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The upper critical solution temperatures, UCST, of a number of mixtures of simple organic substances, including C5 to C10 alkanes, with sulphur hexafluoride are reported. These UCST are analysed in terms of the one fluid model in order to estimate an interaction parameter, ξ, which is a measure of the strength of the interactions between sulphur hexafluoride+organic molecule. The values of ξ are discussed briefly.Several of the systems studied exhibited the barotropic phenomenon.  相似文献   

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Sulphuryl chlorofluoride has no observable reaction with metals and metal oxides at room temperature. Metals like copper, silver, iron, and zinc react with the chlorofluoride in the temperature range 200–400°C. Metal chlorides, metal fluorides and sulphur dioxide are the main products of these reactions. With the corresponding metal oxides, on the other hand, the respective metal sulphates are formed in addition to the metal chlorides and fluorides. In the case of lead and lead oxide, lead chlorofluoride is formed instead of lead chloride and lead fluoride. Sulphuryl fluoride is formed in small quantities in all these reactions by the decomposition of the chlorofluoride. Glass is not attacked by sulphuryl chlorofluoride below 500°C.During the course of our investigations on the reactivity of sulphuryl chlorofluoride, it is observed that sulphuryl chlorofluoride does not react with glass up to 500° C. However, it reacts with metals and metal oxides between 200° to 400° C. The reaction products with metals are the corresponding metal chlorides, metal fluorides and sulphur dioxide. With the oxides, in addition to the metal chlorides and metal fluorides, metal sulphates are formed. The results of these investigations are presented in this communication.  相似文献   

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Summary A preparation of silver granules has been used as an absorbent for halogens and sulphur. Its absorptive capacities for halogens and for sulphur were determined at various temperatures. The capacities are favorably compared with that of electrolytic silver wool. Having a granular form, the material is more conveniently used than electrolytic silver wool, and is applicable to the determination of carbon-hydrogen, halogens, sulphur or oxygen.
Zusammenfassung Gekörntes Silber wurde zur Absorption von Halogenen und Schwefel verwendet. Seine Absorptionskapazität für die genannten Elemente wurde bei verschiedenen Temperaturen bestimmt. Sie ist gleich gut wie die elektrolytisch gewonnener Silberwolle. Die körnige Form ist aber besser zu handhaben als Silberwolle und eignet sich für die Bestimmung von Kohlenstoff und Wasserstoff, der Halogene, des Schwefels und des Sauerstoffs.

Résumé On a utilisé une préparation de grains d'argent comme absorbant des halogènes et du soufre. On a déterminé ses capacités d'absorption pour les halogènes et pour le soufre à températures variées. Le pouvoir absorbant subit une comparaison favorable avec celui de la laine d'argent électrolytique. En raison de la forme granulaire, l'utilisation est plus facile que celle de la laine d'argent électrolytique. On peut l'appliquer au dosage du carbone, d'hydrogène, des halogènes, du soufre ou de l'oxygène.
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The multiple-scattering (or scattered-wave) model has been applied to the sulphur hexafluoride molecule, using an approximate Hartree-Fock potential of the X type. The calculated ionization energies are compared with the data from the X-ray photoelectron spectroscopy (ESCA) experiments, and found to be in better agreement than either the ab initio (SCF MO LCAO) or semi-empirical (CNDO) results.  相似文献   

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Summary Both sulphur hexafluoride and a group of compounds among the perfluorinated cyclic hydrocarbons: perfluorodimethyl cyclobutane, perfluoromethyl cyclopentane, perfluoromethyl cyclohexane and the 1,2- and 1,3-isomers of perfluordimethyl cyclohexane are well known to be good gas tracers, in various applications. Unfortunately different methods have been used for the analysis of SF6 and the perfluorocarbons. Therefore, in many cases, the analytical costs may have hindered the use of both SF6 and the perfluorocarbons in the same tracer experiments. The analytical method described in this paper enables the determination of both types of gas tracer in one single run. The new method has already replaced two former methods and was used to run the gas tracer analysis routinely, proving the reliability of the method.  相似文献   

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The synthesis of some β-carbonylphosphine oxides and phenyl-substituted ethylenediphosphine oxides was carried out. Their complexing with alkali metals cations was studied. Compounds obtained were shown to possess clearly expressed Li/Na selectivity.  相似文献   

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Oxidative coupling of methane over Pr6O11, Mn2O3 and SnO2 oxides supported on -Al2O3 and the same oxides but promoted with alkali metals has been studied. Alkali addition not only modifies the activity and selectivity to C2 of the support and the metal oxide, but also an additional effect is observed.
Pr6O11, Mn2O3 SnO2, -Al2O3, , . C2 , , .
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A flow mixing calorimeter and a vibrating-tube densimeter have been used to measure excess molar enthalpies HmE and excess molar volumes VmE of {xC2H6 +  (1   x)SF6 }. Measurements over a range of mole fractions x have been made at T =  305.65 K and T =  312.15 K and at the pressures (3.76, 4.32, 4.88 and 6.0) MPa. The pressure 3.76 MPa is close to the critical pressure of SF6, the pressure 4.88 MPa is close to the critical pressure of C2H6, and the pressure 4.32 MPa is midway between these values. The measurements are compared with the Patel–Teja equation of state which reproduces the main features of the excess function curves as well as it does for similar measurements on {xCO2 +  (1   x)C2H6 }, {xCO2 +  (1   x)C2H4 } and {xCO2 +  (1   x)SF6 }.  相似文献   

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The suitability of thiourea and its oxides for the hydroxylation of terephthalic acid in aqueous solutions was explored. Allsulfur-containing compounds tested were found to favor the formation of hydroxyterephthalic acid. It was shown that thiourea and its di- and trioxides can act as both traps and promoters of hydroxyl radicals in aqueous solutions.  相似文献   

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