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111.
I. S. Habib 《Applied Scientific Research》1973,28(1):62-72
The cooling effect of liquid droplets introduced into a hot gas stream flowing in an adiabatic duct is analysed. The coupled
interaction between the changes in the droplets and in the surrounding gas conditions is examined as a result of droplets
vaporization. It was found that the use of liquid sprays as a rapid cooling process for a hot gas discharge is quite effective. 相似文献
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Tellurite glasses (TeO2–ZnO–Nb2O5) mono-doped Er3+ and co-doped Er3+/Ce3+ have been prepared using the melt-quenching technique. To evaluate the effect of Ce3+ on the structural, thermal stability of glass hosts and fluorescence properties of Er3+, X-ray diffraction patterns, Ftir spectra, differential scanning calorimeter curves, absorption spectra, fluorescence emission spectra, fluorescence lifetimes, up-conversion emission spectra of glass samples were measured and investigated. Using Judd–Ofelt theory, we calculated intensity parameters (Ω2, Ω4 and Ω6), spontaneous emission probabilities, the radiative lifetime, luminescence branching factors and the quantum yield of luminescence for 4I13/2 → 4I15/2 transition. The co-doping with Ce3+ was effective on the suppression of up-conversion emission of Er3+ owing to the phonon-assisted energy transfer: Er3+:4I11/2 + Ce3+:2F5/2 → Er3+:4I13/2 + Ce3+:2F7/2 which contributed the effective enhancement of 1.53 µm fluorescence emission. The change in optical properties with the addition of Ce3+ ions have been discussed and compared with other glasses. Using the Mc Cumber method for the 4I13/2 → 4I15/2 transition, absorption cross-section, calculated emission cross-section, and gain cross-section values support that TZNEr1Ce1 glass is a potential material for developing broad-band and high-gain erbium-doped fiber amplifiers applied for 1.53 µm. 相似文献
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Habib Ammari Hyeonbae Kang Eunjoo Kim Hyundae Lee 《Mathematical Methods in the Applied Sciences》2009,32(7):863-874
In this paper we propose an efficient method to reconstruct a small inclusion buried inside a body using the perturbation of modal parameters measured on the boundary of the body. We design a reconstruction algorithm based on the asymptotic expansions of the eigenvalue perturbations obtained by Ammari and Moskow (Math. Meth. Appl. Sci. 2003; 26 :67–75). We then implement this algorithm and demonstrate its viability and limitations. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
118.
In this paper, we introduce a noncommutative extension of the Gross Laplacian, called quantum Gross Laplacian, acting on some
analytical operators. For this purpose, we use a characterization theorem between this class of operators and their symbols.
Applying the quantum Gross Laplacian to the particular case where the operator is the multiplication one, we establishes a
relation between the classical and the quantum Gross Laplacians.
相似文献
119.
Considering a two DoF system subject to digital position control, of interest for robotic application, we analyze the dynamics of the system at the intersection of two loci of Neimark–Sacker bifurcations, where a double Neimark–Sacker bifurcation is taking place. In the system, the saturation of the control force is the only nonlinear term considered, other than this, the system is piecewise linear. Starting from the analytical investigation already performed in Part I (Habib et al. in Nonlin. Dyn., under review, 2013), in this paper the effects of an asymmetry of the saturation of the control force are investigated, both analytically and numerically. The results show the increasing complexity of the dynamics for a more and more asymmetric system. First, the asymmetry is making the bifurcation transit from supercritical to subcritical, then it generates a stable torus that breaks down into a strange attractor, associated with a chaotic motion. In the last part of the paper, the torus breakdown and the onset of chaos are investigated, furthermore the evolution of complex dynamics through regions of phase locking and higher-dimensional chaos is outlined. 相似文献
120.
Uzma Habib Amin Badshah Ulrich Flörke Rizwana Aleem Qureshi Bushra Mirza Nazar-ul-Islam Azeem Khan 《Journal of chemical crystallography》2009,39(10):730-734
Abstract The reaction of Cu(OOCCH3)2·H2O with (2,4-diamino-5-(3′,4′,5′-trimethoxybenzyl) pyrimidine (trimethoprim) in ethanolic solution at 80 °C affords the title
complex which has been characterized by elemental, IR, and NMR (1H and 13C).The crystal structure has been determined by single crystal X-ray diffraction. Compound 1 (C36H48Cu2N8O14) is triclinic, space group P-1 with a = 7.2676(4) ?, b = 11.6721(7) ?, c = 12.8279(8) ?, α = 95.839(1)°, β = 93.456(1)°, γ = 105.541(1)°, Z = 1. Two copper atoms are coordinated directly to each other as well as are held together by four bridging aceto groups.
Each copper atom is also bonded opposite the Cu–Cu vector to a trimethoprim molecule through the N(1) atom of the pyrimidine
ring. Trimethoprim acts as a monodentate ligand through the pyrimidine nitrogen N(1) atom. The complex was screened for the
activity against several bacteria, showing more activity against bacteria as compared to trimethoprim.
Graphical Abstract To enhance the activity of trimethoprim, its derivative was prepared and there bacterial activity against several bacteria
was analyzed.
相似文献