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181.
Summary We studied the mineral speciation of Cu, Zn and Hg in fly ash from a large thermal plant burning lignite. By applying various treatments carried out under different conditions and taking into account the solubility and physical properties (boiling and melting point, etc.) and the behaviour towards combustion of the different possible compounds, we concluded that the ash assayed contained 109.6, 114.4 and 14.30 g/g of zinc silicate, zinc oxide and/or zinc sulphide and metal zinc, respectively, as well as 24.5 g/g of copper silicate and 31.2 g/g of a mixture of copper oxide, sulphide and metal. The formation of these compounds in the combustion of lignite is discussed. 相似文献
182.
A method was developed for the chromatographic separation of V(V) and V(IV) based on the different sorption forces of these vanadium species in C18 columns in presence of KH-phthalate. The vanadium species were detected with a flame atomic absorption spectrometer with acetylene/N2O flame. The detection limits (3σ) of V(V) and V(IV) were 0.18 μg/mL and 0.15 μg/mL, respectively. The relative standard deviations (N = 5) are 4.2% and 3.4% for 20–20 μg/mL V(V) and V(IV), respectively. The sampling frequency is 75/h. Because of the special interaction occurring between phthalate and V(IV) on the C18 column and the acetylene/N2O flame atomic absorption detection, practically no interferences can be detected even in large inorganic matrix. 相似文献
183.
Thermal decomposition of molten 6,6-bis-(4-methoxycarbonyl-butyl)-1,2,4,5-tetraoxane has kinetic parameters similar to those of the other dialkyl peroxides: A similar behaviour has also been found for 6,6-bis-(4-aminocarbonyl-butyl)-1,2,4,5-tetraoxane dissolved in dimethylformamide: In the absence of solvent this cyclic dimeric peroxide is uncommonly stable owing to the relatively high melting point. The increase in activation energy and frequency factor (compensation effect) at the decomposition in the absence of solvent is explained by the stabile aggregation of the amino derivative of tetraoxane in the crystalline state.The reaction heat of the exothermic decomposition reaction equals 102 for the methoxy and 96±6 kcal mol?1 for the amino derivative.The measurements of rate constants and reaction heat were carried out by the method of differential enthalpic analysis. 相似文献
184.
Zusammenfassung Ascorbinsäure kann in 1 n salzsaurer Lösung mit Kaliumbromatmaßlösung bei Anwesenheit von Kaliumjodid und Stärke titriert werden.Teil II: diese Z. 161, 38 (1958). 相似文献
185.
By using the dynamically defined reaction path (DDRP) method and starting from various initial polygons, the intrinsic reaction coordinate (IRC) of the H2 + H → H + H2 reaction has been calculated. The numerical stability of the method is illustrated by the evolution phases of the reaction path. Techniques and experiences on the parameter choice and effects of the parameter values on the stability and computer time consumption are discussed. © John Wiley & Sons, Inc. 相似文献
186.
V. Ščasnár M. Zemánek L. Šoltés M. Lukácsová 《Journal of Radioanalytical and Nuclear Chemistry》1989,134(2):433-436
An HPLC method was developed for studying the stability of [3H] stobadin stored in physiological saline or buffers at various pH. Optimum conditions for the separation of degradation products were elaborated. A high-performance liquid chromatograph equipped with a radioactivity detector was used. 相似文献
187.
Given a finite setX of vectors from the unit ball of the max norm in the twodimensional space whose sum is zero, it is always possible to writeX = {x1, , xn} in such a way that the first coordinates of each partial sum
lie in [–1, 1] and the second coordinates lie in [–C, C] whereC is a universal constant. 相似文献
188.
The fluorimetric determination of adrenaline is carried out in a continuous-flow assembly and by means of the molecular dissolved oxygen. The sample solution merges with an NaOH stream, then the resulting mixture is heated at 73 °C and led to the flow-cell of the fluorimeter. The flow-assembly is very simple and the procedure is quick (107 samples h–1) reproducible (R.S.D. 0.6%), selective and suitable to be applied to determination of adrenaline in formulations. Calibrations graph are linear over the ranges 0.05–15 and 20–40 mgl–1. 相似文献
189.
P. Kratochvíl B. Smola I. Stulíková P. Vostrý F. Jandoš J. Šedivec 《Czechoslovak Journal of Physics》1985,35(3):257-260
Static softening of AISI 321 steel after cold and hot deformation characterizing the industrial thermomechanical treatment was studied by means of tensile tests and TEM. The deformation temperature, the strain and the grain size were the main parameters determining the final softening. The results can be applied for optimization of the solution annealing. 相似文献
190.
The second order optical potential for thed system is derived in the framework of the Watson formalism and applied to the calculation of the 1s-state energy shift of the atom and thed scattering lengtha
d
. The results are in good agreement with those of the Faddeev type calculations.The authors wish to thank V. B. Belyaev, R. Mach, M. G. Sapozhnikov and R. A. Eramzhyan for stimulating discussions and helpful advice. 相似文献