Analysis of surface acidity-basicity and related catalytic properties by a “follow up” gas chromatographic pulse technique

The “follow up” technique is a quick and simple GC pulse method by which to determine the quantity of strongly irreversibly bound and strongly reversibly bound adsorbate on the surface of a solid. These quantities may be calculated from the sum of the retained amounts when titrating, in a particular way, the surface by a series of pulses of adsorbate. Some technical developments of the method, including the appropriate choice of the pulse size and the interval between successive pulses, are reported. Determination of the surface acidity of Al(OH)₃ samples used as a seed in the Bayer process, as well as a qualitative characterization of the catalytically active fraction of several oxide surfaces, indicate the wide range of applicability in surface analysis.     

Improved Dyeing with Redox Systems: IV—dyeing of nylon-6 with disperse dyes

The dyeing of nylon-6 fabric with Terasil Red 2GL (CI Disperse Red 72), in the absence and presence of redox systems based on ammonium persulphate [(NH₄)₂S₂O₈] as oxidant and potassium pyrosulphite (K₂S₂O₅), glucose (C₆H₁₂O₆) or thiourea (CH₄N₂S) as reductant, was studied. It was found that for a given set of dyeing conditions the colour strength, expressed as K/S, follows the order

Increasing the (NH₄)₂S₂O₈ concentration (0.00–0.03 m ) as well as the duration (15–60 min) and temperature (65–95° C) of the dyeing process caused significant enhancement in the colour strength and dye fixation. It is postulated that the presence of (NH₄)₂S₂O₈ alters the mode of dye interaction. In the presence of the oxidant component, i.e. (NH₄)₂S₂O₈ , attachment of the disperse dye to the nylon-6 substrate seems to involve covalent bonding in addition to the usual hydrogen bond. This is indicated by the significant colour strength remaining after DMF extraction for dyeings obtained using different disperse dyes and in the presence of (NH₄)₂S₂O₈. A free-radical mechanism for the covalent bond formation between nylon-6 and the disperse dyes is tentatively suggested.     

阿姆河流域耕地变化及水土匹配特征分析

基于中亚阿姆河流域4个分区1990—2015年间土地利用变化和水资源等数据,运用耕地变化速率、洛伦兹曲线和基尼系数法以及水土资源匹配系数对阿姆河流域耕地变化和水土匹配状况进行了综合分析。结果表明:1990—2015年阿姆河流域耕地以146.74 km²/a的速度在扩张,且各时期、各分区扩张的速度不同;在不考虑咸海来水不断减少、生态持续恶化的前提下,绿洲区匹配状况属比较公平和相对合理状况;阿姆河流域水土资源空间分布存在明显的错位现象;全流域生态用水被农业用水严重挤占,阿姆河流域灌溉面积、灌溉用水量成为影响咸海水量及面积变化的重要因素,是一种不可持续的用水方式。     

基于SIFT和NCC的多源遥感影像配准方法

针对多源遥感影像的配准,提出了一种结合SIFT算法和归一化互相关（NCC）匹配算法的配准方法。该方法采用SIFT算法提取特征点并进行匹配得到一定数量的特征点对后,利用SIFT特征点的尺度和方向信息对NCC进行改进,进一步从未能匹配的特征点中获取匹配点对,经粗差滤除后得到有效的匹配特征点对,随之进行影像配准。方法结合了SIFT算法和NCC算法的优点,解决了多源遥感影像因辐射差异和几何差异造成的难以正确配准的问题。实验结果表明,算法具有较强的鲁棒性,并取得了较好的配准精度。     

高分辨率遥感影像桥梁特征提取方法研究*

根据桥梁水体相连的知识,提出了一种基于知识的高分辨率遥感影像水上桥梁提取的实用方法,即在水体提取的基础上将图像细化,通过宽度限制检测桥梁主干线,并对其进行矢量化和特征表达来实现桥梁提取,通过实验证明了该方法的有效性。实验证明此方法不仅适合于水体与陆地灰度差别大,即单峰直方图的影像,还适合于水体与陆地灰度差别不大,即直方图多峰或峰顶不明显的影像。     

基于IHS的高分辨率遥感影像自适应融合算法

在分析几种IHS算法的基础上,提出了一种适合于高分辨率遥感影像的自适应加权融合算法。该算法基于快速IHS变换,从亮度成份构成和空间细节注入程度两个方面加以改进,采用相关系数来调整权重,避免了人工指定权重带来的主观因素偏差,在提高影像空间细节和光谱保持之间取得了较好的均衡,同时还具备了高计算效率。通过融合实验并与几种改进的IHS算法的对比分析,该算法均优于其他几种改进算法。