Abyssinin,a potent insect antifeedant from an african medicinal plant, bersama abyssinica

Chemical investigation of pest insect control agents from the East African Melianthaceae plants has led to the isolation and characterization of abyssinin, a compound which exhibits very strong antifeedant activity against the cotton pest insect, $\text{Heliothis}$$\text{zea}$¹.     

Nonlinearity in cooperative systems-dynamical Bethe-Ising model

The dynamics of the short-range order as well as the long-range order in the nonlinear cooperative system is investigated specifically for a kinetic Ising model in the Bethe approximation. The phenomena of critical slowing down near the transition temperatureT _c and anomalous fluctuation belowT _c are directly related to the instability of the long-range order. The dynamics of the short-range order is essentially a fast mode and is noncritical. However, through the nonlinear coupling the short-range order is also influenced by the critical behavior of the long-range order.     

Three-dimensional ordering of impurity-doped TMMC in a magnetic field

The three-dimensional ordering temperatures of the quasi-one-dimensional antiferromagnet (CH₃)₄NMnCl₃ containing 0, 0.13, 0.25 and 0.48 at% Cu²⁺ ions were studied as a function of an external magnetic field up to 60 kOe by means of proton NMR. A strong increase of T_N(H) with H was found even for the impure system. The T_N versus H curve for the pure system cam be explained by introducing a simple form for the effect of the field on the correlation length, ξ(T, H) = ξ(T) × [1+(λJ/kT)H²], while that for the impure system is unlike the one for the pure system.     

Specific effects of simple organic sulphonate anions on the mercury ion-assisted aquation of chlorocobalt(III) complexes: Deviations from the primary s

Kinetic effects of various 1-1 electrolytes on the CoClL_n² + Hg² reaction (L_n: neutral ligands) were studied with varying concentra     

Surface structure of SrTiO3(100)-(square root of 5 x square root of 5) - R26.6 degrees

Atomic and electronic structures of the SrTiO3(100)-(square root of 5 x square root of 5) - R26.6 degrees surface are studied by using scanning tunneling microscopy (STM) and noncontact atomic force microscopy (NC-AFM). Instead of the well established oxygen vacancy model, it is found that a structural model, consisting of an ordered Sr adatom at the oxygen fourfold site of a TiO2 terminated layer, can explain the experimental results very well. We theoretically simulate the model cluster with the first-principles total-energy calculation. Calculated density of states and images for STM and NC-AFM are in good agreement with the experimental results.