Search Results

You are looking at 1 - 10 of 88 items for

  • Author or Editor: J. Yang x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

A preconcentration method combined with neutron activation technique for the analysis of organic and inorganic mercury in waste water samples at ppb levels is presented. The inorganic mercury is extracted in CCl4 solution with lead diethyldithiocarbamate reagent and the organic mercury is extracted in C6H6 solution. Interfering activities of sodium and bromine are removed from the irradiated samples by this procedure. Two different solvent extraction procedures are also described in detail.

Restricted access

Summary

A simple and sensitive method of high-performance liquid chromatography with fluorescence detection (HPLC-FLD) was developed for the determination of icariin in capsules by precolumn chelation with aluminum. In order to obtain a stable fluorescence signal, the reaction conditions of the fluorescent chelation complex between icariin and aluminum were investigated in detail. Chromatography was carried out on an Agilent Zorbax Extend C18 column (150 mm × 4.6 mm, 5.0 μm) using methanol as mobile phase at a flow rate of 1.0 mL min−1. The excitation and emission wavelengths were set at 430 and 480 nm, respectively. At optimum conditions, the calibration curve was linear in the concentration range from 0.010 to 100.0 μg mL−1 with the limit of detection of 3.5 ng mL−1 (S/N = 3). A comprehensive method was validated for precision and accuracy. The method described here has been successfully applied for the determination of the icariin content in a capsule with satisfactory results.

Full access

Abstract  

Solvent extraction of uranyl nitrate in nitric acid medium with the binary system of DMHMP and DOSO has been investigated. It was found that synergistic effect occurs during the extraction of uranyl nitrate with benzene solution of DMHMP and DOSO, the binary species extracted UO2 (NO3)2·DMHMP·DOSO has been confirmed. From the data the equilibrium constants have been determined.

Restricted access

Quantitative trait loci (QTL) for 11 morphometric body measurements of the hybrids of silver (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) including body weight (BW), standard length (SL), body depth (BD), body thickness (BT), head length (HL), head depth (HD), length of ventral keel (LVK), length of pectoral fin (Lpec), length of pelvic fin (Lpel), length of caudal fin (Lcau) and space between pectoral and pelvic fins (SPP) were located on the sex average microsatellite linkage map constructed using the hybrids of a female bighead and a male silver carp, on which 15 microsatellites were newly mapped. One locus was found to be responsible for BW, LV K and SPP, respectively. As many as 6 loci were found to be responsible for HD. The variances of remaining traits were partitioned by different numbers of loci varying between 2 and 5. The variance explained each locus ranged from 9.1% to 23.8% of the total. The variance explained by all loci responsible for each measurement ranged from 17.7% to 75.1%. It was noted that multiple measurements were mapped on the same locus. For example, a region bounded by Hym435 and Hym145 was found to be responsible for all the measurements analyzed.

Restricted access

Abstract  

The kinetics of thermal decomposition of a series of uranyl nitrate complexes with N-alkylcaprolactams (alkyl=C2H5, C4H9, C6H13, C8H17, C10H21 or C12H25) was studied by means of non-isothermal gravimetry under a nitrogen atmosphere. From the TG-DTG curves, the kinetic parameters relating to the loss of two molecules of coordinated ligand were obtained by employing two groups of methods: (I) a group of conventional methods involving the Coast-Redfern, Freeman-Carroll, Horowitz-Metzger, Dharwadkar-Karkhanavala and Doyle (modified by Zsakó) equations; (II) a new method were suggested by J. Máleket al.. The results obtained using two types of methods were compared, and it emerged that the results of method II were much more meaningful and reasonable in this work. Additionally, the effects of the molecular structure of the ligands on the kinetic data and models were studied and are discussed.

Restricted access

Abstract  

To develop potential new Tc radiopharmaceuticals, a novel compound [99mTc(CO)2(NO)(EHIDA)]0 (EHIDA: 2,6-diethylphenylcarbamoylmethyliminodiacetic acid) has been prepared by reacting [99mTc(CO)3)(EHIDA)] with NOBF4 both in water and acetonitrile. The conversion of [99mTc(CO)3)(EHIDA)] to [99mTc(CO)2(NO)(EHIDA)]0 was supported by TLC, HPLC and eletrophoresis. The radiochemical purity (more than 99%) was proved by TLC and HPLC. The biodistribution in mice demonstrated that [Tc(CO)2(NO)(EHIDA)]0 showed higher uptake in blood, kidney and lung (15 min, blood: 19.24±2.95; kidney: 13.61±3.49; lung: 10.81±1.09.) but a lower uptake in liver (15 min, 5.73±0.74). The slower clearances (120 min, blood: 12.75±1.34; kidney: 13.61±3.49) from blood and kidney were also found. This research describes two methods for the conversion of [99mTc(CO)3]+ into [99mTc(CO)2)(NO)]2+ by using NOBF4 as the source of NO+ both in organic solvent and water. The latter method offers the possibility to introduce the NO-group in high yield in water.

Restricted access

Abstract  

A brown and transparent ionic liquid (IL), [C4mim][FeCl4], was prepared by mixing anhydrous FeCl3 with 1-butyl-3-methylimidazolium chloride ([C4mim][Cl]), with molar ratio 1/1 under stirring in a glove box filled with dry argon. The molar enthalpies of solution, Δs H m, of [C4mim][FeCl4], in water with various molalities were determined by a solution-reaction isoperibol calorimeter at 298.15 K. Considering the hydrolyzation of anion [FeCl4] in dissolution process of the IL, a new method of determining the standard molar enthalpy of solution, Δs H m 0, was put forward on the bases of Pitzer solution theory of mixed electrolytes. The values of Δs H m 0 and the sum of Pitzer parameters:
\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} $$(4\beta _{Fe,Cl}^{(0)L} + 4\beta _{C_4 mim,Cl}^{(0)L} + \Phi _{Fe,C_4 mim}^L )$$ \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} $$(\beta _{Fe,Cl}^{(1)L} + \beta _{C_4 mim,Cl}^{(1)L} )$$ \end{document}
were obtained, respectively. In terms of thermodynamic cycle and the lattice energy of IL calculated by Glasser’s lattice energy theory of ILs, the dissociation enthalpy of anion [FeCl4], ΔH dis≈5650 kJ mol−1, for the reaction: [FeCl4](g)→Fe3+(g)+4Cl(g), was estimated. It is shown that large hydration enthalpies of ions have been compensated by large the dissociation enthalpy of [FeCl4] anion, Δd H m, in dissolution process of the IL.
Restricted access

Abstract  

Monochromatic MeV-energy neutron source for secondary reaction was developed utilizing tritium embedded titanium (Ti-3H) thin film via 3H(p,n)3He reaction. We have measured the neutron energies and the energy spread by resonance reactions of 12C(n,tot) and 28Si(n,tot). The available energy was within the range from 0.6 to 2.6 MeV. Energy spread was 1.6% at energy of 2.077 MeV. The flux in the beam direction was determined to be 3.76·107 n/s/sr by irradiating 197Au by about 2 MeV neutrons. This source was shown to be useful for measurements of nuclear data by measuring the total cross sections of neutrons on Fe and comparing these data to the data of ENDF-6.

Restricted access

Summary  

Cyanocobalamin (CNCbl), a kind of vitamin B12 (cobalamin, Cbl), which has a special binding capability to rapid dividing cells and proliferating tissue, especially tumors, has been modified and labeled by 99mTc. The optimal labeling condition was determined, and the biodistribution of 99mTc-DTPA-b-CNCbl both in normal mice and TA2 mice bearing MA891 mammary tumors were studied. 99mTc-DTPA-b-CNCbl showed low uptake and rapid clearance in nontarget tissues, and renal excretion. About 40% of uptake at 1 hour remained in the tumor at 12 hours p.i. The satisfying ratio of T/NT was acquired at 6 hours p.i.

Restricted access