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641.
We construct a global solution with $\mathcal {C}^{k}$‐estimates for the $\bar{\partial }$‐equation on q‐convex intersections. 相似文献
642.
Garcia P Harrak Y Diab L Cordier P Ollivier C Gandon V Malacria M Fensterbank L Aubert C 《Organic letters》2011,13(11):2952-2955
A variety of allenynamides can undergo cycloisomerization reactions in the presence of silver triflate thus leading to the formation of N-containing heterocycles incorporating cross-conjugated trienes. Access to new dienic 4-piperidinone and azepane motifs was achieved. An extension to one-pot tandem sequences involving silver-catalyzed cycloisomerization/Diels-Alder reaction was also examined. 相似文献
643.
Chemical composition and antibacterial activity of the essential oil of Moroccan Juniperus phoenicea
Fouad B Abderrahmane R Youssef A Rajae H El Fels MA 《Natural product communications》2011,6(10):1515-1518
The antibacterial activity of the essential oil from leaves of Juniperus phoenicea (Cupressaceae) and its chemical constituents were investigated in this study. The essential oil was obtained by hydro-distillation and analyzed by gas chromatography equipped with a flame ionisation detector (GC-FID), and gas chromatography coupled to a mass spectrometer (GC-MS). Sixty-three volatile compounds were identified representing 52 to 92% of the total oil compositions. The main monoterpenes were a-pinene (26.7-78.7%) and 6-3carene (7.6-15.4%). The antibacterial activity of J. phoenicea essential oil, when tested against both Gram-positive and Gram-negative bacteria, showed high activity against all bacteria tested, except Pseudomonas. 相似文献
644.
645.
The efficiency of excited-state interaction between Tb3+ and the industrial product Cilostazol (CIL) has been studied in different solvents. High luminescence intensity peak at 545 nm
of terbium complex in acetonitrile was obtained. The photophysical properties of the green emissive Tb3+ complex have been elucidated, the terbium was used as optical sensor for the assessment of CIL in the pharmaceutical tablets
and body fluids at pH 3.1 and λex = 320 nm with a concentration range 1.0 × 10−9–1.0 × 10−6 mol L−1 of CIL, correlation coefficient of 0.998 and detection limit of 7.5 × 10−10 mol L−1. 相似文献
646.
Khairy M. Hassan Mohamed S. K. Youssef Maher F. El-Zohry Raga Abo El-wafa 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):237-241
Abstract 2-Mercapto-3,5,7-triphenylpyrido[2,3-d]pyrimidine-4(3H)-one (II) was synthesized by the interaction of ethyl-2-amino-4,6-diphenylincotinate (I) with phenyl isothiocyanate in pyridine. The reaction of II with different reagents was carried out to give some condensed heterocyclic systems. 相似文献
647.
In this article, the main target was to study the antitumor and antimicrobial efficacy of new heterocycles conjugated with biphenyl moiety in-vitro. This was implemented by utilizing N'-(1-([1,1'-biphenyl]-4-yl)ethylidene)-2-cyanoacetohydrazide 3 as a material for the synthesis of various heterocyclic compounds. Among of them, some compounds were selected and assayed against two antitumor cell lines as (HepG2) and (HCT-116). Conspicuously, the achieved results showed that compounds 6, 13, and 23 possess significant potency against both cancer cell lines. Particularly, compound 13 exhibited a remarkable efficacy, similar to the standard anticancer drug (doxorubicin), against both cancer cell lines. Noteworthy, compound 13 may serve as a potential anticancer therapeutic drug in the future. On the other hand, In-vitro antifungal and antibacterial activities of selected compounds were assayed and the results indicated that the compound 6 exhibited significant potency against Candida albicans, while compounds 6 and 8 displayed spectacular results for the antibacterial study. 相似文献
648.
A comparative study of energy consumption and physical properties of microfibrillated cellulose produced by different processing methods 总被引:1,自引:0,他引:1
Kelley L. Spence Richard A. Venditti Orlando J. Rojas Youssef Habibi Joel J. Pawlak 《Cellulose (London, England)》2011,18(4):1097-1111
Microfibrillated celluloses (MFCs) with diameters predominantly in the range of 10–100 nm liberated from larger plant-based
fibers have garnered much attention for the use in composites, coatings, and films due to large specific surface areas, renewability,
and unique mechanical properties. Energy consumption during production is an important aspect in the determination of the
“green” nature of these MFC-based materials. Bleached and unbleached hardwood pulp samples were processed by homogenization,
microfluidization, and micro-grinding, to determine the effect of processing on microfibril and film properties, relative
to energy consumption. Processing with these different methods affected the specific surface area of the MFCs, and the film
characteristics such as opacity, roughness, density, water interaction properties, and tensile properties. Apparent film densities
were approximately 900 kg/m3 for all samples and the specific surface area of the processed materials ranged from approximately 30 to 70 m2/g for bleached hardwood and 50 to 110 m2/g for unbleached hardwood. The microfluidizer resulted in films with higher tensile indices than both micro-grinding and
homogenization (148 Nm/g vs. 105 Nm/g and 109 Nm/g, respectively for unbleached hardwood). Microfluidization and micro-grinding
resulted in films with higher toughness values than homogenization and required less energy to obtain these properties, offering
promise for producing MFC materials with lower energy input. It was also determined that a refining pretreatment required
for microfluidization or homogenization can be reduced or eliminated when producing MFCs with the micro-grinder. A summary
of the fiber and mechanical energy costs for different fibers and processing conditions with economic potential is presented. 相似文献
649.
J. Ben Youssef S. Pogossian D.T. Dekadjevi 《Journal of magnetism and magnetic materials》2010,322(17):2593-2595
The dependence of the coercive field and saturated magnetization on the interfacial width is studied to understand the driving mechanism of the coercive enhancement in Fe/Mn and Co/Mn bilayers. We establish a controlled annealing procedure to reveal the origin of this enhancement. Using a model, we reveal that the full interfacial width plays a keyrole, and that no Mn based finite size effects drive the mechanism. We show that this mechanism is common to both type of bilayers. 相似文献
650.
Abdelhalim Hafid Ahmed Taoufik Abella Bouaaddi Hassan Elouaddi Ahmed Tirbiyine Brahim Lmouden Mustapha Bghour Habiba El hamidi Youssef Ait Ahmed 《Chinese Journal of Physics (Taipei)》2018,56(2):754-759
In this paper, the critical current Jc(Θ) have been investigated as a function of magnetic-field angle Θ. Θ is the angle between the c-axis and the applied magnetic field direction. This investigation concerned three temperature values (60?K, 78?K and 81?K). The normalized pinning force fp versus the normalized magnetic field h was also studied (fp?=?Fp / Fpmax and h?=?H / Hmax). The Fp expression was determined based on the Kramer model.The studied sample was a single crystal of YBaCuO thin film deposited by the ablation laser method on the surface (100) of a SrTiO3 substrate.The results of this work show the existence of point core pinning of the normal centers in the low field regime and the occurrence of the flux creep in high field regime. 相似文献