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991.
Ahmed Osman 《International Journal of Theoretical Physics》1981,20(7):481-489
The three-nucleon system is reconsidered. The Faddeev equations are given leading to a set of integral equations. Solving these integral equations, suitable forms are considered for the nucleon-nucleon interaction. In the bound state of three-nucleon system, the form of the nuclear forces from the nucleon-nucleon interaction is important. In the present calculations, we consider the nuclear forces resulting from the nucleon-nucleon interaction by the exchange of a scalar meson, a pseudoscalar meson, and a massless vector meson. With this different meson exchange nucleon-nucleon interaction, the binding energy of the three-nucleon system is calculated by solving the Faddeev integral equations giving a value of 8.452 MeV. 相似文献
992.
The asymptotic form of the wave function for scattering from an initial state of α-particle incident on 8Be, considered as two bound α-particles, with enough energy to give a final state of three free α-particles is given. Our resulted equation with the obtained expression is suitable for numerical calculations. Applying this equation to the analysis of experimental data, very good agreement is obtained. 相似文献
993.
A novel mesoporous silica‐nanotube‐supported 3‐4,5‐dihydroimidazol‐1‐yl‐propyltriethoxysilanedichloropalladium(II) complex was prepared and characterized. 3‐4,5‐Dihydroimidazol‐1‐yl‐propyltriethoxysilanedichloropalladium(II) and mesoporous silica‐supported 3‐4,5‐dihydroimidazol‐1‐yl‐propyltriethoxysilanedichloropalladium(II) were tested for catalytic activity for Heck coupling reactions between styrene and several aryl halides and Suzuki coupling reactions between phenylboronic acid and several aryl halides. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
994.
Simon J. Coles David B. Davies Michael B. Hursthouse Hanıfe İbişoğlu Adem Kılıç Robert A. Shaw 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o51-o54
The reaction of spermidine with 2,2,4,4-tetrachloro-6,6-diphenylcyclotriphosphazene produces a mixture of products of which one of the fractions is a spiro-cis-ansa derivative, namely 12-chloro-14,14-diphenyl-2,6,11,13,15,16-hexaaza-1,12-diphosphatricyclo[10.3.1.01,6]hexadeca-12,14-diene, C19H26ClN6P3. Recrystallization of this fraction from different solvents results in the formation of two different crystalline forms. The rod morphology formed in dichloromethane–n-hexane (1:1) produces a triclinic structure with three molecules in the asymmetric unit. These three molecules adopt different conformations as a result of two NH groups flipping in an ansa-bridged ring system. The plate morphology crystals, grown in dichloromethane–n-hexane–ethyl acetate (1:1:1), produce a C-centred monoclinic structure that adopts a conformation that is essentially the same as one of the forms in the triclinic structure. 相似文献
995.
A new synthesis of trimers of aliphatic monosubstituted ketenes from acid chlorides is described. The structures of the products are shown to be alkyl substituted γ-hydroxy-α-pyrones by NMR. and mass spectroscopy. 13C-NMR. studies indicate, that an acetanilide/aluminium-chloride complex catalyses the formation of the products. 相似文献
996.
Ahmed Osman 《International Journal of Theoretical Physics》1977,16(8):575-583
Using a unitary model operator, the short-range correlations between nucleons in nuclei have been considered. To achieve healing in the wave functions, short-range pseudopotentials are required to be added to the nucleon-nucleon potential. With the introduction of the pseudopotentials, the matrix element for the effective interaction in nuclei is developed with correlated basis wave functions. The tensor forces and the short-range pseudopotentials are renormalized in second-order perturbation theory. Hartree-Fock calculations are carried out for the two finite closed-shell spherical nuclei16O and40Ca. The calculations of the resulting effective Hamiltonian are carried out with an effective interaction derived from the Tabakin potential. The present calculations of the binding energies per particle for the16O and40Ca nuclei are in agreement with the experimental measurements. 相似文献
997.
We investigate the effect of basis set size, correlation effects and interplanar separation on the theoretical electronic structure of stacking complexes of para- and meta-hydroxyaruline with formamidinium cation, constructed as analogs for the complexes of 5- and 6-hydroxytryptamine with imidazolium cation. 相似文献
998.
The theory of nuclear fission is reconsidered. We study the behaviour of the mass parameter as a dynamical quantity of the mass asymmetry. The dependence of the mass asymmetry mass parameter is studied as a function of the five collective coordinates. These parameters are reconsidered by including the temperature to show the temperature dependence of the mass parameter. The cranking model is used in developing all the mathematical and theoretical expressions. Numerical calculations of the obtained analytical expressions are carried out for the two fissioning nuclei 236U and 238U. The mass asymmetry mass parameters are calculated including the temperature as a function of the different five collective coordinates. The present study shows that the values of this mass asymmetry mass parameters are stable against the change of the temperature for temperature values greater than 1 MeV for all the different five collective coordinates. 相似文献
999.
The optical constants of evaporated Se films are calculated following Valeev’s method and applied to Se in the visible region.
The calculated values are in good agreement with published data. 相似文献
1000.