Application of Inductively Coupled Plasma Spectrometric Techniques and Multivariate Statistical Analysis in the Hydrogeochemical Profiling of Caves—Case Study Cloșani,Romania

The aim of the study was to develop the hydrogeochemical profiling of caves based on the elemental composition of water and silty soil samples and a multivariate statistical analysis. Major and trace elements, including rare earths, were determined in the water and soil samples. The general characteristics of water, anions content, inorganic and organic carbon fractions and nitrogen species (NO₃⁻ and NH₄⁺) were also considered. The ANOVA—principal component analysis (PCA) and two-way joining analysis were applied on samples collected from Cloșani Cave, Romania. The ANOVA-PCA revealed that the hydrogeochemical characteristics of Ca²⁺-HCO₃⁻ water facies were described by five factors, the strongest being associated with water-carbonate rock interactions and the occurrence of Ca, Mg and HCO₃⁻ (43.4%). Although organic carbon fractions have a lower influence (20.1%) than inorganic ones on water characteristics, they are involved in the chemical processes of nitrogen and of the elements involved in redox processes (Fe, Mn, Cr and Sn). The seasonal variability of water characteristics, especially during the spring, was observed. The variability of silty soil samples was described by four principal components, the strongest influence being attributed to rare earth elements (52.2%). The ANOVA-PCA provided deeper information compared to Gibbs and Piper diagrams and the correlation analysis.     

YTP高强度调剖剂的研究与应用

分析了影响YTP高强度油田注水井调剖剂成胶时间的因素及其调剖机理.分析表明该调剖剂成胶时间可控、配制简单、方便(现场配制),动用设备少,成本低,对注水井管柱适应性强.室内岩心和64口井的现场试验结果表明:调剖剂对岩心封堵率高,承压能力强,调剖后在相同的注入量条件下,注水压力升高,吸水剖面得到有效调整,在相连通的油井见到明显的增油降水效果.     

A survey of solved problems and applications on bandwidth,edgesum, and profile of graphs

This article provides a survey of results on the exact bandwidth, edgesum, and profile of graphs. A bibliography of work in these areas is provided. The emphasis is on composite graphs. This may be regarded as an update of the original survey of solved bandwidth problems by Chinn, Chvátalová, Dewdney, and Gibbs [10] in 1982. Also several of the application areas involving these graph parameters are described. © John & Sons, Inc. Graph Theory 31: 75–94, 1999     

煤灰及各种矿物质对SO2排放特性的影响

利用TG-DTG采用低加热速率实验研究了煤阶、脱灰及煤中主要矿物质成分对煤燃烧过程中SO2排放特性的影响,并对矿物质成分的影响机理进行了讨论。结果表明,煤中硫质量分数的高低对烟气中SO2的排放有明显影响,排放水平与硫质量分数不成比例;煤中硫向SO2转化率与煤阶之间没有明显的关联;脱灰能较小程度地促进SO2的生成,抚顺煤主要矿物质成分中Na、K、Mg以及Ca等碱金属与碱土金属明显抑制SO2的排放,同时纳米级的TiO2也减少烟气中SO2体积分数,这些成分对SO2抑制作用的顺序为MgNa≈K>Ca>Mg>Ti的次序加速焦炭的氧化;Si和Al属于惰性成分,对煤中硫的迁徙以及煤的燃烧特性没有显著影响。     

Determination of crystallite particle size distribution of polymers from WAXS

A method for the calculation of crystallite size distributions from the profile of wide-angle x-ray reflections is developed. The influence of lattice distortions on the profile is taken into account. The information about the lattice distortions is obtained from the measurement of the integral widths of a number of reflections. The method is applied to samples of (ethylen-1 hexen) copolymers. The change of crystallite size distributions in lateral directions with increasing temperature (20–121°C) is measured. Recrystallization processes at temperatures near the melting point are observed. © 1996 John Wiley & Sons, Inc.     

Y沸石中不同状态铁离子的还原和催化性质

制备了Fe(Ⅲ)处于骨架四面体内、阳离子位及以氧化物形式分散在沸石表面的含铁Y沸石.用TPR方法测定样品的可还原性,发现不同形态的Fe(Ⅲ)其还原情况不同,在800℃以下均不能被还原成金属Fe.以异丙醇脱水和脱氢为探针,考察了样品的酸碱性,证实在沸石结构内引入不同形态的Fe(Ⅲ)可调变沸石的酸碱性.用乙苯脱氢和裂解反应考察了样品的脱氢活性.当样品表面金属离子和强酸位同时存在时,由于二者的协同作用,裂解反应有可能占主导地位.消除强酸位,增加碱性位,可显著提高脱氢的选择性.     

Metal deposits on well-ordered oxide films

Metal oxide interfaces, metal coatings or dispersed metals on oxide supports play an important part in many technological areas. Nevertheless, there is still a lack of fundamental knowledge about the essential properties of thin metal films and small metal particles on oxide supports, although a deeper understanding could help to improve the electronic, mechanical or catalytic performance of such systems. In the past, a number of different approaches have been proposed and explored aiming at the preparation of suitable model systems. In this review, we discuss the possibility to use thin, well-ordered oxide films as supports for the study of deposited metal particles. This approach offers the advantage to permit the unrestricted application of all experimental methods, which rely on a good electrical or thermal conductivity of the sample, like PES, LEED, STM or TDS. With the help of several examples taken from our own work on a thin alumina film, we show that it is feasible to characterise such systems on a microscopic level with respect to all relevant structural, electronic and adsorption properties. In this way, correlations between these features can be established helping to understand the particular chemistry and physics of small metal aggregates.     

Depth profiling of polymer films by confocal Raman spectroscopy

Confocal Raman microspectroscopy has many potential applications in the study of polymer-solvent interactions, including the determination of solvent and polymer-solvent complex depth profiles. This contribution focuses on preventing the formation of polymer-solvent complexes, using surface chemical modification of PVC films. While the surface-specific nature of the film modification is easily demonstrated,^[1] confocal Raman measurements clearly show the effects of film refractive index: the modifier depth profile shows a lack of symmetry and the film thickness is underestimated. A spectral normalisation method is described, and this is shown to result in a modifier depth profile which is in good agreement with data obtained by Raman microspectroscopy following physical cross-sectioning of a sample. Alternative techniques for Raman depth profiling are also discussed.     

α粒子反常扩散效应及等离子体温度空间自洽分布

本文采用多群方法研究了慢化过程中快α粒子反常扩散对其能谱及空间分布的影响，并与本底等离子体的能量平衡方程结合起来求解了等离子体的空间自洽温度分布。以ＩＴＥＲ－ＣＤＡ设计参数为例，分析了不同密度条件下氘氚自持燃烧过程与α粒子反常扩散的关系。