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101.
Sufyan Naji Adil Belhaj Hicham Labrim Mohamed Bhihi Abdelilah Benyoussef Abdallah El Kenz 《International journal of quantum chemistry》2014,114(7):463-467
Motivated by recent experimental and theoretical works dealing with the silicene and the graphene materials and inspired from the root systems of Lie algebras, we study the electronic and the magnetic properties of the iron adatom adsorption on the graphene. The calculations have been performed using the density functional theory method. More precisely, the system we consider here consists of a static single layer of the graphene interacting with the iron atoms which are placed at hollow (H) sites and localized at a distance Δ along the normal direction. This system, involving the G2 hexagons appearing in the classification of rank two Lie symmetries, exhibits, up some details, a nice double hexagonal symmetry required by coverage of 0.666 monolayer placed at H sites. The resulting materials behave like ferromagnetic ones having a strong spin polarization, instead of gapless‐semiconductor with the nonmagnetic features appearing in the pure graphene. The responsible mechanism for such behaviors is the interaction between the iron atoms. It has been realized that there are two interaction types. The first one is associated with the direct interaction between the iron atoms, whereas the second one corresponds to the indirect interaction via the carbon atoms. Using the molecular field approximation, the Curie temperature has been estimated around 367 K. © 2013 Wiley Periodicals, Inc. 相似文献
102.
This work reports a comprehensive electroanalytical study of carbon nanohorns (CNHs) in electrochemical applications. Compared to other types of carbons, the bare CNHs electrode exhibited higher peak current densities and lowest anodic peak‐to‐cathodic peak separation of less than 50 mV for the [Fe(CN)4?]6/[Fe(CN)3?]6 redox couple. Furthermore, CNHs exhibited excellent electrocatalyst supporting properties for porous Pt film towards methanol oxidation reaction reaching a peak current density of 127 mA cm?2 or peak current mass activity 184 mA mgPt?1. Regarding oxygen reduction reaction, an onset potential as positive as 0. 77 V vs. Ag/AgCl was achieved with CNHs/porous Pt film. 相似文献
103.
MANSOURI Said MAJDOUBI Hicham HADDAJI Younesse TAMRAOUI Youssef EL ACHABY Mounir MANOUN Bouchaib ABOURRICHE Abdelkrim HANNACHE Hassan OUMAM Mina 《高等学校化学研究》2020,36(6):1339-1347
This paper discusses the elaboration of adsorbents from oil shale. The experimental designs a response surface methodology(RSM), which has been applied to optimize the significant preparation factors, such as temperature, time, and the activating agent percentage. The results obtained from central composite design(CCD) revealed that the interaction between the factors was significant for the maximum quantity of adsorption(response). Planned results have shown that a maximum quantity of adsorption for methylene blue is 65 mg/g, which could be achieved with a temperature of 275℃ over 2 h and a percentage of the activating agent of 45%. The predicted values agreed with the experimental finding, with a determination coefficient(R2) of 0.96. The model has been validated by experiments after conditions optimization. The new material(RHO) was characterized by cation exchange capacity, zero charge pH, surface functions, X-ray fluorescence, specific surface area, and electron microscopy analysis. Phenol adsorption was determined using Langmuir, Freundlich and Temkin, which were used to describe the adsorption isotherms. The adsorption capacity of the material was about 263 mg/g, and the kinetic studies showed rapid adsorption. 相似文献
104.
105.
Elhassan Boudaia Lahbib Bousshine Hicham Fassi Fihri Gery De Saxce 《Comptes Rendus Mecanique》2009,337(11-12):761-767
This Note introduces an application of the meshless method to the case of machining simulation in small deformations, which is still subjected to numerical limitations. The treatment of the contact problem at the tool/chip interface is presented, and highlights the interest of the coupling of the contact law with friction. Validation results are detailed through typical example. To cite this article: E. Boudaia et al., C. R. Mecanique 337 (2009). 相似文献
106.
Hicham ZilaoutAdri van den Hoogenband Jelle de VriesJos H.M. Lange Jan Willem Terpstra 《Tetrahedron letters》2011,52(45):5934-5939
An unprecedented rhodium-catalyzed 1,4-conjugate addition of arylboronic acids with ethenesulfonamides resulting in the corresponding 2-arylethanesulfonamides is described. The amino substituent, the applied arylboronic acid, the type of Rh-catalyst, and the experimental conditions all affected the reaction outcome. 相似文献
107.
We study a class of nonlinear parabolic equations of the type:b(u)t- div a(x, t, u)▽u + g(u)|▽u|2= f,where the right hand side belongs to L1(Q), b is a strictly increasing C1-function and-div(a(x, t, u)▽u) is a Leray-Lions operator. The function g is just assumed to be continuous on R and to satisfy a sign condition. Without any additional growth assumption on u, we prove the existence of a renormalized solution. 相似文献
108.
Gabor Borzsonyi Martins S. Oderinde Rachel L. Beingessner Bo‐Liang Deng Takeshi Yamazaki Robert McDonald Andriy Kovalenko Hicham Fenniri 《Helvetica chimica acta》2009,92(10):1963-1972
Four heterocyclic compounds are presented which exhibit specific self‐recognition of identical Donor–Acceptor (D–A) H‐bonding arrays, resulting in solid‐state tapes with the same, but anti‐parallel functional‐group distribution on opposite sides. A detailed X‐ray‐crystallographic analysis of these supramolecular structures is described. 相似文献
109.
A. Hamoudi L. Khouchaf C. Depecker B. Revel L. Montagne P. Cordier 《Journal of Non》2008,354(45-46):5074-5078
Combining X-ray diffraction, NMR (CP-MAS and 29Si NMR-MAS) and diffuse reflectance infra-red Fourier transformed spectroscopy (DRIFTS), the local structural changes induced during the reactivity of amorphous (a-SiO2) under alkali–silica reaction (ASR) have been investigated. XRD patterns provide useful and new qualitative information concerning the reactivity of a-SiO2. A shift of the maximum of the halo towards the high values of 2θ is observed when the reaction progresses. NMR shows that ASR is accompanied in a-SiO2 by the diminution of Q4 species and by the formation of Q3 (and to a less extend to Q2) species. This importance played by Q3 species confirms the results obtained with natural alkali–silica gels. The formation of OH bonds observed by DRIFTS can be followed at ca. 950 cm?1 and confirms NMR results. The microstructural state of silica (here represented by the medium- and short-range order (MRO) of amorphous silica) plays a crucial role in governing the kinetics of the ASR. 相似文献
110.
Elhamzaoui H Jousseaume B Riague H Toupance T Dieudonné P Zakri C Maugey M Allouchi H 《Journal of the American Chemical Society》2004,126(26):8130-8131
Hybrid materials where layers of tin oxide alternate with layers of hydrophobic organic chains were prepared by the hydrolysis of distannylated compounds containing an organic chain alpha,omega-disubstituted by tripropynylstannyl groups. In the case of an aliphatic chain, hydrolysis under microemulsion conditions led to the organization of the corresponding hybrid. These hydrolysis conditions also induced a high surface area and a defined mesoporosity in the hybrid. When a mixed aromatic-aliphatic spacer was used, weak hydrophobic interactions between the spacers were sufficient to generate the same type of organization in the corresponding material. 相似文献