ISSN:0021-1915    

DOI:10.1080/10256019008624318

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256019008624319

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

We describe the computer-coupling of a measuring system for local-sensitive detection of gamma-ray to a IBM-PC. The measuring device for technical diagnostic, based on a local-sensitive proportional gasdetector, is represented, the software for control the measuring system by PC is explained.

ISSN:0021-1915    

DOI:10.1080/10256019008624320

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256019008624321

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Catalysts composed of nickel and promoted with different metal oxides proved to be suitable for H/D isotropic exchange between hydrogen and water vapour. They loss their activity due to water condensation on their surfaces. Several nickel/chromium oxide/zirconium oxide catalysts of different composition were prepared by the coprecipitation technique. The liquid phase activity of these catalysts were followed using the hydrogen peroxide decomposition on their surfaces at different temperatures. The surface characteristics of the examined catalysts were followed by applying the BET method. The results were discussed and lead to the required catalyst composition which resists the water condensation on its surface during operation and has relatively high activity in the vapour phase H/D isotopic exchange reaction between hydrogen and water.

ISSN:0021-1915    

DOI:10.1080/10256019008624322

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Annual growth rings in trees were thought to be due to sharp seasonal variations in the precipitation rates during the year. Accordingly temperate zone trees such as Egyptian trees were supposed to be away from this phenomenon. The temperate zones which are ment here are those of no sharp seasonal variations in the precipitation rates. The present study applied carbon-14 dating to prove that the growth rings in some Egyptian trees are annual. The method was based on the tropospheric measurements of C-14 during the period 1954–1981. C-14 exhibited a sharp peak resulting from the ever greater series of nuclear tests during 1963–1965. The presence of this peak for Egyptian trees proved that they form annual growth rings.

ISSN:0021-1915    

DOI:10.1080/10256019008624323

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The application of polarized X-rays in energy dispersive X-ray fluorescence analysis (EDXRF) is prooved to be one method for improvement the sensitivity of trace analysis at rock- and soil-samples. The use of a high power X-ray tube in connection with an amorphous Barkla-scattering target for polarization makes possible the increase of peak-to-background ratios in a wide energy range (5 keV < E < 40 keV) in comparison to direct excitation. The influence of the polarization on the peak-to-background ratios at trace analysis at geological samples will be shown.

ISSN:0021-1915    

DOI:10.1080/10256019008624324

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256019008624325

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The interaction of chloride ions with glassy carbon electrodes is studied by means of36Cl as radiotracer. Chloride ions are bonded on the electrode in case of anodization depending on electrode potential and duration of the polarization. Strong interaction is observed at electrode potentials more positive than +1.3 V. A significant part of the chloride ions bonded at the glassy carbon can not be displaced neither by cathodic polarization nor by rinsing with water or non-labelled solutions. It is concluded that chloride ions are chemically bonded at the surface and the surface region of glassy carbon.

ISSN:0021-1915    

DOI:10.1080/10256019008624326

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Complete adsorption of radiocerium, uranium and plutonium on silica gel surface was attained at pH 5 ± 0.5. Individual separations of the studied radioelements were performed by desorption of the fixed radioelements using 30 ml of 10−4M diaminocyclohexanete-traacetic acid (DCTA) at different pH values.

ISSN:0021-1915    

DOI:10.1080/10256019008624327

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor