Materials Literature
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As a crystal is disordered, a point may be reached where the typical mean free path of phonons is so short that the wavelength and mean free path are no longer sharp concepts, and the textbook phonon-gas model for thermal conductivity breaks down. This paper proposes an alternate theory for the disordered regime, and…
A variety of spray pyrolysis (SP) techniques have been developed to directly produce ceramic powders from solutions. This paper reviews the current status of these processes in terms of the process parameters that enable the formation of particles with controlled morphology and composition. A model incorporating solut…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAdsorption of proteins onto surfaces containing end-attached oligo(ethylene oxide): a model system using self-assembled monolayersKevin L. Prime and George M. WhitesidesCite this: J. Am. Chem. Soc. 1993, 115, 23, 10714–10721Publication Date (Print):November 1, 1993Publicatio…
The structural instabilities towards the formation of a charge density wave (CDW) ground state exhibited by several layered Mo and W bronzes and oxides are reviewed. It is shown that in these two-dimensional (2D) metals, including the purple bronzes A x Mo 6 O 17 (A=K, Na, Tl; x≈1), the γ and η phases of MO 4 O 11 and…
The tungsten oxides and bronzes have been extensively studied since their discovery in the last century, because of their brilliant colors and high electrical conductivity. More recently the driving interest resulted from their potential use in electrochromic displays and other electrochemical systems. Their crystalli…
A brief introduction is presented on transition metal oxide bronzes and their relationship to the phosphate tungsten bronzes; the latter compounds are the major focus of this review. The phosphate tungsten bronzes (PTB) are a new class of quasi-low-dimensional materials which exhibit charge density wave (CDW) instabil…
The physical properties of the low dimensional molybdenum bronzes showing charge density wave (CDW) instabilities are reviewed. The mechanisms of the Peierls transition, CDW and spin density wave (SDW) instabilities are first introduced. The properties of the quasi-one-dimensional (1D) blue bronze, A 0.30 MoO 3 , incl…
The formation of high-quality thin films of polytetrafluoroethylene (PTFE) is important in many applications ranging from material reinforcement to molecular electronics. Laser ablation, a technique widely used to deposit a variety of inorganic materials, can also be used as a simple and highly versatile method for fo…
The lattice parameters a, b and c of TmCu 2 have been measured in the temperature range from 4.2 K up to 300 K using X-ray powder diffraction. The influence of the crystal field on the thermal expansion in TmCu 2 in the paramagnetic region has been determined by comparing the thermal expansion of the non-magnetic YCu…
It is shown that there exists a numerical relationship between the position of the first sharp diffraction peak, Q 1 , and the first interatomic distance, r 1 , which obeys a simple equation d=ar 1 +b where d=2 pi /Q 1 is the equivalent distance and the coefficients (a, b) specify the group of amorphous substances-gla…
Dielectric and thermodynamic properties have been investigated in isotopically mixed crystals ${\mathrm{K}}_{3}$${\mathrm{D}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{H}}_{\mathit{x}}$(${\mathrm{SO}}_{4}$${)}_{2}$ with isolated hydrogen bonds interconnecting the dimeric ${\mathrm{SO}}_{4}^{2\mathrm{\ensuremath{-…
This paper reports electron paramagnetic resonance (EPR) measurements of Cr 3+ ions in YAlO 3 (YAP) at 1.6 K and room temperature along with their optical absorption and luminescence spectra The polarization of the excitation spectrum of the Cr 3+ luminescence has also been measured. The EPR spectrum is ascribed to su…
The phase diagram of dipolar hard spheres has been determined by Monte Carlo simulation for reduced densities ${\mathrm{\ensuremath{\rho}}}^{\mathrm{*}}$ ranging from 0.02--0.3 and reduced temperatures ${\mathit{T}}^{\mathrm{*}}$ from 0.08--0.25. For ${\mathit{T}}^{\mathrm{*}}$\ensuremath{\lesssim}0.15 the particles a…
The non-equilibrium critical relaxation of systems in which the order parameter couples reversibly to conserved densities is investigated. The initial state which may be macroscopically prepared by a quench from a temperature T >> T c to the critical temperature T c is characterized by short-range correlations. In the…
An immersion grating with a high refractive index, n, increases the spectral resolution by a factor n over that of a reflective surface grating of equal length. A silicon immersion grating has been developed and tested; initial results are reported here.
Abstract Blends of Thermoplastic polyurethane (TPU) and poly(styrene‐co‐acrylonitrile) (SAN) (34% acrylonitrile and 24% acrylonitrile) and polyurethane ionomer (PUI) with SAN (34% acrylonitrile) were prepared in the melt. The structural properties and morphology of the blends were investigated. TPU and SAN blends were…
Abstract This article includes the doping and dedoping behaviors, the electrical conductivity, and the spectral properties of poly(2‐ethynylpyridine) and iodine‐doped poly(2‐ethynylpyri‐dine). The doping ability of poly(2‐ethynylpyridine) having a pyridine substituent was greater than that of polyphenylacetylene havin…
Abstract Cellulose fibers were grafted with compatibilizing agents, such as maleated polypropylenes of different molecular weights. Steric effects and surface free‐energy effects were found to stimulate the stretching of grafted chains away from the cellulose fiber surface, giving rise to a brushlike configuration in…
Abstract Preliminary investigations have been conducted on the graft copolymerization of meth‐ylmethacrylate onto Caesarweed fiber, initiated by potassium permanganate and the toluene redox system. The percentage graft yield increased with permanganate up to 132% in the concentration range, 1.0×10 −2 to 5.0×10 −2 M at…
A particularly popular and powerful use of fluorescent indicators is nondestructive monitoring of the activity or free concentration of important ions or messengers such as Ca 2+, H +, Na +, Mg 2+, Cl -, or cyclic adenosine 3′,5′-monophosphate (cAMP) inside living cells and tissues. Successful indicators and chelators…