Search Results

You are looking at 1 - 8 of 8 items for

  • Author or Editor: Z. Qin x
  • All content x
Clear All Modify Search

Studies of thermokinetics in an adiabatic calorimeter

I. Design and testing of an adiabatic automatic calorimeter

Journal of Thermal Analysis and Calorimetry
Authors: S. Zhan, J. Liu, Z. Qin, and Y. Deng

Abstract  

An adiabatic calorimeter in which automation of the control of the adiabatic condition and the thermogram recording is achieved in a simple way has been designed for studies of both thermochemistry and thermokinetics. A new method for specific heat measurements has been proposed and specific heats ofn-heptane were measured to test the reliability of this calorimeter.

Restricted access

Abstract  

An attempt has been made to develop a radiochemical methodology for the decontamination of a trace amount of radioactive cesium from a bulk amount of natural NaCl by liquid-liquid extraction (LLX). Open chain crown ethers, of amide type, namely, N,N,N",N"-tetraphenyl-3,6-dioxaoctanediamide (TDD), N,N,N",N"-tetraphenyl-3,6,9-trioxaundecanediamide and N,N"-dinaphthyl-N,N"-diphenyl-3,6-dioxaoctanediamide (DDD) have been chosen for this purpose. The separation factor between Cs and Na is the highest when 10-4M TDD dissolved in nitrobenzene is used as extractant and 0.4M picric acid at pH 5.0 is used as aqueous phase. About 60% Cs is extracted in this condition in a single run.

Restricted access

Studies of thermokinetics in an adiabatic calorimeter

II. Calorimetric curve analysis methods for irreversible and reversible reactions

Journal of Thermal Analysis and Calorimetry
Authors: S. Zhan, J. Liu, Z. Qin, and Y. Deng
Restricted access

Abstract  

Solvent extraction of protactinium with tri-iso-octyl-amine (TIOA) in xylene, benzene, carbon tetrachloride and chloroform from HCl, HF, HNO3, HClO4 and H2SO4 media was studied using 233Pa as a radiotracer. The extraction efficiencies of protactinium were determined as a function of shaking time, concentrations of mineral acids in aqueous phase, extractant concentrations and diluents in organic phase. The extraction mechanism was discussed. The results show that the extracted species in the organic phase is [(R3NH)nPa(OH)xCl y 5−xy ].

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: H. J. Ding, Y. N. Niu, Y. B. Xu, W. F. Yang, S. G. Yuan, Z. Qin, and X. H. Zhou

Summary  

The extraction of protactinium with Aliquat 336 (methyl-tri-caprylyl ammonium chloride) in toluene, cyclohexane and chloroform from HCl, HNO3, H2SO4, HClO4, HF and mixed HCl-HF media was investigated by radioactive tracer technique. Distribution ratios of protactinium between the aqueous solution and the organic phase were determined as a function of shaking time, concentrations of acid in aqueous solution phase, extractant concentration and type of diluents in the organic phase. Aliquat 336 can almost quantitatively extract protactinium from strong HCl solution. At the same time, small amounts of HF in HCl solutions have a strong effect on Pa distribution.

Restricted access
Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: Y. Zhao, T. Ohtsuki, Y. Nishinaka, K. Tsukada, S. Ichikawa, H. Ikezoe, Y. Hatuskawa, K. Hata, M. Tanikawa, Z. Qin, K. Sueki, Y. Oura, H. Kudo, and H. Nakahara

Abstract  

Two kinds of scission configurations for certain mass division have been verified by the accurate measurements of fragment velocities in protoninduced fission of actinides: compact and elongated scission configurations. A correlation between the binary scission configurations and mass yield distributions reveals that elongated scission configurations are associated with the symmetric mass distribution and compact scission configurations with the asymmetric mass distribution. The elongation properties of nuclei at scission in a wide range of actinides fissions are studied. The results suggest that the compact and the elongated scission configurations in light actinides fission smoothly change to the scission properties of the symmetric and the asymmetic modes in heavy actinides fission.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: Y. Nagame, I. Nishinaka, Y. Zhao, K. Tsukada, S. Ichikawa, Z. Qin, H. Ikezoe, Y. Oura, K. Sueki, H. Nakahara, M. Tanikawa, T. Ohtsuki, S. Goto, H. Kudo, Y. Hamajima, K. Takamiya, K. Nakanishi, and H. Baba

Abstract  

The correlation among the fission threshold energy, the scission configuration and the mass yield distribution has been studied in proton-induced fission of light actinides. It was found that there exist at least two fission paths from the threshold region to the scission. The elongated scission configuration is related with the fission process that goes over a higher threshold energy and results in a symmetric mass division mode, while the compact scission configuration with the process that experiences a lower threshold and ends up with an asymmetric mass division mode.

Restricted access