Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure and selectivity in host-guest complexes of cucurbiturilWilliam L. Mock and Neng Yang ShihCite this: J. Org. Chem. 1986, 51, 23, 4440–4446Publication Date (Print):November 1, 1986Publication History Published online1 May 2002Published inissue 1 November 1986https://…
A rigorous coupled-wave analysis for metallic surface-relief gratings is presented. This approach allows an arbitrary complex permittivity to be used for the material and thus avoids the infinite conductivity (perfect-conductor) approximation. Both TE and TM polarizations and arbitrary angles of incidence are treated.…
A review is given of the studies of the dimensionality characteristics of percolation clusters. The purely geometric nature of a percolation phase transition and the great variety of the quantities exhibiting critical behavior make this geometric approach both informative and useful. In addition to the fractal dimensi…
The direct determination of carbon–carbon bonding in amorphous carbon thin films has been performed by core-electron energy-loss spectroscopy and cross-polarization magic-angle spinning 13C nuclear magnetic resonance (NMR) for a series of varying band-gap amorphous carbon films (1.1–3.0 eV). The amorphous carbon films…
The question of whether scattering by the almost-periodic lattice potentials of recently discovered metallic quasicrystals is able to explain the recently observed short mean free paths (about 1 \AA{}) in these materials is discussed. It is shown that scattering by a three-dimensional, almost-periodic potential cannot…
Low density lipoprotein (LDL) doped with the anticancer mixture of hematoporphyrin derivatives Photofrin II (P2) competes with native LDL for binding to fibroblast receptors, despite a slight increase in the negative net charge related to the presence of acidic residues of porphyrins. P2 delivery to fibroblasts can be…
We report a new approach to the study of electron spectral clustering and wave-function scaling in several one-dimensional quasiperiodic systems. The approach is based on renormalization-group ideas. We introduce a novel decimation technique which generates a simple physical picture of the electron spectral behavior a…
The magnetic properties of surfaces are now being explored with electron spectroscopies that use electron spin polarization techniques. The increased activity in surface magnetic measurements with polarized electron beams is spurred by new scientific and technological challenges and is made feasible by recent advances…
Techniques for analyzing the structure and composition of solid surfaces with electron and photon beams often cause radiation damage in samples. Damage-producing processes compete with information-producing events during measurements, and beam damage can be a serious perturbation in quantitative surface analysis. Ther…
The conductivity σ of highly pure, thin zinc oxide films is investigated in the temperature range 500 to 1000 K and in the oxygen pressure range 0.1 to 15 kPa. The results reveal that two competing equilibria are responsible for the conductivity behaviour. In the high-temperature range the activation energy of σ is 1.…
Cristallisation dans le systeme orthohombique, groupe Pbca et affinement jusqu'a R=0,042. La structure est constituee de 3 tetraedres H 2 PO 3 non equivalents cristallographiquement, de molecules d'eau et d'atomes Mn et Na hexacoodines
From structural results previously reported the equilibrium conditions for ion-ion correlations in \ensuremath{\beta}-alumina are obtained. This provides a theoretical confirmation of the Beevers-Ross--mid-oxygen (BR-mO) model stability which whatever is the composition (1(5/3)) reveals itself to correspond to a lower…
We consider a finite superlattice consisting of unit cells with quantum wells filled with different types of carriers. The density-density correlation function is calculated with use of the random-phase approximation. The theory of resonant Raman scattering and inelastic electron scattering is formulated. The general…
The absorptances of 633-nm photons by silver island films formed on room temperature substrates were measured in an attenuated-total-reflection geometry by the photoacoustic method as a function of the angle of photon incidence. From the data obtained for s-polarized light ∊″, the effective dielectric function for the…
Long-range and local orders for ion-rich \ensuremath{\beta}- and \ensuremath{\beta}''-alumina are determined from conventional crystal-structure determinations and x-ray diffuse scattering. Both materials exhibit composition close to 1.66 ${\mathrm{Na}}^{+}$ per unit plane cell with a compensation mechanism exclusivel…
We study and compare plasmon spectra in semiconductor superlattices with periodic, quasiperiodic (e.g., Fibonacci sequence), and random spacings. Novel mode structures are found in the quasiperiodic cases, particularly for low values of level broadening that arises from inherent disorder effects. We discuss critically…
In any fluid or solid condensed phase, instantaneous atomic positions can be resolved into a combination of inherent packing and of vibrational deformation components. In principle the latter can be removed by quenching the system by (mass-weighted) steepest descent on the potential-energy hypersurface. Inherent struc…
Experiments on the transport of thermal energy through aggregates of small particles at low temperature are discussed. A transition to a weakly-temperature-dependent thermal conductivity, or plateau, appears at the temperature at which the thermal phonon wavelength equals the particle size. This is interpreted as evid…
Evidence from a number of previous experiments is found for Ag-cluster vibrations in enhanced Raman scattering from a Ag surface. By the analysis of the conditions specific to such experiments, the most likely identity of these clusters has been revealed to be ${\mathrm{Ag}}_{4}$${\mathrm{}}^{+}$. To further confirm t…
The reflective and absorptive contributions to the optical modulation in sputter-deposited thin films of crystalline LixWO3 have been determined as a function of lithium concentration (0<x<0.5). The magnitude of the reflective response increases with increasing substrate temperature (Ts) during depositio…