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1.
T. Nakanishi M. Kusakabe T. Aono M. Yamada 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(3):769-776
A technique to determine concentrations of 32P, 33P and 7Be in dissolved and particulate forms, in the upper ocean was developed. By using a large volume in situ filtration and concentration
system (LV-FiCS), several tons of seawater at different depths were filtered concurrently through two kinds of filters. The
dissolved radionuclides were concentrated onto adsorbents in the LV-FiCS. The radionuclides obtained were further purified
by precipitation and ion-exchange chromatography, and quantified by gamma-spectrometry and ultra-low level liquid scintillation
counter measurements. The technique was used with good results in a coastal area of Ibaraki, Japan. 相似文献
2.
Yong Yi Peng Zhou Guangshan Liu 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(1):157-162
The atmospheric deposition fluxes of 7Be, 210Pb and 210Po at Xiamen were measured. The samples were collected from March 2004 to April 2005 and the sampling period was one month.
The 7Be and 210Pb activity were measured using HPGe γ-spectrometer after concentration using Fe(OH)3 co-precipitation method. The 210Po was counted with an α-spectrometer after the sample was digested and spontaneous plated onto a silver planchet. At Xiamen,
the atmospheric deposition fluxes of 7Be varied between 0.11 and 2.93 Bq·m−2·d−1 and the average was 1.64 Bq·m−2·d−1; 210Pb fluxes varied between 0.04 and 0.85 Bq·m−2·d−1, and the average was 0.51 Bq·m−2·d−1; 210Po fluxes varied between 0.002 and 0.133 Bq·m−2·d−1, and the average was 0.061 Bq·m−2·d−1. There were positive correlations between the deposition fluxes of 7Be, 210Pb or 210Po and the amount of precipitation. The residence time of aerosols varied between 6.0 and 54.0 days with a mean of 27.1 days,
which were calculated by 210Po/210Pb fluxes ratios. 相似文献
3.
4.
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
5.
T. Lönnroth K. -M. Källman J -O. Lill D. Agren 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(1):163-165
We report the measurements of 7Be activity in nine vegetable species through the detection of its 477.6 keV γ-ray of 7Li. The plants were grown 10 km south of the city of Turku in south-west Finland, located at approximately about 23E, 62N.
The results show that nettle, salad and cucumber have activities that exceed the detection limit. 相似文献
6.
Target purification of Sα is carried out by distillation at 444±2 °C under N atmosphere and diluting the vapors in CS2. The solution is filtered through fiberglass, Teflon and cellulose to obtain Sα by CS2 evaporation. Once 30 g of this target are irradiated with fast neutron fluxes from 4.5 to 7.4·1012 n·cm−2s−1 from 6 to 12 hours, the nuclear reaction 32S(n,p)32P takes place. So, the irradiated Sα sample is placed in a Pyrex container situated inside a furnace as the most important piece of equipment in one aluminum
and Lucite glove box. The distillation of irradiated sulfur takes place at 444±2 °C under N atmosphere during 1–2 hours. The
vapors are connected to a sulfur diluter containing 20% CS2 aqueous solution, followed by an activated carbon filter and the two similar additional sulfur diluters. Once cooled, the
distillation chamber keeps the radioactive, carrier-free 32P stuck to the wall. Then 25–50 ml of 0.1N HCl acid was injected by suction and heated again at 110±2 °C during 1 hour. The
corresponding chemical reaction takes place and the labeled H3
32PO4 solution is produced. In such a way, industrial production of 32P labeled molecules has started in Mexico, with an initial production of 3700–5550 MBq per week. 相似文献
7.
The changes of decay rates of radionuclide 111in (electron capture) and 32p (β decay) induced by external mechanic motion are studied. The results indicate that, in the external circular rotation in clockwise and anticlockwise centrifuge on Northern Hemisphere (radius 8 cm, 2000 r/min), the half life of 111in compared with the referred (2.83 d) is decreased at 2.83% and increased at 1.77%, respectively; the half life of 32P compared with the referred (14.29 d) is decreased at 3.78% and increased at 1.75%, respectively. When the clockwise and anticlockwise rotations increase to 4000 r/min, the half life of 111in is decreased at 11.31% and increased at 6.36%, respectively; the half life of 32P is decreased at 10.08% and increased at 4.34%, respectively. When the circular rotation is removed, the decay rates of 111in and 32P return back to the referred, respectively. It is found that the external circular rotations in clockwise and anticlockwise centrifuge selectively increased and decreased the decay rates of 111in and 32p, respectively, and the effects are strongly dependent on the strength of circular rotation. It is suggested that these effects may be caused by the chiral interaction. 相似文献
8.
S. Osaki S. Sugihara Y. Maeda T. Osaki 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(1):147-152
Fall water, stem flow water and falling litter in a coniferous forest (C. japonica) and a broad-leaved forest (L. edulis), and rainwater on a grassland near the forests were collected, and their 7Be and 210Pb contents were measured. The average residence times of 7Be and 210Pb in the forest crowns were calculated from the balances of their radionuclides, those in the forest crown of C. japonica were 88 days for 7Be and 9.2 years for 210Pb, and those in the forest crown of L. edulis were 52 days and <1 year, respectively. 相似文献
9.
Young Hyun Cho Wanno Lee Kun Ho Chung Geun Sik Choi Chang Woo Lee 《Journal of Radioanalytical and Nuclear Chemistry》2007,274(3):531-538
The seasonal variation of the 7Be activities in air and the size distribution of the 7Be aerosols were studied by using a continuous air sampler and a five stage cascade impactor. The mean monthly activity level
of 7Be at the Korea Atomic Energy Research Institute (KAERI) site varied from 0.5 to 4.8 Bq·m−3 and revealed a seasonal variation, in which the 7Be activity levels were high in winter and low in summer. The mass size distribution showed a bi-modal distribution with a
higher peak around 0.49 μm and a smaller peak between 3 μm and 7.2 μm. The activity median aerodynamic diameter (AMAD) decreased
with increasing ambient 7Be concentrations. The mean residence times by using a mean growth rate of 0.004 μm·h−1 were estimated to be 2.5–6.4 days. The AMAD has an increasing tendency with higher relative humidity. It seemed that the
high humidity condition facilitated the growth of the aerosol, resulting in increased deposition rates of the aerosols and
the low 7Be content in the surface air. The AMAD of the 7Be aerosols increased with an increasing temperature, but the temperature dependency of AMAD should be explained with geological
and meteorological conditions. 相似文献
10.
I. Lovrencic M. Volner D. Barisic M. Popijac N. Kezic I. Seletkovic S. Lulic 《Journal of Radioanalytical and Nuclear Chemistry》2008,275(1):71-79
Distribution of 137Cs, 40K and 7Be in tissues of the silver fir-tree was studied. Samples of the shoots were taken at six locations in Croatia during five
years. Shoots were cut according to the year of growth and analyzed. Distribution between needles and twigs was also studied.
Samples of the tree rings and the bark were taken at three locations. 137Cs and 40K showed very similar distributions. 137Cs and 40K activities were age-dependent and increased in decreasing age of twigs and needles. The highest activities were measured
in the youngest twigs. The highest 7Be activities were found in the twigs. 相似文献
11.
Zal U’yun Wan Mahmood Che Abd Rahim Mohamed Mei Wo Yii Zaharudin Ahmad Kamaruzzaman Ishak Abdul Kadir Ishak 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(1):107-113
Inventories and fluxes of 210Pb, 228Ra and 226Ra were determined in sediment cores collected at nine stations covering of the southern South China Sea and Malacca Straits
with the thickness of water column between 42 and 83 m depth. The inventories of 210Pb, 228Ra and 226Ra were calculated range from 0.15–2.55 Bq cm−2, 0.05–0.40 Bq cm−2 and 6.83–83.63 Bq cm−2, meanwhile the fluxes ranged from 0.005–0.079 Bq cm−2 yr−1, 0.009–0.048 Bq cm−2 yr−1 and 0.003–0.037 Bq cm−2 yr−1, respectively. The results show that the highest inventories and fluxes for 210Pb, 228Ra and 226Ra were found at station WC 01 and EC 05. Because there are additional sources of 210Pb, 228Ra and 226Ra, where water transport will brings more dissolved isotopes, influence of the transportation and deposition of suspended
particles, fast rate of regeneration and greater production of those radionuclides and others. 相似文献
12.
T. B. Petrova P. S. Mikljaev V. K. Vlasov A. M. Afinogenov O. V. Kirjukhin 《Moscow University Chemistry Bulletin》2009,64(5):317-321
Data from measurements of the volume activity 7Be in the ground layer of the atmosphere, taken at the middle latitudes over a period of five and a half years, are discussed.
The studies allowed us to determine that the course of changes in the volumetric activity (VA) of 7Be over time is a superposition and interaction of three kinds of fluctuations: short-period irregular, caused by meteorological
factors; seasonal, associated with 7Be entering the troposphere from the stratosphere; and long-term, determined by changes in the Galaxy’s cosmic ray flux. 相似文献
13.
Fluorophosphatometallates with the composition K3H3Zr3F3(PO4)5, Rb3H3Zr3F3(PO4)5, Rb3H3Hf3F3(PO4)5, CsH2Hf2F2(PO4)3?2H2O are studied by 31P, 19F, and 1H NMR. It is found that protons enter in the composition of hydrophosphate groups and fluorine atoms occupy the terminal sites in the tetravalent metal environment. Schemes of the crystal structure of fluorophosphatometallates are proposed. It is established that in CsH2Hf2F2(PO4)3?2H2O water molecules are bonded to the phosphate group proton via a strong hydrogen bond and are characterized by a low energy barrier of molecular motions. 相似文献
14.
V. I. Volkov E. V. Volkov S. V. Timofeev E. A. Sanginov A. A. Pavlov E. Yu. Safronova I. A. Stenina A. B. Yaroslavtsev 《Russian Journal of Inorganic Chemistry》2010,55(3):318-324
Water self-diffusion and ion mobilities in various ionic forms (H+, Li+, Na+, Rb+, Cs+, and Ba2+) of perfluorinated sulfocationic membranes MF-4SK were studied by NMR and impedance spectroscopy. When degrees of hydration
are low, the self-diffusion coefficients of water and ionic conductivities are considerably affected by the water content
of the membrane. The self-diffusion coefficients decrease in the order H+ > Ba2+ > Cs+ > Rb+ > Na+ > Li+, whereas the ion mobility decreases in the order H+ > Li+ > Na+ > Cs+ > Ba2+. 相似文献
15.
A. V. Il’yasov N. K. Gaisin B. I. Buzykin R. B. Zaripov 《Russian Chemical Bulletin》2010,59(8):1506-1511
The 1H spin-lattice relaxation times of the proton-bearing groups and the 31P spin-lattice relaxation times in C-phosphorylated oximes R1C(=NOH)P(=O)R2R3 (R1 = Ph, R2 = R3 = OMe; R1 = Ph, R2 = OMe, R3 = OCH2CH2Br; R1 = PhCH2, R2 = R3 = OCHMe2) and dioxime R2P(=O)C(=NOH)(CH2)4C(=NOH)P(=O)R2 (R = OMe) in DMSO-d6 were measured. The characteristic reorientation times of the whole molecules were estimated using the measured values of
the 1H relaxation times and the results of semiempirical PM3 quantum chemical calculations of the molecular geometries. The reorientation
times were used to identify the contributions of different relaxation mechanisms to the rate of 31P spin-lattice relaxation. The anisotropy of the chemical shielding of 31P nuclei was evaluated from the difference between the 31P relaxation rates measured at 101.27 and 161.92 MHz. 相似文献
16.
A. D. Sajeniouk 《Journal of Radioanalytical and Nuclear Chemistry》2005,264(2):337-342
17.
A. V. Belyaev S. N. Vorob’eva M. A. Fedotov 《Russian Journal of Inorganic Chemistry》2012,57(2):231-236
Rhodium(III) complex formation with phosphoric acid in strong acidic solutions has been studied by 103Rh, 17O, and 31P NMR. Phosphoric acid is mainly coordinated to rhodium as a monodentate terminal HPO42− ion, while the coordinated phosphate ion accounts for no more than 7%. 相似文献
18.
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
19.
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
20.
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