Jan 19, 2018Open AccessArticle
Dimethyl ether is a kind
of clean fuel, which is expected to replace traditional fuel to achieve high
efficiency and low emission. The research of hydrogen production by vehicle
dimethyl ether reforming is imminent. This article summarizes and comments the
progress of hydrogen production by dimethyl ether reforming, briefly analyzing
new method of preparing catalyst. Three existing methods for
Nov 17, 2017Open AccessArticle
A CFD (computational fluid dynamics) model has been presented to simulate the steam reforming reaction of DME in this study. A three-dimensional numerical model introduced by the commercial software COMSOL was used to investigate the fluid flow of reformer bed and heating tubes, the energy transport of reformer bed and heating tubes, and the mass transport of reformer bed. The governing equations in the model consist of conservati
Oct 27, 2014Open AccessArticle
The electrostatic and Born-Mayer repulsive
potentials method was used to calculate the higher order elastic constants and
pressure derivatives of alkaline-earth oxide CaO in a wide temperature range
(100 - 1000 K). The calculations have been made starting from primary physical
parameters viz. nearest-neighbour
distance and hardness parameter assuming long- and short- range potentials. The
different results of the calculations are compared with experimental data and
Jun 23, 2014Open AccessArticle
report ab initio studies of the
dipole polarizabilities (α) and first
static hyperpolarizabilities (β) for
a set of substituted hexatriene in which electron donating (D) and electron
accepting (A) groups were introduced either end parts of the hexatriene chain
NO2-(CH=CH)3-D. Geometries of all molecules were
optimized at the Hartree-Fock HF/6-311 G(2d,p) level of theory.
Polarizabilities of these molecules w
Jun 16, 2014Open AccessArticle
The first investigation and analysis of 59Co 2D NMR homonuclear chemical shift correlation spectra for a ruthenium-based tetrahedral mixed-metal cluster HRuCo3(CO)11(PPh3) are reported. For this cluster in solution and by contrast to the conventional COSY NMR experiment, the double-quantum filtered (DQF) COSY NMR spectrum proves the existence of a scalar coupling constant between 59Co nuclei. In order to obtain a value of this coupling, the 2D COSY spectrum for a three-spin 7/2 AX2 system has be...
Jun 06, 2014Open AccessArticle
The structure and formation energies of cation antisite defects for a series of stannate pyrochlores A2Sn2O7 (A = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Lu, and Y) and titanate pyrochlores A2Ti2O7 (A = La, Sm, Gd, Tb, Dy, Ho, Er, Lu, and Y) have been systematically investigated using the first-principles total energy calculations. The calculated results reveal that the lattice parameters increase and the oxygen positional parameters decrease with increasing ionic radii of the lanthanides in the...
Jun 03, 2014Open AccessArticle
In this theoretical study we used density functional theory to calculate the molecular structures of Silver Halo compound, AgF3. The molecular geometry, vibrational frequencies, energies and natural bond orbital (NBO) in the ground state are calculated by using the DFT (B3LYP) methods with LANL2DZ. The T.S guesses were generated by the linear synchronous transit method, at the DFT implemented on Gaussian 98 program. The geometries and normal modes of vibrations obtained from B3LYP calculations a...
May 28, 2014Open AccessArticle
Calculation of electron correlation energy in molecules involves a very important computational effort, even in the simplest cases. Nowadays, using the new parallel libraries (PETSc and SLEPc) and MPI, we can resolve this calculation faster and with very big molecules. This result is a very important advance in chemical computation.