The effect of flow oscillation to the mass transfer between turbulent fluid and solid wall was investigatedby measuring the mass transfer rate between fluid and pipe wall with imposed oscillating flow usingelectrochemical method.The velocity and concentration field in the viscous sublayer which controls the mass trans-fer in such a process was simulated by a simple wave model of single harmonics.Experimental results confirmthat the flow oscillation has no influene on time averaged mass transfer rate,but the phase difference betweenphase averaged velocity field and concentration field shifts with the frequency of imposed oscillating flow.Numeri-cal analysis reveals that the concentration boundarylayer which is responsible for the mass transfer is muchthinner than the viscous sublayer which greatly weakens the influence of imposed oscillating flow on mass transfer.

The crystal size distribution(CSD)was determined with small angle X-ray scattering technique.Theanticoking property of Ni-catalysts was investigated with the steam reforming of n-heptane in a TG-monitoredflow reactor.The results of this study show that the rate of coking on the supported Ni-catalysts depends main-ly on the percentage content of the large size fraction(25-70nm)of Ni-crystallites,and that the dispersion ofNi-crystallites and the anticoking property of the Ni/α-Al_2O_3 catalysts were promoted obviously by theLa_2O_3-modification method.The variation of the Ni-CSD and the anticoking property of the catalysts were fur-ther tested through different periods of hydrothermal treatment.It is found that the content of the largeNi-crystal size fraction and the coking rate pass correspondingly through a maximum.

The generalized van der Waals(vdW)equation of state was proposed by Schmidt and Wenzel(1980)and later modified by Iwai,Margerum and Lu to improve its calculations of pure component liquid densities forthe polar fluid.In this paper,we present a modified vdW equation of state by introducing a new temperaturefunction for representing α(T)and considering u to be dependent on pure component property.

The UNIQUAC excess Gibbs energy model of Abrams and Prausnitz(1975)is extended to represent thevapor-liquid equilibria of polymer solution with only two adjustable parameters.Discussions on the application ofthe Staverman-Guggenheim and the Flory-Huggins combinatorial contribution in the UNIQUAC model are givenin this paper.The UNIQUAC model with either Staverman-Guggenheim or Flory-Huggins combinatorial expres-sion presents results with about the same accuracy for polymer solutions.Comparisons between the UNIQUAC model and the Flory equation show that theUNIQUAC model can give some better results than the Flory equa-tion in general.

Hydrophobic membrane can provide fast mass transfer for absorption-desorption of gasesform liquid to absorbent.The removal of ammonia from ammonia water and absorption with dilutesulphuric acid was studied in a pilot plant with polypropylene hollow fiber column,The removalrate and influences of operation temperature,flow rate and concentration on mass transferperformances were discussed mathematically.Experimental results and computer calculation show thatthe ammonia removal rate is not affected by the feed concentration for a given system.Both partialand overall mass transfer coefficients vary along the axis of the fiber,and the mass transfer for themembrane process is controlled by membrane resistance.

The aqueous two-phase system of PEG-4000/K_3PO_4 is selected to extract interferon-γ(γ-IFN)from the broth of homogenized E.coil cells,which were recombined genetically and werefermented in high expressivity.The effects of pH value and the concentrations of PEG and phos-phate on the partition behavious of γ-IFN and contaminating proteins have been investigated.Theresults show that the pH value is the most influential factor effecting the extraction yield of γ-IFN.Under a suitable condition,an effective separation with high yield of γ-IFN can be achieved.

Extraction equilibria of three low volatility liquids (benzyl alcohol,2-phenethyl alcohol and citronellol)separately with supercritical CO_2 were determined in a semi-flow apparatus at two temperatures(308.2K and318.2K)and pressures up to 20MPa.The solubility data of CO_2 in methyl benzoate were also obtained at thetwo temperatures in two-phase region.The experimental data were correlated by means of the Peng-Robinsonequation of state with two characteristic parameters.