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11.
据英国《金融时报》消息,英国政府于2012年12月13日宣布,在出台更加严格的新规定之后将允许恢复国内页岩气的勘探。这意味着,曾因怀疑水力压裂法或引发小规模地震而被废除的页岩气开采项目时隔1年半后获得解禁。英国能源与气候变化大臣爱德 相似文献
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研究了一种用于测定纸浆中过渡金属含量的样品预处理方法(酸处理法).选择了最具代表性的铁为研究对象,通过对酸的种类和浓度、处理温度和时间等条件的选择及优化,得出最佳处理条件为:采用3 mol/L的硫酸溶液来分散纸浆(浆料浓度可视过渡金属离子含量的多少适当调整),然后将其装入密封的容器内在120℃下处理5h.通过与灰分法和消化法预处理后的测定结果比较可知,采用酸处理法对样品进行预处理,可使测定过渡金属离子含量的误差在7%以内,且克服了灰分法中硅化合物的干扰. 相似文献
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电感耦合等离子体发射光谱法测定岩石矿物中铌和钽的方法 总被引:1,自引:0,他引:1
文章文研究了用电感耦合等离子体发射光谱法(ICP-OES)测定岩石矿物中的铌和钽的方法。实验考察了不同溶样方法及其对样品的溶解程度,确定了称样量及其溶解的方法,选择了恰当的分析线波长,确定了仪器工作条件,讨论了共存元素的干扰情况。针对不同的干扰采取的方法测定。对方法的准确度及精密度进行了考察。 相似文献
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研究建立了用HNO3-HF-HClO4-HCl分解钛铁矿试样,利用电感耦合等离子体发射光谱仪(ICP-OES)同时测定钛铁矿中V、Cu、Mn、Pb等11种杂质元素的测定方法。确定了仪器测定最佳工作条件及分析谱线,采用Y内标元素消除钛、铁基体效应。方法的线性相关系数>0.999,相对标准偏差为0.60%~3.73%,加标回收率为94%~108%。结果表明:本法精密度和准确度较好,方法快速、简便。 相似文献
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《Food Control》2017
Wine vinegars from three Protected Designations of Origin (PDO), Vinagre de Jerez (J), Vinagre de Montilla-Moriles (MM) and Vinagre del Condado de Huelva (CH) from Andalusia, Southern Spain, were investigated for their mineral elements content. Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Sr, V and Zn were determined by inductively coupled plasma optical-emission (ICP-OES). Jerez vinegars had a statistically significant higher Sr content than the others, while with respect to B the same was true for Montilla-Moriles vinegars. Moreover, the ageing time of the vinegars clearly played a role in vinegar mineral content, with higher mineral levels found in aged vinegars than in young ones, especially in samples from Condado de Huelva. Multivariate analysis was performed in order to assess if the vinegars' geographical classification was possible through their elemental profile. Classification models were obtained by LDA and SVM, achieving good prediction abilities, 73 and 80%, respectively. 相似文献
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Vladimir N. Losev Elena V. Borodina Alexander S. Samoilo Anatoly M. Zhyzhaev Boris A. Velichko 《分离科学与技术》2018,53(11):1654-1665
Pine sawdust and malt sprouts modified with orthophosphoric acid and carbamide have been proposed for solid-phase extraction (SPE) of nonferrous, heavy, and precious metals and their subsequent determination in the environmental samples by inductively coupled plasma optical emission spectrometry (ICP-OES). Modified adsorbents were characterized by SEM, TGA, and FT-IR and compared with native matrixes. SPE of some nonferrous and precious metal ions by biosorbents was studied. Depending on the SPE conditions, it was possible to separate nonferrous and heavy metals from alkali and alkaline earth metals. The proposed adsorbents are effective for preconcentration of nonferrous and heavy metals from natural waters and precious metals from solutions after digestion of geological samples. 相似文献
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Allan N.S. Dantas 《Fuel Processing Technology》2010,91(11):1422-1427
The heterogeneous nature of gum samples obtained from the deposits of internal combustion engines is the main difficulty in accurate determination of their metal content. A microwave-assisted digestion method was implemented using factorial experimental design. The optimization of this procedure was carried out by first evaluating the effects of variables on the response (i.e., the residual carbon content or RCC). The variables of maximum heating power, heating time and nitric acid volume were studied. The RCC response was measured by inductively coupled plasma optical emission spectrometry (ICP-OES). The time of maximum heating power was essential to obtain a desired RCC. The surface response was constructed with optimal conditions presented at 6 min and heating power of 700 W. Amounts of aluminum (Al), calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) were determined in 26 gum samples by ICP-OES. Ca, Fe, Mg and Zn were found at mg g−1 levels in the samples, while Al, Cu, Mn, Ni and Pb were found at mg kg−1 levels. Principal component analysis (PCA) was used to establish a correlation between the gum samples and the different metal contents. Three distinct groups were separated according to the characteristics of the collected samples. 相似文献