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51.
Suleiman IA Radny MW Gladys MJ Smith PV Mackie JC Kennedy EM Dlugogorski BZ 《Physical chemistry chemical physics : PCCP》2011,13(21):10306-10311
The effect of chlorine (Cl) chemisorption on the energetics and atomic structure of the Cu(001) surface over a wide range of chlorine pressures and temperatures has been studied using equilibrium ab initio atomistic thermodynamics to elucidate the formation of cuprous chloride (CuCl) as part of the Deacon reaction on copper metal. The calculated surface free energies show that the 1/2 monolayer (ML) c(2 × 2)-Cl phase with chlorine atoms adsorbed at the hollow sites is the most stable structure for a wide range of Cl chemical potential, in agreement with experimental observations. It is also found that at very low pressure and exposure, but elevated temperature, the 1/9 ML and 1/4 ML phases become the most stable. By contrast, a high coverage of Cl does not lead to thermodynamically stable geometries. The subsurface adsorption of Cl atoms, however, dramatically increases the stability of the 1 ML and 2 ML adsorption configurations providing a possible pathway for the formation of the bulk-chloride surface phases in the kinetic regime. 相似文献
52.
Maria C. Blanco Diego G. Franco Yamile Jalit Elisa V. Pannunzio Miner Graciele Berndt Andrea Paesano Jr. Gladys Nieva Raúl E. Carbonio 《Physica B: Condensed Matter》2012,407(16):3078-3080
The samples Bi2BB′O7, with B=Cr and Fe and B′=Nb, Ta and Sb were prepared by solid state method. The crystallographic structure was investigated on the basis of X-ray powder diffraction data. Rietveld refinements show that the crystal structure is cubic, space group Fd-3m. The Bi3+ cation on the eight-coordinate pyrochlore A-site shows displacive disorder, as a consequence of its lone pair electron con?guration. There is also a considerable A-site disorder shown by Rietveld Analysis and confirmed in the case of the iron containing samples with Mössbauer spectroscopy. The magnetic measurements show paramagnetic behavior at all temperatures for the Cr oxides. The Fe pyrochlores show antiferromagnetic order around 10 K. 相似文献
53.
Clayane Carvalho dos Santos Marcelo de Assis Thales Rafael Machado Paula Fabiana dos Santos Pereira Gladys Minguez‐Vega Eloisa Cordoncillo Hector Beltran‐Mir Carlos Doate‐Buendía Juan Andrs Elson Longo 《Particle & Particle Systems Characterization》2019,36(6)
In this work, for the first time, the instantaneous nucleation and growth processes of Ag nanoparticles on Ag3PO4 mediated by femtosecond laser pulses are reported and analyzed. The investigated samples are pure Ag3PO4 sample, electron‐irradiated Ag3PO4 sample, and laser‐irradiated sample. Complete characterization of the samples is performed using X‐ray diffraction (XRD), Rietveld refinements, field emission scanning electron microscopy, and energy dispersive spectroscopy (EDS). XRD confirms that the irradiated surface layer remains crystalline, and according to EDS analysis, the surface particles are composed primarily of Ag nanoparticles. This method not only offers a one‐step route to synthesize Ag nanoparticles using laser‐assisted irradiation with particle size control, but also reports a complex process involving the formation and subsequent growth of Ag nanoparticles through an unexpected additive‐free in situ fabrication process. 相似文献
54.
G. Ooms C. Poelma P. Poesio MJ.B.M. Pourquie J. Westerweel 《International Journal of Multiphase Flow》2008
In an earlier publication some of the authors presented a theoretical model for the calculation of the influence of particle inertia and gravity on the turbulence in a stationary particle-laden flow. In the present publication the model is extended for application to a decaying suspension. Also a comparison is given between predictions made with the model and experimental data (own data and data reported in the literature) on a decaying turbulent flow with particles in a water tunnel or in a wind tunnel. For most of the experiments a prediction with reasonable accuracy and an interpretation is possible by means of the model. 相似文献
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Ysaías J. Alvarado José Caldera-Luzardo Gladys Ferrer-Amado Victoria Mancilla-Labarca Elba Michelena 《Journal of solution chemistry》2007,36(1):1-11
High-precision densitometry and high-accuracy refractometry measurements of extremely dilute solutions of the thiophene-2-
(TCPH), pyrrole-2- (PCPH) and furan-2-carboxaldehyde-phenylhydrazone (FCPH) compounds in acetonitrile have been obtained at
293.15 K. The partial molar volumes V
2^∞ of each compound at infinite dilution were determined. The apparent molar refraction of these solutes at infinite dilution
at 293.15 K has been experimentally determined within the Kohner-Geffcken-Grunwald-Haley approximation. The volumetric and
refractometric results were interpreted in terms of the Pauling electronegativity and intrinsic molar volume of the heteroatom,
and the aromaticity of the heterocyclic rings. The experimental results indicate that solute-solute interactions are negligible
within the concentration range studied. Theoretical calculations at the DFT-B3LYP/6−311++G(3d,3p) level of molecular volumes
support the interpretation that the volumetric contribution from the solute-solvent interactions to the limiting partial molar
volumes of solutes are very small and thus solute molecules are isolated in this medium. 相似文献
60.
Matrix modification with ammonium nitrate, ammonium dihydrogen-phosphate and Triton X-100 proved suitable. Optimization of the graphite furnace parameters allowed cadmium to be quantified at 800°C. The response was 0.1 μgl-1 for 1% absorption, and the relative standard deviation for consecutive determinations of a urine containing 1.5 μg Cd l-1 was 4%. Urinary cadmium levels of 0.4–1.8 μg l-1 were found in five occupationally unexposed persons. 相似文献