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51.
The real part of the interaction potential for several pairs of magic nuclei has been derived from the Skyrme interaction density functional. The matter density of each nucleus is described by a Fermi distribution adjusted to reproduce the Skyrme-Hartree-Fock densities. Exchange effects due to antisymmetrization are taken into account in an approximate way. The tail of the resulting potential can be accurately approximated with a Woods-Saxon shape beyond the inflexion point of the calculated potential. The parameters of these Woods-Saxon potentials show regularities with respect to the masses of the target and projectile. We have tested the validity of the real part of the potential against elastic scattering data by choosing an imaginary part with the same geometry and a variable strength. For the energy range we consider the calculated grazing angles are somewhat larger than the experimental ones. 相似文献
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The line strengths of nine Q-branch lines in the nu(2) fundamental band of the methyl radical in its ground electronic state have been measured by diode laser absorption spectroscopy. The vibration-rotation spectrum of methyl was recorded in a microwave discharge in ditertiary butyl peroxide heavily diluted in argon. The absolute concentration of the radical was determined by measuring its kinetic decay when the discharge was extinguished. The translational, rotational, and vibrational temperatures, also required to relate the line strengths to the transition dipole moment, were determined from relative integrated line intensities and from the Doppler widths of the lines after allowing for instrumental factors. The line strengths of the nine Q-branch lines were used to derive a more accurate value of the transition dipole moment of this band, mu(2)=0.215(25) D. Improved accuracy over earlier measurements of mu(2) (derived from line strengths of single lines) was obtained by integrating over the complete line profile instead of measuring the peak absorption and assuming a Doppler linewidth to deduce the concentration. In addition, a more precise value for the rate constant for methyl radical recombination than available earlier was employed. The new value of mu(2) is in very good agreement with high-quality ab initio calculations. Furthermore, the ratio of the transition dipole moments of the nu(2) and nu(3) fundamental bands in the gas phase is now in highly satisfactory agreement with the ratio determined for the condensed phase. 相似文献
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Lidia Kim Abdelwaheb Hamdi Ana Delia Stancu Rachid Souane Lucia Mutihac Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2010,66(1-2):55-59
The selective active transport through liquid membrane assisted by the pH gradient of amino acid methylesters by using a series of calix[4]arenes substituted by acid and amido functions, glycolic chains, and hydroxyl groups as carriers has been performed. All these receptors have been found to act as carriers for transport of aromatic amino acid methylesters from the aqueous source phase to the aqueous receiving phase aiming at their separation. The receptors bearing diacid and tetraamido functions have the better ability to transport of amino acids than the other receptors studied. The influence of calixarene and amino acid structures upon transport through liquid membrane is discussed. The obtained results are correlated with those acquired by solvent extraction. 相似文献
56.
57.
Ioana Porosnicu Cristian M. Butnaru Ion Tiseanu Elena Stancu Cristian V. A. Munteanu Bogdan I. Bita Octavian G. Duliu Felix Sima 《Molecules (Basel, Switzerland)》2021,26(11)
The innovative strategy of using nanoparticles in radiotherapy has become an exciting topic due to the possibility of simultaneously improving local efficiency of radiation in tumors and real-time monitoring of the delivered doses. Yttrium oxide (Y2O3) nanoparticles (NPs) are used in material science to prepare phosphors for various applications including X-ray induced photodynamic therapy and in situ nano-dosimetry, but few available reports only addressed the effect induced in cells by combined exposure to different doses of superficial X-ray radiation and nanoparticles. Herein, we analyzed changes induced in melanoma cells by exposure to different doses of X-ray radiation and various concentrations of Y2O3 NPs. By evaluation of cell mitochondrial activity and production of intracellular reactive oxygen species (ROS), we estimated that 2, 4, and 6 Gy X-ray radiation doses are visibly altering the cells by inducing ROS production with increasing the dose while at 6 Gy the mitochondrial activity is also affected. Separately, high-concentrated solutions of 25, 50, and 100 µg/mL Y2O3 NPs were also found to affect the cells by inducing ROS production with the increase of concentration. Additionally, the colony-forming units assay evidenced a rather synergic effect of NPs and radiation. By adding the NPs to cells before irradiation, a decrease of the number of proliferating cell colonies was observed with increase of X-ray dose. DNA damage was evidenced by quantifying the γ-H2AX foci for cells treated with Y2O3 NPs and exposed to superficial X-ray radiation. Proteomic profile confirmed that a combined effect of 50 µg/mL Y2O3 NPs and 6 Gy X-ray dose induced mitochondria alterations and DNA changes in melanoma cells. 相似文献
58.
Athanassopoulos C Auerbach LB Burman RL Cohen I Caldwell DO Dieterle BD Donahue JB Eisner AM Fazely A Federspiel FJ Garvey GT Gray M Gunasingha RM Imlay R Johnston K Kim HJ Louis WC Majkic R Margulies J McIlhany K Metcalf W Mills GB Reeder RA Sandberg V Smith D Stancu I Strossman W Tayloe R VanDalen GJ Vernon W Wadia N Waltz J Wang YX White DH Works D Xiao Y Yellin S 《Physical review letters》1996,77(15):3082-3085
59.
Alina Stancu 《Journal of Geometry》2008,88(1-2):162-168
We prove that the sufficiency condition employed to show the existence and, in certain cases the uniqueness, of solutions
to the discrete, planar L
0-Minkowski problem with data containing, at least, a pair of opposite vectors is also a necessary condition.
相似文献
60.
E. Ceauşescu R. Bordeianu E. Buzdugan I. Cerchez P. Ghioca R. Stancu 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(5-7):803-818
Polybutadiene (PB) can be easily halogenated by reaction with iodine chloride or bromine in tetrahydrofuran. The resulting glassy polymers were reacted with n-butyllithium, sec-butyl-lithium, and polystyryllithium in THF. Iodochlorinated PB gave a polybutadiene with a different cis/trans ratio with n-BuLi. The reformation of PB was accompanied by partial crosslinking. The reaction probably involved a halogen-metal exchange followed by intra- and intermolecular elimination of Li halide. With brominated PB, both coupling and elimination took place. With sec-BuLi, an allylic iodine derivative was obtained from iodochlorinated PB, probably by dehydrochlorination. The iodinated intermediate can easily undergo a coupling reaction with further sec-BuLi. Both iodochlorinated and brominated polybutadienes gave graft copolymers by reaction with polystyryllithium in THF. Grafting was always accompanied by gel formation. 相似文献