Search Results

You are looking at 1 - 10 of 10 items for

  • Author or Editor: Cui Yu x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

The extraction of uranyl nitrate by the novel extractant N,N’-dimethyl-N,N’-dioctylsuccinylamide (DMDOSA) from aqueous nitric/nitrate solutions was investigated. The effects of concentration of HNO3 and DMDOSA on the U(VI) extraction distribution was studied. The extraction mechanism was established and the stoichiometry of the main extracted species was confirmed to be UO2(NO3)2·2DMDOSA. The value of ΔH of the extraction is −23.9±1.7 kJ·mol−1. A IR spectral study of the U(VI) extracted species was also made.

Restricted access

Abstract  

Co-combustion experiments of mixture of Huadian oil shale and Heshan coal with high sulphur content have been conducted using a thermogravimetric analyzer. The effects of five different Ca/S mol ratios on the combustion characteristics of mixture fuel are analyzed using TG and DTG curves. The results show that the initial temperature of combustion of mixture fuel is decreased with an increase in the oil shale content of mixture fuel. The combustion characteristic of mixture fuel is superior to that of Heshan coal. Adding about 20 mass% Huadian oil shale into Heshan coal is feasible for desulfurization of mixture fuel during combustion.

Restricted access

Summary  

This work is focused on the extraction of U(VI) with three new unsymmetrical monoamides, N-methyl-N-octyloctylamide (MOOA), N-methyl-N-octyldecanamide (MODA), and N-methyl-N-octyldodecanamide (MODOA), from nitric acid solution employing toluene as diluent. The effects of nitric acid, sodium nitrate and extractant concentrations and also the temperature on the distribution ratio have been investigated. The extracted species were studied by IR spectrometry.

Restricted access

Abstract  

N,N-dialkylamides, (octan-, decan- and dodecanamides) having ethyl and butyl groups as alkyl substituents, were synthesized in order to investigate their selectivity and capability in the extraction of Th(IV) from acidic nitrate media (3 and 6M HNO3) in nuclear reprocessing. The distribution ratios of Th (IV) with the amides in kerosene decrease with the increase of the alkyl chain length (C8, C10, C12), probably due to steric hindrance.

Restricted access

Abstract  

The extraction behavior of N,N,N',N'-tetrabutylmalonamide (TBMA) employing toluene as diluent toward Dy(III) has been investigated. The effect of the concentrations of nitric acid, lithium nitrate and extractant and also of the temperature on the distribution ratio has been studied. The stoichiometry found for the Dy(III) extracted species suggests a structure such as Dy(NO3)3 .3TBMA. An attempt has been made to establish the structure of the isolated extracted species recurring to the data of IR.

Restricted access

Abortion in dairy cattle causes considerable economic losses to the dairy industry. Aborted fetuses and samples from the corresponding aborting dams from 12 dairy herds in Beijing were tested for 9 abortifacient infectious pathogens by PCR between 2008 and 2010. From a total of 80 abortion cases collected during this period, infectious agents were detected in 45 (56.3%) cases, 22 (48.9%) of which represented co-infections with two or three infectious agents. The detected pathogens included infectious bovine rhinotracheitis virus (36.3%) and Neospora caninum (31.3%), followed by bovine viral diarrhoea virus (7.5%), Brucella abortus (6.3%), Tritrichomonas foetus (5%) and Toxoplasma gondii (1.3%). Campylobacter fetus, Coxiella burnetii and Chlamydophila psittaci were not detected in any abortion case. Findings from this study indicated that infectious bovine rhinotracheitis virus and Neospora caninum were the main potential causes of abortions in Beijing dairy herds, whereas the bacterial pathogens were not, in contrast to reports from other countries. This is the first study to test nine abortifacient infectious agents by PCR at the same time, and it is also the first time to report the involvement of a variety of infectious agents in bovine abortion cases in China.

Restricted access

Abstract  

The half-life of79Se, a long-lived fission product nuclide, has never been measured accurately. The value quoted in the literature is an upper limit, 6.5·104 y, measured in 1949. In the present work we measured accurately the half-life of79Se to be (4.8±0.4)·105 y using a radiochemical method.

Restricted access
Reaction Kinetics, Mechanisms and Catalysis
Authors: Lixia Wang, Wanchun Zhu, Dafang Zheng, Xue Yu, Jing Cui, Mingjun Jia, Wenxiang Zhang, and Zhenlu Wang

Abstract  

The reaction of direct transformation of ethanol to ethyl acetate was investigated on reduced Cu/ZrO2 catalysts prepared by a co-precipitation procedure. The catalytic performances of these Cu–Zr mixed oxides were considerably influenced by changing the molar ratio of Cu to Zr. The highest selectivity to ethyl acetate was found over Cu/ZrO2(1) catalyst (molar ratio of Cu to Zr was 1). A variety of characterization techniques, such as N2 adsorption, XRD, XPS, TPR and NH3-TPD were carried out on the catalysts. The results revealed that the presence of a certain amount of Cu+ species may play very important role in improving the selectivity to ethyl acetate of the Cu/ZrO2 catalysts.

Restricted access

Abstract  

The extraction of U(VI) from nitric acid solutions with di-(1-methylheptyl) phosphoric acid has been investigated. The dependence on nitric acid concentration, DMHPA concentration and temperature has been considered and the infra-red spectra of extracted species and extractant were recorded. The mechanism of extraction is discussed in the light of the results obtained.

Restricted access

Abstract  

Interfacial tension and interfacial adsorption parameters for benzyloctadecyldimethyl ammonium chloride (BODMAC) in three organic diluents were determined and interpreted. The interfacial activity of BODMAC is affected by the type of the organic diluent and the composition of the aqueous phase. The general order of interfacial activity of BODMAC is n-heptane (5% isobutanol) > carbon tetrachloride > chloroform. The effectiveness of adsorption of BODMAC is not only dependent on the organic diluent, but also on the inorganic electrolytes in the aqueous phase.

Restricted access