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41.
A. G. C. Nair A. Srivastava B. K. Srivastava S. Prakash M. V. Ramaniah 《Journal of Radioanalytical and Nuclear Chemistry》1984,84(2):263-267
67Ga is produced by the66Zn(d,n) reaction at 9 MeV bombarding energy. Deuterons of about 30 A obtained from the T-11 Tandem accelerator are used to bombard targets of natural Zinc prepared by electroplating onto thick copper disks. Radiochemical separation of gallium is performed by using a cation exchange column. The optimum conditions for an efficient separation are given in detail. 相似文献
42.
Summary The stability of emulsion of Toluene in water stabilized by partially flocculated ferric hydroxide sol has been studied. The
size of the emulsion droplets as determined by size frequency analysis is found to be of 1.1 μ radius. The flocculation studies were carried out haemocytometrically at different amount of electrolytes and at different
pH values. The electrokinetic potential ‘ζ’ was determined micro-electrophoretically at different amounts of electrolytes and
also at different pH's. In the case of tri and tetra valent anions the charge reversal was observed. In the light of the D.V.O. theory the interaction
energy profiles were drawn and 2–6 kT deep secondary minima obtained showing thereby the occurrence of reversible flocculation. Degree of aggregation has been
calculated theoretically at different values of ‘A’ and the value of A was found to be 1.0×10−12 erg to fit the value of degree of aggregation obtained haemocytometrically. The charge densities and binding parameters have
also been calculated. 相似文献
43.
Thiotropolone forms chloroform-soluble reddish-brown and violet complexes with cobalt(II) and nickel(II), in the pH range 7.0-8.5 and 6.0-9.0 respectively. Based on this, a sensitive and rapid method for the spectrophotometric determination of traces of cobalt and nickel in metals and alloys has been developed. The two metals can be determined accurately in the range 0.6-2.6 ppm of cobalt and 0.75-4.57 ppm of nickel, simultaneously. 相似文献
44.
K. P. Madhusudanan Rashmi Srivastava D. K. Kulshreshtha D. Fraisse 《Journal of mass spectrometry : JMS》1987,22(6):368-372
Substitution of amino for hydroxyl groups in certain sesquiterpene alcohols has been studied by chemical ionization mass spectrometry using ammonia and ammouia-d3 as the reagent gases, and by mass-analysed ion kinetic energy spectrometry and collision-induced decomposition mass-analysed ion kinetic energy measurements. Depending upon the source conditions and the nature of the substrates, both SNi and SN1 mechanisms have been found to operate. No evidence is obtained for an SN2 mechanism in these compounds. In centdarol and isocentdarol, addition of NH3 to the double bond, followed by elimination of H2O, also contributes to the substitution process. Attack of [NH4]+ on the epoxide function, followed by loss of H2O, appears to lead to the substitution ions in epoxycentdarol, epoxyisocentdarol and epoxyhimachalol. 相似文献
45.
The force constants, Coriolis coupling constants and mean amplitudes of vibration at 0, 298.16 and 500 K for GaF63?FeF63? have been reported for the first time employing recent vibrational data. The results are discussed in the light of available information. 相似文献
46.
Semi theoretical models have been proposed to account for the mechanism of membrane oscillations involving, electrokinetic phenomena in systems where (i) concentration difference deltaC is finite and deltaP is varying but the current is fixed, and (ii) deltaC=0, pressure difference deltaP is fixed across the membrane and imposed current is fixed. The formalism leads to the van der Pol equation in both cases. Computer simulation has also been attempted, which indicates oscillations in the former case. 相似文献
47.
A model iodophenyl imidazole ribonucleoside has been synthesized to study biodistribution properties in laboratory animals. The key intermediate 5-amino-1-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)imidazole-4-[N-(p-iodophenyl)carboxamide] ( 5 ) was synthesized by coupling N-succinimidyl-5-amino-1-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)imidazole-4-carboxylate ( 4 ) and p-iodoaniline. Deacetylation of the intermediate compound gave 5-amino-1-β-D-ribofuranosylimidazole-4-[N-(p-iodophenyl)]carboxamide ( 6 ). Ring annulation via diazotization of 5 gave 7-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)imidazo[4,5-d]-v-triazin-[3-N-(p-iodophenyl)]-4-one ( 7 ). Subsequent deacetylation of 7 afforded 7-β-D-ribofuranosylimidazo[4,5-d]-v-triazin-[3-N-(p-iodophenyl)]-4-one ( 8 ). The radiolabeled compounds, [125I] 5 and [125I] 6 were prepared in a manner similar to the corresponding unlabeled compounds except that p-[125I]iodoaniline was used for coupling with 4 . Biodistribution studies of iodine-125-labeled 5 and 6 were performed in female Fischer rats and tumor bearing nude mice. Compound 6 showed uptake in the brain and proliferating tissues such as tumor and bone-marrow. 相似文献
48.
The authors present six general integral formulas (four definite integrals and two contour inegrals) for theH-function of several complex variables, which was introduced and studied in a series of earlier papers by H. M. Srivastava and R. Panda (cf., e.g., [25] through [29]; see also [14] through [18], [20], [24], [32], [34], [35], [37], and [38]). Each of these integral formulas involves a product of the multivariableH-function and a general class of polynomials with essentially arbitrary coefficients which were considered elsewhere by H. M. Srivastava [21]. By assigning suiatble special values to these coefficients, the main results (contained in Theorems 1, 2 and 3 below) can be reduced to integrals involving the classical orthogonal polynomials including, for example, Hermite, Jacobi [and, of course, Gegenbauer (or ultraspherical), Legendre, and Tchebycheff], and Laguerre polynomials, the Bessel polynomials considered by H. L. Krall and O. Frink [9], and such other classes of generalized hypergeometric polynomials as those studied earlier by F. Brafman [3] and by H. W. Gould and A. T. Hopper [8]. On the other hand, the multivariableH-functions occurring in each of our main results can be reduced, under various special cases, to such simpler functions as the generalized Lauricella hypergeometric functions of several complex variables [due to H. M. Srivastava and M. C. Daoust (cf. [22] and [23])] which indeed include a great many of the useful functions (or the products of several such functions) of hypergeometric type (in one and more variables) as their particular cases (see,e. g., [1], [10] and [39]). Many of the aforementioned applications of our integral formulas (contained in Theorems 1, 2 and 3 below) are considered briefly. Further usefulness of some of these consequences of Theorems 1 and 2 in terms of the classical orthogonal polynomials is illustrated by considering a simple problem involving the orthogonal expansion of the multivariableH-function in series of Jacobi polynomials. It is also shown how these general integrals are related to a number of results scattered in the literature. 0261 0262 V 相似文献
49.
IR relative integrated intensities and half-widths of rocking (R) and wagging (W) bands of water in MnCl2 · 2H2O and CoCl2 · 2H2O are presented at 300 K and 120 K. Departure of observed intensity into DW/DR from those predicted by the fixed dipole model is attributed to anisotropic dynamic changes in dipole during these oscillations. A quantity representing the variation of this anisotropy between W and R oscillations is computed and its origin is discussed. An increase by 20% to 50% in both DW and DR on lowering the temperature has also been discussed. 相似文献
50.
P. Richards T. Prach S. C. Srivastava G. E. Meinken 《Journal of Radioanalytical and Nuclear Chemistry》1981,65(1-2):47-50
Preliminary results are described of a123Xe filled device to serve as a combination123I generator/iodination kit.123X was produced in the Brookhaven Linac Isotope Producer (BLIP) by the reaction127I(p, 5n)123Xe. The device consists of a small glass ampoule containing an internal glass breakseal and a flanged neck on which was crimped
a multi-injection type septum. The ampoule contained a hydrogen sulfide atmosphere to assure that the iodine generated from
the decay of the xenon was in the form of iodide. Following an adequate period for123Xe to decay (this period can be used for shipment), a needle is forced through the septum breaking the seal and residual gases
are pumped off. The123I in the form of iodide can then be rinsed from the ampoule with any desired solvent or reagent added directly to the device
to carry out an iodination in an enclosed environment. Preliminary results of both iodine recovery and iodinations have been
promising.
This research was supported by the US Department of Energy under Contract No. DE-ACO2-76CH0016. 相似文献