Calorimetric and dielectric studies of ferroelectric sodium nitrite confined in a nanoscale porous glass matrix

Heat-capacity measurements of the sodium nitrite confined in a nanoscale porous glass matrix show that the intermediate incommensurate phase, present in the bulk, has disappeared and that the first-order ferroelectric transition becomes suppressed and gradual. The ferroelectric transition temperature is shifted considerably to lower temperatures. Two noncritical dielectric modes were observed; however, the observed giant growth of the dielectric constant on heating through the transition temperature TC is shown to be mainly due to the electrode polarization effect.     

The (n, α) reaction on 11B induced by 14.4 MeV neutrons

The ¹¹B(n, α)⁸Li reaction has been studied at 14.4 MeV in a geometry that allows simultaneous detection of the emitted and recoil particles. The angular distributions have been measured for the transitions to the ground and first excited states of the ⁸i nucleus and compared with PWBA for knock-on and heavy-particle pick-up processes. The total cross sections for the respective transitions have been deduced.     

On the relation between the formal atomic charges and total molecular energies

It is shown that the total SCF molecular energies are fairly well reproduced by the sum of electrostatic potentials exerted on the nuclei calculated in the point-charge approximation. Hence, there is a very simple relation between the total energies and formal atomic charges in molecules. The semiempirical SCC-MO charges have the same performance as the ab initio DZ ones.     

Solvent effects in dense gases

The effects of perturber gases, partial pressures in the range 0–50 atm, on the absorption spectra of high-n Rydbergs, n ≥ 10, in methyl iodide and benzene have been investigated. The perturbers were rare gases and H₂. It has been shown that the spectroscopic energy shift Δ = Δ(ρ, n) is given by Δ = Δ°ρ, where ρ is the number density of the perturber, for n ≥ 10. The shift data can be interpreted using a Fermi model, and values of scattering lengths for perturbers can be extracted. These scattering lengths are internally consistent, independent of the absorber, and in excellent agreement with electron-swarm results. Given that the Fermi model is nonspecific and microscopic, scattering shifts and lengths for mixtures of perturber gases can be predicted. These predictions, having been verified by experiment for He/Ar mixtures, provide a means of “tailoring” any required scattering length. Finally, it is shown empirically that the determinative scattering parameter is the polarizability of the perturber, and a universal relationship a = ?0.26α + 1.18 between scattering length a, in Bohr radii, and polarizability α is found to exist.     

Estimation of possible airborne elemental inputs to the Slovenian marine environment

In evaluation of the influence of environmental pollution on the ecosystem, data about the elemental concentrations of the atmospheric aerosols, combined with information about particle size and meteorological data, are of significant importance. They are also necessary prerequisites for source/receptor studies and long-range transport modeling. As such, these data are irreplaceable for the estimation of potential elemental input from air to the sea, an understanding of which is one of the tasks of the Mediterranean Pollution Programme (MED POL). Three sampling locations (Sečovlje, Koper, and Iskrba) in Slovenia were chosen for the present study, two at the coast and the third one in a scarcely inhabited, almost unpolluted area, as a reference point, and the element concentrations in the collected particulate matter (PM) were determined. From the Iskrba data the wet scavenging coefficient of airborne sulphur due to precipitation was estimated as k = (1.0±0.3)·10⁻⁴s⁻¹ (at 1.5 mm·h⁻¹).     

Molecular Lesion Spectra as Radiation Signatures

It is suggested that the distribution of DNA molecular lesions (i.e., molecular lesion spectrum. MLS) produced by a particular electromagnetic radiation characterizes that radiation, and that these distributions may serve as radiation signatures. These signatures can have the advantages of (1) high fidelity, (2) persistence times at least ten orders of magnitude greater than track structures, and (3) a space-time cellular position which is approximately half way between initial insult and ultimate biological dysfunction. Spectra are presented for 405nm, 254nm and γ-ray radiations. These MLS's are visually distinctive. Comparable data bases for most other radiations, particulate and electromagnetic, are generally incomplete. We propose the application of adaptive feature recognition and classification techniques to the extraction of radiation signatures for such incomplete data sets. In this work, however, such an application is restricted to quantitation of the degree of orthogonality of the three patterns (i.e., MLS's) for 405nm, 254nm and γ-rays.     

Fabrication of Pascal‐triangle Lattice of Proteins by Inducing Ligand Strategy

A protein Pascal triangle has been constructed as new type of supramolecular architecture by using the inducing ligand strategy that we previously developed for protein assemblies. Although mathematical studies on this famous geometry have a long history, no work on such Pascal triangles fabricated from native proteins has been reported so far due to their structural complexity. In this work, by carefully tuning the specific interactions between the native protein building block WGA and the inducing ligand R‐SL , a 2D Pascal‐triangle lattice with three types of triangular voids has been assembled. Moreover, a 3D crystal structure was obtained based on the 2D Pascal triangles. The distinctive carbohydrate binding sites of WGA and the intralayer as well as interlayer dimerization of RhB was the key to facilitate nanofabrication in solution. This strategy may be applied to prepare and explore various sophisticated assemblies based on native proteins.