Search Results

You are looking at 1 - 10 of 35 items for

  • Author or Editor: Feng Zhao x
  • All content x
Clear All Modify Search

Abstract  

The extraction of uranium(VI) with bis(hexylsulfinyl)methane (BHxSM) from nitric acid aqueous solution has been investigated. It was found that the extraction increased with increasing nitric acid concentration up 8.5 mol/l and then decreased. Extraction distribution ratio also increased with the bis(hexylsulfinyl)methane concentration. The extraction species appear to be UO2(NO3)2 .2BHxSM. The influences of temperature, salting-out concentration and oxalate concentration on the extraction equilibrium were also investigated, and the enthalpy of the extraction reaction was obtained. The result shows that the reaction of uranium(VI) extraction with BHxSM is an exothermic one.

Restricted access

Abstract  

The thermodynamic extraction of uranium(VI) with hexyloctylsulfoxide (HxOSO) has been studied. It was found that the distribution ratio increases with increasing nitric acid concentration up to 2.3 mol/l and then decreases. The distribution ratio also increases with increasing extractant concentration. The extracted species appears to be UO2(NO3)2 .2HxOSO. The influences of temperature, sodium nitrate and oxalate concentrations on the extraction were also investigated, and the thermodynamic functions of the extraction reaction were obtained.

Restricted access

Abstract  

The psi function ψ(x) is defined by ψ(x) = Γ′(x)/Γ(x) and ψ (i)(x), for i ∈ ℕ, denote the polygamma functions, where Γ(x) is the gamma function. In this paper, we prove that the functions
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$[\psi '(x)]^2 + \psi ''(x) - \frac{{x^2 + 12}} {{12x^4 (x + 1)^2 }}$$ \end{document}
and
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\frac{{x + 12}} {{12x^4 (x + 1)}} - \{ [\psi '(x)]^2 + \psi ''(x)\}$$ \end{document}
are completely monotonic on (0,∞).
Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: Gao Feng, Zhou Meiying, Zhao Xialing, Zhang Sunxi, and Wang Guoping

Abstract  

Endothelin (ET) is a novel endothelium-derived vasoconstrictive peptide, purified from porcine aortic endothelial cells.125I-ET was prepared by lodogen method and purified by HPLC, the specific activity was 62.9 TBq/mmol. The stability of125I-ET was investigated in different storage conditions by radioimmunoassay.

Restricted access

Abstract  

The liquid-liquid extraction behavior of 2-ethylhexyltolylsulfoxide (EHTSO) towards uranium(VI) contained in nitric acid aqueous solution has been investigated. It was found that the extraction increases with increasing nitric acid concentration up to 5.0 mol/l and then decreases. Extraction also increases with increasing extractant concentration. The extracted species appears to be UO2(NO3)2 .2EHTSO. The influences of temperature, NH4NO3 and Na2C2O4 concentrations on the extraction equilibrium were also investigated and the thermodynamic functions of the extraction reaction were obtained.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: Zhen Chen, Huan Meng, Hui Yuan, Gengmei Xing, Chunying Chen, Feng Zhao, Yun Wang, Chengcheng Zhang, and Yuliang Zhao

Abstract  

Nanosized copper particles are widely used in fields of lubricants, polymers/plastic, metallic coating and ink. Recently, we found that copper particles in different sizes can lead to different toxicological effects. To clarify the target organs of copper particles of different sizes, the inductively coupled plasma mass spectroscopy (ICP-MS) was employed to evaluate the distribution of copper in different organs of mice after a single dose oral exposure. The results suggest that the main target organs for copper nanoparticles are kidney, liver and blood. Liver is the main damaged organ.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: Huan Meng, Zhen Chen, Gengmei Xing, Hui Yuan, Chunying Chen, Feng Zhao, Chengcheng Zhang, Yun Wang, and Yuliang Zhao

Abstract  

Recently, it was reported that the toxicity of copper particles increases with the decrease of the particle size on a mass basis. To understand this phenomenon, inductively coupled plasma mass spectrometry (ICP-MS) techniques and in vitro chemical studies were carried out to explore how they produce toxicity in vivo. The results suggest that when the sizes of particles become small and down to a nanoscale, copper becomes extremely reactive in a simulative intracorporeal environment. The nanosized copper particles consume the hydrogen ions in stomach more quickly than micron ones. These processes further convert the copper nanoparticles into cupric ions whose toxicity is very high in vivo.

Restricted access

Abstract

The purpose of this study is to simulate the early age concrete behaviors and evaluate the cracking risk with the thermal and thermal stress analysis. A new finite element method program associated with ANSYS program is developed for the computation of thermal field and thermal stress field for early age concrete considering the following characters: degree of hydration, thermal properties (such as specific heat, thermal diffusivity), thermal boundary conditions, and mechanical properties (such as shrinkage, creep) which occur at early age. The results from simulation compared with experimental values found in the literature show a good agreement. Finally, based on this user-developed subroutine, the effects of hydration heat, ambient temperature, wind velocity, shrinkage, and length-height ratio on cracking risk were analyzed for a concrete wall which is one part of the structure of Maridal culvert in Norway. By which, the measures to control the cracking were provided for the engineering application.

Restricted access

Abstract  

The liquid-liquid extraction behavior of octyldodecylsulfoxide (ODoSO) towards uranium(VI), contained in nitric acid aqueous solution, has been investigated. It was found that the extraction increased with increasing nitric acid concentration up to 2.0 mol/l and then decreased. Extraction also increases with increasing extractant concentration. The extracted species appears to be UO2(NO3)2 .2ODoSO. The influences of temperature, sodium nitrate and oxalate concentrations on the extraction were also investigated and the thermodynamic functions of the extraction reaction were obtained.

Restricted access

Abstract  

The complexes of rare earth bromides with alanine, REBr33AlanH2O (RE=Ce, Pr, Sm, Eu, Gd and Tb, n=3; RE=Dy and Y, n=2.5 Ala=alanine), were prepared and characterized by means of chemical analysis, elemental analysis, molar conductivity, thermogravimetry, IR spectra and X-ray diffraction. The thermal decomposition in N2 of these complexes was studied by means of TG-DTG techniques from ambient temperature to 1000C. During heating, the hydrated complexes of Ce, Pr and Y lose waters in one step, but the hydrated complexes of Sm, Eu, Gd, Tb and Dy lose waters in two steps. Then anhydrous complexes lose 2.5 alanine molecules except the complexes of Eu which lose three alanine molecules. Apparently, only be complex of Eu has an intermediate, EuOBr. All complexes finally decompose to oxides.

Restricted access