排序方式: 共有10条查询结果,搜索用时 15 毫秒
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Zahra Shariatinia Mauricio F. Erben Carlos O. Della Védova Majid Abdous Saman Azodi 《Structural chemistry》2011,22(6):1347-1352
Intermolecular interactions between α-, β-glucose, and methacrylic acid (MAA) have been investigated. Twenty-two possible
conformations have been optimized at the DFT(B3LYP) level of theory with the 6-31G(d) basis set. The geometrical parameters
for the most stable configurations of hydrogen bonding sites in the optimized systems have been determined. The binding energies
ΔE
bind have been calculated at the MP2/6-311++G(d,p) level of approximation taking into account the basis set superposition error
(BSSE) and the zero-point vibrational energies corrections. Results indicate that the most stabilized complexes form hydrogen
bonds either through carboxylic and hemiacetal oxygen atoms acting as proton acceptors. Both, α- and β-anomers are studied
in the pyranose six-membered ring. In all complexes, the nuclear quadrupole coupling constants (χ) for 17O nuclei were obtained about 10.0 MHz, while for the 2H atoms they vary from ≈200.0 to ≈350.0 kHz. 相似文献
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Multivariate kernel density estimators are known to systematically deviate from the true value near critical points of the density surface. To overcome this difficulty a method based on Rao–Blackwell's theorem is proposed. Local corrections of kernel density estimators are achieved by conditioning these estimators with respect to locally sufficient statistics. The asymptotic as well as the small sample size behavior of the improved estimators are studied. Asymptotic bias and variance are investigated and weak and complete consistency are derived under mild hypothesis. 相似文献
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A. Imani H. Modarress A. Eliassi M. Abdous 《The Journal of chemical thermodynamics》2009,41(7):893-896
The phase separation of (water + salt + polyethylene glycol 15000) systems was studied by cloud-point measurements using the particle counting method. The effect of three kinds of sulphate salt (Na2SO4, K2SO4, (NH4)2SO4) concentration, polyethylene glycol 15000 concentration, mass ratio of polymer to salt on the cloud-point temperature of these systems have been investigated. The results obtained indicate that the cloud-point temperatures decrease linearly with increase in polyethylene glycol concentrations for different salts. Also, the cloud points decrease with an increase in mass ratio of salt to polymer. 相似文献
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F. Abdous R. Ghaderi A. Ranjbar S. H. Hosseinnia H. Soltani J. Ghasemi 《Journal of Applied Mathematics and Computing》2009,31(1-2):151-163
The main goal of this study is to present a technique to find a state response of multivariable time varying systems. In this paper a novel Homotopy Perturbation based Method (HPM) will be presented to find a dynamic response of time varying system. According to this method, the linear part of the described system is partitioned into two time varying and invariant subsections. Time invariant part analytically constructs the state transition matrix. This matrix is a core of the rest of time varying differential equation without any further changes in a sequence order. The main advantage of this method is only the necessity to solve the time invariant part of the state transition matrix. Simulation results verify the significance of the proposed analytic and asymptotic method. 相似文献
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This work, we report a cost effective method to decompose ITO thin layer on polycarbonate as flexible substrate by means of
spin coating technique. Three calcinations techniques were carried out. The coating were deposited by spin and cured by heat,
ultraviolet (UV) irradiation and Nd-YAG pulse laser. The resistivity change on annealing of the amorphous film by thermal,
UV and laser was investigated by X-ray diffraction, scanning electron microscopy, atomic force spectroscopy and UV–Vis spectrometer.
It is shown that the resistance of coated film on polymer decreases dramatically to less than impedance spectroscopy (600 Ω)
when using combination of low heat treatment and laser irradiation with a wavelength of 1,100 nm and energy of 6–25 J. 相似文献
6.
Nouri Parouch Ahmad Koukabi Nadiya Abdous Elham 《Research on Chemical Intermediates》2020,46(7):3295-3310
Research on Chemical Intermediates - In the present study, a magnetically separable potent solid acid nanocatalyst with a facile preparation technique was fabricated via incorporation of fibroin as... 相似文献
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This paper presents a new estimation procedure for the limit distribution of the maximum of a multivariate random sample. This procedure relies on a new and simple relationship between the copula of the underlying multivariate distribution function and the dependence function of its maximum attractor. The obtained characterization is then used to define a class of kernel-based estimates for the dependence function of the maximum attractor. The consistency and the asymptotic distribution of these estimates are considered. 相似文献
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Belkacem Abdous Bruno Remillard 《Annals of the Institute of Statistical Mathematics》1995,47(2):371-384
Recently, quantiles and expectiles of a regression function have been investigated by several authors. In this work, we give a sufficient condition under which a quantile and an expectile coincide. We extend some classical results known for mean, median and symmetry to expectiles, quantiles and weighted-symmetry. We also study split-models and sample estimators of expectiles.Work supported by the Natural Science and Engineering Council of Canada and by the Université du Québec à Trois-Rivières. 相似文献
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