Nash模型参数估计的熵法

本文提出了一种Nash模型参数估计方法——熵法。该法以Nash模型的数学表达形式同于Γ分布为基础，应用最大信息熵原理，构造参数估计方程；然后将对数均值展为泰勒级数，并略去高阶项，导出相应的计算公式。通过假想水文资料检验这一方法，并与矩法的估计值相比较，结果表明本文提出的方法优于矩法。     

Isobaric vapour-liquid equilibrium for the binary mixtures of 1-bromobutane with isomeric butanols at 40.0 and 101.3 kpa

A dynamic recirculating still was employed to measure isobaric vapour-liquid equilibrium at 40.0 and 101.3 kPa for the binary systems 1-bromobutane and each of the isomers of butanol. All mixtures show azeotropes at both pressures. The experimental VLE data are thermodynamically consistent and were correlated using Margules, Van Laar, Wilson, NRTL and UNIQUAC equations.     

Electric self‐heating behavior of acetylene carbon black filled high‐density polyethylene composites

The electric self‐heating behavior of carbon black (CB) filled high‐density polyethylene (HDPE) was studied in relation to the time‐dependent current and surface temperature under various voltages and to the voltage‐dependent surface temperature at electric–thermal equilibrium. The resistance increase due to self‐heating restricts the current flow through the sample and thus stabilizes the electric power and the self‐heating temperature to their saturation values, which vary with the voltage. A simple phenomenological model shows that self‐heating at electric‐thermal equilibrium is involved in the initial resistance, the electric field induced positive temperature coefficient (PTC) transition and the heat dissipation. The influences of annealing and irradiation crosslinking on the self‐heating behavior are discussed. Copyright © 2004 Society of Chemical Industry     

Application of an extended Lee-Kesler corresponding-states technique to prediction of vapor-liquid equilibria in multicomponent mixtures containing polar components

Mixing rules for an extended Lee-Kesler (ELK) corresponding-states method for prediction of thermodynamic properties are presented. The mixing rules, which do not contain adjustable parameters, permit calculation of vapor-liquid equilibria in mixtures containing one or more polar components. While a single heat-of-mixing datum may be included for strongly associating components, generally only pure component properties are used in the calculations. A comparison of calculated bubble-point pressures and equilibrium vaporization ratios to experimental values is made for 26 ternary mixtures (791 points) and 5 quaternary mixtures (175 points). Bubble-point pressures are predicted quite well with ELK (9.1 % AAD for ternaries and 7.9% for quaternaries). Composition predictions are difficult to compare in multicomponent systems, but ELK predictions appear to be acceptable on both a system-by-system and an overall AAD basis.Paper presented at the Tenth Symposium on Thermophysical properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

化学当量法研究季铵型树脂在含铀酰的硫酸盐溶液中的吸附平衡

关于强碱性季铵型阴离子交换树脂在铀酰的硫酸盐溶液中吸附平衡的研究,虽然有不少报道。但是,对于组成接近铀水冶条件的溶液中吸附平衡的研究是相当不充分的。本文采用化学当量法研究了上述树脂在这种溶液中的吸附平衡。 强碱性季铵树脂从铀酰的硫酸及硫酸钠溶液中吸附UO_2(SO_4)_3~(4-),UO_2(SO_4)_2~(2-),SO_4~(2-)及HSO_4~-四种离子。我们用硝酸钠溶液将它们一起洗脱下来,测定相应组分的含量。由于     

Phase equilibrium in the system water-hydrogen sulphide: Experimental determination of the LLV locus

Experimental data are presented for the liquid-liquid-vapour (LLV) equilibrium for the system water-hydrogen sulphide. Conditions ranged from the hydrate-liquid-liquid-vapour quadruple point (29.4°C and 2.23 MPa) to beyond the critical temperature of hydrogen sulphide (100.3°C). The maximum temperature at which three phases can exist is 106.2°C at 9.39 MPa. This is 6°C higher than previously believed.     

On chemical equilibrium of pseudo-one-element systems: Application to oligomerization

For a chemical system involving reacting species (such as oligomers) whose molecular formulae are of the form [(E₁)_a1 (E₂)_a2 … (E_M)_aM]n, where E is an element, both the equilibrium distribution and sensitivity analysis can be computed as for a one-element system. The resulting simplification means that the former requires the solution of a single polynomial equation, and the latter allows explicit calculation of the relevant sensitivity coefficients. The treatment is illustrated for the catalytic oligomerization of olefins.     

Two-phase solvent extraction of canola

The equilibrium relationships in the extraction process that was developed in our research laboratory for the treatment of canola were studied. In the process, hexane is used as well as CH₃OH that contains 5% (vol/vol) H₂O and 0.08% (w/w) NaOH to simultaneously produce improved meal and high-quality oil. Equilibrium data for canola oil in the hexane-CH₃OH/H₂o/NaOH, meal-hexane, and meal-CH₃OH/H₂O/NaOH-hexane systems are reported. A high partition coefficient for oil between hexane and the polar phase provided a large driving force for mass transfer. The presence of the CH₃OH phase improved oil extraction, probably by rupturing the cell structure. The process proved to be a somewhat less desirable replacement for CH₃OH/H₂O/NH₃ extraction and recovered 93.5% of the oil and 91.8% of the protein in the seed, while with CH₃OH/H₂O/NH₃, the oil and protein recoveries were 96.8 and 94.0%, respectively. The NaOH treatment removed only 50.2% of the glucosinolates, and some of the oil was hydrolyzed by the NaOH, making the process less effective, despite its simplicity.     

Re‐evaluation of the Optimal Operating Conditions for the Primary End of an Integrated Steel Plant using Multi‐objective Genetic Algorithms and Nash Equilibrium

Some existing work on optimizing the operational cost of the primary end of an integrated steel plant containing two blast furnaces utilizing both pellets and sinters, an electric furnace and a basic oxygen furnace was further advanced using a multi‐objective genetic algorithm, along with a Nash equilibrium analysis. The new formulation was able to improve the earlier results very significantly, suggesting the efficacy of the multi‐objective approach over the more conventional single objective genetic algorithms.     

Saturated Humidity, Entropy, and Enthalpy for the Nitrogen-Water System at Elevated Temperatures and Pressures

A model is used to calculate saturated thermophysical properties (humidity, entropy, and enthalpy) of a nitrogen-water mixture at elevated temperatures and pressures. In the model, a modified Redlich–Kwong equation of state is used to calculate fugacity coefficients for the vapor phase, and the liquid phase follows Henry's law. The model has been investigated by comparing the calculated results with the available experimental data. The comparison shows that the model can be used to calculate saturated thermodynamic properties for the nitrogen-water mixture reliably up to 523.15 K and 300 bar.