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1.
The kinetics of oxidation of Fe2+ by [Co(C3H2O4)3]3? in acidic solutions at 605 nm showed a simple first-order dependence in each reactant concentration. The second-order rate constant dependence on [H+] is in accordance with eqn (i) k2 = k′2 + k3[H+] (i) where k′2 and k3 have values of 73.4 ± 14.0 M ?1 s?1 and 353 ± 41 M?2 s?1, respectively, at 1.0 M ionic strength (NaClO4) and 25°C. At 310 nm the formation and decomposition of an intermediate, believed to be [FeC3H2O4]+, was observed. The increase in the rate of oxidation with increasing [H+] was interpreted in terms of a “one-ended” dissociation mechanism which facilitates chelation of Fe2+ by the carbonyl oxygens of malonate in the transition state. 相似文献
2.
N. H. Agha K. H. Nashat N. N. Yousif 《Journal of Radioanalytical and Nuclear Chemistry》1989,134(2):333-341
A formulation of stannous-diethyl-IDA freeze-dried kit, containing 50 mg diethyl-IDA and 0.4 mg hydrated stannous chloride, to be labelled with technetium has been developed for hepatobiliary scintigraphy. Gel chromatography column scanning technique has been applied for determination of technetium fractions in the preapration. The optimal pH value of the preparation with a high hepatobiliary specificity was found between 5.5 to 6.0. Effect of ligand to metal ratio on the stability of the prepared Sn-diethyl-IDA solution prior mixing with technetium has been investigated. The reaction conditions (initial pH) between the ligand and stannous ion affects the percent hydrolysis of the labelled compund, i.e. the formation rate of the complex. The organ distribution data of99mTc-diethyl-IDA in mice for 60 minutes post injection were satisfactory. The radiopharmaceutical exhibits rapid blood clearance, great hepatic clearance and very short hepatocyte transit time. Uptake of the radiopharmaceutical in various organs of mouse at 5 minute post injection showed that the greater part of the injected radioactivity has distributed between liver and intestine. However, about 12% and 60% of the injected dose has been found in liver and intestine respectively. The renal uptake of the HB agent in mice is relatively low and decreases with time to become about 0.3% at 60 minutes post injection. Blood clearance data of the radiopharmaceutical kit in rabbits showed that the HB agent is-rapidly cleared, since the initial decrease was very fast with a half-time of 1.5 minutes. 相似文献
3.
Using the new expression for the dynamic multipole polarizabilities in terms of effective oscillator strengths and effective transition energies derived from the variational procedure based on the total energy expansion in terms of induced multipole moments, we have calculated the long-range dispersion force coefficients and the leading relativistic correction to the long-range potential between H, He+, He, and Li+. We have in addition calculated the oscillator strength sum rules for the above systems. Our results are comparable with those obtained using both a hydrodynamic model to quantum mechanics and double perturbation theory. 相似文献
4.
Lindsay BG McDonald KF Yu WS Stebbings RF Yousif FB 《The Journal of chemical physics》2004,121(3):1350-1356
Absolute partial and total cross sections for electron-impact ionization of CCl4 and CCl2F2 are reported for electron energies from threshold to 1000 eV. The product ions are mass analyzed using a time-of-flight mass spectrometer and detected with a position-sensitive detector whose output demonstrates that all product ion species are collected with equal efficiency irrespective of their initial kinetic energies. Data are presented for production of CCl3(+), CCl2(+), CCl+, C+, Cl2(+), and CCl3(2+) from CCl4; and for production of CCl(2)F+, CClF2(+), CClF(+), (CCl+ + CF2(+)), Cl+, CF+, F+, and C+ from CCl2F2. Data are also reported for formation of (CCl2(+),Cl+) and (CCl+, Cl+) ion pairs from CCl4. The total cross section for each target is obtained as the sum of the partial cross sections. The overall uncertainty in the absolute cross sections for most of the singly charged ions is +/- 5-7 %. The present partial cross sections for lighter fragment ions are found to be considerably greater than had been previously reported but the most recent total cross section measurements agree well with those reported here. Neither the binary-encounter-Bethe theory nor the Deutsch-Mark theory reproduces the experimental cross sections correctly for both targets. 相似文献
5.
Paul Fijolka Yousif Shahab 《Journal of polymer science. Part A, Polymer chemistry》1968,6(5):1217-1225
The mechanism of copolymerization of monomethyl and dimethyl maleates and fumarates with styrene was studied by analysis of the conformation of the acid units of the resulting copolymers. The absorption bands for C?O stretching and OH stretching in the spectra of the copolymers are fully identical. They are quite different from the spectra of the copolymers obtained from maleic anhydride and styrene that are subsequently treated with absolute methanol to give the monoester which is then esterified with diazomethane to give the diester. The acid units of the copolymers derived from maleic anhydride exist in a gauche configuration; copolymers derived from fumaric units exist in a trans conformation. The identity of copolymers derived from maleic units with those derived from fumaric units but not with those derived from maleic anhydride indicates that the first step in the copolymerization of the maleic units is an isomerization to fumaric units, which are actually the genuine comonomers. 相似文献
6.
A hyperfine field of 46.9±4.0 T at Gd nuclei in the intermetallic compound ZrFe2 was measured by the time-differential perturbed angular correlation method. This result indicates an additional contribution of 81 T to that measured in gadolinium metal and suggests a similarity between the magnetic properties of ZrFe2 and those of the rareearth intermetallic compounds. 相似文献
7.
Summary The copper(III)-imine-oxime complexes [CuIII(Enio)]+ and [CuIII(Pre)]+ {EnioH2 =N,N-ethylene bis(isonitrosoacetylacetoneimine) and PreH2 = N,N-propylene bis (isonitrosoacetylacetoneimine)} react very rapidly with iodide. The rate law under fixed conditions for the reaction is given by the equation: –d[CuIII]/dt = (2k2[I–] + 2k3[I–]2)[CuIII] The [CuIII(Enio)]+ reaction was pH-independent whereas the [Cu (Pre)]+ reaction rate increased with increasing pH. Both the k2 and the k3 pathways are believed to involve one-electron transfer. An inner-sphere mechanism may operate in the pathway, first-order in [I–]. 相似文献
8.
9.
Omer R. M. Al-Tikrity E. T. B. Yousif E. El-Hiti G. A. Ahmed D. S. Ahmed A. A. 《Russian Journal of Applied Chemistry》2020,93(12):1888-1898
Russian Journal of Applied Chemistry - Polyphosphates containing 4,4'-methylenedianiline moiety were synthesized and their use as polyvinyl chloride (PVC) additives to enhance PVC... 相似文献
10.
S. Y. Yousif Al-Mulla 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,42(1):11-14
Differential cross sections for the elastic scattering of electrons from the
ground states of
copper for the configuration 3d10 4s and the excitation state 2D
with the configuration 3d9 4s2
have been calculated. Local density approximations to the exchange and
correlation potentials
have been used in these calculations, and it is confirmed that Hara exchange
coupled with a
Hedin-Lundqvist electron-gas-type correlation potential joined to an
adiabatic polarization
potential gives good predictions for differential cross sections.
A comparison of the calculated results with other experimental and
theoretical data are presented and discussed. 相似文献