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81.
Driss El Manouni Jean-Marc Benech Mounya Benramdane Marc Lecouvey Gerard Leger Yves Leroux 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract Several methods for the preparation of symmetrical bisphosphonates of general type (RO)2P(O)(R′OH)P(O)(OR)2, have been developed, and investigated for their pharmacological. Pharmacological screening of these bisphosphonates have shown that these compounds have potent cardiovascular activity and are. potentialy useful in the treatment of hypertension. In this work we described of new method “one pot” for the synthesis of hydroxy bis and tetra phosphonates (I, II, III and IV). 相似文献
82.
83.
Mohamed Nohair Ouafae Britel Nabil Souaf Driss Zakarya Abdelmjid Hafid Noura Mallouk 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1772-1781
We have used a new, robust model mapping technique—a Bayesian-regularized neural network—to develop a quantitative relationships model for the synthesis of the phosphocalcic hydroxyapatite by precipitation from a calcium carbonate solution and a phosphoric acid solution. This model was preformed by using a set of factors consisting on the pH of reactional medium, the Ca/P molar ratio of the reagents, reaction time, and the initial concentration of calcium. The results show that the method is robust and gives satisfied results. The Levenberg–Marquardt's algorithm implemented in the neural network Matlab's toolbox allowed a drastic improvement of the performance of the model. Very satisfactory results are then obtained by testing the validity by cross-validation technique. We have also turned our interests to the explanatory capacities of our methodology to explore the relative contribution and/or the contribution profile of the input factors by using Garson weight portioning method. 相似文献
84.
Abstract
The synthesis and Crystal structure are given for the bis (N,N,N′,N′-tetramethylethylendiammonium) octaiodo pentachloroantimonate (III) salt. An X-ray investigation has shown that the title compound crystallizes in a monoclinic system, space group P21/m with the following lattice parameters a = 9.786(2) Ǻ, b = 14.024(5) Ǻ, c = 14.336(3) Ǻ, β = 91.35(2)° and Z = 2. The structure was solved from 3085 independent reflections with R 1 = 0.0402 and wR 2 = 0.0952 and refined with 152 parameters. The structure shows a layer arrangement perpendicular to the [(b)\vec] \vec{b} -axis: planes of [SbCl5]2−, I3 − and I5 − anions alternate with planes of [(CH2)2(NH(CH3)2)2]2+ cations. The [SbCl5]2− square pyramids present an active lone electron pair (LEP) on the Sb atoms and they are interconnected by means of N–H···Cl hydrogen bond originating from [(CH2)2(NH(CH3)2)2]2+ entities. The polyiodides (I3 − and I5 −) anions form a planer zigzag polymeric chains via I···I linking interactions. These chains are linked to the [SbCl5]2− anions by a long range contact. 相似文献85.
86.
Journal of Russian Laser Research - Under the cross-Kerr effect, we investigate two different forms of quantum correlations in an optomechanical system consisting of a mechanical mode coupled with... 相似文献
87.
In this paper, we prove that the Gorenstein analogue of the well-known Auslander's theorem on the global dimension holds true. Namely, we prove that the Gorenstein global dimension of a commutative ring R is equal to the supremum of the set of Gorenstein projective dimensions of all cyclic R-modules. 相似文献
88.
Dorra Driss Anissa Haddar Raoudha Ghorbel Semia Ellouz Chaabouni 《Applied biochemistry and biotechnology》2014,173(6):1405-1418
Penicillium occitanis xylanase 2 expressed with a His-tag in Pichia pastoris, termed PoXyn2, was immobilized on nickel-chelate Eupergit C by covalent coupling reaction with a high immobilization yield up to 93.49 %. Characterization of the immobilized PoXyn2 was further evaluated. The optimum pH was not affected by immobilization, but the immobilized PoXyn2 exhibited more acidic and large optimum pH range (pH 2.0–4.0) than that of the free PoXyn2 (pH 3.0). The free PoXyn2 had an optimum temperature of 50 °C, whereas that of the immobilized enzyme was shifted to 65 °C. Immobilization increased both pH stability and thermostability when compared with the free enzyme. Time courses of the xylooligosaccharides (XOS) produced from corncob xylan indicated that the immobilized enzyme tends to use shorter xylan chains and to produce more xylobiose and xylotriose initially. At the end of 24-h reaction, XOS mixture contained a total of 21.3 and 34.2 % (w/w) of xylobiose and xylotriose with immobilized xylanase and free xylanase, respectively. The resulting XOS could be used as a special nutrient for lactic bacteria. 相似文献
89.
Yves Leroux Driss El Manouni Brahim Ben Jaafar Ramon Burgada 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-3):205-208
Abstract - Addition of trivalent phosphorus compounds with α, β ethylenic ketones and esters leads to examples of prototropy or cyclisation or rearrangement with ring expansion from 5 to 7 atoms. When trivalent phosphorus compounds react with acetylenic ketones and esters, the 1, 3 dipolar species can be trapped with an electrophilic reagent (aldehydes or the original acetylenic compound) or a protic reagent (alcohol, acid, amide, phenol, etc…) Ylides, phosphoranes, spirophos-phoranes and phospholes can be obtained. 相似文献
90.
A. Dakhlaoui L. S. Smiri A. Driss 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1967-1976
The title compound has been synthesized under mild hydrothermal conditions (autogenous pressure, 368 K, 24 h). It crystallizes in the P2 1 /c (N°14) space group with a = 15.9323(4) Å b = 9.6203(1)Å c = 8.8024(2)Å β = 103.828(2)°; V = 1310,07(5) Å 3 ; and Z = 4. Its structure, determined from X-ray single-crystal data (1266 reflexions with I > 2σ (I), R = 7.4%, Rw = 20.6%), consists of inorganic [Zn(HPO 4 )Cl]? sheets lying parallel to the (100) plane between which are located the protonated organic molecules. The infrared spectroscopy and the thermogravimetric analysis are reported. 相似文献