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101.
Quantitative structure–property relationships of retention indices of some sulfur organic compounds using random forest technique as a variable selection and modeling method 下载免费PDF全文
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Salim A. Messaoudi Nasser‐eddine Tatar 《Mathematical Methods in the Applied Sciences》2007,30(6):665-680
In this paper the nonlinear viscoelastic wave equation in canonical form with Dirichlet boundary condition is considered. By introducing a new functional and using the potential well method, we show that the damping induced by the viscoelastic term is enough to ensure global existence and uniform decay of solutions provided that the initial data are in some stable set. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
105.
Preparation and coordination complex of the first imine-bridged tetrathiafulvalene-pyridine donor ligand 总被引:1,自引:0,他引:1
Chahma M Hassan N Alberola A Stoeckli-Evans H Pilkington M 《Inorganic chemistry》2007,46(10):3807-3809
The first imine-bridged pyridyltetrathiafulvalene building block (TTF-CH=N-Py, 1) has been synthesized via the Schiff base condensation of formyltetrathiafulvalene and 2-aminopyridine. The preparation, X-ray crystal structure, electrochemical and magnetic characterization of a 1:1 copper complex [CuII(hfac)2(TTF-CH=N-Py)] (2) are reported. The crystal structure reveals that the imine N atom participates in chelation to the paramagnetic center, thus making this ligand an attractive precursor for the assembly of pi-d systems. 相似文献
106.
Nasser?Mohammed?HosnyEmail author Abdel-Hamid?M.?Shallaby 《Transition Metal Chemistry》2007,32(8):1085-1090
Coordination compounds of MnII, CuII, FeIII and ZnII ions with 4-acetylpyridine nicotinoylhydrazone (4-APNH) were synthesized and characterized by elemental analyses, molar conductivity,
magnetic moments, i.r., u.v./vis., m.s., 1H-n.m.r. and thermal analyses. I.r. spectra show that the ligand can act either in the enol form as monovalent bidentate or
in the keto form as neutral bidentate depending on the metal salt used. Octahedral structures are proposed for Fe complex
and square – planar for the Cu complex, while tetrahedral structures were suggested for Zn and Mn complexes on the basis of
magnetic and spectral evidences. Semi-empirical calculations ZINDO/1 have been used to study the molecular geometry and the
harmonic vibrational spectra with the purpose to assist the experimental assignment of the complexes.
In memory of the late Professor Dr. Abdel Hamid M. Shallaby 2/5/2006 相似文献
107.
Mohamed I. Hegab Nasser A. Hassan Emad M. El‐Telbani Ibrahim S. Ahmed Farag Farouk M. E. Abdel‐Megeid 《Heteroatom Chemistry》2003,14(3):223-228
Hydrazones 12a–c and ketazines 13a–c were prepared by the reaction of ketones 11a–c with hydrazine hydrate depending on the temperature and the reaction time. Some ketone (aryl)hydrazone derivatives 14a,c,e reacted with thionyl chloride to afford the chlorothiadiazoline derivatives 15a–c . Surprisingly, the chlorine atom in the latter compounds was found to undergo smooth nucleophilic substitution, and by boiling these compounds in absolute ethanol gave the corresponding ethoxythiadiazoline derivatives 16a–c . The structure of the ethoxythiadiazoline 16b was confirmed by single crystal X‐ray determination. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:223–228, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10125 相似文献
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In this article, the propagation of an intense laser pulse through underdense collisional plasma in the presence of planar magnetostatic wiggler is studied. It is shown that the electron density distribution, in the presence of planar wiggler with increasing of the normalized plasma length, increases initially and then reaches a peak for different values of wiggler amplitudes. In addition, it is found that the existence of wiggler field leads to an increase in the electron density distribution and subsequently enhancement of electric field. Moreover, it is observed that by increasing the wiggler field, as a result of the increase of the electron density distribution, the dielectric permittivity constant is reduced. It is seen that while wiggler magnetic field was applied appropriately, the total absorption coefficient in the underdense collisional isothermal magnetized plasma improves. In fact, increase of wiggler magnetic field causes the enhancement of the total absorption coefficient of plasma medium. 相似文献