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81.
S. El-Sharkawy M. K. Hegab M. M. Sherif O. M. Osman M. A. Jilany 《Zeitschrift für Physik A Hadrons and Nuclei》1993,346(3):237-242
Central collisions of24Mg nuclei with the heavy (AgBr) group of emulsion nuclei are selected and analysed according to several selecting criteria. Theoretical calculations concerning cross sections for central events, average number of interacting protons from both projectile and target nuclei, multiplicity distributions of shower particles and dispersions, all based on the Glauber model, are performed to evaluate various criteria to select central events. The selection criterion based on the high multiplicity of total charged particles provides satisfactory agreement with the theoretical calculations. 相似文献
82.
Summary The reactions of Omega Chrome Black Blue G with a large number of cations is studied. This study has shown in many cases high sensitivity limits of detection of metals. It also showed that this dye can be used as an indicator for EDTA titrations of zinc, cadmium, manganese and lead. It is also a suitable indicator for the step wise titration of calcium and magnesium in blood serum and water. 相似文献
83.
84.
Bromination of 3-bromo-6,7-benzobicyclo [3.2.1] octa-2,6-diene at ?50°C gave anti-tribromo adduct (5) in essentially quantitative yield. The double dehydrobromination of (5) was achieved using potassium tert.- butoxide to give 2-bromo-benzobarrelene (7). Reaction of (7) with n-BuLi and subsequent quenching with CH3I, CO2, and dimethylformamide afforded the corresponding substituted benzobarrelenes in high yield. 相似文献
85.
86.
87.
Ahmed Osman 《International Journal of Theoretical Physics》1983,22(4):341-353
Faddeev equations are considered in the case of three charged particles interacting with both separable nuclear two-body interactions and also including Coulomb forces. Modified Faddeev equations with Coulomb Green's functions are introduced. The three-body amplitudes are given into pure Coulomb and distorted-Coulomb amplitudes. Introducing a decomposition in the angular momentum states, a set of three-body integral equations is obtained. The effect of pure coulomb amplitudes is studied in direct nuclear reactions and found to give a large contribution to the cross sections. The three-body integral equations obtained are applied for direct nuclear reactions. The angular distributions for12C(6Li,d)16O,16O(6Li,d)20Ne, and12C(6Li,α)14N transfer reactions are calculated as well as for the6Li elastic scattering on12C. From the good agreement between the theoretically calculated and experimental data, better spectroscopic factors are extracted. The effect of including Coulomb forces in the three-body problem is found to improve the results by about 16.26%. 相似文献
88.
Excitation functions for a number of proton groups for the reactions 23Na(d, p)24Na and 27Al(d, p)28Al were measured in the energy range Ed = 1.5 to 3.0 MeV. The angular distributions for a number of proton groups were measured at a number of deuteron energies below 3.0 MeV for the three reactions 12C(d, p)13C, 23Na(d, p)24Na and 27Al(d, p)28Al. The theory of deuteron stripping reactions at incident energies below the Coulomb barrier has been considered. A closed analytical form for the differential cross-section has been obtained considering three cases according to the incident deuteron and outgoing proton energies. An attempt has been made to fit the angular distribution measurements at a number of deuterons bombarding energies accordingly. 相似文献
89.
Reaction of tetralinol 5 with phenylboronic acid removed the isopropylidene group with concomitant formation of phenylboronate 12. Oxidation of the latter with PCC gave keto-ester 13, a key intermediate in the synthesis of enantiopure anthracyclinones. Attempts at cleavage of the isopropylidene group in 5 by the usual procedures led first to substitution and epimerization at the benzylic position, then removal of the acetonide followed by formation of the cyclic ether 11a as the final product. 相似文献
90.
This paper describes the relative acoustical performances established by scale model testing of a number of relatively novel noise barriers in typical highway situations. The various barriers were thin, wide, T-profiled, cylindrically topped, corrugated, inclined, Y-profiled, arrow-profiled and of the thnadner principle, and some were treated with sound absorptive material. The highway situations involved a single barrier with a protected receiver (i.e., a receiver behind the barrier), a single barrier with a receiver on the opposite side of the highway, and parallel barriers, one on each side of the highway. In the single barrier, protected receiver case, higher noise reduction was found for wide top barriers, especially those of T-profile, and especially T-profile absorptive top barriers with cap widths of 0·6 m (2 ft) or more and of small cap thickness. Absorptive side treatment was effective in reducing a small, but measurable sound increase found when a reflective sided barrier is installed on the opposite side of the highway to receivers, and in reducing the degradation in performance that occurs when there is a barrier on each side of the highway rather than on just one. 相似文献