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1.
Summary Th(IV) was quantitatively extracted from 1 . 10-3M HNO3 using 1 . 10-3M Cyanex302 in xylene and was stripped from the organic phase with 5M HCl. The effect of different parameters affecting the
extraction was systematically studied to achieve optimum conditions for the extraction of thorium. Based on the data some
separations of thorium from binary and complex mixtures and its recovery from monazite sand were achieved. The method is reproducible
with a relative standard deviation of 0.4%. 相似文献
2.
DETECTION OF DNA-PSORALEN PHOTOADDUCTS in situ 总被引:1,自引:0,他引:1
ZOFIA ZAREBSKA† MARIA JARZABEK-CHORZELSKA ‡ GENOWEFA RZSA WIESLAW GLISKI MARIA PAWIKA TADEUSZ CHORZELSKI STEFANIA JABLOKA 《Photochemistry and photobiology》1984,39(3):307-312
Abstract— An immunological method, with the use of specific immune serum, has been developed for detection of 8-methoxypsoralen (8-MOP) photoadducts to DNA, formed in situ in cell nuclei, after combined treatment with 8MOP and UV-A irradiation (Zarçbska et al. , 1978). Lymphocytes fixed on slides or in suspension, and cryostat sections of different mammalian tissues, served as antigenic substrate, after treatment with 8-MOP and UV-A in vitro. Specific fluorescence in these substrates was detected in the nuclei after treatment with 30 ˜ 140 kJ/m2 UV-A in the presence of 0.1-0.3 μg/cm2 8-MOP. PHA-stimulated-lymphocytes appeared to be the most sensitive substrate.
However, hairless mice treated with high doses of UV-A in vivo , 70 ˜ 360 kJ/m2 did not reveal a specific fluorescence of epidermal nuclei, unless a high local concentration of 8-MOP was attained.
The apparent discrepancy in the level of photoadduct detection between the in vitro and in vivo treated specimens was explained by the low number of DNA-8-MOP-photoadducts formed in vivo under these experimental conditions. The relevance of these findings to the role of DNA-8-MOP-photoadducts formed during PUVA photochemotherapy is discussed. 相似文献
However, hairless mice treated with high doses of UV-A in vivo , 70 ˜ 360 kJ/m
The apparent discrepancy in the level of photoadduct detection between the in vitro and in vivo treated specimens was explained by the low number of DNA-8-MOP-photoadducts formed in vivo under these experimental conditions. The relevance of these findings to the role of DNA-8-MOP-photoadducts formed during PUVA photochemotherapy is discussed. 相似文献
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An organanophosphinic acid extractant Cyanex272 was impregnated on a macroporus polymeric solid support Amberlite XAD-2 and packed in a column to study sorption and desorption of U(VI) in HNO3 media. Various physio-chemical parameters such as influence of HNO3 concentration, amount of Cyanex272, nature of eluents, sample and eluent flow rates were studied systematically to optimize conditions for sorption and desorption of U(VI). The breakthrough volume for U(VI) was >1000 mL and column reusability was more than 50 cycles. U(VI) was selectively separated from some commonly associated rare earth elements and certain d-block elements in binary and synthetic mixtures. The method developed for U(VI) was applied for its recovery from uranmicrolite (leachate) ore tailings and an industrial effluent sample. 相似文献
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A simple SPE method for determination of cobalt(II) using a C18 bonded silica membrane disk impregnated with Cyanex 272 has been developed. Cobalt(II) was quantitatively sorbed at pH 6.0 from a sample solution and eluted using 10.0 mL 1.0 M HNO3 prior to its flame atomic absorption spectrometric determination. The influence of eluting agents, the minimum volume and maximum flow rate of the eluent, and interfering ions on cobalt(II) was studied. The method developed for cobalt(II) had an LOD of 1.4 microg/L, and a preconcentration factor > 200 with an RSD of 0.6%. The reusability of the modified disk was for 40 cycles. The method was applied for the determination of cobalt in certified samples, urine, and industrial sludge samples. 相似文献
7.
Surface composition and depth profile of native oxide on Fe67Co18B14Si1 metallic glass has been investigated using Auger electron spectroscopy. The native oxide is compared with chemisorbed oxygen on the cleaned surface. Results indicate that boron segregates on the surface in the presence of oxygen. The low energy L23M45M45 peak of iron in metallic glass is compared with that in crystallized sample and pure iron foil. 相似文献
8.
P.P. Karve M.G. Thube S.K. Kulkarni A.S. Nigavekar 《Solid State Communications》1984,50(11):1027-1031
Native oxide and in situ oxidation of amorphous Ni36Fe32Cr14P12B6 have been investigated at room temperature using Auger Electron Spectroscopy. The Ni36Fe32Cr14P12B6 sample has been annealed as ~ 800 K in UHV and its oxidation behaviour has been studied at room temperature. A comparison of in situ oxidized amorphous and crystallized samples has been carried out. 相似文献
9.
ABSTRACT. Let G be the group ?[t, t ?1] x ?. By studying the action of the braid group Bn on the set Gn , we obtain representations of Bn into a wreath product of the symmetric group and the general linear group over ?[t, t ?1]. This in particular recovers the Burau representation of the braid group. Furthermore, some quotients of the braid group are obtained by using the representations found. 相似文献
10.
R. S. Karve A. K. Nayak S. K. Sarlar K. V. S. Rama Rao J. P. Mittal 《Applied physics. B, Lasers and optics》1989,49(6):571-576
Isotope separation of tritium by multiple photon dissociation process in multiple frequency fields of a TEA-CO2 laser is reported for the first time. A ten-fold improvement in the bulk selectivity was obtained in 8.5 Torr CTF3/CHF3 in the presence of buffer gas at room temperature using 9R(8) to 9R(14) CO2 laser lines compared to single frequency excitation. Investigations of various process parameters such as exciting laser frequencies, pulse energy, sample and buffer gas pressure indicate that this is a promising technique for the separation of tritium. 相似文献