Materials Literature
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Interaction of benzene with boron trichloride at 800 °C yields a graphite-like metallic solid of composition BC3, and chlorine–pyridine mixtures at 800 °C give a nitrogen–carbon also having a graphite-like structure.
The oxidation of pyrrole by iron(III) chloride in aqueous solutions of methylcellulose yields colloidal solutions of conducting polypyrrole which can be used to prepare thin films with maximum conductivity of 0.2 S/cm.
This article describes the progress in experimental studies of liquid-crystalline blue phases during the past 5 years. Additionally, these results are compared critically with the predictions of theories of the blue phases. Areas considered in this review include (i) the thermodynamic stability of the three polymorphi…
Approche unifiee a l'algebre de la polarisation en utilisant les groupes unitaires speciaux SU(2) et SU(4) et leurs homomorphismes respectifs et les groupes orthogonaux reels O + (3) et O + (6)
Since 1935, various mechanisms have been suggested for the formation of subsurface lesions and, in particular, the surface layer covering enamel lesions. The relatively intact mineral-rich and porous surface layer is most likely caused by kinetic events. The suggested mineral-rich outer layer in sound enamel, the orga…
Biological mineralization processes are extremely diverse and, to date, it is an act of faith rather than an established principle that organisms utilize common mechanisms for forming crystals. A systematic analysis of the structural organization, as far as possible at the molecular level, of five different extracellu…
Abstract There is given a list of 323 taxa of freshwater diatoms occurring in waters of Central Europe. Each taxon is characterized by 10 balls of saprobic valence, the indicative weight of species (I i ) and by the individual saprobic index (S i ) indicating its position on a conventional scale of saprobity. Diatoms…
This book attempts to provide basic knowledge about the structure, properties, and processing of engineering materials and their applications. The first chapter gives an introduction to materials science and engineering and briefly describes the main types of engineering materials. Chapters 2 to 4 cover basic material…
Homopolymers and copolymers of 3-alkylthiophenes incorporating alkyl groups equal to or greater than butyl in size can be handled in solution and form highly conducting, environmentally-stable compositions on doping.
Tractable polythiophenes which are soluble in ordinary organic solvents at ambient temperatures are prepared by the electrochemical polymerization of thiophenes having a long alkyl chain.
The electrochemical oxidation of aromatic heterocyclic compounds thiophene, pyrrole, and indole and benzenoid and nonbenzenoid polycyclic hydrocarbons azulene, fluorene, and pyrene yield electrically conducting polymers with conductivities of 10 −5 –10 S/cm. The presence of substituents affects the electrical conducti…
ZSM-5 zeolites containing Cu2+ ions showed unusually high and steady state activity for the catalytic decomposition of nitrogen monoxide; for example, the degrees of conversions of NO, and of conversion into N2 and O2 were 97, 85, and 70%, respectively, at 823 K with a contact time of 10.0 g s cm–3 over 73% exchanged…
Various thermoelectric linear transport coefficients are defined and calculated for two reservoirs connected with ideal multichannel leads and a segment of an arbitrary disordered system. The reservoirs have different temperatures and chemical potentials. All of the inelastic scattering (and, thus, the dissipation) is…
Introduction. Basic theory. Antireflection coating. Neutral mirrors and beam splitters. Multilayer high-reflectance coatings. Edge filters. Band-pass filters. Tilted coatings. Production methods and thin-film materials. Factors affecting layer and coating properties. Layer uniformity and thickness monitoring. Specific…
A technical overview discussed the rationale for using edible films for preventing moisture loss from films while allowing permeability of oxygen and carbon dioxide to prevent anaerobic bacterial growth within the encased food. Detailed attention also is given to the characteristics of the types of edible films, cover…
The properties of various types of amorphous carbon and hydrogenated amorphous carbon are reviewed with particular emphasis on the effect of atomic structure on the electronic structure. It is shown how the proportion of sp3 and sp2 sites not only defines the short-range order but also a substantial medium-range order…
The emeraldine salt form of polyaniline, conducting in the metallic regime, can be synthesized electrochemically as a film exhibiting a well defined fibrillar morphology closely resembling that of polyacetylene. Cyclic voltammograms of chemically synthesized and electrochemically synthesized polyaniline are essentiall…
The orientational optical nonlinearity of the mesophases of liquid crystals (LCs) is attracting ever more attention, owing to the high values of the constants characterizing it, owing to the many interesting specific features that LCs introduce even into traditional nonlinear optical effects, and owing to the potentia…
Calculated volumes of formation for substitutional impurities in alkali halides are shown to be approximately consistent with the empirical rule that for miscible crystals the average volume per ion pair scales linearly between the two single-component extremes (Vegard's rule). The small deviations found from the rule…
We present the first experimental study of shear-flow--induced behavior in a two-dimensional anisotropic fluid: circular, freely suspended films of smectic-C liquid crystals. Depending on the topology of the in-plane director configuration, we observe either a phase winding state, where \ensuremath{\Phi}, the phase de…