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Abstract  

A new extractant for protactinium has been studied. This paper describes the extraction behaviour of Pa from HCl system by morin-isoamylol. The whole procedure can be completed in 100 sec., yield of extraction is 99.2%.

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Abstract  

Direct anchoring of the synergistic extractant TOPO-P204 onto the inner walls of mesoporous molecular sieve generates a non-stoichiometric synergistic extractive membrane absorbent: MCM-TP which has well-spaced and structurally well defined active sites. Specifically, the feasibility of applying the MCM-TP absorbent with an absorption capacity of 0.02 mmol[Pd]/gabsorbent to the recovery of non-radioactive palladium from spent nuclear fuels has been examined showing an advantage over the liquid-liquid extraction or precipitation method. MCM-TP studied by powder XRD, TEM and29Si MAS NMR indicates that it has 35 Å regular, well-defined channels and an improved hydrothemal stability.

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This is a study for criteria to judge the melting point of semi-crystalline polymers from the DSC endotherm for polymer melting. Beyond standard indium DSC melting results an evaluation has been made on a series of polyethylenes for which crystal sizes were measured and predicted from Raman LAM analysis. The results confirm the conclusion of Prof. Wunderlich that the DSC content of melting is the proper basis of reporting melting points.

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Abstract  

The surface structure of triuranium octaoxide (U3O8) and the effect of CO on surface behaviour have been studied by X-ray photoelectron spectroscopy (XPS). An intensity analysis of the composite U4f photoelectron spectrum of U3O8 shows that this compound should be written as U2 VIUIVOg. After exposure to 7.2·106 L CO (1 L=1.33·10–4 Pa·s), the oxygen content in the surface is decreased and the O1s/U4f ratio decreases about 10%. The investigation indicated that the surface layer of triuranium octaoxide was partially reduced in the atmosphere of carbon monoxide.

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Abstract  

The surface reactions of uranium metal with carbon monoxide at 25 and 200 °C have been studied by X-ray photoelectron spectroscopy (XPS); respectively. Adsorption of carbon monoxide on the surface layer of uranium metal leads to partial reduction of surface oxide and results in U4f photoelectron peak shifting to the lower binding energy. The content of oxygen in the surface oxide is decreased and O1s/O4f ratio decreases with increasing the exposure of carbon monoxide. The investigation indicates the surface layer of uranium metal has resistance to further oxidation in the atmosphere of carbon monoxide.

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Study of the immobilization of226Ra

I. Cement solidification of226Ra waste

Journal of Radioanalytical and Nuclear Chemistry
Authors:
R. Wang
,
X. Yang
, and
Q. Wu

Abstract  

A study of the immobilization for226Ra waste has been carried out. Cement-based concrete was used as a matrix for the solidification of radium waste. The experimental results show that the cement mixture with water/cement between 0.46–0.54 has higher strengh (above 20 MPa), and the compressive strength was not reduced by addition of 1% barite or the radium waste (RaSO4) into the concrete solid.

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Study of the immobilization of226Ra

II. Predictive model of radionuclide leaching behavior in a cement-based solid

Journal of Radioanalytical and Nuclear Chemistry
Authors:
X. Yang
,
W. Zhou
, and
R. Wang

Abstract  

A three-dimensional leaching model was developed to describe the leaching of radionuclide from a cement-based concrete solid. The film mass transfer and interparticle diffusion were considered simultaneously. On the basis of the derived model the long-term behavior of radium-226 leaching from the waste solid has been quantitatively investigated.

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Abstract  

A new method of thermal desorption chromatography, in which hydrogen is used as carrier instead of helium, and a water bath instead of an air bath, is presented for determining the specific surface area of uranium compounds. The method proposed has a higher accuracy and a better applicability.

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Abstract  

The paper is concerned with endomorphism algebras for weak Doi-Hopf modules. Under the condition “weak Hopf-Galois extensions”, we present the structure theorem of endomorphism algebras for weak Doi-Hopf modules, which extends Theorem 3.2 given by Schneider in [1]. As applications of the structure theorem, we obtain the Kreimer-Takeuchi theorem (see Theorem 1.7 in [2]) and the Nikshych duality theorem (see Theorem 3.3 in [3]) in the case of weak Hopf algebras, respectively.

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