We consider a generalized anisotropic planar-rotor model on a triangular lattice for interchain orientational ordering of undoped and doped polyacetylene, and investigate the effects of various terms on the symmetry and the range of stability of the observed herringbone (HB) phases. Dipole, quadrupole, and octopole interactions are included in the model with sixfold crystal-field anisotropy and...

The crystal structure of phage 434 Cro protein in complex with a 20 base-pair D1VA fragment has been determined to 2.5 A resolution. The DNA fragment contains the sequence of the OR1 operator site. The structure shows a bent conformation for the DNA, straight,er at the center and more bent at the ends. The central base-pairs adopt conformations with significant deviations from coplanarity. The ...

We demonstrate highly efficient evanescent-wave detection of fluorophore-labeled biomolecules in aqueous solutions positioned in the air holes of the microstructured part of a photonic crystal fiber. The air-suspended silica structures located between three neighboring air holes in the cladding crystal guide light with a large fraction of the optical field penetrating into the sample even at wa...

A calculational scheme is presented to model the interaction of light with active dielectric media, represented by four-level atomic materials, surrounded by photonic crystals. Optically pumped lasing is studied in three model systems: a Fabry-Perot cavity, a line of defects in a two-dimensional square lattice of rods, and a cylindrical photonic crystal. Field profiles and conversion efficienci...

The crystal structures, thin-film properties, and field-effect transistor (FET) characteristics of tetrathiafulvalene (TTF) derivatives with two phenyl groups are systematically investigated. The highest mobility, 0.11 cm(2) V(-1) s(-1), is observed in biphenyl-substituted TTF (1). The correlation between the crystal structures and the FET properties demonstrates that good transistor properties...

We find that the photoelectron angular distributions from the Fermi surface of a monolayer Ni film on Cu are identical to those from thick Ni films and single-crystal Ni(001), and agree well with theoretical predictions for bulk Ni. This bulklike behavior in the monolayer film is attributed to the short screening length of electrons in metals, the similarity of the Ni and Cu cores, and a hybrid...

The parameters of the interaction 3 d electron states with an electromagnetic wave, as well probabilities magnetic and electric dipole transitions between ground term iron ion, which is split by crystal field, exchange interaction, spin–orbit coupling, have been calculated. dependences absorption lines on magnitude direction applied field determined. It has shown that optical diode effect disco...

The title compound was prepared via a cross-coupling reaction and its crystal structure has been determined. It crystallized in the triclinic space group P-1 with cell parameters: a = 8.552(2) Å, b = 11.310(2) Å, c = 16.150(3) Å, α = 109.55(3)°, β = 91.45(3)°, γ = 91.28(3)°, V = 1470.6(5) Å3, Z = 2 at 296 K. There is one molecule in the asymmetric unit. In the crystal structure, the neighboring...