the Cu²⁺ signal. A multiple linear regression (MLR) calibration model was made for each analyte using real bioleaching samples, which demonstrated high coefficients of determination and adequate standard errors. The methods developed were used to monitor bioleaching of chalcopyrite for 4 months. The electroanalytical methods are particularly well-suited for analysing Cu²⁺, Fe³⁺ and Fe²⁺ concentration in acidic mine drainage (AMD) and bioleaching environments.     

Replacing Mg2+ by Fe2+ for RNA-Cleaving DNAzymes

It has been proposed that Mg²⁺ and Fe²⁺ are very similar in interacting with ribozymes and some protein-based enzymes, but their activities with DNAzymes have yet to be studied. Here, the activity of Fe²⁺ as cofactor for a few RNA-cleaving DNAzymes is investigated. 17E is a well-studied DNAzyme that is active in the presence of many different divalent metal ions; it is highly active with Fe²⁺ with an apparent K_d of 29.7±2.3 μm and a k_obs of 1.12±0.11 min⁻¹ in the presence of 1 mm Fe²⁺ at pH 7.5. Fe²⁺ has 21-fold higher activity than Mg²⁺. Six different DNAzymes are then tested, and only the DNAzymes active with Mg²⁺ (17E, 8–17, and E5) are active with Fe²⁺. Fe²⁺ has 25 and one- to twofold higher activity than Mg²⁺ for the 8–17 and E5 DNAzymes, respectively. In pH>7 buffer and in presence of air, 1 mm Fe²⁺ results in a nonspecific degradation of the DNA strand due to reactive oxygen species (ROS). Cleavage reactions in anoxic environment and antioxidant ascorbate can be used to overcome the effect of oxidation. The findings provide insights for potential DNAzyme catalysis in the early Earth, and they further support the similarity between Mg²⁺ and Fe²⁺ in enzyme catalysis.     

化学镀Ni-Fe-P镀液中Ni2+、Fe2+的容量分析

研究了络合滴定法测定Ni-Fe-P化学镀液中Ni^2 、Fe^2 浓度的方法和影响滴定结果的因素。研究表明，对Ni^2 进行滴定时，以三乙醇胺为掩蔽剂、紫脲酸铵为指示剂进行滴定，可以得到较准确的结果；对Fe^2 进行滴定时，以酒石酸为掩蔽剂、碘基水扬酸为指示剂进行滴定，测定结果较好。     

Fe2+/Fe3+和Mn2+对低氧曝气过程总氮去除与转化途径的影响

为短期快速实现实际生活污水自养脱氮,采用含有厌氧氨氧化菌的实际污水处理厂活性污泥,针对Fe²⁺/Fe³⁺和Mn²⁺对低氧曝气过程中氮的去除效果进行了研究,分析确定了氮素转化的途径。研究结果表明,Fe²⁺/Fe³⁺和Mn²⁺均可提高活性污泥中厌氧氨氧化菌（AnAOB）丰度,但由于Fe²⁺/Fe³⁺对氨氧化菌（AOB）也存在一定抑制作用,因此,短期投加Fe²⁺/Fe³⁺条件下,低氧曝气过程中总无机氮去除率为25%,但投加Mn²⁺条件下总无机氮去除率可达44%。通过氮素平衡分析,发现投加Fe²⁺/Fe³⁺条件下,氮素主要通过反硝化作用去除;而投加Mn²⁺条件下,氮素主要通过厌氧氨氧化（anammox）作用去除。因此,传统活性污泥可通过短期投加Mn²⁺增强厌氧氨氧化活性,促进低氧曝气过程中氮的去除,利于快速实现一体化自养脱氮。     

铁矿中全铁和Fe2+连续测定方法

1 前言 目前,由于科学技术的高速发展,促使化学领域的分析手段必须不断更新,新的大型分析仪器陆续出现,但因其价格昂贵、测定方法局限性等因素,多数企业仍采用化学分析手段对产品进行测定,尤其是对高含量的无机化工产品及原料,化学分析比仪器分析准确度高,成本低,简便易行.     

Catalytic Mechanism of Cu2+ and Fe3+ in Alkaline O2 Oxidation of Lignin

The catalytic mechanisms of Cu²⁺ and Fe³⁺ in the alkaline oxidation of lignin are discussed. Best aldehyde yields were obtained by using Cu²⁺ and Fe³⁺ as catalysts. Without these two ions present or in the absence of one or other of them, yields were lower. It is clear that Cu²⁺ and Fe³⁺ significantly influence the reactions. Cu²⁺, acting as the electron acceptor, accelerates the formation of the phenoxy radical, thus speeding up the radical reaction. In order to interpret the effect of Fe³⁺ on oxidative degradation of lignin and formation of aldehydes, formation of an intermediate, O₂-Fe³⁺-lignin complex and its catalytic mechanism have been proposed.     

氨水中Fe~ (2+)、Fe~(3+)含量的控制及分析方法

介绍了氨水中Ｆｅ２＋、Ｆｅ３＋含量的控制指标及其分析原理和分析方法     

循环水系统腐蚀与其Fe^2＋和Fe^3＋总质量浓度的关系

论述了循环水系统Fe2 和Fe3 (总铁质量浓度)来源,碱度对总铁质量浓度的影响,现场监测结果与总铁质量浓度的平衡及余氯对总铁质量浓度的影响.结果表明,循环水系统总铁质量浓度的高低与补充水中总铁质量浓度、浓缩倍数、碱度控制范围有关.在碱度较低时,循环水中总铁质量浓度与碱度呈负相关关系.当系统碱度超过一定范围(130 mg/L)以后,大部分铁离子形成沉积垢,总铁质量浓度基本维持在低位且变化不大,此时用总铁质量浓度判断系统腐蚀趋势已失去意义,应以现场监测结果为准.如果总铁质量浓度稳定在一定范围内,并不持续升高,应属正常,否则就要细查原因,尤其要查氧化性杀菌剂的投加方式和投加量引起的系统腐蚀问题.