Materials Literature
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An exact result is calculated numerically for the dilute limiting, zero shear viscosity of bimodal suspensions of hard spheres. The required hydrodynamic functions are calculated from recent results for the resistivities of unequal spheres. Both the hydrodynamic and Brownian contributions to the Huggins coefficient ex…
In this paper we calculate how a pendant drop evolves at the end of a nozzle when the volume of the drop increases steadily with time. We find that the character of the evolution is strongly dependent on the growth rate of the drop and the radius of the nozzle. Typically we find that once the drop has become unstable,…
Extensive LDA and quasi-particle calculations have been performed on boron nitride (BN) single-wall and multi-wall nanotubes. Strain energies are found to be smaller for BN nanotubes than for carbon nanotubes of the same radius, owing to a buckling effect which stabilizes the BN tubular structure. For tubes larger tha…
A reciprocal space formulation of the Cluster Variation is used in order to extract effective pair interactions in alloys from experimental short-range order diffuse intensities. The method is applied to the analysis of the short range order contribution to the neutron diffuse scattering of a $Fe-19.5 {\%} Al$ single…
A fourth fatty acid condensing enzyme was isolated from Escherichia coli by its ability to restore elongating activity to a protein extract which had been treated with cerulenin, a condensing enzyme-specific inhibitor. The purified beta-ketoacyl-[acyl carrier protein] (ACP) synthase IV [3-oxoacyl-ACP synthase; acyl-AC…
The crystal structure of an allosteric chorismate mutase, the Thr-226-->Ile mutant, from yeast Saccharomyces cerevisiae has been determined to 2.2-A resolution by using the multiple isomorphous replacement method. Solvent-flattening and electron-density modification were applied for phase improvement. The current crys…
Two decay components of luminescence of oxygen-vacancy centres were observed in alkaline-earth fluoride and barium fluorohalide crystals at 17-300 K. We denoted them as slow and very slow components. Very slow components are observed in all crystals except for type II oxygen centres in BaFBr. Above 100-150 K the integ…
Linear as well as non-linear contributions to the Zeebeck and Peltier coefficients of a metallic film in contact with the equilibrium metal are calculated within a simple model. The non-linear part of the thermoelectric response survives down to a very low temperature which in principle permits thermoelectric cooling…
We present the first low frequency (0.1-20 Hz) measurements of the complex elastic constant on KSCN single crystals. Our measurements show very slow sample-size dependent elastic relaxations, at temperatures ranging from ${T}_{c}\ensuremath{-}40$ K up to the order-disorder phase transition temperature ${T}_{c}$. The d…
A ferroelectric instability is predicted to occur in an experimentally accessible temperature range in a main-chain (semiflexible) liquid crystalline polymer with directed polar mesogenic segments. The long-range part of the dipole-dipole interaction is separated and its effect is completely accounted for in the avera…
Effects of compression on the Raman and IR modes of KOH(D), RbOH(D) and CsOH(D) have been measured at pressures up to 20 GPa and temperatures down to 100 K using the diamond anvil technique. For all three hydroxides an ordering transition into the respective hydrogen-bonded low-temperature phases was found below 1 GPa…
Optical spectra are measured for transparent and colorless TbAlO3 single crystals grown by the Czochralski method in a reducing atmosphere, although those grown in an inert atmosphere show blackbody color due to broadband absorption of Tb4+ ions. This is a report on strong Tb3+ emission spectrum at room temperature of…
Ferroelectric films described by an Ising model in a transverse field have been studied under the mean-field approximation. We discuss an N-layer film of simple cubic symmetry with nearest-neighbour exchange in which the exchange strength and transverse field are assumed to be different from the bulk values in N s sur…
The theory of the $2{k}_{F}$ and $4{k}_{F}$ instabilities in quarter-filled band organic conductors is revisited. The phase angles of the $2{k}_{F}$ bond and charge density waves change as electron correlation is turned on, and this switching of the phase angle is critical for understanding the bond distortion pattern…
It is well known that thin films develop large intrinsic stress during their preparation. The intrinsic stress either originates from strained regions within the films (grain boundaries, dislocations, voids, impurities, etc.) or at the film/substrate (lattice mismatch, different thermal expansion, etc) and film/vacuum…
Abstract Optical properties and stability of hydrogenated silicon clusters are investigated using density functional pseudopotential calculation. The dipole transitions between the band‐edge orbitals are allowed, in contrast to the indirect gap in bulk silicon. Evolution of a small amount of hydrogen atoms enhances th…
Abstract Experimental results on 3 d O h complexes in insulators reveal that 10 Dq α R − n , where R is the metal–ligand distance and n is close to five. This strong dependence determines the Huang–Rhys factor, S ( A 1 g ), associated to the symmetric A 1 g mode of the first excited state of complexes like MnX and CrX…
Abstract The geometrical structures and properties of small cationic boron clusters B ( n = 2–14) have been investigated using the local spin density ( LSD ) formalism. The nonlocal correction has also been calculated. The linear search for minima on the potential energy surface has been performed using analytical gra…
Exciton effects on soliton and bipolaron lattice states are investigated using an electron-lattice Peierls model with long-range Coulomb interactions. The Hartree-Fock (HF) approximation and the single-excitation configuration- interaction (single-CI) method are used to obtain optical absorption spectra. We discuss th…
Optical thin film multilayer systems at oblique angles of incidence exhibit polarization effects because of the differences between the reflectances, transmittances, and phase shifts of the p and s states of polarization. It is shown that a thin film system is equivalent to a combination of two polarization elements,…