排序方式: 共有75条查询结果,搜索用时 15 毫秒
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Kamel Hachama Mohamed Khodja Saad Moulay Hocine Boutoumi Lothar Hennig Dieter Sicker 《Journal of heterocyclic chemistry》2013,50(2):413-416
Five novel 3‐(2‐oxo‐2H‐benzo[b][1,4]oxazin‐3‐yl)propanoates were synthesized under mild conditions from 2‐aminophenols and dimethyl‐2‐oxoglutarate. Biological assays of these 1,4‐benzoxazinones were conducted with three bacterial strains and one yeast. All compounds were active against a Candida albicans ATCC 10231, whereas only methyl 3‐(6‐methyl‐2‐oxo‐2H‐benzo[b][1,4]oxazin‐3‐yl)propanoate showed a general moderate activity against the bacterial strains tested. 相似文献
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Moulay A. Barkatou 《Journal of Pure and Applied Algebra》2008,212(9):2129-2139
In this paper we give an algorithm to recognize triangulable locally nilpotent derivations in dimension three. In case the given derivation is triangulable, our method produces a coordinate system in which it exhibits a triangular form. 相似文献
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M. Rabah D. Rached R. Khenata N. Moulay 《Journal of Physics and Chemistry of Solids》2008,69(11):2907-2910
We report local density-functional calculations using the full-potential linearized muffin-tin orbital method (FP-LMTO) for platinum carbide (PtC) in the, rock-salt (B1), zinc-blende (B3), wurtzite (B4), nickel-arsenide (B8) and PbO (B10) structures. The ground state properties such as the equilibrium lattice constant, elastic constants, the bulk modulus and its pressure derivative of PtC in these phases are determined and compared with available experimental and theoretical data.Our calculations show that the ground state phase of PtC to be zinc-blende (B3) structure at zero pressure and the nickel-arsenide (B8) structure is a high-pressure phase. The transition pressures at which this compound undergoes the structural phase transition from (B3) to (B8) and from (B3) to (B1) are found to be 34.25 and 51.28 GPa, respectively. The highest bulk modulus values in the nickel-arsenide (B8), zinc-blende (B3), rock-salt (B1) and PbO (B10) structures indicate that PtC is a hard material. 相似文献
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Moulay Taïb Belghiti Boutayeb El Ammari Laurent P. Gendre 《Comptes Rendus Mathematique》2018,356(11-12):1125-1130
We study the problem of global approximation by polynomials in Whitney -flat jet classes on irregular compacts of . 相似文献
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In an epidemiological model, time spent in one compartment is often modeled by a delay in the model. In general the presence of delay in differential equations can change the stability of an equilibrium to instability and causes the appearance of oscillatory solutions.In this paper we consider a SIS epidemiological model with demographic effects: birth, mortality and mortality caused by infection. The delay is the period of infection. We define the concept of oscillation in the sense that solutions of the model studied fluctuate around a steady state. Our goal is to show that in this model, there are oscillating solutions for certain parameters values. We determine a large set of initial data for which solutions of this model are slowly oscillating. 相似文献
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Three Nematogen Azobenzene-Based Stationary Phases for Capillary GC: Synthesis and Comparative Study
Azzedine Addoun Ouassila Ferroukhi Mohamed Dahmane Saliha Guermouche Jean Pierre Bayle Moulay Hassene Guermouche 《Chromatographia》2014,77(19-20):1367-1377
In this paper, three laterally substituted liquid crystals termed LCC1, LCC3 and LCC4 were synthesized. Characterization of these substances was carried out by 1H NMR and 13C NMR; they possess similar core and differ in their lateral substituents. Their thermal stability was conducted by thermogravimetric analysis and showed decomposition beginning at 212, 233 and 264 °C related to LCC1, LCC3 and LCC4, respectively. Thermal properties were determined by differential scanning calorimetry, thermomicroscopy and inverse gas chromatography. The three novel compounds exhibited a nematic mesophase at a defined range of temperatures, which varied from 81 to 55 °C. Lengthening of the lateral substituent seemed to affect the nematic range by decreasing it. Fused-silica capillary columns (30 m × 0.32 mm) were employed for the analytical study. Numerous mixtures of components of various properties were injected. Particular attention was given to the selectivity towards the close-boiling isomers. These investigations indicated that lateral attached groups had considerable effect on the thermal and chromatographic properties of the liquid crystal compounds. These interesting results may guide in improving the development of new type of liquid crystals with desired properties for a widespread application. 相似文献
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