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51.
M. I. El-Zaiki W. Z. Megalaa H. R. Saad A. A. Youssef 《Zeitschrift für Physik A Hadrons and Nuclei》1970,234(5):398-404
Angular distributions of gamma rays following the inelastic scattering of protons from Mn55 have been measured at proton energies below 2.50 MeV. The mixture multipole orders for the transition 983→126 keV and 1,530→0 in Mn55 have been obtained. 相似文献
52.
J. Goulon A. Rogalev F. Wilhelm N. Jaouen C. Goulon-Ginet G. Goujon J. Ben Youssef M. V. Indenbom 《JETP Letters》2005,82(11):696-701
X-ray detected magnetic resonance (XDMR) has been measured for the first time on exciting the Fe K-edge in a high-quality yttrium iron garnet film epitaxially grown on a gadolinium gallium garnet substrate. This challenging experiment required resonant pumping of yttrium iron garnet at high microwave power, i.e., in the foldover regime. X-ray magnetic circular dichroism (XMCD) was used to probe the change in the longitudinal component of the magnetization M Z induced by the precession of magnetic moments located at the iron sites. Since XMCD at the Fe K-edge refers mostly to the equilibrium contribution of magnetically polarized 4p orbital components, XDMR at the Fe K-edge should reflect the precessional dynamics of the latter orbital moments. From the measured precession angle, we show that there is no dynamical quenching of the polarized orbital components at the iron sites in yttrium iron garnet. 相似文献
53.
Youssef Naït-Si Jean-Dominique Fourneron 《Monatshefte für Chemie / Chemical Monthly》2004,135(10):1319-1326
Summary. Hypericin and pseudohypericin in extracts of St. Johns Wort (Hypericum perforatum) are assayed using UV-Vis, measuring the absorbance at 588nm of a methanolic solution of the compounds. The value of the absorption coefficient is difficult to define insofar as none of the routine purity criteria can be applied to these two compounds. Analysis of the entire UV-Vis spectrum from 220 to 740nm would seem to be a reliable way of comparing different samples. A UV-Vis spectrum was recorded for each of the compounds using a Photodiode array detection system. A more accurate way of determining the levels of hypericin and pseudohypericin in extracts of St. Johns Wort using these reference spectra is described. 相似文献
54.
In the present paper, we report the first results concerning a centimetre cantilever driven through non-linear effects in thin magnetostrictive films. Bimorph centimetre beams (24 mm x 5 mm) were designed using 160 microns thick glass and 0.4 micron thick multilayer TbFe/Fe films deposited via RF sputtering, using several sputtering conditions. Dynamic magneto-elastic excitations were studied experimentally on the few eigenresonance modes of the cantilevers. Sub-harmonic excitation at half or one-third of the frequency of an eigenresonance mode has been achieved near the spin reorientation transition and the efficiency is as good as for eigenfrequency excitation. Specific magnetic properties of the samples led to a model of the thermodynamic potentials and behaviour of the excited resonator. 相似文献
55.
Utility of 4‐Benzylidene‐2‐phenyl‐5(4H)‐oxazolone in Synthesis of Triazine,Oxadiazole and Imidazole Derivatives of Anticipated Biological Activity 下载免费PDF全文
Ahmed S. A. Youssef Fatma A. El‐Mariah Fatma T. Abd‐Elmottaleb Heba E. Hashem 《Journal of heterocyclic chemistry》2015,52(5):1467-1473
Treatment of oxazolone 1 with hydrazine hydrate at room temperature gave the (Z)‐configurated isomer hydrazide (Z)‐ 3 (high yield). However, refluxing 1 with hydrazine hydrate yielded the (E)‐configurated isomer hydrazide (E)‐ 2 (low yield).The hydrazide derivative (Z)‐ 3 has been utilized as synthon for the synthesis of 1,2,4‐triazinone, imidazolone, and oxadiazole derivatives through appropriate routes. The thiosemicarbazide and semicarbazide derivatives are synthesized by different routes. The structures of the new compounds were established on the basis of IR, 1H‐NMR, mass spectral data, and elemental analysis. 相似文献
56.
Chiraz Youssef Hamed Ben Ammar Mohamed Belhouchet Kassem Beydoun Ridha Ben Salem Henri Doucet Pierre H. Dixneuf 《Journal of heterocyclic chemistry》2011,48(5):1126-1131
2‐(Arylidene)cyanomethylbenzoxazoles have been prepared in water from benzoxazole‐2‐ylacetonitriles. Using multi‐component reactions, a variety of heterocycles containing benzoxazole and nitrile functionality has been prepared. J. Heterocyclic Chem., (2011). 相似文献
57.
The elastic differential cross-section forē-Na scattering in the presence of non-resonant laser field is studied for the exchange ofℓ=0, 1, 2 photons. The undressed contribution is evaluated within the framework of the eikonal Born series approximation and
the effect of exchange is taken into account via the Ochkur approximation. The sodium atom has been treated in the frozen
core approximation with special attention to the effect of the dressing of the target by the laser field. The ‘dressing’ of
the target leads to quite an increase in the cross-section over the ‘undressed’ value near the forward direction for the exchange
of one or two photons. 相似文献
58.
Ahmed S. Hammam Mohamed S. K. Youssef Ferial M. Atta Thana A. Mohamed 《Chemical Papers》2008,62(2):194-206
The reaction of two equivalents of sodium azide with diarylaminodibromo-p-benzoquinone (I) in DMF for 15–24 h produced quinoxalinophenazinediones together with a byproduct identified as diarylaminodiaminobenzoquinone.
On the other hand, the reaction of bromanil with active methylenes, such as diethyl malonate and ethyl acetoacetate, resulted
in disubstitution products which, on treatment with primary amines, cyclized into benzodipyrroletetrones. Comparative antifungal
and antibacterial studies were made. 相似文献
59.
In this paper, we characterize the d-symmetric d-orthogonal polynomials of Brenke type. We obtain two new families of polynomials and the moments of the corresponding d-dimensional vectors of linear functionals. Weights, providing integral representations for these moments, were also given. 相似文献
60.
The presence of copper atoms as continuous networks at the grain boundaries of an aluminium-copper alloy has been considered not preventing the moving of dislocations during creep (or at least partially). The dislocations can bs absorbed by these boundaries and penetrate through them. That leads to changés of shape and structure of grains and also to the sliding of grains against each other. This was deduced from the accelerating increase in the sensitivity of the steady state creep rate to the applied stress of an aluminium 2·8 wt% copper alloy examined at wide range of temperatures (50–350 °C) and applied stresses (7–170 MPa). This rapid increase in the sensitivity parameter of the steady state creep rate occurs in Al-Cu alloys at quite higher ranges of applied stresses and may be attributed mainly to the contribution of the grain boundary movements to the creep strain. 相似文献