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[en] Highlights: • Low-lying electronic states of the AlC and GaC molecules. • Transition probabilities and radiative lifetime. • Molecular constants. The electronic states correlated to the first dissociation channel, around 25,500 cm−1, of the AlC and GaC molecules have been investigated by CASSCF/MRCI methodology with aug-cc-pV5Z basis set. Our work focused on the accurate description of the potential energy curves, dissociation energies, transition moment functions, radiative lifetimes, dipole moments and molecular constants. The B4Σ− electronic state has been previously detected for AlC molecule and it is probably not detectable in GaC molecule due to the predissociative character which affects all its vibrational levels. The characterization of the GaC low-lying electronic states were carried out for the first time.
[en] In this study we demonstrate that the activity of phosphoros and antimony shallow donors in n-type Ge is passivated by hydrogenation in a remote dc H plasma treatment. The passivation of the shallow impurities is correlated with the formation of electrically inactive P–H and Sb–H complexes. Using reverse bias annealing (RBA) we demonstrate that the complexes dissociate at temperatures slightly above room temperature. The dissociation follows first-order kinetics and the dissociation enthalpy of the P–H and Sb–H complexes was found to be 1.45±0.06 eV and 1.51±0.07 eV, respectively. The RBA experiments confirm the presence of the negatively charged H in n-type Ge. (paper)
[en] Highlights: ► Solubility of fluoromethane in water as a function of (T, p) was observed. ► Liquid + hydrate + vapor phase equilibrium of the system was observed. ► Ice + hydrate + vapor equilibrium of the system was observed. ► Dissociation enthalpies were found for both equilibria. ► Stoichiometry of fluoromethane hydrate was determined. - Abstract: A study of the (fluoromethane + water) system was conducted at temperatures between 255 K and 298 K, and pressures from 0.09 to 2.6 MPa. The solubility of fluoromethane in liquid water was measured from 280 K to 298 K, at pressures up to the hydrate formation pressure. The p–T behavior of the liquid + hydrate + vapor (LHV) three-phase equilibrium was measured from 273 K to 295 K. The p–T behavior of the ice + hydrate + vapor (IHV) three-phase equilibrium was measured from 251 K to 273 K. The intersection of the LHV and IHV curves was used to find the lower quadruple point, Q1, at T = 272.55 K and p = 0.2442 MPa. Solubility-corrected enthalpies of dissociation were determined at the lower quadruple point using the Clapeyron equation. The de Forcrand method was used to determine the hydration number of the hydrate at Q1. The results show that not all of the cages in the SI hydrate structure are filled.
[en] We study analytically as well as numerically the role that large-amplitude vibrations play during the process of molecular dissociation. Our model consists of a linear three-atom molecule composed of identical atoms interacting with their nearest neighbors by Morse potentials. We find a close relation between energy localization and bond breaking and evaluate numerically the corresponding reaction paths
[en] The energy transfer reactions involved in the isotope separation of molecular mixtures by selective two-step photodissociation are discussed. Results of computer experiments show the validity of the theoretical model. Isotope enrichment may be predicted. (author)
[en] We study various compounds resulting from the interaction of UO2F2 with H2O and HF (gas), and various triple compounds UO2F2 - H2O - HF; the conditions of decomposition and the thermodynamic limits of stability are specified. (author)
[fr]Nous etudions divers composes formes par reaction de UO2F2 avec H2O et HF (gaz) et divers composes triples UO2F2 - H2O - HF, en essayant de preciser les decompositions et domaines d'exisfence thermodynamiques de ces corps. (auteur)
[en] We have stored positively charged fullerene ions Cn+ (n even, from 48 to 70 and 76), C602+ and C702+ in an electrostatic storage ring and have measured the rate of emission of neutral fragments as a function of time. In the time range of the measurements, 50 μs to a few milliseconds, the rate decreases strongly due to radiative cooling of the molecules. Using the cooling rate predicted from a dielectric model, we have extracted the dissociation energies for C2 loss from the measurements. As expected, the energies are largest for the 'magic' fullerenes, C50, C60, and C70, and the value of 9.8±0.1 eV for C2 loss from C60+ is in reasonable agreement with theory and with other recent experiments
[en] To compile the tables of reference data on nitrogen dioxide thermal conductivity in liquid and gas phases one needs to obtain the thermal conductivities at intermediate parameters. The problem specified is to construct the experimental data integration that would allow to calculate the thermal conductivities not covered by the experiment with the accuracy acceptable for engineering calculations. A semiempirical expression for thermal conductivity coefficients of gas mixture formed during dinitrgen tetroxide dissociation is obtained. The equation describes experimental data in the temperature range of 300-650 K and pressure range of 0.1-10 MPa as well as the thermal conductivities at the saturation line from the vapour side up to the temperatures of 430 K. The equation can be applied for compiling reference data tables and engineering calculations