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21.
Research on Chemical Intermediates - In the current work, an acidic ionic liquid ([{(IMC)-4-OMBH}BIM][HSO4]3) has been utilized as an effective and recyclable catalyst for the synthesis of... 相似文献
22.
We extend some fundamental spectral properties of classic regular Sturm--Liouville problems to discontinuous boundary-value problems with eigenvalue-dependent boundary conditions. We suggest a new approach for investigation of such type discontinuous problems. 相似文献
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Rotational-particle coupling (RPC) model calculations have been performed for the positive parity states of 19F using a deformed oscillator potential (Nilsson) and a deformed Woods-Saxon potential. The energy spectra and spectroscopic factors (for the 18O(3He, d)19F reaction) are very similar for both calculations and in good agreement with experimental values and with recent full intermediate coupling shell-model calculations. 相似文献
24.
A. SH. Hussein Z. HassanS.M. Thahab S.S. NgH. Abu Hassan C.W. Chin 《Applied Surface Science》2011,257(9):4159-4164
The effect of Al mole fractions on the structural and electrical properties of AlxGa1−xN/GaN thin films grown by plasma-assisted molecular beam epitaxy (PA-MBE) on Si (1 1 1) substrates has been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and current-voltage (I-V) measurements. X-ray results revealed that the AlGaN/GaN/AlN was epitaxially grown on Si substrate. By applying Vegard's law, the Al mole fractions of AlxGa1−xN samples were found to be 0.11, 0.24, 0.30 and 0.43, respectively. The structural and morphology results indicated that there is a relatively larger tensile strain for the sample with the smallest Al mole fraction; while a smaller compressive strain and larger grain size appear with Al mole fraction equal to 0.30. The strain gets relaxed with the highest Al mole fraction sample. Finally, the linear relationship between the barrier height and Al mole fraction was obtained. 相似文献
25.
S.H. Naqib M. Borhan Uddin J.R. Cole 《Physica C: Superconductivity and its Applications》2011,471(23-24):1598-1601
The out-of-plane (c-axis) resistivity, ρc(T), of high-Tc cuprates have been modeled in this study. The non-Fermi liquid like temperature dependence of ρc(T) has been described by considering (i) the full impact of the pseudogap (PG) in the electronic density of states (EDOS) and (ii) the presence of a quantum critical point (QCP) beneath the superconducting dome at slightly overdoped region. This simple phenomenological model describes the experimental ρc(T) data over a wide range of hole content (from the underdoped to slightly overdoped regions) remarkably well. The PG energy scale, εg (dominated by the anti-nodal parts of the Brillouin zone) extracted from the analysis of ρc(T) data was found to decrease almost linearly with increasing hole concentration, p, in the CuO2 planes. We have also discussed about the possible origin of more conventional behavior of ρc(T) observed in the deeply overdoped side of the T–p phase diagram in this paper. 相似文献
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Wafa I. Abdel-Fattah M.SH. Fayed SH.R. Gooda W.F.F. Mekky 《Journal of Sol-Gel Science and Technology》1998,13(1-3):981-985
-Eucryptite solid solution (LAS) Li2O : Al 2O3 : 3SiO2(113) was prepared via a sol-gel route. Complex solutions of lithium or aluminum salts in ethanol/water mixtures were catalysed by inorganic acids (catalyst/alkoxide ratio 0.1). Different ratios of H2SO4 catalyst were also used.TGA showed that the maximum % yield of LAS 113 occurred using H2SO4 catalyst. Above 400°C exothermic peaks occurred in DSC followed by the glass transition. XRD and IR showed a high crystallinity of -eucryptite solid solution using all acids at the 0.1 ratio with the highest crystallinity for the 0.05 H2SO4 ratio. SEM revealed similar grain sizes in spite of higher acid concentrations. XRD data indicated a change to a tetragonal modification with higher catalyst ratio. 相似文献
28.
A smooth affine algebraic variety X equipped with an algebraic volume form ω has the algebraic volume density property (AVDP) if the Lie algebra generated by complete algebraic vector fields of ω-divergence zero coincides with the space of all algebraic vector fields of ω-divergence zero. We develop an effective criterion of verifying whether a given X has AVDP. As an application of this method we establish AVDP for any homogeneous space X = G/R that admits a G-invariant algebraic volume form where G is a linear algebraic group and R is a closed reductive subgroup of G. 相似文献
29.
An ab initio investigation of vibrational,thermodynamic, and optical properties of Sc_2AlC MAX compound
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The structural vibrational, thermodynamical, and optical properties of potentially technologically important, weakly coupled MAX compound, Sc2 Al C are calculated using density functional theory(DFT). The structural properties of Sc_2AlC are compared with the results reported earlier. The vibrational, thermodynamical, and optical properties are theoretically estimated for the first time. The phonon dispersion curve is calculated and the dynamical stability of this compound is investigated. The optical and acoustic modes are observed clearly. We calculate the Helmholtz free energy(F), internal energy(E), entropy(S), and specific heat capacity(Cv) from the phonon density of states. Various optical parameters are also calculated. The reflectance spectrum shows that this compound has the potential to be used as an efficient solar reflector. 相似文献
30.
New ternary superconducting compound La Ru_2As_2:Physical properties from density functional theory calculations
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In this paper, we perform the density functional theory(DFT)-based calculations by the first-principles pseudopotential method to investigate the physical properties of the newly discovered superconductor LaRu_2As_2 for the first time.The optimized structural parameters are in good agreement with the experimental results. The calculated independent elastic constants ensure the mechanical stability of the compound. The calculated Cauchy pressure, Pugh's ratio as well as Poisson's ratio indicate that LaRu_2As_2 should behave as a ductile material. Due to low Debye temperature, LaRu_2As_2 may be used as a thermal barrier coating(TBC) material. The new compound should exhibit metallic nature as its valence bands overlap considerably with the conduction bands. LaRu_2As_2 is expected to be a soft material and easily machinable because of its low hardness value of 6.8 GPa. The multi-band nature is observed in the calculated Fermi surface. A highly anisotropic combination of ionic, covalent and metallic interactions is expected to be in accordance with charge density calculation. 相似文献