Production of a base population and its responses to F-1 selection in the bay scallop, Argopecten irradians irradians Lamarck (1819)

A base population of the bay scallop, Argopecten irradians irradians Lamarck, was produced by crossing two cultured bay scallop populations. After 1 year of rearing, the top 10% truncation selection of the top 10% (i=1.755) was carried out in the base population of about 1300 adults. A control parental group with a an identical number to the select parental group was randomly selected from the entire population before isolation of the select parental group. The result showed that, at the larval stage, the growth rate of larvae in the selected line was significantly higher than that of the control (P < 0.05), and that the genetic gain was 6.78%. Owing to the lower density of control at the spat stage, the mean shell length of the control line was larger than that of the select line at day 100. When the same density was adjusted between two lines in the grow-out stage (from day 100 to 160), the daily growth rate of the selected line was significantly higher than that of the control line (P < 0.05). Survival of the select line was significantly larger than that of the control line in the grow-out stage. In conclusion, the results obtained from this experiment indicate that selective breeding from a base population with a high genetic diversity established by mass spawning between different populations appears to be a promising method of genetic improvement in bay scallop, A. irradians irradians Lamarck.

Aminic nitrogen-bearing polydentate Schiff base compounds as corrosion inhibitors for iron in acidic media: A quantum chemical calculation

Quantum chemical calculations based on DFT method were performed on three polydentate Schiff base compounds (PSCs) used as corrosion inhibitors for iron in acid media to determine the relationship between the molecular structure of PSC and inhibition efficiency. The structural parameters, such as the frontier molecular orbital energy HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), the charge distribution of the studied inhibitors, the absolute electronegativity (chi) values, and the fraction of electrons (Delta N) transfer from inhibitors to iron, were also calculated and correlated with inhibition efficiencies. The results showed that the inhibition efficiency of PSCs increased with the increase in E-HOMO and decrease in E-LUMO-E-HOMO; and the areas containing N atoms are most possible sites for bonding the metal iron surface by donating electrons to the metal. (C) 2007 Elsevier Ltd. All rights reserved.

Structure and base properties of calcined hydrotalcites

Five hydrotalcites with Mg/Al molar ratio range of 3-15 were prepared. The structure and basicity of Mg-Al mixed oxides (Mg(Al)O) transformed from hydrotalcites were investigated by TPD, XPS, XRD, FT-IR and NMR techniques. The results of elemental analysis and XPS indicate that Al is enriched in the surface regions of Mg(Al)O, and its amount increases with the Mg/Al molar ratio and, the calcination temperature. Al-27-MAS-NMR results show that Al exists in two chemical environments: tetrahedral aluminium (Al(t)) and octahedral aluminium (Al(o)) in Mg(AI)O. The amount of Al(t) increases with the Mg/Al molar ratio and the calcination temperature. It is assumed that Al(t) may be mainly from the surface Al. Temperature-programmed desorption (TPD) of CO2 shows that the number of basic sites of Mg(Al)O samples increases with the Mg/Al molar ratio, and the maximum number of basic sites is obtained for hydrotalcite calcined at 773 K. Infrared spectra of adsorbed CO2 and B(OCH3)(3) reveal that there are two kinds of basic sites: weak basic OH- sites and strong basic O2- sites on the Mg(AI)O samples, the base strength depends on the Mg/Al molar ratio and calcination temperature.

Synthetic studies on optically active Schiff-base ligands derived from condensation of 2-hydroxyacetophenone and chiral diamines

Three optically active Schiff-base ligands have been prepared by condensation of 2-hydroxyacetophenone with (IR,2R)-(-)-1,2-diaminocyclohexane, (1S,2S)-(-)1,2-diphenylethylenediamine or R-(+)-2,2'-diamino-1,1'-binaphthalene, respectively. The products have been characterized by their IR, H-1- and C-13-NMR spectra.