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71.
Mustapha Aitali Larbi El Firdoussi Abdellah Karim Alejandro F. Barrero Miguel Quirs 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1088-1089
The title compound, [(S)‐2‐(anilinomethyl)pyrrolidine‐N,N′]‐chloro(η6‐para‐cymene)ruthenium(II) chloride, [RuCl‐(C10H14)(C11H16N2)]Cl, has been synthesized by the reaction of [RuCl2(p‐cymene)]2 (p‐cymene is para‐isopropyltoluene) with (S)‐2‐(anilinomethyl)pyrrolidine in triethylamine/2‐propanol. The Ru atom is in a pseudo‐tetrahedral environment coordinated by a chloride ligand, the aromatic hydrocarbon is linked in a η6 manner and the amine is linked via its two N atoms. The chloride anion is involved in hydrogen bonding with the diamine moieties through N—H?Cl interactions, with N?Cl distances of 3.273 (4) and 3.352 (4) Å. 相似文献
72.
We study here some linear recurrence relations in the algebra of square matrices. With the aid of the Cayley–Hamilton Theorem, we derive some explicit formulas for An (nr) and etA for every r×r matrix A, in terms of the coefficients of its characteristic polynomial and matrices Aj, where 0jr−1. 相似文献
73.
Mustapha Muhammad Huda M. Alshanbari Ayed R. A. Alanzi Lixia Liu Waqas Sami Christophe Chesneau Farrukh Jamal 《Entropy (Basel, Switzerland)》2021,23(11)
In this article, we propose the exponentiated sine-generated family of distributions. Some important properties are demonstrated, such as the series representation of the probability density function, quantile function, moments, stress-strength reliability, and Rényi entropy. A particular member, called the exponentiated sine Weibull distribution, is highlighted; we analyze its skewness and kurtosis, moments, quantile function, residual mean and reversed mean residual life functions, order statistics, and extreme value distributions. Maximum likelihood estimation and Bayes estimation under the square error loss function are considered. Simulation studies are used to assess the techniques, and their performance gives satisfactory results as discussed by the mean square error, confidence intervals, and coverage probabilities of the estimates. The stress-strength reliability parameter of the exponentiated sine Weibull model is derived and estimated by the maximum likelihood estimation method. Also, nonparametric bootstrap techniques are used to approximate the confidence interval of the reliability parameter. A simulation is conducted to examine the mean square error, standard deviations, confidence intervals, and coverage probabilities of the reliability parameter. Finally, three real applications of the exponentiated sine Weibull model are provided. One of them considers stress-strength data. 相似文献
74.
Effect of thermooxidation on tinuvin 783 in LDPE films: Characterization by UV and ftir spectroscopy
The effect of thermooxidation on Tinuvin 783 which is a hindered amine light stabilizer in LDPE films has been investigated by UV and FTIR spectroscopy. Initially, a standard curve describing the variation of the concentration of Tinuvin 783 in LDPE films was plotted using the method of integration of the band area. The relation obtained was: band area = 19.6249 × [Tinuvin 783]. This equation was then applied to measure the variation of the concentration of Tinuvin 783 in the 0.2%wt stabilized samples which have undergone thermooxidation at 90°C for 98 days. The results showed a considerable decrease in the concentration of Tinuvin 783 by 35% during the first 30 days due to probably the formation of nitroxyl radicals. After this, the concentration was observed to be unchanged and may correspond to the phase of nitroxyl radical regeneration. On the other hand, no chemical change in the stabilized LDPE films was observed by FTIR spectroscopy at 90°C during 98 days while the band characteristic of ketone groups (1720 cm−1) was detected for the unstabilized samples after only 11 days. (LDPE: low density polyethylene; HALS: hindered amine light stabilizer) 相似文献
75.
On résoud le problème de Cauchy pour des opérateurs aux dérivées partielles à coefficients polynomiaux par rapport aux variables d'espace dans des classes de Gevrey projectives. Nos résultats sont des versions globales du théorème de Cauchy-Kowalewski et du théorème de Nagumo. 相似文献
76.
Sami Mustapha 《Journal of Theoretical Probability》2006,19(4):773-787
It is shown in this paper that the transition kernels corresponding to simple random walks on certain unimodular solvable
p-adic groups admit upper Gaussian estimates.
相似文献
77.
In this work we study the blow up phenomena for some scalar delay differential equations. In particular, we make connection
with the blow up of ordinary differential equations that are related to the delay differential equations.
The first author is supported by a Grant from TWAS under contract No: 03-030 RG/MATHS/AF/AC.
The second author is supported by a grant from the Lebanese National Council for Scientific Research. 相似文献
78.
Mustapha Remouche Rabah Mokdad Ayoub Chakari Patrick Meyrueis 《Optics & Laser Technology》2007,39(7):1454-1460
Curvature of a multimode integrated optical waveguide reduces the numerical aperture and induces radiation losses. In this paper, we study this phenomenon and we present a geometrical approach to calculate the local numerical aperture and the intensity attenuation. We exploit the bending effect on the local numerical aperture to make a new intrinsic temperature sensor. The simulation results are validated for the silica/silicone integrated optical case. The principal performances of the silica/silicone temperature sensor are the extended temperatures range (−50 to 200 °C) with an excellent linearity response (1%) between 20 and 200 °C. 相似文献
79.
Mustapha Khelladi Nicolas Leclerc Denis Jacquemin Antoinette De Nicola Gilles Ulrich 《Tetrahedron letters》2018,59(10):878-881
New symmetrical and non-symmetrical benzoBODIPYs have been synthesized from diketones. For the two series the 3 and 5 positions have been substituted by different aromatic rings and onto benzo sub-units different groups have been introduced. The methodology of diketones self-condensation provides symmetrical dyes. By cross-condensation reaction, these positions can be differentiated and specific functions connected to the desired positions. These molecules have been fully characterized and their optical properties analyzed by both experimental and theoretical means. They are red to NIR emitters with a range of emission from 679 to 780?nm in CH2Cl2. They show maxima of absorption between 651?nm and 732?nm, strong ε of around 100,000?M?1?cm?1 and quite good quantum yields from 16% to 75%. The thienyl moiety on α-positions of the nitrogens generates the highest red shifts. Meanwhile dimethylamino groups in the same positions bring, besides chemical properties, proton sensitive dyes. The bromine atom onto the dibenzo sub-units exhibits good reactivity through Sonogashira coupling reactions. This approach provides multifunctional red to NIR dyes with endless possibilities of combination of chemical properties. 相似文献
80.
Bruno Ameduri Bernard Boutevin Mustapha Nouiri 《Journal of polymer science. Part A, Polymer chemistry》1993,31(8):2069-2080
The radical grafting of CnF2n +1 CH2CH2SH (n = 6,8) onto the double bonds of hydroxyl-terminated liquid polybutadienes (HTPBD) was studied. Various methods for investigating the amount of grafting (titration of residual thiol and fluorine analysis) were used and compared. The nature and the amount of the initiator, the quantity of thiol, the temperature and the time of the reaction. the solvent, and the microstructure of HTPBD were optimized. The kinetic aspect showed that the thiol disappeared according to a first-norder law. A method using up to 100% of grafting fluorinated mercaptan was described and standards were set up with fluorine contents of 5–59% to evaluate the physicochemical properties of these thioether group-containing polymers: solubility, refractive index, intrinsic and dynamic viscosities, and thermal characteristics (glass transition and decomposition temperatures). Finally, the surface properties of these standards showed improvements of surface energy as low as 9 mN m?1 for a totally saturated fluorinated HTPBD. © 1993 John Wiley & Sons, Inc. 相似文献