Materials Literature
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Switching times 1000-times faster and transition temperatures 50 K lower than those of the first mesogenic palladium complexes characterize the palladium complexes 1 (n =10, 14) reported here. Thus, applications may also become possible for ferroelectric liquid crystals from metallomesogens.
The high-field electrical properties of ferroelectric lead-lanthanum-titanate (PLT) thin films deposited by multi-ion-beam reactive sputtering are presented. Space-charge-limited (SCL) conduction theory incorporating the effects of electron traps is used to explain the current-density dependence on applied voltage. Th…
Different forms of soil aluminum (Al) are involved in the retention of anions and cations, phytotoxicity of Al in acid soils, CEC reduction and soil physical properties such as aggregate stability and water infiltration. Therefore it is desirable to quantify the different forms of Al in soil especially acidic soils. A…
The question of the conditions under which one-dimensional systems support extended electronic eigenstates is addressed in a very general context. Using real-space renormalization-group arguements we discuss the precise criteria for determining the entire spectrum of extended eigenstates and the corresponding eigenfun…
We report on a laboratory study of the role of O 3 , NO 2 , and SO 2 in the sub‐parts per‐million range on the atmospheric corrosion of zinc. Each sample was exposed individually to synthetic atmospheres with careful control of pollutant concentrations, relative humidity, and flow conditions. In addition, we studied t…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructural investigation into the steric control of polyether complexation in the lanthanide series: macrocyclic 18-crown-6 versus acyclic pentaethylene glycolRobin D. Rogers, Andrew N. Rollins, Russell D. Etzenhouser, Eric J. Voss, and Cary B. BauerCite this: Inorg. Chem. 1…
Three laboratory-based accelerated corrosion tests were investigated to develop improved procedures for assessing corrosion protection properties of organic paint films. The methods investigated were: standard salt-spray (ASTM Standard B-117), a wet/dry cycle corrosion test using a low-concentration ammonium sulfate/s…
peer reviewed
X-ray diffraction in thin layers containing small randomly placed defects is described by means of the kinematical diffraction theory and optical coherence formalism. The method enables us to calculate both the diffracted intensity and its angular distribution, so that it can be used for simulating double crystal and…
The adhesive-sphere interaction potential provides a good model system to study the influence of the attractive well depth on phase behavior and interfacial phenomena. We investigate the solid–fluid phase behavior of adhesive spheres with the modified weighted density approximation (MWDA) of Denton and Ashcroft. We th…
A four-orbital model is used to map the overall dependence of β, the first electronic hyperpolarizability, on \nchemical parameters such as donor/acceptor strength and coupling between bridge and donor/acceptor orbitals. These \ncalculations are used to develop general structure-property relationships for β an…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHeats of formation of silicon hydride oxide (SiHnO and SiHnO2) calculated by ab initio molecular orbital methods at the G-2 level of theoryCynthia L. Darling and H. Bernhard SchlegelCite this: J. Phys. Chem. 1993, 97, 31, 8207–8211Publication Date (Print):August 1, 1993Publi…
A large fraction of the chemical and refinery processes are catalytic in nature. While the worldwide sales of catalysts are only about $4 billion annually, the economic impact of catalysis comes from the fact that approximately $200 worth of products are manufactured for every $1 worth of catalyst consumed [1]. The ac…
The most important factors contributing to line broadening and background intensity in electron spectra are identified and new design principles for high quality measurements are presented. It is shown that time-dependent potential gradients in the gas cell are responsible for a large part of the ‘‘normal’’ line broad…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of the spacer moiety on the rates of electron transfer within bis-porphyrin-stoppered rotaxanesJean Claude Chambron, Anthony Harriman, Valerie Heitz, and Jean Pierre SauvageCite this: J. Am. Chem. Soc. 1993, 115, 16, 7419–7425Publication Date (Print):August 1, 1993Pub…
New experimental results of low-frequency Raman scattering from different glasses are presented. They are compared to the vibration density of states obtained from inelastic neutron scattering to deduce the light-vibration coupling coefficient C(ω) as a function of the vibration frequency. It was found that C(ω)∝ω2 at…
We report measurements of the specific heat ${\mathit{C}}_{\mathit{p}}$(T), magnetic susceptibility \ensuremath{\chi}(T), and magnetization M(H) of icosahedral ${\mathrm{Al}}_{70}$${\mathrm{Mn}}_{9}$${\mathrm{Pd}}_{21}$ at low temperatures. Below room temperature, the static magnetic susceptibility is well described b…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and properties of novel aromatic polyimides of 2,3-bis(4-aminophenoxy)naphthaleneChin Ping Yang and Wen Tung ChenCite this: Macromolecules 1993, 26, 18, 4865–4871Publication Date (Print):August 1, 1993Publication History Published online1 May 2002Published inissue…
The atomic displacements of many of the atoms in a macromolecular structure can be modelled in terms of group motions described in the harmonic approximation by T, L and S tensors. Relevant groups may be planar side groups of protein chains, units of secondary structure such as α-helices or whole protein domains. For…
Abstract Four new epoxy monomers have been synthesized and characterized as part of a program to prepare novel liquid crystal thermoset (LCT) materials. Three of the new epoxy monomers contained a biphenyl mesogen and were not liquid crystalline (LC). The remaining epoxy monomer, which contained a 1,4‐dibenzoyloxybenz…