An Estimate for the Attraction Domains of Difference Equations with Periodic Linear Terms

We consider the quasilinear systems of difference equations with periodic coefficients in linear terms. We obtain estimates for the attraction domain of the zero solution and establish inequalities for the norms of solutions. The results are stated in terms of Lyapunov-type matrix series.     

The role of 60Co γ-ray irradiation on the interface states and series resistance in MIS structures

The effect of γ-ray exposure on the metal–insulator–semiconductor (MIS) structures has been investigated using the electrical characteristics at room temperature. The MIS structures are irradiated with ⁶⁰Co γ-ray source. The energy distribution of interface states was determined from the forward bias I–V characteristics by taking into account the bias dependence of the effective barrier height and ideality factor. The value of series resistance decreases with increasing dose. Experimental results confirmed that γ-ray irradiation have a significant effect on electrical characteristics of MIS structures.     

Asymptotic Stability of Solutions to Perturbed Linear Difference Equations with Periodic Coefficients

We consider perturbed linear systems of difference equations with periodic coefficients. The zero solution of a nonperturbed system is assumed asymptotically stable, i.e., all eigenvalues of the monodromy matrix belong to the unit disk {||<1}. We obtain conditions on the perturbation of this system under which the zero solution of the system is asymptotically stable and also establish continuous dependence of one class of numeric characteristics of asymptotic stability of solutions on the coefficients of the system.     

Temperature dependence of the quadrupole splitting and μeff for [FeCl2(Dena)4]·DmgH2

Mössbauer spectrometry and magnetochemical methods have been applied to a complex known as catene: -dimethylglyoxime dichlorotetra(N,N-diethylnicotinamide) iron· (II) [FeCl₂(Dena)₄]·DmgH₂, where Dena is N,N,diethylnicotinamide and DmgH₂ is dimethylglyoxime. The compound has a high-spin state for the iron(II) (S=2). The magnetic susceptibility follows the Curie-Weiss law with a small value of , The E_Q=f(T) relation shows that the symmetry of the immediate environment of the iron is less than tetragonal: ₁=190 cm^–1, ₂=490 cm^–1.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, No. 1, pp. 56–60, January–February 1992.     

Dynamic Nuclear Polarization in Some Aliphatic and Aromatic Solutions as Studied by Fluorine‐Electron Double Resonance

Dynamic nuclear polarization experiments were performed to study the solutions of the stable free radical α,γ‐Bisdiphenylene‐β‐phenyl allyl complex with benzene (1∶1) in some highly fluorinated aliphatic and aromatic solvents. In solutions examined in this study, the Overhauser effect, which normally arises due to both dipolar and scalar interactions between the unpaired electrons of the free radical molecules and fluorine nuclei of solvent molecules occurs mainly. 1‐Iodotridecafluorohexane, 2,2,3,4,4,4‐Hexafluoro‐1‐butanol, N‐methyl‐bis‐trifluoroacetamide, hexafluoroacetylacetone, octafluorotoluene, and hexafluorobenzene were used as the solvents. The experiments were performed at a low field double resonance NMR spectrometer, which operates at 1.53 mT. The NMR enhancements depend on competition between intermolecular magnetic interactions. The measurements were performed at four different temperatures to test the dipolar and the scalar part of the coupling between the fluorine nucleus (¹⁹F) and the unpaired electron. It was found that the dipolar interactions are more effective for the aliphatic solvents, while the scalar interactions are more effective for the aromatics. The nuclear‐electron coupling parameter varies between 0.018 and 0.157 in all aliphatic solvents and between ?0.063 and ?0.035 in aromatic solvents.     

Metal-mediated self-assembly of protein superstructures: influence of secondary interactions on protein oligomerization and aggregation

We have previously demonstrated that non-self-associating protein building blocks can oligomerize to form discrete supramolecular assemblies under the control of metal coordination. We show here that secondary interactions (salt bridges and hydrogen bonds) can be critical in guiding the metal-induced self-assembly of proteins. Crystallographic and hydrodynamic measurements on appropriately engineered cytochrome cb562 variants pinpoint the importance of a single salt-bridging arginine side chain in determining whether the protein monomers form a discrete Zn-induced tetrameric complex or heterogeneous aggregates. The combined ability to direct PPIs through metal coordination and secondary interactions should provide the specificity required for the construction of complex protein superstructures and the selective control of cellular processes that involve protein-protein association reactions.