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21.
The aluminium species in different tea infusions were investigated, by determining their stability constants and concentration. This was done for some particular samples using a simple experimental method based on the sorption of aluminium on the strongly sorbing resin Chelex 100, by a batch procedure. From the thermodynamic information obtained it is possible to calculate the concentration of the different species, and in particular that of the free metal ion, which is very important for evaluating the adsorption of aluminium on biological membranes. It was found that aluminium in the tea infusions here considered is present at high total concentration, approximately 0.1 mM, but mainly linked to strong complexes, for instance with side reaction coefficient higher than 10(5.11) at pH 3.95 in one case (tea 1). This could be the reason for the low toxicity of aluminium in tea. These strong complexes were not dissociated even in the presence of Chelex 100. In this case only a limiting value of the reaction coefficient could be evaluated. The presence of the very strong complexes was found in all the tea sample here considered. In two of the considered samples (one black and one green tea) a part of Al(III) was linked to less strong complexes, for example with a reaction coefficient 10(4.14) (tea 2, pH 4.20). The presence in the considered tea infusions of other substances able to complex aluminium was also detected, by the well known ligand titration procedure, at concentration ranging from 0.65 to 3.37 mM in three tea infusions, and at somewhat higher concentration in the case of the ready drink, which was also considered for comparison. 相似文献
22.
IR LASER BACKSCATTERING FROM AN ARBITRARILY SHAPED DIELECTRIC OBJECT WITH ROUGH SURFACE 总被引:2,自引:0,他引:2
吴振森 《电子科学学刊(英文版)》1993,10(4):298-306
The backscattering of light wave from arbitrarily convex dielectric objects withrough surface is investigated and formulas for calculating the backscattering cross-section of bothcoherent and incoherent fields are obtained.In the infrared wave-band,the influence of the ge-ometry,permittivity and statistical characteristics of the rough surface on LRCS is analyzed,byusing rough sphere and ellipsoids as examples. 相似文献
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24.
O. J. Svec 《国际能源研究杂志》1987,11(4):573-581
This paper presents a historical background of ground source heat pump technology, followed by a review of its current shortcomings. Based on these observations the author assesses the R&D needs and recommendations for future research. 相似文献
25.
Wayne S. Walker Josef M. Kellndorfer Michael Hoppus 《Remote sensing of environment》2007,109(4):482-499
Exploiting synergies afforded by a host of recently available national-scale data sets derived from interferometric synthetic aperture radar (InSAR) and passive optical remote sensing, this paper describes the development of a novel empirical approach for the provision of regional- to continental-scale estimates of vegetation canopy height. Supported by data from the 2000 Shuttle Radar Topography Mission (SRTM), the National Elevation Dataset (NED), the LANDFIRE project, and the National Land Cover Database (NLCD) 2001, this paper describes a data fusion and modeling strategy for developing the first-ever high-resolution map of canopy height for the conterminous U.S. The approach was tested as part of a prototype study spanning some 62,000 km2 in central Utah (NLCD mapping zone 16). A mapping strategy based on object-oriented image analysis and tree-based regression techniques is employed. Empirical model development is driven by a database of height metrics obtained from an extensive field plot network administered by the USDA Forest Service-Forest Inventory and Analysis (FIA) program. Based on data from 508 FIA field plots, an average absolute height error of 2.1 m (r = 0.88) was achieved for the prototype mapping zone. 相似文献
26.
本文介绍了一种利用数字信号处理器TMS320C25用作雷达数据实时处理,利用图形处理器TMS34010用作雷达视频图象处理,完成雷达视频图象彩色显示的雷达终端。 相似文献
27.
介绍探地雷达探测方法,探讨使用高频探地雷达探测粘土心墙堆石坝坝顶混凝土路面裂缝,达到快速、无损查明坝顶混凝土裂缝的性质与成因的目的. 相似文献
28.
近年来,贵溪冶炼厂贫化电炉渣含铜呈逐年上升趋势,究其原因较多,其中在贫化电炉中处理固铍是主要原因之一.文章主要是时贵溪冶炼厂固铍处理生产现状进行介绍,对贵冶固铍处理的几种可能方法进行分析和讨论,并进行相应的技术经济比较. 相似文献
29.
植被散射实验数据的特性分析 总被引:1,自引:0,他引:1
本文根据电波所获取的各种樾 射实测数据,分析了它们对不同极化波的响应特性。 相似文献
30.