Materials Literature
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We studied the metal $d$ and O $2p$-derived electronic states of Ru${\mathrm{O}}_{2}$, Ir${\mathrm{O}}_{2}$, ${\mathrm{Ru}}_{0.65}$${\mathrm{Ir}}_{0.35}$${\mathrm{O}}_{2}$, and ${\mathrm{Ru}}_{0.77}$${\mathrm{Ir}}_{0.23}$${\mathrm{O}}_{2}$ by photoemission spectroscopy with synchrotron radiation. Our data are in quali…
Pyroelectric properties of α-LiIO3 in the temperature range between 320 and 120 K are measured. It is found that α-LiIO3 has low dielectric constant, low tan δ, and useful pyroelectric properties at low temperature about 125 K. The primary and secondary pyroelectric contributions at 253 K are estimated.
The first pressure derivatives fo the elastic moduli for three austenitic stainless steels, AISI 304, 310, and 316, have been determined from the variation of the sound velocity under pressure. All pressure derivatives are lower than the corresponding ones for pure iron. The elastic Grüneisen constant, derived from th…
X-ray investigations performed on the rotator phases of n alkanes CnH2n+1 with 26≤n≤34 prove that their structures are different from those exhibited by lower-numbered compounds. Two kinds of phases with monoclinic and triclinic symmetries are encountered both with the molecules tilted with respect to the layer plane.…
A new tight-binding band calculation is presented for the layer compound boron nitride which correctly describes the widths of both $\ensuremath{\sigma}$ and $\ensuremath{\pi}$ bands. The binding energy and wave function of the B $1s\ensuremath{\rightarrow}2p$ core exciton are studied. The core exciton is found to be…
Electrical properties, such as dielectric, resistive, ferroelectric, and piezoelectric properties, of bismuth layer-structured ferroelectrics (BLSF) are studied on grain orientation prepared by the hot-forging (H.F.) method. The BLSF compound which can stand the high temperature poling process is Pb(1−x) (NaCe)x/2 Bi4…
Zinc oxide films were prepared on unheated glass substrates by rf magnetron sputtering under an applied external dc magnetic field in pure argon gas, and electrical and optical properties of the deposited films were investigated. Highly transparent films with resistivity as low as 10−4 Ω cm, which were weakly oriented…
We consider a semi-infinite superlattice structure, with constituent $A$ characterized by dielectric constant ${\ensuremath{\epsilon}}_{A}(\ensuremath{\omega})$ and constituent $B$ by ${\ensuremath{\epsilon}}_{B}(\ensuremath{\omega})$, and examine collective excitations of the system in the absence of retardation effe…
High-resolution infrared absorption and photoconductivity spectra of several S- and Se-related donor centers in silicon are presented. These include isolated, probably substitutional, impurities and impurity pairs, as well as more complex centers. The spectra of the isolated impurities are consistent with ${T}_{d}$ sy…
The effective-mass-approximation differential equations appropriate for impurities in a graphite host are constructed and are used to solve self-consistently for the screening response surrounding a single intercalant atom. The screening cloud is found to have a very slow algebraic decay with a characteristic length o…
Abstract The siliceous cell wall of diatoms is formed in a silica deposition vesicle that is delimited by a membrane, the silicalemma. Once the siliceous wall matures, it is expelled and a new plasmalemma is formed underneath. Underlying wall formation is a multitude of events and processes, some of which are now know…
Abstract The minerals of biology have two components, one of which is inorganic and the other organic. Understanding rests initially in the description of the factors that control the nucleation and growth of the inorganic components in the absence of organic materials, and in the study of the organic materials in the…
Collagen is the principal organic matrix in bone. The triple helical region of the molecule is 1014 amino acids long. In fibrils these molecules are staggered axially by integers of 234 residues or 68 nm (D). This axial shift occurs by self-assembly and can be understood in terms of a periodicity in the occurrence of…
Abstract Coccoliths are delicate calcified structures produced by marine unicellular algae. In the species Emiliania huxleyi the calcium carbonate (mostly calcite) is closely associated with a complex, acidic polysaccharide which binds calcium ions specifically, interferes with the in vitro crystallization of calcium…
Small polystyrene particles coated with a high Mr non-ionic surfactant (Poloxamer 338) are diverted from the reticuloendothelial system of the liver and spleen to other tissue sites. These results are discussed in terms of the adsorption of the Poloxamer to the particle surface and the implications for drug targeting.
Abstract Mollusc shells are used as a model for studying ‘organic-matrix -mediated’ biomineralization, in which crystals are nucleated and grow in a pre-formed structural framework composed of proteins and polysaccharides. In particular, the possibility that the organic matrix functions as a template for crystal forma…
Abstract High-resolution electron microscopy, in conjunction with controlled specimen preparation procedures, has enabled the nature and structure of novel {100} platelet defects found in TiO2-x (0 < x < 0.0035) to be studied at close to atomic resolution The precipitation of these platelet defects, ofte…
The incommensurate phase of krypton on graphite is studied by use of the molecular-dynamics simulation technique for systems with graphite substrate dimensions comparable to present-day laboratory capabilities. At low temperature and for all coverages, honeycomb networks of "heavy" domain walls are observed for the fi…
Abstract A new chlorination mechanism has been suggested for polyethylene crystals. Based on electron microsocopy and infrared spectroscopy of chlorinated high‐density polyethylene single crystals, it is proposed that beyond the initial chlorination of the lamellae surfaces, which accounts for only 2‐3% chlorine uptak…
Abstract The 13 C NMR spectra of tetraalkyl‐porphyrin and ‐chlorin complexes of nickel(II) were studied. The 13 C NMR of (5,10,15,20‐tetramethylchlorinato)nickel(II) supports the model of asymmetric charge distribution in this chlorin, as derived from the structure analysis and from previous proton NMR studies.