ISSN:0021-1915    

DOI:10.1080/10256017708544022

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Es werden die Massenschwächungskoeffizienten verglichen, die sich bei der Berechnung mit der empirischen Formelsowie der theoretischen Formel von Schmidt (1906), bei der der effective Massenscwächungskoeffizienteines Stoffgemisches als Product eines effektiven wahren Massenschwächungskoeffizientenund eines effektiven Umwegfakors Ū ist, ergeben. Die numerischen Ergebnisse für zahlreiche Substanzen sehr unterschiedlicher Zusammensetzung lassen erkennen,eine Näherung vonfür den Fall von Stoffgemischen aus Substanzen nicht zu unterschiedlicher Kernladungszahlen Zider Komponenten (Gehalte pi, Massenschwächungskoeffizienten μi= μ(Zi)) ist und daß dieser Einschrānkung eine um so geringere Bedeutung zukommt, je geringer die Krümmung der Kernladungszahlabhängigkeit des Massenschwächungskoeffizienten für Elemente ist.

ISSN:0021-1915    

DOI:10.1080/10256017708544023

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Es wurde die Möglichkeit erprobt, mittels der radioaktiven Werkzeugverschleiβmessungen routinemäβige Schnelluntersuchungen von Inhomogenitäten des Drehmaterials durchzufführen. Nach aktivierungsanalytischer Bestimmung der langlebigen Radioisotope von Wendeschneidplättchen aus Hartmetall und der notwendigen Bestrahlungszeit wurde eine Methode zur verlustfreien Erfassung der Drehspäne entwickelt. Die Nachweisgrenze des Abriebes beträgt ca.10−8g bei Meβzeiten von 5 – 10 min, ohne das besonders aufwendige Strahlenschutzmaβnahnen getroffen warden müssen. Eine Analyse des Abriebes ergab, daβ bei Beginn des Zerspanens der Kobalt-Anteil um das 6fache höher ist als in der normalen Zusammenstzung der verwendelen Schneidplättchen.

ISSN:0021-1915    

DOI:10.1080/10256017708544024

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

A simplified analytical X-ray fluorescence technique is presented for the rapid identification of stainless steel-316. This method is based on the principle of excitation of characteristic X-rays from Molybdenum in SS 316 by indirect excitation with an241Am source and detection of these X-rays by a suitable radiation detector. Emphasis has been placed on designing a low cost instrument that is easy to operate in factories and workshops. The portable radioisotope X-ray fluorescence detector consists of a detector head with a Krypton filled end window Geiger Mueller Counter and a suitable radioisotope X-ray source connected to a count rate-meter with relay switch.

ISSN:0021-1915    

DOI:10.1080/10256017708544025

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

A scale comprising nine degrees similar to that established for eartquakes is proposed in the paper for indicating radioactive radiation, dose rate. Each degree corresponds to one order of the dose rate ranging from 10 μR/h to 1000 R/h. A display consisting of nine lamps serves as an indicator of the dose rate degree in the measuring instrument designed on the basis of this scale. The dose rate degree is indicated by the number of the lighted lamps. Some other solutions are also proposed but, according the author's opinion, the variant with the lamps is most suitable.

ISSN:0021-1915    

DOI:10.1080/10256017708544026

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

By computer calculation three cases of multiplication of isotope effect, corresponding to peculiar parameters of isotopic exchange reaction between U(IV)resinand U(VI)solutionwere considered: 1) inverse break-through; 2) direct break-through and 3) band displacement processes. In the first case the interesting part is located at the end of the elution curve, where a sharp decrease of235U content occurs. In the second case the frontal part is enriched in235U. Although the band displacement is a combination of both direct and inverse break-through processes, only in this case it is possible to obtain an equilibrium isotopic composition of the band, corresponding to the maximal isotopic modification of the whole uranium adsorbed in the band. The stationary equilibrium isotopic composition depends on the displacement lenght of the band, which is increased when the band is longer; it depends also on the physico-chemical factors and especially on the equilibrium constant (separation factor) of the isotopic exchange reaction.

ISSN:0021-1915    

DOI:10.1080/10256017708544027

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

A ternary system composed of Ni/Cr2O3/MgO-Mixture was prepared by co-precipitation from the corresponding metal nitrates using Na2CO3at room temperature. The precipitant was thermally treated at 350 °C in nitrogen atmosphere, followed by reduction at 320 °C, and then stabilized against spontaneous oxidation in air by impregnating it in bidistilled water and allowing slow oxidation to lake place while water evaporates. The specific catalytic activity of the prepared Ni/Cr2O3/MgO mixture for the isotopic exchange of deuterium between hydrogen and water vapour was measured using an exchange apparatus. The specific surface area for the catalyst mixtures was evaluated by nitrogen adsorption al liquid nitrogen temperature and application of the BET-equalion. The specific metallic surface area, the degree of dispersion and the average particle size of Ni/Cr2O3/MgO catalyst mixtures were also calculated through chemisorption of pure hydrogen. Comparison of the specific catalytic activity with the surface characteristics of the mixed catalysts indicates that the catalyst of the highest activity for the deuterium exchange between hydrogen and water vapour exhibit maximum specific metallic surface area, maximum percentage dispersion and minimum particle size.

ISSN:0021-1915    

DOI:10.1080/10256017708544028

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Für den Wirkungsquerschnitt der Reaktion88Sr(n,p)88Rb wurde ein Wert von (0,0155 ± 0,0017) mb erhalten. Er befindet sich in guter Übereinstimmung mit berechneten Werten von Roy und Hawton, Calamand sowie Nasyrov.

ISSN:0021-1915    

DOI:10.1080/10256017708544029

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256017708544030

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256017708544031

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor