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91.
Noureddine Said Soufiane Touil et Hèdi Zantour 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1891-1899
The reaction of β-ketophosphonates 1 with active methylenenitriles 2 and sulfur in basic conditions led to new 2-amino-5-phos-phonothiophenes 3 and 2-amino-4-(phosphonomethyl)thiophenes 3′. The structure of all obtained products was confirmed by NMR (1H, 31P, 13C), IR spectroscopy and in some cases by mass spectrometry. 相似文献
92.
Noureddine Said Soufiane Touil Hédi Zantour 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2487-2496
The reaction of β-keto-δ-carbethoxyphosphonates and phosphineoxides 1 with active cyanoarylidenes 2 in basic conditions provides a convenient access to the new 2-amino-6-(phosphonomethyl)-4H-pyranes 3. The reaction is found to be highly regioselective. The structure of all obtained products is confirmed by NMR ( 1 H, 31 P, 13 C), IR spectroscopy, and in some cases by mass spectrometry. 相似文献
93.
Felipe Alcudia Inmaculada Fernandez Noureddine Khiar Jose Manuel Llera 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):393-394
Abstract A short, efficient and general route for the preparation of o.p. alkyl and aryl sulfinates is described. Both epimers at sulfur can be obtained using DAG as unique inductor of chirality and, only by choosing the adequate base (Py or i-Pr2NEt), the configuration at sulfur can be predicted. The efficiency of this methodology has been demonstrated by the synthesis of o.a. alkyl aryl and dialkyl sulfoxides with high e.e. (up to 100%). 相似文献
94.
Meriem Toumi Noureddine Raouafi Khaled Boujlel Issa Tapsoba Jean-Paul Picard Michel Bordeau 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2477-2490
Electrogenerated cyanomethyl anion promotes the reaction between primary or secondary amines, carbon disulfide, and alkyl or benzyl halide. Secondary amines are converted to alkyl or benzyl dithiocarbamates, whereas primary amines give N-substituted alkyl or benzyl 3-amino-2-cyanodithiocrotonates. The mechanisms are discussed. 相似文献
95.
Z. Aloui S. Abid M. Rzaigui 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1725-1736
Cobalt dimethylphenylpiperazinium cyclotetraphosphate hexahydrate, Co[C12H19N2]2P4O12.6H2O, was synthesized by a reaction between cyclotetraphosphoric acid H4P4O12, cobalt carbonate, and 1-(2,4-dimethylphenylpiperazine). It crystallizes in the triclinic system, space group P, with the following unit cell parameters: a = 7.336(1), b = 8.413(1), c = 14.926(2) Å, α = 87.46(1), β = 83.13(1), γ = 82.98(1)°, V = 907.3(2) Å3, and Z = 1. The atomic arrangement can be described as layers containing P4O12 rings a and Co(H2O)6 octahedra spreading in the (001) planes between which are located the dimethylphenylpiperazinium groups via H-bonds. The synthesis and characterization by X-ray diffraction, IR absorption, and thermal analysis are described. 相似文献
96.
Leroy P Berry A Herzog P Atalla N 《The Journal of the Acoustical Society of America》2011,129(1):154-164
This article presents the experimental implementation and results of a hybrid passive/active absorber (smart foam) made up from the combination of a passive absorbent (foam) and a curved polyvinylidene fluoride (PVDF) film actuator bonded to the rear surface of the foam. Various smart foam prototypes were built and tested in active absorption experiments conducted in an impedance tube under plane wave propagation condition at frequencies between 100 and 1500 Hz. Three control cases were tested. The first case used a fixed controller derived in the frequency domain from estimations of the primary disturbance at a directive microphone position in the tube and the transfer function between the control PVDF and the directive microphone. The two other cases used an adaptive time-domain feedforward controller to absorb either a single-frequency incident wave or a broadband incident wave. The non-linearity of the smart foams and the causality constraint were identified to be important factors influencing active control performance. The effectiveness of the various smart foam prototypes is discussed in terms of the active and passive absorption coefficients as well as the control voltage of the PVDF actuator normalized by the incident sound pressure. 相似文献
97.
A new disubstituted hexahelicene derivative 3 bearing methoxy functions at positions 3 and 14 has been prepared in racemic form through a Heck reaction followed by photocyclodehydrogenation. Suitable crystals of rac‐3 were analyzed by X‐ray crystallography and showed similar geometry to the structure of hexahelicene itself. Deprotection of 3 using boron tribromide led to 3,14‐dihydroxyhexahelicene 4 in quantitative yield. The complexation of transition metal atoms seemed to be quite possible by these two bidentate hexahelicene derivatives. 相似文献
98.
In this paper, a dual-microphone speech enhancement algorithm for the mobile phones is proposed. The adopted method exploits the coherence function algorithm and the Kalman filter. This algorithm has a simple implementation that does not need a prediction of interfering signals statistics. In addition, this algorithm can be used in small devices with so closely distance between the two microphones. Moreover, the use of such algorithm allows reducing multiple noise sources at many azimuths positions. Finally, the new algorithm proves its performances referring to the perceptual evaluation of speech quality and the time domain waveforms. 相似文献
99.
We establish a priori estimates for solutions to ultraparabolic equations which play a crucial role in the solvability of
the initial value problem. A class of these equations came from population dynamics, namely from a fish larvae model.
相似文献
100.
Magdalena Żurowska Przemysław Morawiak Wiktor Piecek Michał Czerwiński Anna Spadło Noureddine Bennis 《Liquid crystals》2016,43(10):1365-1374
New compounds (S)-4?-(1-methylheptyloxycarbonyl)biphenyl-4-yl 4-[3-(2,2,3,3,4,4,5,5,5-nonafluoropentyloxy)prop-1-oxy]benzoates were synthesised and characterised. Their mesomorphic properties were tested by means of polarising optical microscopy and differential scanning calorimetry. The multicomponent antiferroelectric high tilt mixture with long pitch has been also formulated and characterised. The helical pitch of prepared mixture was estimated with selective reflection method. 相似文献