Materials Literature
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X-ray scattering studies of Nb${\mathrm{Se}}_{3}$ show the formation of two independent, incommensurate charge-density waves (CDW) with wave vectors ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}}_{1}=(0, 0.243, 0)$ and ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}}_{2}=(0.5, 0.263, 0.5)$ at ${T}_{1}=144$ K and…
Effects of refraction of $p$-polarized light are shown to be of importance in understanding angle-resolved photoemission data from surface states on metals as a function of the photon energy. Special attention is paid to photon energies near the bulk-plasmon energy of the metal, and it is shown that refraction effects…
In this work, we provide a simple classical model to explain the enormous intensity enhancement observed for Raman scattering from molecules adsorbed on electrode surfaces. It is proposed that the origin of the intensity enhancement arises from very large changes in the polarizability derivative with respect to a norm…
The special-point formulas generated from product Gauss-Chebyshev integration formulas for fcc and bcc lattices are compared with those resulting from the special treatment suggested by Monkhorst and Pack. It is found that the Monkhorst-Pack special-point formulas are more efficient for formulas with few points and le…
A method to obtain the X-ray photoabsorption spectra of a bulk sample based on the specular reflection of continuous radiation on its surface is proposed.
LEED crystallography is reviewed by describing the four stages of a typical surface-structure analysis by LEED, namely (i) the experimental procedure, (ii) the identification of structural model, (iii) the calculation of LEED intensities expected from the chosen models, (iv) the evaluation of the agreement between cal…
Yeast poly(adenylic acid)-containing messenger ribonucleic acid isolated from two strains of Saccharomyces cerevisiae was fractionated by preparative polyacrylamide gel electrophoresis in the presence of formamide. Three messenger ribonucleic acids, present at high intracellular concentration, were electrophoretically…
Isolated single-layer edge dislocations in smectic liquid crystals are observed by polarization microscopy. The modification of the smectic-$A$---smectic-$C$ transition temperature by the strain field of the dislocations is used to make them visible. Observations of periodic arrays in thin samples, by various polariza…
X-ray photoemission spectra of $4f$ and valence electrons in surface atoms of gold have been obtained. The surface-atom $4f$ level is shifted 0.40\ifmmode\pm\else\textpm\fi{}0.01 eV to lower binding energy relative to the bulk value. The surface density of states is narrowed by (7.6 \ifmmode\pm\else\textpm\fi{} 1.1)%…
The three-body attachment coefficient in oxygen is calculated by a Boltzmann equation method using the electron collision cross section for this process which is proportional to the gas number density. The calculated values of the coefficient agree well with previous experimental values and represent well the gas pres…
The collagens of all major invertebrate phyla have been studied, but characterization has been thorough in only a few classes and in no case in the detail (such as sequence analysis) known for vertebrate collagen. Biochemical data on insect collagen are particularly sparse. Invertebrate and vertebrate collagens are st…
A new phase in Cs${\mathrm{H}}_{2}$P${\mathrm{O}}_{4}$ is induced by pressures above about 3.3 kbar; this phase is confirmed to be antiferroelectric by the observation of $P\ensuremath{-}E$ double hysteresis loops. The qualitative change from the paraelectric-ferroelectric to the paraelectric-antiferroelectric transit…
A method is developed for computing the discharge threshold voltages in SF6, N2 as well as their mixtures above atmopheric pressure. In electronegative gases, and for both uniform and nonuniform field gaps of positive polarity, there is a critical pressure above which field emission from the cathode surface has a sign…
The spontaneous polarization was measured by means of the Sawyer-Tower method in mixtures of chiral smectic C liquid crystal with smectic C liquid crystal. Induced circular dichroism in the chiral smectic C phase was also measured on the same mixtures. It was found that the magnitude of spontaneous polarization was de…
The distortion of the pyrazine molecule in its triplet excited state, as revealed by the appearance of the group theoretically forbidden bands in the sublevel phosphorescence, is analyzed in terms of the polarization of the originally forbidden bands in the sublevel phosphorescence. The experimental results together w…
Abstract Many papers have reported on the thermal shrinkage mechanism of drawn polymers. The cause of the thermal shrinkage is very complex, because that relates to many factors. In this study, atactic polystyrene, a noncrystalline polymer, was used to eliminate factors related to the melting and crystallization effec…
An iterative method of computation has been applied to determine the activation stress of emerging segments of dislocations, anchored beneath the free surface, in the case of a homogeneous applied stress field. The calculation has been performed for a series of orientations of the Burgers vector and of source lengths.…
During rapid growth, the excretion of pyrimidines, predominantly uracil, is a common phenomenon in procaryotes and eucaryotes. In Escherichia coli, some K-12 strains excrete orotic acid and not uracil. This is caused by a mutation in the pyrF gene.
The infrared absorption and laser Raman spectra of BaCl 2 ·2H 2 O powder and single crystals as well as BaCl 2 ·2D 2 O, partially deuterated, and isotopically dilute samples have been analyzed in the range from 30 to 4000 cm −1 . A revised interpretation of the observed water bands is given. The influence of the bond…
Ordinarily one expects the structural and magnetic properties of a given substance to be intimately related, with the dimensionality of the magnetic or electrical interactions that are present reflecting the lattice dimensionality. For example, a cluster of two interacting magnetic ions should obey a theoretical model…