Application of Fluorescence Technique for Rapid Identification of DOM Fractions in Source Waters

Dissolved organic carbon has been typically used as a measure of organic content in source waters. However, dissolved organic carbon is an aggregate parameter and does not provide information on the organic character of natural organic matter in water. The spectral fluorescent signatures technique coupled with a multiple linear regression model was applied for the rapid identification of six dissolved organic matter (DOM) fractions (hydrophobic acid, hydrophobic neutral, hydrophobic base, hydrophilic acid, hydrophilic neutral, and hydrophilic base) along a major river in a New Jersey watershed. The technique∕model enabled rapid spatial and temporal determination for the rapid qualitative and quantitative measurement of the DOM fraction(s) in the river. The analysis of DOM fractions also enables screening of the watershed for variations in humic and nonhumic substances input/output along the reaches.     

高炉在用烧损冷却壁快速更换技术的探讨

阐述开发宝钢3BF在用烧损冷却壁快速更换技术的必要性、可行性及设备方面的难点,并对冷却壁快速更换技术的实施方法进行了初步的探索.     

九十年代原子荧光光谱法的技术进展

从仪器装置、测定技术两个方面对九十年代国内外原子荧光光谱法技术的进展进行了评述．     

流动注射荧光熄灭法快速测定痕量铜

本文研究了铜─钙黄绿素流动注射荧光熄灭法测定铜的条件,此法操作简便、快速、重现性好,进样频率１２０次／ｈ,相对标准偏差小于１．５％,检测限０．０２３μｇ／ｍｌ．用于测定牛肝、山药及污水中痕量铜,结果满意。     

X射线荧光光谱法快速分析烧结块中硫含量

将样品压制成片,用MXF-2400型X射线荧光光谱仪测定烧结块中硫的含量。方法简单快速、准确,满足生产分析要求。     

连铸中间包定径水口快速更换保护浇注技术

介绍了莱钢炼钢厂开发的第二代定径水口快速更换保护浇注技术的工艺措施以及在莱钢 3 #、4#连铸机的推广应用情况。该快换水口保护浇注工艺克服了塞棒控制工艺的不足 ,使钢水收得率由 95 .72 %提高到 99.60 % ,具有提高钢水收得率、减少耐材消耗、提高铸坯质量、稳定生产组织等优点。     

利用X荧光能谱仪快速测定合金钢中钼元素

在合金钢能量色散X射线荧光光谱的研究基础上,使用国产的XRF-6型X射线荧光能谱仪对合金钢中钼元素进行了测定分析。钼元素的Kα特征射线能量值为17.443 keV,铁元素的K_α特征射线能量值为6.40 keV,通过与基体铁元素特征射线强度值之比得到的工作曲线可以实现合金钢中钼元素的快速定性及定量分析。合金钢中成分元素铌对钼元素测定存在一定的干扰,有效地克服干扰元素对钼元素测定数据的影响是数据处理的技术关键。研究结果表明铌元素等的干扰能被有效克服,X射线荧光能谱可解决合金钢中钼元素的快速分析问题。     

Development of an Analytical Technique to Determine the Fractions of Vanadium Cations with Different Valences in Slag

The current work aimed to develop a reliable method to analyze the amounts of different vanadium cations in metallurgical slag. The application of the technique to the samples of supercooled slag showed its applicability and reliability.     

钆镁合金X荧光光谱点滴滤纸片薄样测定法的研究

建立了滤纸制样,以锰作内标,X射线荧光光谱测定钆镁合金中主量元素的方法。准确度与精密度良好。方法操作简单、方便、快速。     

低碳贝氏体复相钢相鉴别技术

普通金相侵蚀方法观察材料的显微组织虽然简洁快速,但往往只能显示晶界和相界,并且难以有效地区分多于两相的显微组织。特别是低碳贝氏体复相钢组织比较复杂,普通金相侵蚀方法很难满足需要,通过分析普通显微技术,彩色金相技术和电子背散射衍射技术,在各相定量分析方面进行了一些尝试和探索,并取得了一系列成果和进展。     

Rapid and Simple Identification of Free Magnesia in Steelmaking Slag Used for Road Construction Using Cathodoluminescence

Metallurgical and Materials Transactions B - Reuse of steelmaking slags is important for the effective use of natural resources. Free magnesia (f-MgO) in steelmaking slag may cause serious problems...     

Contaminant Detection, Identification, and Quantification Using a Microchip Laser Fluorescence Sensor

This paper describes a series of laboratory tests conducted to assess the performance of a novel fluorescence-based in situ sensor for environmental contaminants. The sensor, which can be deployed downhole in a monitoring well, or incorporated into the shaft of a cone penetrometer, is less than 4?cm in diameter and uses a miniature microchip laser that produces ～ 200?ps pulses of ultraviolet radiation at a high repetition rate ( ～ 10?kHz) to excite fluorescence in a wide range of compounds. Results from laser induced fluorescence tests on single compound aqueous solutions of benzene, toluene, and o-xylene (BTX) demonstrate the sensor’s ability to perform contaminant analyses on compounds with fluorescence lifetimes on the order of 1?ns. A linear relationship between contaminant concentration and fluorescence intensity was observed for concentrations over several orders of magnitude from the sensor’s detection limit (<1?ppm for o-xylene) to solutions of pure BTX compounds at aqueous solubility. Owing to the microchip laser’s short pulse length, fluorescence lifetimes were obtained directly from measurements without the need for spectral deconvolution. Analysis of data from these tests highlights the importance of differentiating a sensor’s ability to detect, identify, and quantify compounds of interest—performance thresholds that ultimately define potential applications for the device.     

粉末压片法-能量色散X荧光光谱快速测定高炉渣

高炉渣是炼铁的副产品，其中的碱度及硫的高低对高炉冶炼有很大的指导作用。但一般应用化学湿法分析周期长，操作复杂，消耗大。为满足生产低成本、高速度、高准确度的要求，我们进行了能量色散Ｘ荧光粉末压片法分析研究。本文采用西安二六二厂ＦＪ－２８１０Ｇ能谱仪。采用自制内控标样绘制工作曲线，并进行了适当的校正，确立了快速低成本、高准确度的分析方法。实践证明能完全满足生产需要。１实验部分１．１仪器和工作条件化学制样粉碎机；ＭＰ－５０型压片机（岛津公司）；ＦＪ－２８１０Ｇ能量色散Ｘ荧光光谱仪（西安二六二厂）。电压…     

快速划伤法研究裸露金属的点蚀热力学

采用快速划伤法对18-8Ti、316L不锈钢和Incoloy800合金在氯化钠溶液中的裸表面临界点蚀电位E_c进行了精确的测量。分析了金属裸表面上点蚀的形成机理,指出了裸表面临界点蚀电位的物理意义。研究表明,E_c与氯离子浓度成半对数关系。比较并分析了E_c与动电位法测得的点蚀击破电位E_b、保护电位E_p之间的关系。研究表明,E_c与E_b在不同pH值的氯化钠溶液中表现出相同的变化规律,并通过测得再钝化系数的变化规律来说明pH值对E_c和E_b的影响。     

Rapid Sinterability of Mechanically Alloyed MgAl/MgO Composite with the Field-Assisted Sintering Technique

Russian Journal of Non-Ferrous Metals - In this study, a Mg22Al/10MgO composite could be produced at nearly full density by the field-assisted sintering technique at relatively low temperatures and...     

Rapid Smoking as a Technique of Behavior Modification: Caution in Selection of Subjects.

Comment by Robert Hauser regarding the article by Lichtenstein, Edward; et al (see record 1973-21539-001) on the modification of smoking behavior. Hauser states that rapid smoking as a method of aversion therapy must be seriously questioned because of the potentially harmful effects it can have on certain people with advanced coronary artery disease. Unless extensive screening techniques are used to evaluate each participant in advance of aversive therapy, the procedure could possibly precipitate a fatal heart attack. While the method probably would not seriously affect people without coronary disease, it should be noted that rapid smoking can lead to the absorption of increased amounts of nicotine into the system. As a result of ethics, Hauser cannot condone the further use of the technique in studies on the modification of smoking behavior unless subjects are first given adequate medical evaluation and clearance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative Analysis of FeMo Alloys using Lithium Tetraborate Fusion Technique by X‐Ray Fluorescence Spectrometry

A quantitative analysis method of molybdenum in FeMo alloys by X‐ray spectrometry using borate fusion technique was proposed. Homogeneous glass disks were prepared under the following conditions: lithium tetraborate as flux with sample dilution (1:33), with the addition of lithium nitrate (LiNO₃) as oxidizer by slow heating from 888 to 1123 K for 45 min followed by fusion at 1273 K for 3 min in an O₂‐blowing atmosphere. The complete pre‐oxidation of FeMo alloys by adding oxidizer and by employing O₂‐supplying apparatus was ascribed to the reproducible preparation of homogeneous fused glass disks. Nine FeMo standard materials were employed to establish the XRF calibration curves for Mo and Fe. The calibration curves were used in the quantitative analysis of standard materials and unknown plant samples with satisfactory precision and accuracy, considering the matrix effects and line overlap corrections. It is believed that the newly proposed method of preparing fused glass disks of FeMo alloys employing an automated fusion system can replace the conventional preparation requiring the labor intensive and time consuming procedure.     

Introducing the Planar Laser-Induced Fluorescence Technique (PLIF) to Measure Mixing Time in Gas-Stirred Ladles

Metallurgical and Materials Transactions B - The planar laser-induced fluorescence (PLIF) technique was implemented to measure mixing time in a 1/17 water model of a 200-ton ladle furnace. The...