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101.
氯化钠存在下氯化亚锡—罗丹明B—水体系浮选分离铱 总被引:5,自引:1,他引:5
研究了Ir(Ⅲ)在NaCl存在下SnCl2-罗丹明B-水体系中的浮选行为,在1.0mol/L HCl介质中,Ir(Ⅲ)与Pd,Pt,Rh,Au同时被浮选,Ir(Ⅲ)的浮选率为99.2%,并与常见贱金属离子分离,被浮选分离的Ir可采用原子吸收法测定,结果与火试金分离富集法相符。精密度试验,相对标准偏差(RSD,n=5)<3%。 相似文献
102.
微量元素在植物光谱中的响应机理研究 总被引:26,自引:0,他引:26
微量元素与植物光谱特征的研究是光学遥感定量化研究的重要内容之一。本研究利用高光谱地面光谱仪(GER)在湖南黔阳地区不同地质地球化学背景下的同一垂直剖面上分别测量了岩石、土壤植物(林灌草)的反射光谱曲线和植物叶片的8种微量元素含量。通过研究微量元素Fe,Mn,Cu,Zn,Co,Cr,Mo,B与植物(包括林灌草)反射光谱间的相关性研究发现Co的含量与植物光谱绿区(0.56μm附近)反射率存在强的负相关,Mn,B,Mo和Zn分别在可见光、近红外、短波红外存在较好的相关性和光谱响应。 相似文献
103.
104.
不同石墨炉技术对钒原子化信号的影响 总被引:2,自引:0,他引:2
研究了钒元素在不同石墨炉技术、不同类型石墨管中的原子吸收曲线,探讨了产生这些差异的根本原因。 相似文献
105.
Flux-energy spectra of precipitating electrons are derived from electron density profiles measured by the EISCAT radar during auroral absorption events in the morning/noon local-time sector. The inversion technique uses effective recombination coefficient profiles computed on the basis of a previously validated theoretical model of the lower ionosphere. It is shown that flux-energy spectra for the energy range 30–200 keV are in reasonable agreement with those derived for the same events using trapped flux-energy spectra from geosynchronous satellite data and a model for diffusion of trapped electrons into the loss cone by scattering on whistler waves. During individual events, strongly varying precipitating fluxes are found to be due primarily to varying pitch-angle diffusion. 相似文献
106.
The effectiveness of tuned mass dampers (TMD) in vibration control of buildings was investigated under moderate ground shaking caused by long‐distance earthquakes with frequency contents resembling the 1985 Mexico City (SCT) or the 1995 Bangkok ground motion. The elastic–perfectly plastic material behaviour was assumed for the main structure, with linear TMDs employed by virtue of their simplicity and robustness. The accumulated hysteretic energy dissipation affected by TMD was examined, and the ratio of the hysteretic energy absorption in the structure with TMD to that without it is proposed to be used, in conjunction with the peak displacement ratio, as a supplementary TMD performance index since it gives an indication of the accumulated damage induced in the inelastic structures. For the ground motions considered, TMD would be effective in reducing the hysteretic energy absorption demand in the critical storeys for buildings in the 1.8–2.8 s range. The consequence is reduction in damage of the buildings which would otherwise suffer heavy damage in the absence of TMD, resulting in economical restorability in the damage control limit state. This is of practical significance in view of the current trend toward performance‐based design. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
107.
The heat capacity of natural chamosite (XFe=0.889) and clinochlore (XFe=0.116) were measured by differential scanning calorimetry (DSC). The samples were characterised by X-ray diffraction, microprobe analysis and Mössbauer spectroscopy. DSC measurements between 143 and 623?K were made following the procedure of Bosenick et?al. (1996). The fitted data for natural chamosite (CA) in J?mol?1?K?1 give: C p,CA = 1224.3–10.685?×?103?×?T ??0.5???6.4389?× 106?×T ??2?+?8.0279?×?108?×?T ??3 and for the natural clinochlore (CE): C p,CE = 1200.5–10.908?×?103?×T ??0.5?? 5.6941?×?106?×?T ??2?+?7.1166?×?108?×?T ??3. The corrected C p-polynomial for pure end-member chamosite (Fe5Al)[Si3AlO10](OH)8 is C p,CAcor = 1248.3–11.116?× 103?×?T ??0.5???5.1623?×?106?×?T ??2?+?7.1867?×?108×T ??3 and the corrected C p-polynomial for pure end-member clinochlore (Mg5Al)[Si3AlO10](OH)8 is C p,CEcor = 1191.3–10.665?×?103?×?T ??0.5???6.5136?×?106?×?T ??2?+ 7.7206?×?108?×?T ??3. The corrected C p-polynomial for clinochlore is in excellent agreement with that in the internally consistent data sets of Berman (1988) and Holland and Powell (1998). The derived C p-polynomial for chamosite (C p,CAcor) leads to a 4.4% higher heat capacity, at 300?K, compared to that estimated by Holland and Powell (1998) based on a summation method. The corrected C p-polynomial (C p,CAcor) is, however, in excellent agreement with the computed C p-polynomial given by Saccocia and Seyfried (1993), thus supporting the reliability of Berman and Brown's (1985) estimation method of heat capacities. 相似文献
108.
Absorption cross-section measurements of NO2 performed in our laboratory have been extended to the 200–300 nm region at ambient temperature. Low pressures have been used, limiting the effects of the dimer N2O4 which has an absorption cross-section from one to two orders of magnitude larger than that of NO2 in this region. The results have been compared to those of previous authors and are now available for atmospheric purposes at 0.01 nm intervals.Unité de Recherche Associée au CNRS. 相似文献
109.
本文通过对地形通视分析的基本设想的描述及其实践途径中有关问题的探讨,结合实例阐明了计算机自动进行通视分析的基本方法和处理技巧,并附有具体程序。 相似文献
110.
偏岭石及煅烧高岭石的红外光谱研究 总被引:3,自引:0,他引:3
通过对偏岭石和相应煅烧高岭石的红外光谱测定,发现偏岭石同煅烧高岭石在结构上有很大的差异。在偏岭石中不存在非晶态SiO_2相,其中Si—O_4四面体同Al—O_6八面体是相互聚合的:煅烧高岭石(600~995℃)中则不同,其中Si大部分是以独立的非晶态SiO_2相存在,而同其中的Al_2O_3相分离。偏岭石同煅烧高岭石的关系是:对偏岭石进行一定温度的煅烧,它可以转变成像煅烧高岭石一样的结构状态。 相似文献