摘要:

Investigations at natural gas fields as well as modelling experiments have pointed out that changes of the chemical and isotopic composition occur in the course of migration, accumulation and dispersion of natural gas. Dissolution and sorption processes as well as in particular the diffusion process come into consideration as elementary processes of the separation. The influence on dissolved and freely flowing gases and on stationary gas accumulation are described by differential equations. The simulation of the following phenomena are shown:

ISSN:0021-1915    

DOI:10.1080/10256018708623816

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In the last few years molecular dynamics has become a valuable tool in calculating the thermodynamical, structural and transport behaviour of a lot of many-particle systems in different fields of science and application. First the aims and essential features of molecular dynamics (MD) are described. In the second part self-diffusion coefficients of N2/CH4mixtures for isotope substituted methanes in dependence on temperature, pressure, mass and diameter are calculated. Avoiding large computational efforts the calculations are performed by a kinetic hard sphere theory fitting the hard sphere diameters by MD runs.

ISSN:0021-1915    

DOI:10.1080/10256018708623817

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

It is known, that pectolite exhibits the lowest deuterium content among all the hydrominerals. This is due to pecularities of its structure. In present work the kinetics of extraction of crystallic water from pectolite and from muscovite is examined. In the first case preferently “heavy” water (i.e. enriched in its deuterium content) is expelled from the mineral and in the second case – “light” water. An activation energy of 60 keal/mole may be attributed to dehydratation of both the minerals. Experiments show, that delta D in synthetic pectolites does not depend on the isotopic composition of surrounding water.

ISSN:0021-1915    

DOI:10.1080/10256018708623818

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Synergistic solvent extraction of Co(II) from aqueous perchlorate medium with toluene-3,4-dithiol/dibenzylamine diluted with chloroform and with nitrobenzene is investigated at different temperatures. An increase in the extraction of the investigated metal cation was observed with increasing temperature without any change in the formula of the extracted species. The calculated values of ΔH and ΔS are used to elucidate the mechanism of synergism in this system.

ISSN:0021-1915    

DOI:10.1080/10256018708623819

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Non-isotopic exchange in gamma irradiated mixed crystals of K2SO4-Na2SO4doped with51Cr(III) has been investigated before and after annealing treatments. Oxidation of51Cr(III) to51Cr(VI) and formation of51CrO2−4matrix occured as a result of gamma irradiation. The results have been discussed in the light of oxygen-vacancies formation and recombination reactions.

ISSN:0021-1915    

DOI:10.1080/10256018708623820

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Using15N labelled amino acids the amount of nitrogen in amino acid fractions, resulting from the impurity of the applied chemicals of the Kjeldahl method, was estimated. The study shows that the measured15N values are dependent on the nitrogen content of the sample and the level of15N labelling. Within the range of 250 μg … 1000 μg nitrogen in the sample and in the case of15N-excess >1 Atom% a correction of the measured15N excess values is recommended

ISSN:0021-1915    

DOI:10.1080/10256018708623821

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The aim of this work is to follow the concentration of radioactive contamination in air resulting from Chernobyl accident. A sudden and sharp increase was detected seven days after the start of the mishap. This increase amounted to about 650 times the normal air-borne activity.

ISSN:0021-1915    

DOI:10.1080/10256018708623822

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Mica Track Microfilters (MTM) are successful applied to separate two different and strongly mixed liquid phases (emulsion). The organic and the inorganic phase of the emulsion were 30% tributyl phosphate (TBP) in kerosene and 2 N HNO3(or H2O), respectively. Mica filters with sharp edges (i.e. etched with H2F2) and having pore sizes k of 8 μm > k > 2 μm are used to get under some well defined conditions a rather complete extraction of the aqueous phase out of the emulsion. The system was calibrated with the pure phases (water as well as TBP in kerosene), and the liquid throughput is shown as a function of the pore size of the filter. The throughput depends mainly on the pore size and not that much on the kind of liquid, it is slightly larger for water as compared to that of TBP in kerosene.

ISSN:0021-1915    

DOI:10.1080/10256018708623823

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Im Zusammenhang mit on-line-Bestrahlungsexperimenten har sich vor allem die He-Jet-Technik einen festen Platz erobert [1- 5], der nicht in Frage gestellt werden soll. Unge-uchtet dessen erseheint es zweekmäßig, ergänzend Techniken zu entwickeln, die ausschließlich auf Verwendung von flüsigen Phasen basieren. Das erlaubt es, die vielfältigen Möglichkeiten zu nutzen, welehe die Chemie in Lösungen für Trenn- und Anreicherungsaufgaben bietet. Dabei wird von der Grundannahme ausgegangen, daß bezüglich der Transportgeschwindigkeit die entsprechenden Parameter der Gas-Jet-Technik durch rein flüssige Varianten bestenfalls erreicht jedoch kaum übertroffen werden können. In der zur Verfügung stehenden Literatur wurde lediglich vonAronssonu. a. 1973 ein System beschrieben, wo in einer n, γ-Reaktion eine Lösung direkt bestrahlt wird [6], dieses findet sich jedoch in der späteren Literatur nicht wieder.

ISSN:0021-1915    

DOI:10.1080/10256018708623824

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256018708623825

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor