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1.
Synthesis and crystal structure of EnH<Superscript>2</Superscript>[IrCl<Superscript>6</Superscript>]
I. A. Baidina S. V. Korenev E. V. Makotchenko S.A. Gromilov 《Journal of Structural Chemistry》2005,46(4):725-731
The preparation of EnH2[IrCl6] is described. Crystal data for C2H10Cl6IrN2 are: a = 6.8972(11) Å, b = 6.9435(16) Å, c = 7.3354(11) Å; α = 88.269(3)°, β = 65.495(2)°, γ = 60.305(2)°, V = 270.76(9) Å3, space group P1, Z = 1, dcalc = 2.864 g/cm3. Crystal chemical analysis of the general motif of the structure was performed by the translation sublattice identification technique. It has been found that complex anions [IrCl6]2? follow the nodes of a rather regular rhombohedral subcell with the parameters ac = 7.1 Å, αc = 64°. 相似文献
2.
González Iglesias H Fernández Sánchez ML García Alonso JI Sanz-Medel A 《Analytical and bioanalytical chemistry》2007,389(3):707-713
A quantitative methodology has been developed to differentiate between endogenous and supplemented selenium in lactating rats
using two enriched selenium isotopes. Lactating rats were fed for 2 weeks with formula milk containing one enriched Se isotope,
77Se, as the metabolic tracer. The isotopic composition of selenium in serum and urine samples was then measured by collision
cell ICP-MS after the addition of a solution containing another enriched isotope, 74Se, as quantitation tracer, before analysis. Isotope pattern deconvolution allowed the transformation of measured Se isotopic
abundances into concentrations of natural abundance (endogenous) selenium and enriched 77Se (supplemented) present in the samples. The proposed methodology was validated using serum and urine reference materials
spiked with both 77Se and 74Se. The obtained results are discussed in terms of selenium exchange and half-life in lactating rats (11–12 days) and selenium
levels in serum in comparison with non-supplemented rats and control rats after maternal feeding. 相似文献
3.
The first inorg/organic hybrid complex incorporating the macrocyclic oxamide, of formula [(NiL)2Cu2(μ-NSC)2(NSC)2] (1), (NiL, H2L = 2, 3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien), have been synthesized and structurally characterized. The crystals crystallize in the triclinic system, space group P-1, for (1) a = 8.319(3) Å, b = 10.434(4) Å, c = 14.166(5) Å, a = 107.030(5)°, β = 91.257(5)°, γ = 107.623(5)°. The complex involved both bridging N, S-ligand, and oxamide ligand, C–H?S interactions and NCS → Ni weak coordination interactions making the complex superamolecular. 相似文献
4.
Chang Heon Lee Moo Yul Suh Kwang Yong Jee Won Ho Kim 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(1):187-194
A sequential separation procedure has been developed for the determination of 99Tc, 94Nb, 55Fe, 90Sr and 59/63Ni in various radioactive wastes generated from nuclear power plants. Ion exchange and extraction chromatography were adopted
for individual separation of the radionuclides. Precipitation was supplementarily utilized for both purification of the individual
radionuclides and preparation of the radionuclide sources for use in a radioactivity measurement. The chromatographic separation
behavior of the radionuclides both from the sample matrix metals and from one another was investigated using stable metals,
Re (as a surrogate of 99Tc), Nb, Fe, Sr and Ni. The validity of the procedure for reliability and applicability was evaluated by measuring the recovery
of the metal carriers added to synthetic radioactive waste solutions. The recoveries by the chromatographic separation were
in the range of 84.8 to 102.2% with 2s of less than 8.6%, the recoveries by the precipitation being in the range of 84.3 to 97.3% with 2s of less than 10.9%. 相似文献
5.
Dimitrios C. Xarchoulakos Konstantina Kehagia Nikolaos Kallithrakas-Kontos Constantinos Potiriadis 《Journal of Radioanalytical and Nuclear Chemistry》2017,312(2):285-292
For the first time, a radiological study for the dissolved 238U, 234U, 210Pb and 210Po was held in major Greek rivers across the country. 234U/238U activity ratios are above one in all samples and 210Po/210Pb activity ratios are respectively below the unit indicating the disequilibrium in the samples. Quite satisfactory correlations were observed among 234U and 238U as well as among 210Po and 210Pb values. Uranium isotopes were separated by ion exchange and electroplated on stainless steel plates. 210Po was spontaneously deposited on nickel plates, while 210Pb was indirectly determined through the ingrowth of 210Po. The sources were measured by a-spectrometry. 相似文献
6.
Marin Ayranov Dorothea Schumann 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(3):649-654
The station for pions cancer therapy was operated at PSI from 1980 to 1992. After a cooling time of 12 years it’s made of
copper beam dump was cut and samples were taken for analytical purposes. The sampling collected about 500 g of high active
copper chips that can be used for separation of exotic radionuclides. The analyses by gamma spectrometry, LSC and AMS showed
main nuclides present to be 60Co, 54Mn, 22Na, 65Zn, 26Al, 53Mn, 59Ni, 63Ni, 55Fe and 60Fe and 44Ti with a daughter nuclide 44Sc. In the frame of ERAWAST project a procedure combining selective precipitation and ion exchange for the separation of the
rare radionuclides from the copper beam dump was developed. The proposed separation procedure is easy for remote controlled
implementation in a hot cell. The ion exchange separation of Ni, Al, Mg, Ti and Fe was complete and high decontamination factors
for copper and cobalt were achieved. Based on the developed procedure a remotely controlled system for separation of exotic
radionuclides from the copper chips was set up. The full scale system was installed in a hot cell where high activity levels
can be handled. In order to evaluate the reliability and functionality of the system extensive tests have been done. During
the test period 13.86 g in total of the proton irradiated copper beam dump were processed for separation of 26Al, 59Ni, 53Mn, 44Ti and 60Fe. The results showed that the system was operational and the radionuclide separation was selective with high chemical yield.
The procedure manages as well the generated liquid wastes containing high level of 60Co activity. 相似文献
7.
A. Ortiz S. Ramos-Bernal A. Negrón-Mendoza T. Martínez G. Sanchez-Mejorada 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(3):573-575
The thermoluminescense (TL) behavior of solid solutions of cadmium and manganese doped single crystals under γ-irradiation
is reported. Various compositions of single crystals of NaCl doped with Cd2+ and Mn2+ have been irradiated with ionizing radiation. The increase in the glow curve was followed as a function of the F-centers
produced by the dose. The analysis shows the potential use of these materials as dosimeters. 相似文献
8.
Claudia Landstetter Christian Katzlberger 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(2):467-471
Screening measurements for 3H, 226Ra, 222Rn and 238U in ground water were performed within a ground- and drinking water project in Austria. The aim of this project is to get
an overview of the distribution of natural radionuclide activity concentration levels in ground water bodies. In some cases
this water is used for drinking water abstraction. In this paper methods and results of the screening measurements are presented.
Regions with high activity concentrations were identified and in these regions further investigation for 228Ra, 210Pb and 210Po will be conducted. 相似文献
9.
S. Osaki S. Sugihara Y. Maeda T. Osaki 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(1):135-140
Depth distribution of atmospheric 210Pb and 7Be and 90Sr and 137Cs fission products was measured in two types of aeolian soils (desert dust and volcanic ash), irrigated paddy soil and strongly
acidic soil. The depth dependence of 210Pb, 7Be and 137Cs show that these radionuclides have been diffused as solid soil particles in surface soil layers. In aeolian soil layers,
about 50% of 90Sr were diffused in surface soil layer and the remaining 50% had penetrated to deeper layers. The half of the fission particles
containing 90Sr were shown to have decomposed over the past 35 years. 相似文献
10.
V. I. Pet’kov A. A. Alekseev E. A. Asabina E. Yu. Borovikova A. M. Koval’skii 《Russian Journal of Inorganic Chemistry》2017,62(7):870-878
The compounds AMMgE(PO4)3 (A = Na, K, Rb, Cs; M = Sr, Pb, Ba; E = Ti, Zr) were synthesized by the sol–gel procedure followed by heat treatment and studied by X-ray diffraction, differential thermal and electron microprobe analysis, and IR spectroscopy. The phosphates crystallize in the kosnarite (KZr2(PO4)3, space group \(R\bar 3\)) and langbeinite (K2Mg2(SO4)3, space group P213) structural types. The structure of KPbMgTi(PO4)3 was refined by full-profile analysis (space group P213, Z = 4, a = 9.8540(3) Å, V = 956.83(4) Å3). The structure is formed by a framework of vertex-sharing MgO6 and TiO6 octahedra and PO4 tetrahedra. The K and Pb atoms fully occupy the extra-framework cavities and are coordinated to nine oxygen atoms. A variable-temperature X-ray diffraction study of KPbMgTi(PO4)3 showed that the compound expands isotropically and refer to medium-expansion class (linear thermal expansion coefficients α a = α b = α c = 8 × 10–6°C–1). The number of stretching and bending modes of the PO4 tetrahedron observed in the IR spectra is in agreement with that predicted by the factor group analysis of vibrations for space groups \(R\bar 3\) and P213. A structural transition from the cubic langbeinite to the rhombohedral kosnarite was found for CsSrMgZr(PO4)3. In the morphotropic series of ASrMgZr(PO4)3 (A = Na, K, Rb, Cs) the kosnarite–langbeinite transition occurs upon the Na → K replacement. The effect of the sizes and electronegativities of cations combined in AMMgE(PO4)3 on the change of the structural type was analyzed. 相似文献
11.
A. D. Sajeniouk 《Journal of Radioanalytical and Nuclear Chemistry》2005,264(2):337-342
12.
Separation and purification of <Superscript>249</Superscript>Cf and <Superscript>245</Superscript>Cm
There is a need to provide radioactivity standards of the higher actinides in support of both decommissioning and remediation
activities as well as routine environmental analysis. In the case 249Cf, this will provide a useful calibration nuclide for both α-and γ-spectrometry as well as improving knowledge of the decay
scheme for this nuclide. There is anecdotal evidence to suggest that the chemical yield of americium and curium may differ
in radiochemical analysis. Thus, a chemical yield tracer of 245Cm may help to resolve this issue and will be suitable for both, suitable for use as a chemical yield tracer for both α-particle
spectrometry and mass spectrometry. An aged source of 249Cf was used as the source material for the separation of these two nuclides by cation-exchange, using 2-hydroxy-2-methyl-propanoic
acid at controlled pH as an eluant, 249Cf being eluted before the 245Cm daughter. The purity of both nuclides was measured by γ-ray spectrometry. 相似文献
13.
Matthias J. Brunnermeier Stefanie A. K. Schmied Robert Schupfner 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(3):1285-1290
The period of date of death of an elephant can be assessed by analyzing four different radionuclides, 14C, 90Sr, 228Th and 232Th in its ivory. These nuclides are supposed to have variing concentrations at different parts of a tusk. The reason is the
procedure of growth which takes place at the butt-site of a tusk. Therefore the site of sampling could have a big influence
on the assessed date of death. However, to find out if the position of sampling is important a complete tusk was analyzed
regarding the distribution of these nuclides. Results show that the concentration activity of 14C and 228Th varies in different parts of a tusk. The activity concentration of 90Sr is very similar in all analyzed parts. The conclusion is that sampling at the butt of a tusk is recommended for age assessment. 相似文献
14.
A. G. Nozad S. Meftah M. H. Ghasemi M. Aghazadeh 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(13):2270-2277
DFT calculations of electric field gradient (EFG) tensors at the sites of 14N, 17O, and 2H nuclei are carried out to characterize the hydrogen bond (HB) interactions in the sulfapyridine crystal structure. One-molecule
(monomer) and hydrogen-bonded hexameric cluster models of sulfapyridine are constructed according to available X-ray coordinates
where the proton positions are optimized. Then, EFG tensors are calculated for both monomer and target molecule in the hexameric
cluster of sulfapyridine to show the effect of HB interactions on the tensors. The calculated EFG tensors are converted to
the experimentally measurable nuclear quadrupole resonance (NQR) parameters: quadrupole coupling constant (C
Q
) and asymmetry parameter (η
Q
). The results reveal different contribution of various nuclei to N-H⋯N and N-H⋯O HB interactions in the cluster where the
N2 and O1 have major contributions. The computations are performed with B3LYP and B3PW91 functionals DFT method and 6-311+G*
and 6-311++G** standard basis sets using the Gaussian 98 package. 相似文献
15.
D. Cui A. Puranen J. Devoy A. Scheidegger O. X. Leupin P. Wersin R. Gens K. Spahiu 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(2):349-354
To understand the fate of 79Se in a repository-like environment, the interactions between iron canister surface with dissolved selenite (SeO3
2−) and selenate (SeO4
2−) in anaerobic solutions have been investigated. Se(IV) immobilization on iron surface was observed to be about 100 times
faster than that of Se(VI) at same conditions. An iron surface coated with a FeCO3 layer corrosion product is more reactive than a polished iron to immobilize Se(IV) and Se(VI). The reacted iron surfaces
were analysed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), X-ray diffraction (XRD), Raman
spectrometry and micro-X-ray Absorption Spectroscopy (XAS). The result show that Se(IV) and Se(VI) were reduced and precipitated.
The dominating phase was found to be FeSe2. 相似文献
16.
E. Yu. Ladilina T. S. Lyubova V. V. Semenov A. Yu. Dolgonosova M. A. Baten’kin 《Polymer Science Series A》2011,53(2):102-109
The hydrolysis of trifunctional alkoxysilanes RFOCH2 Si(ORF)3, where RF = CH2CF3, CH2CF2CF3, CH2CF2CF2CF3, or CH2CF2CF2CF2CF3, during the action of atmospheric moisture in the presence of 3-aminopropyltriethoxysilane under mild conditions yields new
ladderlike polysiloxanes. Their structure is studied via 1H NMR spectroscopy, GPC, TGA, and AFM. Polymer coatings prepared on their basis are found to be low-energy and hydrophobic.
The total surface energy and polarity of the surface of polysiloxane films decrease, while their hydrophobicity increases
with lengthening of the fluoroorganic substituent at the silicon atom. 相似文献
17.
Y. Spasova U. Wätjen T. Altzitzoglou 《Journal of Radioanalytical and Nuclear Chemistry》2008,277(1):211-215
Recently, the Institute for Reference Materials and Measurements (IRMM) has assumed responsibility for organizing regular
measurement comparisons among those laboratories which provide radioactivity monitoring data from their country to authorities
of the European Commission (EC) under various EC legislation articles. The most recent exercise under this International Comparison
Scheme for Radioactivity Environmental Monitoring (ICS-REM) in measuring the 137Cs, 40K and the 90Sr activity concentration in milk powder is presented here. The complete cycle of the comparison is described, including the
establishment of reference values traceable to SI units, the demonstration of the homogeneity of the distributed samples,
the treatment and measurement of samples in the participating laboratories, and the evaluation of the results. 相似文献
18.
Mei-Yan Wei Guang-Ying Chen Yu Wang Xiu-Li Zhang Chang-Yun Wang Chang-Lun Shao 《Chemistry of Natural Compounds》2011,47(4):571-573
A terrestrial fungal metabolite, chrodrimanin B (1), has been isolated for the first time from the fermentation broth of a marine-derived fungus Aspergillus sp. collected from
the South China Sea. Detailed assignments for the proton and carbon of 1 have been unambiguously elucidated by combined spectroscopic methods including 1D and 2D NMR spectral data, and the relative
configurations were also confirmed by single- crystal X-ray data. 相似文献
19.
S. Pommé E. García-Toraño G. Sibbens S. Richter R. Wellum A. Stolarz A. Alonso 《Journal of Radioanalytical and Nuclear Chemistry》2008,277(1):207-210
High-resolution alpha-particle spectrometry was performed on three uranium materials enriched in 235U. Besides the 235U peaks, separate peaks belonging to impurity traces of 234U could be quantified. Relying on the isotopic composition of the uranium, as determined by mass spectrometry, the ratio of
the half-lives of 238U and 235U was determined via the activity ratio of 234U and 235U in the materials. As an intermediate link, the 234U/238U half-life ratio was taken from published mass spectrometric analyses of ‘secular equilibrium’ uranium material. The resulting
half-life ratio T
1/2(238U)/T
1/2(235U) = 6.351±0.031 is in agreement with the commonly adopted half-life values determined by Jaffey et al. 相似文献
20.
A. H. Al-Rayyes M. Al-Oudat A. Al-Hamwi H. Mukhallalati 《Journal of Radioanalytical and Nuclear Chemistry》2007,274(1):139-143
The experiment aimed to evaluate the vertical migration of 134Cs, 90Sr and 238Pu in the main types of Syrian soils; entisol, inceptisol, alluvial (rock outcrops) and gypsiferous soils, using soil columns
through which the aqueous solution of the radionuclides percolated. The results show that the vertical migration of the studied
radionuclides through the soil profile depend on the radionuclide and the soil type. More than 97% of 134Cs and 238Pu concentrated in the upper 2 cm of the entisol, inceptisol, and alluvial soils, whereas only 46.2% to 68.6% of the 90Sr was retained in the upper 2 cm of these soils. The vertical migration of the studied radionuclides in the gypsiferous soil
was different from the other soils. The distribution of the radionuclides in the gypsiferous soil was irregular through the
soil profile and reached the deeper layer of the soil. This may be due to its physical characteristics; poor structure stability,
high permeability and low retention capacity. 相似文献