Search Results

You are looking at 1 - 3 of 3 items for :

  • Author or Editor: Xuan Zhang x
  • Chemistry and Chemical Engineering x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

The oscillatory behavior of the reaction of partial oxidation of methane has been investigated over metallic nickel surfaces. It was found that the chemical compositions and the reaction temperature within the reactor exhibited regular oscillations over a range of reactor temperatures between 710 and 930 °C with different feed gas compositions at flow rate ratios (Ar/CH4/O2) ranging from 30:29:1 to 30:12:18 cm3 min−1. When the reactor temperature increased, the oscillation frequency increased showing indicative correlations, while the amplitude decreased with the rise in system temperature. Varying feed gas composition resulted in complex changes in oscillatory waveforms, frequencies, amplitudes, and product selectivities. The oscillation was attributed to the cyclic reduction and oxidation of the nickel surface under the reaction conditions.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors:
Li Yu-guo
,
Huang Xuan
,
Liu Riu-li
,
Li Qing-nuan
,
Zhang Xiao-dong
, and
Li Wen-xin

Summary  

The water-soluble fullerene derivative C60(OH)x was radiolabeled with 67GaCl3. The labeling yields were determined by radio-PLC. The effects of pH, reaction time, temperature and the amount of C60(OH)x on the labeling yields were studied. The stability of 67Ga-C60(OH)x was also examined. The results showed that the labeling yields could reach 97% under the best labeling conditions and the radiochemical purity of 67Ga-C60(OH)x solution kept at 37 °C remained at 88% after 212 hours. The biodistribution studies of 67Ga-C60(OH)x in mice showed a high localization of 67Ga-C60(OH)x in the bone marrow, bone, liver and spleen with slow clearance and a negligible accumulation in the blood. These data suggest that the water-soluble C60(OH)x, having the same properties as microcolloids, may be used as a carrier of drug system for lymphatic targeting.

Restricted access

Abstract  

The mechanism of solvent extraction of uranium(VI) from highly concentrated chloride solution with a quaternary ammonium salt, benzyloctadecyldimethylammonium chloride (BODMAC, R4NCl), dissolved in chloroform was studied. The compositions of the extracted species were R4N.UO2Cl3 and (R4N)2 .UO2Cl4. The extraction process is exothermic (ΔH° = -8.42±0.54 KJ/mol). Kex 1 and Kex 2 are calculated to be (3.62±0.55).10-2 and (1.06±0.17).103, respectively. In the extraction process, a W/O uranium(VI) rich emulsion solution has been formed between the organic and aqueous phases, its volume increased with the increase of BODMAC in the system. The influences of temperature, NaCl, MgCl2 and MgSO4 concentrations on the extraction equilibrium were also studied.

Restricted access