Materials Literature
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We performed dielectric- and electrooptical measurements of a ferroelectric liquid crystal film as a function of temperature, frequency and bias field. Starting with the homeotropic texture, obtained with a silane coating, we measured the dielectric properties in the direction of the helical axis. After realigning to…
The two databases ICSD and TYPIX are described. ICSD is a comprehensive compilation of crystal structure data of inorganic compounds (about 39 000 entries). TYPIX contains 3600 critically evaluated data sets representative of structure types formed by inorganic compounds.
Abstract A norbornadiene tetracarboxylic acid was synthesized the p K s of which can be changed by irradiation forming the quadricyclane derivative or by catalytical reisomerization to the norbornadiene. The p K s difference of both isomers in the second and fourth dissociation step is 0.59 and 0.68 units. Photochemic…
Abstract The characteristics of hydrated mineral fillers are discussed with reference to their use as fire retardant additives for polymers. Particular consideration is given to their mode of action and criteria which influence their performance, both in reducing polymer flammability and in suppressing smoke evolution…
It is expected that the use of electrical equipment at high temperatures will increase in the future, and the demand for heat-resistant insulation that can be used at temperatures above 300/spl deg/C will increase. In addition, this high temperature electrical equipment will need to be higher in voltage and have a lar…
The effect of chain modification on the transport properties of two types of polyethylene-based polymers is reviewed in this work. Attention is focused on a polyketone terpolymer (0.93 : 0.07 : 1 ethylene/propylene/carbon monoxide) and on an ethylene—acrylic acid ionomer in order to determine their gas and water vapor…
Dealloying of a binary noble alloy produces a porous layer rich in the more noble element. Application of a tensile load initiates a brittle intergranular (IG) crack in the dealloyed layer that advances into the unattacked material. This study showed that the crack penetration depth (Cd) is proportional to the thickne…
Hydride precipitation and dissolution in a zirconium matrix have been simulated numerically using a finite element technique. The evolution of the accommodation energy associated with such phase transformations has been evaluated for isotropic and anisotropic misfitting hydrides in an infinite stress-free body. It was…
The morphology of the carbon nitride (C1−xNx) thin films deposited by the reactive ion beam sputter deposition technique has been studied. A pure graphite target has been sputtered using nitrogen ions. Some of the deposited films have been irradiated with the primary nitrogen ion beam during the deposition. The films…
The surface-induced enhancement of UV–visible absorption and Raman spectra of cyanine dye D266 molecules adsorbed on ZnO colloids is reported. The Raman enhancement factor is estimated to be more than 50. The enhancement mechanisms are discussed. The surface-induced absorption enhancement is the main cause of the Rama…
Optical nonlinearity was induced in fused silica through proton implantation. Average χ(2) of the order of 1.0 pm/V were induced in low-water fused silica, with isolated regions exhibiting χ(2) as high as 1.6 pm/V. A minimum dosage of 0.25–0.5 mC was found to be effective in generating the second harmonic in fused sil…
Abstract The first radical polymerization of 1‐methoxy‐ o ‐quinodimethane (2) generated by thermal ring‐opening isomerization of 1‐methoxybenzocyclobutene (1) is described. The polymerization of 1 in the presence of a radical initiator afforded an MeOH‐insoluble polymer (3) in moderate yield at temperatures above 90°C…
We investigate the structure of 13-particle clusters in binary alloys for various size ratios and different concentrations via molecular-dynamics simulation. Our goal is to predict which systems are likely to form local icosahedral structures when rapidly supercooled from the melt. We calculate the energy spectrum of…
We report on the growth and subsequent work function measurements of diamond film covered surfaces. Diamond films were grown via a thermal chemical vapor deposition technique. The feed gas mixture used was 1% CH4/99% H2. Raman spectroscopy was used to verify diamond growth. Electron emission was investigated and work…
Phosphate (P) sorption isotherms have been widely used to characterize the P status and to establish fertilizer requirements of soils. Recently, mechanistic models have successfully described the nutrient uptake by plants under changing soil and plant parameters. Phosphorus sorption characteristics of eleven represent…
Stress relaxation of commercial poly(vinyl chloride) (PVC) is measured at strains below 3% and at different temperatures below the glass transition temperature. First it is shown that below the yield point the material follows a linear viscoelastic behavior. Then the data at a fixed deformation level (0.03) are fitted…
During the past several years, the study of interfacial instability and pattern formation phenomena has preoccupied many researchers in the broad area of nonlinear science. These phenomena occur in a variety of dynamical systems, far from equilibrium, especially in some practically very important physical systems, alw…
Abstract The mechanism of the strictly alternating anionic copolymerization of phenyl glycidyl ether (PGE) and phthalic anhydride (PA) was initiated by various imidazoles. Because of the strictly alternating copolymerization polyesters with a repeating unit of PGE‐PA were obtained. The mechanism of the reaction was an…
The coenzyme specificity of isocitrate dehydrogenase from an extreme thermophilic bacterium was converted from NADP-dependent to NAD-dependent by replacing a "module" involved in the coenzyme binding site. The conversion was not possible with the replacement of a few residues that interact with the coenzyme. In additi…
The dynamic compressibility of air in fibrous materials has been computed for two assumed configurations of fibers which are close to the geometry of real fiber materials. Models with parallel cylinders placed in a regular square lattice and placed randomly are treated. For these models the compressibility is computed…