Papers by Author: Lian Sheng Wang

Abstract: Marine ecosystems are affected by aromatic hydrocarbons. The predicting ability based on the quantitative structureactivity relationships (QSAR) model of unknown aromatic hydrocarbons toxicity is one of the tasks of security precaution. To establish the QSAR model between the physical and chemical properties of aromatic hydrocarbons and the inhibited activity of Chlorella vulgaris(C. Vulgaris), the optimized geometries, based on the 96 hr-EC₅₀ of 25 aromatic hydrocarbons with C. Vulgaris were carried out at the B3LYP/6-311G** level by density functional theory (DFT) calculation. With matlab2 010(a) software, genetic algorithm principal components regression (GAPCR) methods was used to develop the QSAR model and compared to traditional PCR model. PC1+PC3+PC5+PC6+PC8 were finally selected by GAPCR method. The of training, prediction data set and LOO cross validation are 0.918, 0.956 and 0.933, respectively. Meanwhile, the results of PCR were 0.949, 0.755 and 0.825, respectively. The results of this work showed that the GAPCR method has great results and good generalization capability. Comparing two motheds results indicting that GAPCR gives superior results to traditional PCR procedure.

Abstract: Mill is always weighed by its longitudinal stiffness. The prediction precision of longitudinal stiffness related strip geometric accuracy. Taking 1700mm hot strip line as research object, stiffness of housing, bearing wall and roll was calculated by finite elements method(FEM), hydraulic system stiffness was obtained by theoretical formula. Analyzing vertical system and structural symmetry of mill, functional relationship between longitudinal stiffness and its components stiffness was derived according to series or parallel connection with various components. Longitudinal stiffness was the basis on thickness set-up model. Calculation result was verified by practical test.

Abstract: In order to analyze the effect of entry strip thickness, entry strip crown and intermediate roll shifting on strip profile and rolling force distribution, a three dimension finite element model of rolls-strip in UCM mill was established and employed. The results showed that the increases of entry strip thickness and entry strip crown would lead to the increase of exit strip crown and edge drop under the same total rolling force; the strip crown and edge drop would be decreased if the intermediate roll shifting δi was decreased. Moreover, the rolling force distribution also was analyzed in details by changing the entry strip thickness, the entry strip crown and the intermediate roll shifting.