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201.
Mohammed Sydia Mohamed Said Ould Bahia Djerrari M'Barek El Abbassi Jilali Fifani El‐Mokhtar Essassi Brahim El‐Bali Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e165-e166
The title compound, C14H16N2O2, contains a diazepine ring, which appears in a boat conformation. An intramolecular hydrogen bond is formed between the NH group of the diazepine ring and a carbonyl O atom of one of the side chains. 相似文献
202.
Ayoub Abdelkader Mekkaoui Sanaa Jennane Abderrazak Aberkouks Brahim Boualy Ahmad Mehdi Mustapha Ait Ali Larbi El Firdoussi Soufiane El Houssame 《应用有机金属化学》2019,33(10)
We report the preparation of palladium nanoparticles supported on mesoporous natural phosphate (Pd@NP) using a wetness impregnation method. The prepared catalyst was characterized using various techniques. Furthermore, the reduction and preparation of the palladium nanoparticles was followed using UV–visible spectra. Based on the Scherrer equation, the crystallite size of the as‐synthesized palladium nanoparticles was 10.88 nm. The performance of the synthesized catalyst was investigated in the reduction of 4‐nitrophenol as a model substrate to 4‐aminophenol using NaBH4 as a hydrogen source. Moreover, catalytic reduction of various nitroarenes was studied and monitored using UV–visible spectroscopy and gas chromatography. The Pd@NP catalyst showed a high activity for the selected reaction and could be recycled. 相似文献
203.
Inside Cover: Confined Carbon Mediating Dehydroaromatization of Methane over Mo/ZSM‐5 (Angew. Chem. Int. Ed. 4/2018) 下载免费PDF全文
204.
Touayba Ahl el haj El Mejdoubi Khalid Sadraoui Khadija Brahim Chafik El idrissi Sallek Brahim 《Kinetics and Catalysis》2022,63(6):707-715
Kinetics and Catalysis - Our work is around the heterogeneous catalysts based on phosphate. This is all the more important as Morocco has a significant wealth of world reserves of this mineral.... 相似文献
205.
Dr. Brahim Ait Addi Prof. Brahim El Ibrahimi Prof. Abdelaziz Ait Addi Dr. Abdul Shaban Prof. El-Habib Ait Addi Prof. Mohamed Hamdani 《Electroanalysis》2021,33(3):804-819
The influence of hydrogen phosphate (HPO42−) and molybdate ions (MoO42−) on the behavior of tin corrosion in 0.2 M maleic acid was compared using experimental and theoretical techniques. The experimental studies consisted of the electrochemical investigations (potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS)), along with the surface analytical techniques (SEM and EDX). Additionally, the theoretical analysis (the chemical quantum computations at MP4/SDD level of theory in the aqueous phase), was conducted. The experimental outcomes illustrated that the inhibition efficiency (η%) increases with the concentration of the inhibitors, reaching 88 % and 81 % at 2×10−2 M concentration of MoO42− and HPO42−, respectively. The potentiodynamic polarization curves revealed that HPO42− performance is a cathodic-type inhibitor, while MoO42− shows a mixed-type behavior. The increase in temperature decreased the η% values of both inhibitors. Based on surface analysis and thermodynamic study, the presence of the two inhibitors formed protective films on the tin surface through a physisorption mechanism. The chemical quantum computations using the complete fourth-order Møller Plesset perturbation theory (MP4 with SDD basis) method results outlined the favorable affinity of the investigated inorganic inhibitors to interact with the tin surface, which interprets the well-observed inhibition efficiencies. 相似文献
206.
The Ramanujan Journal - In this paper, we state some q-analogs of the famous Ramanujan Master Theorem. As an application, we compute some values of Jackson’s q-integrals that involve... 相似文献
207.
The role of Lewis and Brønsted acid sites in the Diels-Alder cycloaddition (DAC) of ethylene to 2,5-dimethylfuran (2,5-DMF) to p-xylene was investigated. Amorphous silica catalysts containing Al3+ (ASA), Ga3+ (ASG), and In3+ (ASI) were prepared via homogeneous deposition-precipitation. Silica modified with Zr4+ (ASZ) was prepared by impregnation. Their acidic properties were characterized by various IR and NMR spectroscopic techniques. Measurements using pyridine as a probe molecule highlighted the presence of mostly Lewis acid sites (LAS) in all materials. Using CO as a probe, in contrast, demonstrated the existence of Brønsted acid sites (BAS) in ASA and ASG, which were nearly absent in ASI and ASZ. Differences in basic strength can explain the contrast in results observed between the two probe molecules. The highest p-xylene yield (~20 %) in the DAC reaction, could be achieved with ASA and ASG. The lack of BAS in ASI and ASZ resulted in inferior performance in the DAC, with p-xylene yields below 5 %. These results indicate the importance of BAS for the DAC reaction. Several other heterogeneous and homogeneous catalysts were explored for the DAC reaction to show the generality of our conclusion that BAS play a critical role in obtaining p-xylene from 2,5-DMF and ethylene. 相似文献
208.
Héla Habli Leila Mejrissi Noureddine Issaoui Saud Jamil Yaghmour Brahim Oujia Florent Xavier Gadéa 《International journal of quantum chemistry》2015,115(3):172-186
The potentials, spectroscopic properties and electric dipole moments of SrH+ are computed for 63 molecular states dissociating up to Sr2+ + H? using an ab initio approach. The ab initio formalism is based on large basis sets, nonempirical atomic pseudopotential for strontium core, correlation treatment for core valence through the effective core polarization potentials and for valence through full valence configuration interaction. Our theoretical molecular constants match published values very well and a large amount of new results is produced. Unusual potential shapes are found in 1Σ+ states often caused by avoided crossing series between them and imprinted by the ionic state Sr2+H?. The high potential energy curves suggest, it is possible to form H? or at least to neutralize H+ in collisions with strontium. © 2014 Wiley Periodicals, Inc. 相似文献
209.
Feriel Bouhjar Brahim Bessaïs Bernabé Marí 《Journal of Solid State Electrochemistry》2018,22(8):2347-2356
This work proposes a new strategy to prepare a hematite (α-Fe2O3) bilayer photoanode by hydrothermally depositing α-Fe2O3 (B) on the α-Fe2O3 (A) films prepared by electrochemical deposition. Compact smooth surfaced α-Fe2O3 (A) films were electrochemically deposited on FTO (SnO2:F) substrates from an aqueous bath. The α-Fe2O3 (A), α-Fe2O3 (B), and α-Fe2O3/α-Fe2O3 bilayer films’ characteristics were defined by X-ray diffraction (XRD) measurements, field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray (EDX) spectroscopy. Pure crystalline α-Fe2O3 (B) films with a typical anisotropic-like nanoparticle formation, which exhibited nanostructured rods covering the substrate and formed the characteristic mesoporous film morphology, were hydrothermally deposited on α-Fe2O3 (A) films prepared by electrochemical depositing in a solution bath at 25 °C and a potential of ??0.15 V. The photocurrent measurements exhibited increased intrinsic surface states (or defects) at the α-Fe2O3 (A)/α-Fe2O3 (B) interface. The photoelectrochemical performance of the α-Fe2O3 (A)/α-Fe2O3 (B) structure was examined by chronoamperometry, which found that the α-Fe2O3 (A)/α-Fe2O3 (B) structure exhibited greater photoelectrochemical activity than the α-Fe2O3 (A) and α-Fe2O3 (B) thin films. The highest photocurrent density was obtained for the bilayer α-Fe2O3 (A)/α-Fe2O3 (B) films in 1 M NaOH electrolyte. This great photoactivity was ascribed to the highly active surface area, and to the externally applied bias that favored the transfer and separation of photogenerated charge carriers in α-Fe2O3 (A)/α-Fe2O3 (B). The improved photocurrent density was attributed to an appropriate band edge alignment of semiconductors and to enhanced light absorption by both semiconductors. The best performing samples were α-Fe2O3 (A)/α-Fe2O3 (B), which reached the maximum incident photon conversion efficiencies (IPCE) of 400 nm at the potential of 0.1 V. In this case, the IPCE values were 3-fold higher than those of the α-Fe2O3 (A) and α-Fe2O3 (B) films. 相似文献
210.
Dr. Nikolay Kosinov Alexandra S. G. Wijpkema Evgeny Uslamin Roderigh Rohling Ferdy J. A. G. Coumans Brahim Mezari Alexander Parastaev Artem S. Poryvaev Dr. Matvey V. Fedin Dr. Evgeny A. Pidko Prof. Emiel J. M. Hensen 《Angewandte Chemie (International ed. in English)》2018,57(4):1016-1020
Non‐oxidative dehydroaromatization of methane (MDA) is a promising catalytic process for direct valorization of natural gas to liquid hydrocarbons. The application of this reaction in practical technology is hindered by a lack of understanding about the mechanism and nature of the active sites in benchmark zeolite‐based Mo/ZSM‐5 catalysts, which precludes the solution of problems such as rapid catalyst deactivation. By applying spectroscopy and microscopy, it is shown that the active centers in Mo/ZSM‐5 are partially reduced single‐atom Mo sites stabilized by the zeolite framework. By combining a pulse reaction technique with isotope labeling of methane, MDA is shown to be governed by a hydrocarbon pool mechanism in which benzene is derived from secondary reactions of confined polyaromatic carbon species with the initial products of methane activation. 相似文献