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51.
52.
本文着重于辐射作用于物质最初生成的产物,包括激发态的离子与分子,能量超过热能的次级电子等的反应以及电荷和激发能的转移,并试图论述它们的最新发展。 相似文献
53.
D. L. Wakefield 《International Journal of Thermophysics》1988,9(3):365-381
This paper is the final in a series of three viscosity and density studies of pure n-alkanes and selected binary and quaternary mixtures. A standard U-tube viscometer was used for viscosity measurements, and a Pyrex flask-type pycnometer was used for density determinations. Results are given here for pure alkane and selected binary mixtures of n-tetradecane + n-octane, for selected quaternary mixtures of n-hexadecane + n-dodecane + n-decane + n-hexane, and for pure and selected quaternary mixtures of n-hexadecane + n-dodecane + n-nonane + n-heptane at 303.16 and 308.16 K. The principle of congruence was tested, as was the Grunberg and Nissan equation, as they have been shown to be useful as prediction techniques for other n-alkane binary mixtures. Comparisons were made between the two groups of quaternary alkane mixtures and the binary n-tetradecane + n-octane mixtures of the same pseudo composition to understand better the dependence of mixture viscosities on the composition parameter. 相似文献
54.
A new method has been developed for predicting liquid activity coefficients in ternary mixtures from group contributions. In this method, activity coefficients are obtained from the excess Gibbs free energy of mixing at constant temperature and pressure. In calculating this excess function, the constituent and mixture Gibbs free energies are each represented by an expansion about a pure reference fluid in powers of ratios of hard-sphere diameters and molecular attraction parameters. When the pure component differs from the reference by a single structural group, these ratios represent, respectively, the size contribution and the attraction contribution of this group to the thermodynamic property of the pure fluid. Contributions of intermolecular repulsion to the excess Gibbs free energy are calculated directly from hard-sphere equations of state for the mixture and pure components. The effect of polar contributions calculated by a Padé approximant is also examined. Results indicate that the method developed from the hard-sphere expansion corresponding-states theory is useful for predicting activity coefficients in ternary mixtures when unlike-pair interaction parameters are fitted to binary activity coefficient data. Furthermore, the method shows promise in providing a theoretical basis for applying group contributions to activity coefficients.Nomenclature
A
Residual Helmholtz free energy
-
C
p
Constant-pressure heat capacity
- H
vap
Heat of vaporization
-
P
s
Saturated vapor pressure
-
R
Gas constant
-
T
Temperature
-
U
HS
Hard-sphere internal energy
-
V
c
Critical volume
-
V
L
Liquid volume
-
x
Dimensionless residual thermodynamic property
-
Z
Compressibility factor
-
d
Center-to-center distance between two touching molecules
-
k
Boltzmann constant
-
n
Moles
-
x
Liquid mole fraction
-
y
Vapor mole fraction
-
Volume expansivity
-
Liquid activity coefficient
-
Minimum molecular attraction potential
-
Isothermal compressibility
-
Permanent dipole moment
-
3.14159...
-
Density
-
Fugacity coefficient
Paper presented at the Ninth Symposium on Thermophysical Properties, June 24–27, 1985, Boulder, Colorado, U.S.A. 相似文献
56.
57.
58.
K. G. Shkadinskii N. I. Ozerkovskaya S. V. Kostin 《Combustion, Explosion, and Shock Waves》2004,40(3):285-294
The specific features of dynamics of the thermal explosion in systems porous reagent–active gas–solid product under conditions where the heattransfer and masstransfer regions are separated from the ambient medium are considered. In addition to the competition of heat release and heat removal, the process of initiation of exothermal chemical interaction in these systems under normal pressures depends significantly on conditions of filtration transport of the gaseous reagent. The induction and postinduction periods of the thermal explosion are studied. The theoretical analysis of thermalexplosion issues is supplemented by an experimental study of the process for the porous titanium–nitrogen–titanium nitride system. 相似文献
59.
通过对离子膜电解槽停车泄料时发生的闪爆事故的分析,找出引起闪爆事故的主要原因是由漏入的氯气和氢气在A槽阳极室内达到爆炸极限后遇到尖端的放电造成的电火花所致。同时分析了A槽槽电压升高的原因,介绍了预防事故发生的措施。 相似文献
60.
1 INTRODUCTIONThe CSP(Corresponding States Principle)has been considered to be a useful methodfor the prediction of fluid properties from a minimum amount of information.One ofits form,the shape factor methods is developed through relating the pVT of any interestedpure fluid"a"to that of another"0"by writing 相似文献