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1.
Mithlesh Kumar R. M. Kadam T. K. Seshagiri V. Natarajan A. G. Page 《Journal of Radioanalytical and Nuclear Chemistry》2004,262(3):633-637
Thermally stimulated luminescence (TSL) and electron paramagnetic resonance (EPR) investigations were carried out on gamma irradiated SrBPO5 samples doped with CeO2 and co-doped with CeO2 and Sm2O3. On gamma-irradiation at room temperature, BO3
2–, O2
– and O– radicals were produced. It was seen that the O– radical ion disappeared in the sample annealed at 500 K. It is proposed that the recombination between trapped electrons and O– radical ions results in transfer of recombination energy to the impurity centre Ce3+ resulting in TSL glow peak at 485 K. In the case of co-doped samples energy transfer occurs between Ce3+ to Sm3+ resulting in increase in the intensity of glow peak at 485 K.The authors are grateful to Dr. V. K. Manchanda, Head, Radiochemistry Division, BARC for his keen interest and encouragement during the course of this work. 相似文献
2.
Photoluminescence (PL), photostimulated luminescence (PSL), thermally stimulated luminescence (TSL) and electron paramagnetic resonance (EPR) studies were carried out on LiYF4:U4+ and pure LiYF4 crystals. The PL and EPR investigations have identified the presence of Eu3+, Tb3+ and Gd3+ ions in both of these crystals possibly due to their existence in the starting materials. The luminescence observed during afterglow, PSL and TSL revealed that emission occurs at wavelength positions 382, 413, 437 and 544 nm, which are characteristic of Tb3+ ions. The present investigations using PSL and TSL in combination with PL studies before and after gamma irradiation have revealed that selective energy transfer to Tb3+ ions occurs during electron–hole recombination processes like PSL and TSL. Even though other luminescent ions (U4+ and Eu3+) are present in the system and U4+/U3+ ions are participating in electron capture/release processes, the selective energy transfer results in Tb3+ ions acting as luminescence centers. 相似文献
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A method is described for the determination of the novel hydroxymethyl glutaryl coenzyme A reductase inhibitor RP 61969 (I) and its hydrolysis product, the dihydroxy acid RP 62420 (II), in human plasma. A structural isomer of I is used as internal standard. Both I and II were extracted from acidified plasma with diethyl ether. The dried residues were reconstituted in the high-performance liquid chromatography mobile phase and chromatographed on a 5 microns ODS2 column. The mobile phase used was aqueous dipotassium phosphate +tetra-n-butyl ammonium bromide (both 10 mM)-acetonitrile-methanol (60:40:5, v/v). At a flow-rate of 1.5 ml min-1 and ambient temperature, the retention time of II is 3.5 min, that of the internal standard is 5 min, and that of I is 8 min. The method has been validated and applied to the assay of plasma samples resulting from a cell-plasma distribution experiment in human whole blood. 相似文献
10.
R. Veeraraghavan N. S. Hon A. G. Page 《Journal of Radioanalytical and Nuclear Chemistry》2004,261(1):69-72
A method based on synergic extraction has been evolved for the recovery of tens of milligrams of americium from analytical
wastes in 7-8M HNO3 medium containing excess uranium as a two step procedure viz., (1) separation of uranium by contacting with TBP in dodecane
and (2) recovery of americium by an extraction-cum-strip cycle using a synergic mixture of PMBP-TBP in dodecane after decreasing
the acidity of the solution. Other transition metals such as iron found in significant proportion were separated from Am by
using the difference in the kinetics of extraction of iron and americium into HPMBP-TBP-dodecane mixture by short duration
contacts. About 99% of Am could be recovered into about 20% of its initial volume.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献