Effects of surface and shear forces on nano-confined smectic-A liquid crystals studied by X-ray diffraction

The orientational behavior of a smectic-A liquid crystal (4-cyano-4′-octylbiphenyl, 8CB) confined between mica surfaces as well as between silica surfaces with a nanometer scale thickness was investigated by synchrotron X-ray diffraction measurement.

Host Plant Species of Bemisia tabaci Affect Orientational Behavior of the Ladybeetle Serangium japonicum and Their Implication for the Biological Control Strategy of Whiteflies

Serangium japonicum Chapin (Coleoptera: Coccinellidae) is a predominant predator with a preference for Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). To date, the orientational behavior of S. japonicum toward B. tabaci-infested plants has seldom been reported. In this study, greenhouse cage experiments and bioassays with wind tunnels, a Y-tube olfactometer and B. tabaci-induced plant volatiles were executed to clarify this behavior. In greenhouse cage experiments, B. tabaci adults significantly preferred eggplant, cucumber and tobacco to cotton and tomato, whereas S. japonicum adults preferred B. tabaci-infested eggplant, cucumber and cotton to tobacco and tomato. In wind tunnel bioassays, B. tabaci showed a clear preference for eggplant, cucumber and tobacco. Compared with B. tabaci-infested eggplant, cucumber or cotton, B. tabaci-infested tobacco was rarely visited by S. japonicum. In Y-tube bioassays, S. japonicum did not distinguish between B. tabaci-infested and uninfested eggplant. Nine common plant volatiles were detected in different plant species, suggesting that these volatiles may play an important role in the process by which S. japonicum looks for prey. In light of the current results, we discuss the implications of our findings and put forward to a new strategy—i.e., an eggplant + B. tabaci + S. japonicum system—to control B. tabaci damage in the integrated management of whitefly.

Парамагнитные ионы в легированном европием искаженном перовските YAlO-=SUB=-3-=/SUB=-

In yttrium orthoaluminate crystals doped with the 151Eu isotope, the paramagnetic centers Eu2+, Cr3+, Gd3+, and Mo3+ have been detected. The fine structure parameters of the spin Hamiltonian of these centers were determined or refined. The account of the orientational behavior of previously unobserved forbidden transitions has been taken for the Cr3+ centers. It is shown that two Mo3+ signals that are detected in magnetic fields parallel to the crystallographic axes do not belong to different molybdenum centers, but are two intra-doublet transitions of the same center.