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201.
Eslami Mahboobeh Nikkhah Sousa Javan Eslami Elham Hashemianzadeh Seyed Majid 《Structural chemistry》2020,31(5):2051-2062
Structural Chemistry - Drug delivery plays a substantial role in a more effective treatment of diseases of the central nervous system; therefore, the selection of an appropriate drug carrier system... 相似文献
202.
Daghlavi Amneh Kowsari Elaheh Abdouss Majid Ghasemi Mohammad Hadi Asadi Elham 《Research on Chemical Intermediates》2020,46(7):3593-3605
Research on Chemical Intermediates - A practical and efficient method for the synthesis of thiazolidine derivatives via Nef-isocyanide three-component reaction using supported phosphoric acid on... 相似文献
203.
Mir Ali Farajzadeh Shirin Ghochi Eskandar Ali Ranji Elham Feyz 《Mikrochimica acta》2007,159(3-4):363-369
A high performance liquid chromatography (HPLC) method is presented for the determination of Chimassorb 944 in polymeric matrix.
A reversed phase column octadecyl silane (ODS) is used as a stationary phase. As a mobile phase, a mixture of THF:methanol:triethanol
amine (90:10:1.5) (v:v:w) is used. The HPLC system was equipped with an UV detector and the absorbance of the analyte was
recorded at 240 nm. In the case of polymers, 0.5 g of them along with 100 mg Irganox 1010 (for preventing oxidation of Chimassorb
944) were dissolved in boiling xylene, and then extracted with sulfuric acid 1 M four times. The extract was neutralized with
sodium hydroxide solution and the analyte was re-extracted into carbon tetrachloride and then injected to the HPLC system.
This method is an accurate and relatively fast technique for determination of Chimassorb 944 in polymers. 相似文献
204.
Elham M. Abdalla 《Journal of Analytical and Applied Pyrolysis》2003,70(2):687-697
The thermal decomposition study of Co(II)–malate, tartarate and phthalate complexes with imidazole was monitored by TG, DTG and DTA analysis in static atmosphere of air. The complexes and their calcination products were characterized by IR spectroscopy. The decomposition course and steps were analyzed and the kinetic parameters of the non-isothermal decomposition were calculated. The results revealed that the decomposition processes of these complexes are the best described by a random nucleation mechanism. The stability order found for these complexes follows the trend tartarate>phthalate>malate in terms of the dicarboxylic acid ligands. 相似文献
205.
Habibi MH Askari E Amirnasr M Amiri A Yamane Y Suzuki T 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(3):666-671
Mononuclear Mn(III) complexes have been prepared via the Mn(II) reaction of an equimolar of Schiff-bases derived from reaction of 2-hydroxy-3-methoxybenzaldehyde or 2-hydroxy-5-methoxybenzaldehyde with 1,2-diaminopropane. Axial ligands L include: pyridine (py) and H(2)O. The resulting complexes have been characterized by FT-IR and UV-vis spectroscopy. The crystal structures of the complexes were determined and indicate that in the solid state the complex adopts a slightly distorted octahedral environment of the imine N and hydroxo O with the two axial ligands. The electrochemical reduction of these complexes at a glassy carbon electrode in acetonitrile solution indicates that the first reduction process corresponding to Mn(III)-Mn(II) is electrochemically quasi-reversible. Thermal stability of these complexes was determined by TG and DTG. Layers of these complexes were formed on nanostructure zinc oxide thin film and a red shift was observed when zinc oxide thin film is modified by complex. 相似文献
206.
Purpose
The main objective of this work is to develop an algorithm to use the Lattice Boltzmann method for solving free surface thermal flow problems with solid/liquid phase changes.Approach
A multi-distribution function model is applied to simulate hydrodynamic flow and the coupled thermal diffusion-convection problem.Findings
The free surface problem, i.e. the reconstruction of the missing distribution functions at the interface, can be solved by applying a physical transparent momentum and heat flux based methodology. The developed method is subsequently applied to some test cases in order to assess its computational potentials.Practical implications
Many industrial processes involve problems where non-isothermal motion and simultaneous solidification of fluids with free surface is important. Examples are all castings processes and especially foaming processes which are characterized by a huge and strongly changing surface.Value
A reconstruction algorithm to treat a thermal hydrodynamic problem with free surfaces is presented which is physically transparent and easy to implement. 相似文献207.
Mehdi Yoosefian Heidar Raissi Emad Saleh Nadim Farzaneh Farzad Mustapha Fazli Elham Karimzade Alireza Nowroozi 《International journal of quantum chemistry》2011,111(14):3505-3516
Density functional calculations with Beck's three‐parameter hybrid method using the correlation functional of Lee, Yang, and Parr (B3LYP) were carried out for investigation of the intramolecular hydrogen bond strength in Nitroso‐oxime methane and its derivatives. Also, vibrational frequencies for them were calculated at the same level of theory. The π‐electron delocalization parameter (Q) and as a geometrical indicator of a local aromaticity, the geometry‐based harmonic oscillator measure of aromaticity index has been applied. Additionally, the linear correlation coefficients between substituent constants and selected parameters in R position have calculated. The obtained results show that the hydrogen bond strength is mainly governed by the resonance variations inside the chelate ring induced by the substituent groups. The topological properties of the electron density distributions for O? H ··· O intramolecular bridges have been analyzed in terms of the Bader theory of atoms in molecules (AIM). Correlations between the H‐bond strength and topological parameters have been also studied. The electron density (ρ) and Laplacian (?2ρ) properties, estimated by AIM calculations, show that O ··· H bond have low ρ and negative (?2ρ) values (consistent with covalent character of the HBs), whereas O? H bond have positive (?2ρ) Furthermore, the analysis of hydrogen bond in this molecule and its derivatives by quantum theory of natural bond orbital (NBO) methods fairly support the ab initio results. Natural population analysis data, the electron density, and Laplacian properties as well as υ(O? H) and γ(O? H) were further used for estimation of the hydrogen bonding interactions and the forces driving their formation. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
208.
Elham Safaei Hamid SheykhiAndrzej Wojtczak Zvonko Jagli?i?Anna Kozakiewicz 《Polyhedron》2011,30(7):1219-1224
A glycine derivative of bis(phenol)amine ligand (HLGly) was synthesized and characterized by 1H NMR and IR spectroscopies. The iron(III) complex (LGlyFe) of this ligand was synthesized and characterized by IR, UV-Vis, X-ray and magnetic susceptibility studies. X-ray analysis reveals that in LGlyFe the iron(III) center has a distorted trigonal bipyramidal coordination sphere and is surrounded by an amine nitrogen, a carboxylate and two phenolate oxygen atoms. The mentioned carboxylate group acts as μ-bridging ligand for iron centers of neighbor complexes. The variable-temperature magnetic susceptibility indicates that LGlyFe is the paramagnetic high spin iron(III) complex. It has been shown that electrochemical oxidation of this complex is ligand-centered due to the oxidation of phenolate to the phenoxyl radicals. The LGlyFe complex also undergoes an electrochemical metal-centered reduction of ferric to ferrous ion. The oxygenation of 3,5-di-tert-butyl-catechol, with LGlyFe in the presence of dioxygen was investigated. 相似文献
209.
The two‐dimensional Dirac equation in the presence of vector and scalar Cornell potentials as well as an external magnetic field by a quasiexact methodology are investigated. The closed form of the eigenfunctions is reported and the energy behavior for different states is numerically discussed. 相似文献
210.
In this paper, we consider the prediction problem in two-sample case and study the non-parametric predicting future progressively Type-II censored order statistics based on observed $k$ -records from the same distribution. Also, prediction intervals for progressively Type-II censored spacings are obtained based on $k$ -record spacings. It is shown that the coverage probabilities of these intervals are exact and do not depend on the underlying distribution. Moreover, optimal prediction intervals are derived for each case. Finally, for illustrating the proposed procedure, we consider a real data set and numerical computations are given. The results of Ahmadi and Balakrishnan (Statistics 44:417–430, 2010) can be achieved as special cases of our results. 相似文献