Materials Literature
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The configurational entropy theory of glass formation is used to derive the composition dependence of the glass transition temperature (Tg) and of supercooled liquid transport properties for binary mixtures which obey the laws of regular solutions. The relations between expressions derived subject to specified approxi…
The influence of high external stress (τ ≤ 340 N/mm2 on the dissociation of dislocations in silicon has been investigated. At 420°C the dislocations are strictly parallel to 〈110〉 directions. From the orientation of the compression axis a reduction in the dissociation width is to be expected. We have found screw dislo…
A new apparatus for reflection high energy electron diffraction (RHEED) provided with an electron gun with a sharply focused electron beam and operated under ultrahigh vacuum condition has been constructed. It has a specially devised fluorescent screen which enables us to take new type RHEED patterns corresponding to…
A nuclear framework structure termed the nuclear matrix has been isolated and characterized. This matrix forms the major residual structure of isolated nuclei and consists largely of protein with smaller amounts of RNA, DNA, carbohydrate, and phospholipid. The nuclear matrix can be further resolved by combined treatme…
The mechanism of field‐assisted pore formation in 15% wt aqueous solutions was studied by O 18 tracing techniques. Compact base layers were first formed in an O 18 labeled solution and further oxidized in a nonlabeled solution, leading to field‐assisted pore formation. The O 18 content and depth distribution was measu…
The crystal structure of a polysaccharide can be obtained by first determining the crystal structures of its oligosaccharide single crystals. By extrapolation and comparison with the fiber diagram, the structure of the polysaccharide is obtained. This is the classical approach for polymer structures and some efforts a…
(Most chapters end with References and Problems). 1. Nuclear Engineering. 2. Atomic and Nuclear Physics. Fundamental Particles. Atomic and Nuclear Structure. Atomic and Molecular Weight. Atomic and Nuclear Radii. Mass and Energy. Particle Wavelengths. Excited States and Radiation. Nuclear Stability and Radioactive Dec…
Results obtained on the polymerisation, copolymerisation, and graft copolymerisation of vinyl fluoride, various properties of the polymers thus produced, and also possible fields of application are discussed on the basis of 435 references published up to the beginning of 1976.
CONTENTS 1. Introduction 432 2. The Electronic State of Adsorbed Atoms 432 3. Interaction of Adsorbed Particles. Dependence of Heat of Adsorption and Work Function on Concentration of Adatoms 437 4. Atomic Structure of Submonolayer Films and Phase Transitions in Them 441 5. Conclusion 448 References 449
We report the structure and electronic properties of ${(\mathrm{SN}{\mathrm{Br}}_{0.4})}_{x}$ and the first chemical modification of the polymeric superconductor ${(\mathrm{SN})}_{x}$. Its dc conductivity at 300 K is ten times greater than that for ${(\mathrm{SN})}_{x}$ and the thermoelectric power is positive rather…
Abstract Systematic measurements of the core-electron binding energies of the rare-earth metals terbium to lutetium, and their surface and bulk oxides, have been made with a VG-ESCA3 X-ray photoelectron spectrometer coupled with a PDP/8E computer. Comparison of the measured binding energies for the core levels with ac…
The linear thermal expansion of a polycrystalline sample has been measured in the ranges 1.5<T<34K, 55<T<90K, and at room temperature; and its heat capacity in the range 1.3<T<16K. Expansion is strongly negative at low temperatures, with Gruneisen parameters gamma 0 th =-2.4+or-0.4 and gamma min th =…
Abstract When a high molecular weight polymer, in a solution of concentration above the critical concentration for entanglement, is lightly crosslinked to effect only a few bonds per macromolecule, its solution viscosity is significantly affected. The random coil model predicts a monotonous increase in viscosity as a…
Ternary chalcopyrite crystals are well studied and some of the promising crystals are finding useful applications in nonlinear optical devices. Two other groups of diamond-like crystals are considered: stannite and famatinite which are derived from chalcopyrite. Nonlinearity and average refractive index are calculated…
It is shown that the strong far-infrared absorption in small Al particles, recently observed by Granqvist et al., may be explained as arising from the dielectric losses in the amorphous oxide layers covering the particles. Aggregation of particles into clusters is found essential in order to produce the observed depen…
The low-frequency (0 to 500 cm−1) Raman spectra are recorded at different temperatures between 40 and 413 K through the different structural modifications: P21/c ↔ P42/ncm ↔ Cmca ↔ ↔↔ I4/mmm. The results agree with previous NMR data and show that the three higher-temperature tetragonal and orthorhombic phases exhibit…
The growth of LiYO2 and its structure are discussed. The absorption and luminescence spectra of Nd3+ in LiYO2 monocrystals are recorded at 4.2, 50, 77, and 300 K in the region from 250 to 2500 nm. The Nd3+ ion energy level diagram is constructed on the basis of the spectral data. Theoretical calculations of the intrin…
The isotope effect for diffusion of $^{113}\mathrm{Sn}$ and $^{121}\mathrm{Sn}^{m}$ in Ti has been measured at five temperatures in the bcc $\ensuremath{\beta}$ phase. Separation of the Sn isotopes was effected by $\ensuremath{\beta}$ spectroscopy on electroplated sources. The effect is small and highly temperature de…
Measurements of the $^{77}\mathrm{Se}$ nuclear magnetic resonance as a function of temperature are reported for the $2H$ polytypes of Nb${\mathrm{Se}}_{2}$ and Ta${\mathrm{Se}}_{2}$. Below the critical temperatures, the charge-density waves (CDW) produce a distribution of Knight shifts resulting in an asymmetrical bro…
The torsion-effusion method, with simultaneous torque angle and weight loss measurements, was used to study the thermal decomposition of MgSO4 and CaSO4. The initial step in the decomposition/vaporization process appears to be the evolution of an SO3 molecule from the lattice, followed by conversion to SO2 and O2 on t…