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1.
The thermal functions S0T, -(G0T-H0O)/T and (H0T-H0O) have been calculated from structural and spectroscopic data for the gaseous organometallics C5H5BeX (X = Cl, Br and BH4), C5H5MX3 (M = Ti and Ge; X = Cl, Br and I) and CH3TiX3 (X = Cl, Br and I). The rotational barriers of the C5H5 and CH3 groups have been evaluated and discussed. 相似文献
2.
Using three different techniques, the vapour pressure of α-iodonaphthalene was measured in the temperature range 322–422 K. The pressure equation log P(kPa) = 8.82 ± 0.29 ? (3719 ± 300) /T, was determined. The enthalpy of vaporization change, ΔH0298 = 69.4 ± 4.0 kJ mole?1, was determined as the average of the results obtained by second-and third-law treatment of the experimental data. Antoine's constants, A = 6.258, B = 2010 and C = 171, were also derived. 相似文献
3.
V. Pelino F. Pegoraro 《Communications in Nonlinear Science & Numerical Simulation》2012,17(5):2122-2131
The basic properties of planetary flows are studied within the framework of the noncanonical Hamiltonian approach formulated by Morrison. A zonal-symmetric decomposition is applied in order to characterize the contributions of the different dynamical terms. Steady states and the Lorenz energy and angular momentum cycles are also written within the Lie-Poisson bracket formalism. 相似文献
4.
L. Barbieri A. Karamanov A. Corradi I. Lancellotti M. Pelino J. Ma. Rincon 《Journal of Non》2008,354(2-9):521-528
Vitrification by melting is being proposed as a convenient method to solidify different kinds of silicate and other oxide-based inorganic wastes. Incinerator bottom and fly ashes have been mixed with glass cullet, feldspar and clay by-products as melting fluxing agents. Washing, drying, and grinding pre-treatments followed by melting at 1450 °C lead to the formation of glasses and glass-ceramics, depending on the starting materials composition and thermal treatment. The obtained glasses have been studied by SEM, chemical durability tests in aqueous and alkaline environment, leaching test (UNI 10802), and by differential thermal analysis. The glass-ceramics morphology was investigated by XRD and SEM. The results were explained by the structure of the glasses caused by the presence of different amount of modifiers in the glassy lattice. The obtained glasses show good chemical resistance, in particular in alkaline environment and thermal characterization highlighted that the materials are also suitable to obtain glass-ceramics. 相似文献
5.
The vapor pressures of benzoylferrocene and 1,1′-dibenzoylferrocene were measured by torsion-effusion technique. The following pressure-temperature equations were derived benzoylferrocene log P(kPa) = 10.75±0.22?(5314±82)/T 1,1′-dibenzoylferrocene log P(kPa) = 9.29±0.24?(4898±91 )/T Second-law treatment of the experimental data yielded the sublimation enthalpies for benzoylferrocene and 1,1′-dibenzoylferrocene: ΔH0sub,298 = 116.3±6.0 kJ mole?1 and ΔH0sub,298 = 109.3±6.0 kJ mole?1 respectively. Thermal functions of these compounds were also estimated. 相似文献
6.
By using different techniques the vapor pressure of ferrocene, mono-acetyl ferrocene and 1,1′-di-acetyl ferrocene was measured. The following pressure—temperature equations were derived ferrocene log P(kPa)= 9.78 ± 0.14 ? (3805 ± 46)/T mono-acetyl ferrocene log P(kPa) = 14.83 ± 0.14 ? (5916 ± 48)/T 1,1′-di-acetyl ferrocene log P(kPa) = 8.82 ± 0.11 ? (4289 ± 44)/T By second- and third-law treatment of the vapor data the ΔH0sub,298 = 74.0 ± 2.0 kJ mole?1 for the sublimation process of ferrocene was calculated and compared with the literature data. For the sublimation enthalpy of mono- and 1,1′-di-acetyl ferrocene the values ΔH0sub,298 = 115.6 ± 2.5 kJ mole?1 and ΔH0sub,298 = 91.9 ± 2.5 kJ mole?1 were derived by second-law treatment. Thermal functions of these compounds were also estimated. 相似文献
7.
Glass-ceramic materials, obtained by sinter-crystallization of melted alkaline-olivine basaltic tuffs, were investigated. The kinetics of bulk crystallization was evaluated by differential thermal analysis (DTA) at different heating rates. The phase formation and the sintering behavior of glass powders (<75 μm) were studied in air and in nitrogen atmospheres by DTA and dilatometry, respectively. The crystalline phases formed were identified by X-ray diffraction. The DTA traces showed an unusual phase formation behavior with a higher crystallization trend for the bulk samples. The crystallization activation energy was evaluated as 590 ± 20 kJ/mol in the range 1080–1110 K. A value of about 3 of the Avrami constant, corresponding to three-dimensional growth on a fixed number of nuclei, was evaluated by Ozawa and Augis–Bennet methods. The densification at low-temperatures is reduced by the intensive crystallization process in both air and nitrogen atmospheres. The sintering starts again at 1150–1250 K. In air atmospheres, due to the FeO oxidation, the sintering temperature increases and the percentage of formed crystal phase decreases by 15–20%. 相似文献
8.
M.?GianfeliceEmail author F.?Maimone V.?Pelino S.?Vaienti 《Communications in Mathematical Physics》2012,313(3):745-779
Lie-Poisson structure of the Lorenz’63 system gives a physical insight on its dynamical and statistical behavior considering
the evolution of the associated Casimir functions. We study the invariant density and other recurrence features of a Markov
expanding Lorenz-like map of the interval arising in the analysis of the predictability of the extreme values reached by particular
physical observables evolving in time under the Lorenz’63 dynamics with the classical set of parameters. Moreover, we prove
the statistical stability of such an invariant measure. This will allow us to further characterize the SRB measure of the
system. 相似文献
9.
Youssef M. Quinelato A. Youssef F. Pelino J. E. Pelizon Salvadori M. C. Mori M. 《Laser Physics》2008,18(4):472-477
We compare an ultrasound bur with a conventional one and an Er:YAG laser for cavity preparations. Human molars were embedded in resin and sliced for this study. The surface abrasion was performed by a high-speed instrument and ultrasound. The cavity preparation was initially performed with a high-speed diamond bur. After this, a 2.94-μm laser with 400 mJ/pulse at 4 Hz, and a pulse width from 250–500 μs was applied to the tooth surface for 30 s in a sweeping motion. The samples were analyzed by SEM. The abrasion surface with a conventional bur showed structure removal with different grooves, a smear-layer presence, and occluded dentinal tubules. The abraded surface with the CVD bur suggested a removal process in layers. The laser-irradiated surface showed a rough aspect with opened tubules and the absence of a smear layer. The results of this study suggest that a high-speed diamond bur, ultrasound, and laser were able to perform cavity preparation. However, the CVD bur presented a higher surface quality. 相似文献
10.
In the present work, the influence of the nucleation time-lag on the non-isothermal glass crystallization is discussed. Differential thermal analysis (DTA) results of an iron-rich glass nucleated by Cr2O3 were obtained at different heating rates. The activation energy of crystallization, Ec, and the Avrami parameter, m, estimated by Kissinger's and Ozawa's equations were shown to be dependent on the heating rate. The value of Ec, obtained at 2.5, 5 and 7.5 K/min heating rates was calculated as 299 kJ/mol, while the value of Ec, obtained at 10, 15 and 20 K/min was as 499 kJ/mol. The value of m for ‘low' and ‘high' heating rates were 2.57 and 1.45, respectively. The results were interpreted on the basis of the non-steady state nature of the nucleation process. It was assumed that at high heating rates no nucleation takes place and the crystals grow on a existing fixed number of nuclei; the activation energy of crystal growth, Eg, can be estimated by applying the Kissinger equations. At low heating rates nucleation occurs and the number of nuclei formed is influenced by the heating rate; Eg can be estimated by the Matusita and Sakka equation. 相似文献