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91.
Activity coefficients in the aqueous quaternary system sodium chloridepotassium chloride-magnesium chloride were derived from isopiestic measurements at 25°C. The isopiestic data were treated by the various procedures of Scatchard, Friedman, and Reilly, Wood, and Robinson, and results obtained agreed fairly well with those obtained by pseudoternary transforms. Interaction parameters obtained indicated the preponderance of pairwise interactions. Excess Gibbs free energies of mixing were calculated. 相似文献
92.
Spectrophotometric studies on the reaction between germanium ions and phenylfluorone were discussed including the reaction condition to develop a spectrophotometric method for the determination of germanium. The absorbance was measured at 525 nm after 20 min from the moment of adding the reagent. Beer's Law is obeyed, the relative standard deviation is 2%, the senstivity of the method is 2.55 × 10−3 mg/cm3, and the molar absorbtivity based on germanium is 1.75 × 103. 相似文献
93.
94.
Saad S. M. Hassan 《Fresenius' Journal of Analytical Chemistry》1974,270(2):125-126
Ohne Zusammenfassung
Limits of detection of the six structural-isomeric xylenols (dimethyl phenols) on ready-made foils UV 254 and silica gel G with different spraying reagents相似文献
95.
Summary The closed-flask combustion products of some nitrogen compounds were studied. The percentage of nitrogen oxides formed (expressed as nitrate-nitrogen) was determined. Combustion of these samples, after mixing with inorganic oxidants, in a stream of oxygen was also investigated. Trials for the application of the oxygen-flask method for the microdetermination and detection of nitrogen in many organic compounds are reported.
Zusammenfassung Die aus einigen Stickstoffverbindungen bei der Verbrennung im sauerstoffgefüllten Kolben entstehenden Produkte wurden untersucht. Der Anteil an Stickstoffoxiden (ausgedrückt als Nitratstickstoff) wurde bestimmt. Ebenso wurde auch die Verbrennung dieser Substanzen im Sauerstoffstrom bei Gegenwart anorganischer Oxydantien untersucht. Über Versuche, die Kolbenmethode zum Nachweis und zur Bestimmung des Stickstoffs in vielen organischen Verbindungen anzuwenden, wurde berichtet.相似文献
96.
97.
M. A. Abuzeid M. I. El-Zaiki N. A. Mansour A. I. Popov H. R. Saad V. E. Storizhko 《Zeitschrift für Physik A Hadrons and Nuclei》1967,199(5):506-517
Total yields and angular distributions of gamma rays following the inelastic scattering of protons from Cr50 and Cr54 have been measured at proton energies below 2.5 MeV. Gamma ray spectra resulting from the proton radiative capture by Cr50 and Cr54 were obtained. Transitions from most of the Mn51 and Mn55 low-lying levels have been observed. The experimental results are in good agreement with predictions of the statistical compound nucleus theory. 相似文献
98.
Jafar Al-kabi Peter H. Gore Esmat F. Saad David N. Waters Gerald F. Moxon 《国际化学动力学杂志》1983,15(8):697-703
The system of a sequence of five first-order reactions, A → B → C → D → E → F, has been analyzed kinetically. An actual example is proposed in the reaction of mesitonitrile in 89.8% (w/w) sulfuric acid at 98.3°C. The analysis provides estimates of concentration ratios as functions of time, and the progress of the buildup and decay of the intermediate species can be monitored. The kinetics have been measured for the hydration of mesitonitrile, the hydrolysis of mesitamide, and the sulfonation of mesitylenesulfonic acid in 89.8% sulfuric acid. The calculated values of the concentration ratios of mesitylenedisulfonic acid as a function of time were satisfactorily close to those found in experiment. 相似文献
99.
Saad Alshehri John Burgess Katherine A. Darcey Marttand S. Patel 《Transition Metal Chemistry》1994,19(1):119-122
Summary Solubilities of tris(ethylmaltolato)iron(III) (ethylmaltol = 3-hydroxy-2-ethyl-4-pyrone) were measured in MeOH-H2O, t-BuOH-H2O and diol-H2O mixtures, and in several primary alcohols. Solvation of the ethylmaltol ligand and of two 4-pyridinone analogues has been investigated through solubility measurements in MeOH- H2O and in t-BuOH-H2O mixtures, and in a series of primary alcohols. The solvation characteristics of these compounds are compared with those of the parent maltol, its iron(III) complex and a number of other nonelectrolytes. 相似文献
100.
This study evaluates the effects of gamma radiation on structure, electrochemical corrosion behavior and Vickers hardness of commercial dental Nikkeli–Kromi–Polttosekoitus [Ni65.2Cr22.5Mo9.5X2.8 (X=Nb, Si, Fe and Mn)] alloy. The corrosion rate of Ni65.2Cr22.5Mo9.5X2.8 (X=Nb, Si, Fe and Mn) alloy with 0.5 M HCl is increased with increasing the exposure rate of gamma radiation. The corrosion resistance of Ni65.2Cr22.5Mo9.5X2.8 (X=Nb, Si, Fe and Mn) is varied and reaches a minimum value at 30 KGy. The corrosion potential value also is varied and reaches its highest value at 30 KGy. The Vickers hardness value of Ni65.2Cr22.5Mo9.5X2.8 (X=Nb, Si, Fe and Mn) alloy is decreased by increasing the gamma radiation dose. Also it is obvious from our results that the effects of gamma radiation at the surface are much higher as compared with deeper parts and the structure of the alloy is changed due to its exposure to gamma radiation. 相似文献