Activity Interaction Coefficients of Si in Cu-Ti-Si Melts at 1550℃

Activitibs of Si in binary Cu-Si and ternary Cu-Ti-Si melts were measured at 1 550℃ by using a method of chemical equilIbrium between gas and liquid. The activity interaction coefficients of Si in the melts have been determined from the experimental data (lny = -5.69. s = 6.69. P2: = -26.22. E; =-43.96) and activity interaction coefficients of Ti in binary Cu-Ti melt at 1550℃ has been estimated from Sommer's data based on the regular solution model (lny =-1 .10. : = 2.95.p:=-2.10).

SOLUBILITY OF Ca IN Mn AND INTERACTION COEFFICIENTS OF Al AND Fe ON Ca IN Mn AT 1350℃

Solubility of Ca in manganese and manganese alloys was measured under sealed conditions at 1350℃.The interaction coefficients of Al and Fe on Ca in Mn were evaluated with the exper- imental data.The standard free energy of liquid Ca in liquid Mn based on the 1 wt-% solu- tion standard was estimated as well.

SELF-INTERACTION COEFFICIENTS OF Ca AND Mg IN DILUTE Sn-BASED SOLUTION

The interaction coefficients of Ca.Ti and Mg in the dilute Sn-based solution have been de- termined at 1500℃.Experimental measurements were taken by equilibrating the slag-alloy systems with metallic Sn as flux and graphite as reducing agent under Ar atmosphere mixed with different portion of CO.It was found that a considerable error may produce if the coefficients of ε_(Ca)^(Ca),ε_(Mg)^(Mg)and ε_(Ti)^(Ti)in the molten Sn were neglected when the activities of the components CaO,MgO and TiO_2 in the slags were estimated by this method.

Parallel Processing Based on Ship Maneuvering in Identification of Interaction Force Coefficients

The parallel processing based on the free running model test was adopted to predict the interaction force coefficients （flow straightening coefficient and wake fraction） of ship maneuvering. And the multipopulation genetic algorithm （MPGA） based on real coding that can contemporarily process the data of free running model and simulation of ship maneuvering was applied to solve the problem. Accordingly the optimal individual was obtained using the method of genetic algorithm. The parallel processing of multiopulation solved the prematurity in the identification for single population, meanwhile, the parallel processing of the data of ship maneuvering （turning motion and zigzag motion） is an attempt to solve the coefficient drift problem. In order to validate the method, the interaction force coefficients were verified by the procedure and these coefficients measured were compared with those ones identified. The maximum error is less than 5%, and the identification is an effective method.

Comparison of Some Methods on Prediction of Activity Interaction Coefficient

Based on Miedema's semiempirical formation enthalpy model for binary alloys, free volume theory and ageneral solution model, a new model for prediction of activity interaction coefficient ε is proposed. The calculatedresults are better in agreement with the experimental values than the two previous models. The related theories andmodels are discussed according to the degree of agreement with experimental values.

THERMODYNAMICS OF Mn-C-j MELTS AT 1350℃

The solubility of C in Mn melt at different contents of Si at 1350℃ was determined.The sol- ubility of Ca in Mn melts containing C in CaC_2 crucible under sealed condition at 1350℃ was ascertained.With these data,evaluation of the activity interaction coefficients e_C^(Si),e_C^C, e_C^(Ca) as well as γ_C^0 was made.The standard free energy of solution of C in liquid Mn based on the 1 wt-% solution standard,formulated in relation to T,was also estimated.Brief dis- cussion was made as to the confiormability of results with those given in the literature.

Concentration and temperature dependence of viscosity of uranium solutions in H2O and 3mol／L HNO3

Viscosities of uranium solutions in H2O and 3 mol/L HNO3 medium were measured by Ubbelhode flow vis-cometer in the concentration range of 0.5%3.0% from 10 篊 to 30 篊 at 5 篊 interval. Viscosity data were interpreted in terms of an empirical equation; h =aoexp(boM+coM2). Values of coefficients ao, bo and co were calculated for all the three systems studied. Flow activation energies and thermodynamic parameters were also evaluated.

Thermodynamics of Fe-P-C in Mn-Based Solutions

The solubilities of carbon in Mn based alloys containing P have been measured at 1 400 ℃ based on X C=0.271 9-0.094 0 X Fe -1.195 4 X P. By means of thermodynamic derivation and calculation, the relative activity coefficients and interactive parameters were derived.

Relationship between Thermodynamic Parameters for Mn-Fe Melt and Temperature

The carbon solubility in Mn-Fe melts were measured at 1350℃,1375℃,1425℃and 1450 ℃,and accordingly the calculated equations were obtained.By thermodynamic derivation and calculation,some relationships between thermodynamic parameters for Mn-Fe melt and temperature were obtained.

Local buckling of thin plate on tensionless elastic foundations under interactive uniaxial compression and shear

This paper uses a mathematical method to develop an analytical solution to the local buckling behaviour of long rectangular plates resting on tensionless elastic Winkler foundations and under combined uniform longitudinal uniaxial compressive and uniform in-plane shear loads. Fitted formulas are derived for plates with clamped edges and simplified supported edges. Two examples are given to demonstrate the application of the current method： one is a plate on tensionless spring foundations and the other is the contact between the steel sheet and elastic solid foundation. Finite element （FE） analysis is also conducted to validate the analytical results. Good agreement is obtained between the current method and FE analysis.

THERMODYNAMICS OF Cu-Ce-I(I=Al,Si,Ti,Fe)LIQUID SOLUTIONS

The iso-activity of[Ce]of samples reached in multiple-hole-graphite crucibles by controlling the oxygen potential through the reaction 2[Ce]+3CO=Ce_(2)O_(3)+3C.Combining conjugate gradient method of solving ill-conditioned equations,the activity interaction coeffients between Ce and Al.Si,Ti and Fe alloying elements were determined.The equilibrium constant of the reaction 2[Ce]+3[O]=Ce_(2)O_(3)and the standard free energy of formation of Ce203 in liquid Cu were obtained at 1.200 C.

EQUILIBRIUM OF Mg-S IN Ni MELTS

The equilibrium of Mg-S in Ni melt was studied by the method of vapour equilibrium in a sealed chamber.At 1530℃ the equilibrium constant of the reaction MgS_(s)=Mg_(Ni)+S_(Ni)and the activity interaction coefficient were determined as K_(MgS)=6.76×10^(-5)and e_S^(Mg)=-9.1.

Thermodynamic Properties of Fe-C-N and Fe-C-B-N Melts

The saturated solubility of carbon and nitrogen in Fe-C-N and Fe-C-B-N melts was measured experimentally at 1 485℃ to obtain the activity interaction coefficients between components in these melts. A new method was used to treat experimental results. Using thermodynamic derivation and calculation, some important interac- tion coefficients between components in these melts were obtained.

Vapor-liquid equilibrium modeling for binary system of R152a/R1234ze(E)

At present,the environment impact of refrigerants has been given attention.The binary mixture R152a/R1234ze(E)is an environmentally friendly refrigerant,which solves problems of poor cooling performance of the R1234ze(E)cycle and flammability of R152a.In order to obtain its basic thermal and physical parameters,it is necessary to carry out vapor-liquid equilibrium(VLE)research,and the cubic equation of states(EOS)is often used in the calculation of the thermodynamic properties of mixtures.In this paper,the VLE predicted models for R152a/R1234ze(E)in the temperature range of 298.15-328.15 K were constructed using Soave-Redlich-Kwong(SRK),Peng-Robinson(PR)equations of state(EOS)combined with van der Waals(vd W),Huron-Vidal(HV)mixing rules,respectively.The equilibrium pressures and vapor-phase mole fractions of the models were obtained by calculation,and all four models presented an extreme correlation with the experimental data.And it can be concluded that the calculated results of the PR+HV model are closer to the experimental data than those of the other three models,with the average absolute deviation of 0.0027 for vapor-phase mole fraction(AAD(ycal))and the average absolute relative deviation of 0.243%for equilibrium pressure(AARD(pcal)),which provides a basis for accurately calculating the thermophysical properties of the mixture R152a/R1234ze(E).

THERMODYNAMIC PROPERTIES OF Fe-V-Ce LIQUID SOLUTION

Thermodynamic properties of the Fe-V-Ce liquid solutions have been studied in the tempera- ture range of 1550-1650℃. The temperature dependences of the equilibrium constants of re- action Ce_2O_2S = 2[Ce]+2[O]+[S] and the standard free energy of formation of Ce_2O_2S have been obtained. The temperature dependences of the interaction coefficients e_v^(Ce) and e_(Ce)~v have also been determined.

Thermodynamics of Fe-C-j (j=Al, Si, P, S) Melts

Based on a proposed method, the mathematical expressions between carbon solubility in Fe-C-j (j=Al, Si, P, S) melts and temperature were obtained. The expressions show the relation of the affecting factors of component j and temperature on carbon solubility, and the activity interaction coefficient of j upon carbon depends on atomic number, covalent radius and electro-negativity. The affecting factors of four elements on carbon solubility are all negative. There is a linear relationship between covalent radius and electro-negativity.

Research of Interaction Force Coefficients Based on Model Test in Loading Condition

It is very difficult,for the component-type ship mathematical model,to estimate the interaction force coefficients among the hull,propeller and rudder. Some coefficients such as wake fraction and flow straightening coefficient were studied from the model tests in diffierent loading conditions and the normal force of rudder was tested in captive model tests to obtain the coefficients. From these results of the tests,the flow straightening coefficients increase with the increase of trims or drafts. Similarly,wake fraction coefficients are larger for the large drafts,however,become small as the trims increase. The resistance is obviously different in fully loaded condition with the trims by stern,however ,the difference is not evident when the draft decreases and the bulbous bow is above the water surface.

Deoxidation of Molten Steel by Aluminum

The deoxidation equilibrium of liquid steel was investigated from a new perspective. Dissolved associate MmOn was used to describe the interaction between dissolved M and dissolved oxygen instead of the interaction parameter of Wagner. The concentration of unassociated oxygen could be considered as the activity of oxygen. Or, the percentage of unassociated oxygen in the total dissolved oxygen was the activity coefficient of oxygen. When the content of deoxidizer was low, the dissolved oxygen was mainly composed of the unassociated oxygen, while more and more MxO formed with gradually increasing M content. The present model gave a good description to the aluminum deoxidation equilibrium after considering AlO and Al2O. Furthermore, the higher the con- tent of A1 was, the higher the content of Al2O relative to the content of AlO would be.

Thermodynamic Properties of Mn-C Melts

Carbon solubility in Mn-Fe melts（xMn=0.161-0.706,xFe=0.034-0.633）was measured experimentally at various temperatures.By thermodynamic derivation and calculation,the relationship between activity coefficient of carbon in infinite dilute solution of manganese in Mn-C system and temperature was obtained.Using Gibbs-Duhem relationship,the experimental results of this study,and experimental data reported in references,the relationship between other thermodynamic properties in Mn-C system and temperature were obtained by thermodynamic derivation and calculation.

Acid-catalyzed heterogeneous reaction of 3-methyl-2-buten-1-ol with hydrogen peroxide

Acid-catalyzed heterogeneous oxidation with hydrogen peroxide（H2O2） has been suggested to be a potential pathway for secondary organic aerosol（SOA） formation from isoprene and its oxidation products. However, knowledge of the chemical mechanism and kinetics for this process is still incomplete. 3-Methyl-2-buten-1-ol（MBO321）, an aliphatic alcohol structurally similar to isoprene, is emitted by pine forests and widely used in the manufacturing industries. Herein the uptake of MBO321 into H2SO4-H2O2mixed solution was investigated using a flow-tube reactor coupled to a mass spectrometer. The reactive uptake coefficients（γ） were acquired for the first time and were found to increase rapidly with increasing acid concentration. Corresponding aqueous-phase reactions were performed to further study the mechanism of this acid-catalyzed reaction. MBO321 could convert to 2-methyl-3-buten-2-ol（MBO232） and yield isoprene in acidic media. Organic hydroperoxides（ROOHs） were found to be generated through the acid-catalyzed route,which could undergo a rearrangement reaction and result in the formation of acetone and acetaldehyde. Organosulfates, which have been proposed to be SOA tracer compounds in the atmosphere, were also produced during the oxidation process. These results suggest that the heterogeneous acid-catalyzed reaction of MBO321 with H2O2 may contribute to SOA mass under certain atmospheric conditions.