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.
Authors:Y. Wen, S. Lahiri, Z. Qin, X. Wu, and W. Liu
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.
Authors:H. Ding, Y. Niu, Y. Xu, W. Yang, S. Yuan, Z. Qin, and X. Wu
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 [(R3N−H)nPa(OH)xCl
Authors:H. J. Ding, Y. N. Niu, Y. B. Xu, W. F. Yang, S. G. Yuan, Z. Qin, and X. H. Zhou
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.
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
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.
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
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.