Materials Literature
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BaO 2 , M r =169.3, tetragonal, I4/mmm, a=3.8016 (4), c=6.7786 (8) A, V=97.97 (2) A 3 , Z=2, D x =5.74 g cm -3 , λ(Mo Kα)=0.71069 A, μ=198.5 cm -1 , F(000)=144, T=293 K, final R=0.0092 for 58 unique reflections. BaO 2 adopts the CaC 2 structure; Ba is bound to ten O atoms, eight at 2.788 (1) A and two at 2.648 (5) A.…
The magnetocrystalline anisotropy behavior of the 3d sublattice was studied in the face-centered-cubic system Zr6Co23−xMx (M=Fe,Ni). A remarkably high anisotropy field was required to saturate the magnetization along both the [100] and [110] hard directions. The values found are, respectively, HA=43 kOe and HA=33 kOe…
Detailed investigation of the luminescence features due to the recombination of the exciton--free-carrier process in GaSe is presented. This process shows a well-resolved luminescence line and it is an efficient recombination process in this semiconductor, even at low temperatures. We report accurate photoluminescence…
Abstract The permeability coefficient of a wide range (0/100–100/0 octanelactam/laurolactam [OL/LL] mol/mol) of novel copolyamides (nylon 8/nylon 12) was determined and related to the diffusion rate over a range of temperatures: T g –30 to T g + 40°C. An inflection in the plot of permeability vs. 1/ T (K) provided an…
Abstract A computer‐controlled chemiluminescence (CL) instrument incorporating a differential scanning calorimeter was used to simultaneously acquire photochemical and enthalpic data for poly( N ‐vinyl‐2‐pyrrolidone) (PVP). Samples were subjected to a linear temperature ramp under nitrogen and their luminescence respo…
We have performed a detailed adsorption isotherm study of Ar on BN for temperatures between 65 and 80 K. The isothermal compressibility of the films was obtained from adsorption data. At monolayer coverages, a small isotherm substep is present at melting. We found two isothermal compressibility peaks in the first laye…
Monte Carlo simulations were performed on lattice gas systems with Coulombic interactions. Emphasis was placed on two lattice gases. The first consists of both mobile anions and cations while the second is composed of mobile anions and a random distribution of fixed cations. Comparisons are made to a strictly repulsiv…
High-energy-resolution photoemission spectra, taken on three quasi-one-dimensional crystals, ${\mathrm{TaTe}}_{4}$, ${\mathrm{NbTe}}_{4}$, and (${\mathrm{NbSe}}_{4}$${)}_{3}$I confirm the general phenomenon of the suppression of the photoemission intensity near the Fermi level in one dimension. We analyze the possible…
The electron affinity of platinum has been measured to be 17 125(9) cm−1. A pulsed dye laser beam perpendicular to an ion beam photodetached the Pt−. The relative cross section near threshold was measured by detecting the fast neutrals. The threshold was determined by fitting the cross section to the Wigner law.
Abstract The dielectric properties of 30% crystalline dry Nylon‐12 have been measured over the frequency range 10–10 5 Hz and temperature range 300–450 K, and the effect of its annealing at 423 K investigated both by dielectric measurement and differential scanning calorimetry. Annealing causes its crystallization to…
In the present work, systematic Monte Carlo simulations were applied to calculate the intensity of elastically backscattered electrons as a function of energy and exit angle for 27 elements in the energy range from 50 to 2000 eV. By comparison to available experimental data, it is found that the applied theory account…
A novel tumor-associated protein, termed 90K, and recognized by mAb SP-2 was purified from serum of breast cancer patients, ovarian cancer ascitic fluid and conditioned medium of human breast cancer cells. In these three sources, native 90K is present as a high molecular weight complex that was dissociated by SDS-PAGE…
High-resolution 4f core-level spectra of the Ta(110) surface region have been obtained at 80 and 300 K with 70- and 100-eV synchrotron radiation. The data show that the subsurface core-level binding-energy shift (compared to deeper-lying atoms) for a close-packed bcc(110) surface can be substantial: 65\ifmmode\pm\else…
We present Raman spectra of natural Ge, $^{70}\mathrm{Ge}$, and $^{70}\mathrm{Ge}_{0.5}$ $^{76}\mathrm{Ge}_{0.5}$ in the TO phonon region. The spectrum of the isotopically pure $^{70}\mathrm{Ge}$ shows only the Raman-active phonon with k\ensuremath{\rightarrow}=0 (\ensuremath{\Gamma}), as required by k\ensuremath{\rig…
Surface reaction kinetics for diamond growth by chemical vapor deposition (CVD) was investigated experimentally. The temperature dependence for the growth rate exhibited surface-reaction controlled kinetics with the activation energy of about 23 kcal/mol below 900 °C. The dependence of the growth rate on the other CVD…
Using a tight-binding, total-energy model, we have calculated relaxed surface atomic positions, surface-state energies, and densities of states for the reduced and stoichiometric (110) surfaces of rutile-structure tin dioxide (cassiterite). Both relaxed surfaces display a small rumple of the top atomic layer and small…
Abstract Cascade (dendritic) polymers are discrete, highly branched, monodisperse polymers that possess branching patterns described by a mathematical progression. A systematic nomenclature that accurately represents these molecules is described. © 1993 John Wiley & Sons, Inc.
The growth-sector dependence of fine structure in the first-order Raman diamond line is investigated for the first time in high resolution spectra taken from large isolated diamond single crystals grown using microwave plasma chemical vapor deposition on tungsten wire tips. The volumes of crystal beneath the (100) and…
In this Monte Carlo simulation the authors study the glass transition of a dense three-dimensional polymer melt using a lattice model (a bond-fluctuation model on a simple cubic lattice) that was highly optimized for a vector supercomputer. Long bonds are energetically favoured to create a competition between bond ene…
We present a tight-binding calculation of the interband optical transitions in semiconductor quantum dots (QD's). The calculated optical-absorption spectra are in good agreement with the existing experimental spectra of CdS and CdSe QD's. We establish a correspondence between the tight-binding (TB) energy levels and t…