Materials Literature
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In this paper we examine the stability of corona- and electron-beam-charged 25-μm FEP-A in open circuit by using thermally stimulated (TSC) measurements. We show that electrets charged with electron beams of 10 keV or higher are more stable than corona-charged foils. The inferior stability of corona-charged samples is…
Abstract The catalytic activity of metal porphyrins for the electroreduction of carbon dioxide was investigated by the measurements of current-potential curves on the Hg(Pt) electrode in aqueous electrolytic solutions. Metal-free, cobalt, iron and copper porphyrins(mesotetracarboxyphenylporphyrins, tetraphenylporphine…
The ability of Salmonella typhimurium to synthesize enterochelin (enterobactin; ENT) affects its capacity to grow both in vivo and in vitro. An ENT mutant (96-1), blocked in the conversion of chorismate to 2,3-dihydroxybenzoate, was derived from SR-11, a strain of high mouse virulence. This mutant was unchanged in the…
Abstract A new analysis has been made on studies of the influence of imino acid content on the changes of collagen thermal stability ( t m ). It is shown that, for the interstitial vertebrate collagens, there is a strict regularity in the changes of t m depending on hydroxyproline content. No correlation is observed b…
A theoretical study of domain walls in uniaxial displacive ferrodistortive systems is presented. We start from a generalized Langevin equation of motion for the movements of the ions, which includes dissipative terms and external fields, in addition to anharmonic and strain-force terms. We obtain large- and small-ampl…
The kinetics of the electrochromic process and the stability with different electrodes (evaporated film, electrodes obtained by anodic oxidation of W, polycrystalline, and single crystal) were studied. Cyclic voltammetry and chronoamperometry, together with optical absorption measurements in the electrochromic region…
Abstract A permanganic etchant has been developed which reveals lamellar and other fine detail in surfaces of at least three crystalline polyolefines, viz., polyethylene (of both high and low density), isotactic polypropylene, and isotactic poly(4‐methylpentene‐1). In typical treatments of high‐density polyethylene ca…
Isolated air crazes have been produced in thin films of polystyrene (PS) bonded to copper grids by straining these in tension. The craze thickness profile, r(x), was directly determined from a series of transmission electron micrographs taken along the craze. Local values of the craze fibril volume fraction v 1 and fi…
Abstract The crystal structure of a synthetic boehmite sample has been refined to an R of 0.047 in the space group Amam from X-ray powder diffraction data. Inclusion of hydrogen atoms and/or refinement in the space group A2 1 am gave poorer results. Cell dimensions were determined as a = 3.6936 (± 0.0003), b = 12.214…
We have grown and measured the optical second-harmonic coefficient dijk of the new nonlinear crystal 2-methyl-4-nitroaniline (MNA). We find that the dijk are very large with d12 being 5.8 times larger than d31 of LiNbO3 giving a birefringence phase-matching figure of merit d2/n3 which is 45 times larger than LiNbO3. T…
A theory is presented which quantitatively accounts for the important features of conduction in ZnO-based metal-oxide varistors. This theory has no adjustable parameters. Using the known values of the ZnO band gap, donor concentration n0, and low-voltage varistor leakage-current activation energy, we predict a varisto…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTwo-dimensional chemical state plots: a standardized data set for use in identifying chemical states by x-ray photoelectron spectroscopyC. D. Wagner, L. H. Gale, and R. H. RaymondCite this: Anal. Chem. 1979, 51, 4, 466–482Publication Date (Print):April 1, 1979Publication His…
Fixation - Washing, Dehydration and Embedding - Sectioning - Staining - Support Films - Cryofixation - Negative Staining - References - Index
The dielectric constants ${\ensuremath{\epsilon}}_{〈110〉}$ and their change with uniaxial $〈1\overline{1}0〉$ stress in monodomain $〈001〉$SrTi${\mathrm{O}}_{3}$ samples have been measured as a function of temperature. Between 4 K and 0.3 K these quantities are independent of temperature. In one sample $\ensuremath{\eps…
The Fermi gas model of one-dimensional conductors is reviewed. The exact solutions known for particular values of the coupling constants in a single chain problem (Tomonaga model, Luther-Emery model) are discussed. Renormalization group arguments are used to extend these solutions to arbitrary values of the couplings.…
Abstract The monomer sequence CF 2 CF(CF 3 )CH 2 CF 2 CF 2 CF(CF 3 ) has been identified by 19 FNMR as the selectively base‐sensitive site of poly(vinylidene fluoride/hexafluoropropylene). Similar studies of other vinylidene fluoride (VF 2 ) copolymers with either tetrafluoroethylene (TFE) or perfluoro(methyl vinyl et…
A Raman study of the three-solid-state phase transitions in diamantane is presented. The low-temperature transition at T c1 =35K is characterised by a zone-centre soft librational mode; this mode has been fitted to a damped harmonic oscillator function, and the damping and static susceptibility of the soft mode obtain…
The room-temperature direct allowed energy gap E g =3.425 eV was obtained for single crystals of GeS 2 which have an orthorhombic structure. The far-infrared transmission spectrum was measured with unpolarised light in the range of 100-250 cm -1 . The reflectivity spectrum was obtained, also with unpolarised light, in…
The following investigation concerns the identification of mechanisms responsible for the blue emission obtained with bismuth-doped lanthanum phosphate LaPO 4 (Bi). Observations of absorption, excitation and fluorescence spectra, together with measurements of the decay time from liquid He up to room temperature are pr…
A set of total cross sections for scattering of electrons by Ne, Ar, Kr and Xe has been evaluated over the energy range of about 20 to 3000 eV by means of the analysis of experiments and theories on total cross sections for elastic scattering, ionisation and excitation, and on differential cross sections for elastic a…