The Two-fluid Model of Turbulent Buoyant Recirculating Two-Phase Flow

Taking refined forecasting model of oil pollution as basic target,this pa-per widely deals with the theory and method of refined simulation of turbulent two-phaseflow.The two-fluid model of turbulent buoyant recirculating two-phase flow and the cor-responding method of numerical computation are developed in this paper.The motion ofeach phase is described by a unified multi-fluid model in an Eulerian coordinate system.The laws of turbulent transportation for each phase,and the restriction of each other be-tween the two phases are completely simulated.The complex two-phase turbulence withbuoyancy and recirculating flow is selected to examine numerically.Comparison of the re-sults of numerical simulation with the experimental data is conducted.Then the forecastsfor oil-water two-phase turbulence are carried out.It has been shown that the results ofnumerical simulation are satisfactory.

Structure Analysis of Streptococcal Protein G Fc Binding Domain

The gene fragment (191 bp) encoding protein G IgG Fc binding domain was isolated by PCR from group G streptococcus (CMCC32138), and a clone containing this gene fragment was found to give fine reactivity to human IgG when expressed in Escherichia coli. The complete nucleotide sequence of the gene fragment was determined. One base pair differs from previously reported protein Gnucleotide sequences, and resultsin an amino acid change (Ala-Thr), but this variation makes no difference in binding to the IgG Fc part by ELISA.The secondary structure of the protein G IgG Fc binding domain has been estimated by circular dichroism and assigned by computer algorithm.It shows a typical α-helix region in this domain.By breaking this α-helix region with recombinant DNA techniques, a 44 peptide, which contained the N-terminal 27 amino acid residues of this domain, was expressed in E. coli and showed no reactivity to IgG.The hydropathicity of this domain was also analyzed and compared with that of protein A relevant domain. Some similarity was found. These results suggest that the binding mechanism of protein G to the IgG Fc part depends on hydrophobic action which comes from the α-helix in protein G molecule, just as protein A binding to IgG Fc part.

Predictable component analysis of a system based on nonlinear error information entropy

Based on the theory of information entropy concerning nonlinear errors, the growth rules for the nonlinear errors of the Lorenz system and its predictable components are studied. The results show that the impact of the uncertainties, both in the initial error and in the system itself, needs to be considered in a quantitative estimation of the system predictability. The nonlinear error growth is related to the magnitude of the initial error, and to the spatial distribution of the initial error vectors. Even if these initial errors have the same magnitude but different directions, there are also differences in the nonlinear error growth. The predictability of nonlinear error growth is related to the error component, but not related to the ratio of these components. The component with the highest/lowest rate of enntribution does not necessarily have the greatest/least predictability. The different components have different predictabilities, and in different time periods, the different predictable components also have different predictabilities.