Materials Literature
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Aqueous solutions of tobacco mosaic virus are ideal systems for visualizing ``molecular'' distributions in the nematic phase by freeze-fracture electron microscopy. The order parameter in well aligned regions is measured to be greater than 0.9. Twist deformations appear to be most common, confirming that the twist ela…
The authors report NMR measurements of the $^{93}\mathrm{Nb}$ resonance in the charge-density-wave (CDW) conductor ${\mathrm{NbSe}}_{3}$ on aligned, multicrystalline samples. They have observed the resonance with and without current flow in the sample at temperatures above 59 K, where a single incommensurate CDW is pr…
Absorption and desorption of hydrogen by the permanent magnet material Nd2Fe14B have been studied using a microcomputer-controlled, thermomanometric analyzer with an initial hydrogen pressure of approximately 1 bar. Primary absorption occurs in the range 200–300 °C and results in the formation of a stable hydride with…
From photoinduced absorption and light-induced electron-spin resonance, we demonstrate that the dominant photocarriers generated in polythiophene with excitation above the energy gap (${E}_{g}$) are charged bipolarons (spin 0). The observation of bipolarons (${B}^{2\ifmmode\pm\else\textpm\fi{}}$) rather than polarons…
Abstract E. p. r. at microwave frequencies in single crystals of lanthanum nicotinate dihydrate (LaND) doped with ca. 0.01 mole fraction of thulium shows no spectrum of isolated Tm3+ ions, but does exhibit spectra from coupled pairs of nearest-neighbour Tm3+ ions. The spin hamilton parameters are approximately the sam…
Abstract For many purposes the natural‐synthetic fiber‐blend fabrics are more suitable than pure natural or synthetic products. It is often possible to obtain a maximum in clothing and textile technical properties by compensating the defects of one fiber by using an other totally different fiber. Many problems, howeve…
Abstract A postirradiation process was evaluated in polymerizing vinyl monomers on poly(ethylene terephthalate) (PET) film, fiber, and fabric. The use of DMF, pyridine, and DMSO as swelling agents to facilitate monomer incorporation and effective polymerization were also investigated. The solvents were effective in pr…
Abstract Reaction of cellulose with hexamethylphosphoric acid triamide has been investigated under various physical conditions. Dimethylamine hydrochloride was found to be an efficient catalyst for the system. The thermal degradation of cellulose and its phosphoramide products in air was studied by DTA, TG, and DTG te…
Abstract Tri‐ O ‐methyl‐, ‐ethyl‐, ‐ n ‐propyl‐, ‐ n ‐butyl‐, ‐ n ‐pentyl‐, ‐iso‐amyl‐, ‐ n ‐hexyl‐, ‐ n ‐heptyl‐, ‐ n ‐octyl‐, ‐ n ‐decyl‐, and ‐3‐phenoxypropyl‐celluloses have been prepared with powdered sodium hydroxide and the corresponding alkyl iodides or bromides in one of nonaqueous cellulose solvents, SO 2 ‐d…
Abstract Crosslinked xerogels in the form of rods have been prepared to > 99.9% conversion by the γ‐ray initiated copolymerization in vacuo ob n ‐butyl acrylate (BA) with N ‐vinyl‐2‐pyrrolidone (VP) in the presence and absence of a crosslinking agent. Thin (about 0.5 mm) disks were swollen in water at 21°C, the fin…
Abstract Hyperfine data and g factors are reported for the radical cations of tetrathiafulvalene (TTF; 1 ) and of its derivatives 2–13 . From the intense satellite spectra of 1 + – 13 + not only the coupling constants of the 33 S isotopes in the TTF moiety could be determined, but also, in favourable cases, those of t…
Abstract Studies on impact behaviour of the blend of isotactic polypropylene (PP) with styrene‐ b ‐ethylene‐co‐butylene– b ‐styrene triblock copolymer (SEBS) in the composition range 0–25 wt % SEBS at three temperatures, viz., ambient, −30°C, and −190°C, are presented. Dynamic mechanical properties on a torsion pendul…
Abstract Chiral metals are so far practically unknown. The synthesis of a chiral substrate for possible organic conductors and superconductors is described.
We observed that the photoemission intensity from solids may depend explicitly on the spin state of the photoexcited electrons. This new phenomenon is explained by spin-dependent transmission through the surface of solids with nonvanishing spin-orbit coupling. It is demonstrated for photoemission from Pt(111) with ell…
X-ray diffraction measurements were performed at atmospheric pressure on a high-density form of amorphous ice obtained by pressurizing crystalline ice Ih at 77 K, up to 2 GPa. The low--momentum-transfer region of the determined structure factor is quite different from that corresponding to the low-density form of amor…
Secondary grain growth in thin Au films on SiO2 substrates is reported. Secondary grains have {111} texture which minimizes the surface energy. This indicates that surface energy anisotropy provides selectivity in the driving force for growth of secondary grains. In thin Au films on SiO2, surface-energy-driven seconda…
For a given temperature below the smectic-A (SmA)--chiral--smectic-C (${\mathrm{SmC}}^{\mathrm{*}}$) transition of DOBAMBC, polarization (P) and tilt-angle (theta) have been measured almost simultaneously with high resolution. The ratio P/theta stays fairly constant for ${\mathrm{T}}_{\mathrm{c}}$-T>2 K and shows a…
Dense tetragonal zirconia-yttria ceramics has been prepared with grain sizes between 0.1 and 0.5 µm. The fracture toughness and flexure strength at room temperature are independent on grain size and composition in the tetragonal phase region with YO1.5 larger than 5 at.%. The ageing rate of the mechanical properties i…
Methods for the solution of thermal-hydraulic problems in liquid-metal fast breeder reactors arising primarily from transient accident analysis are reviewed. Principal emphasis is given to the important phenomenological issues of sodium boiling and fuel motion. Descriptions of representative phenomenological and mathe…
The authors prepare double borates of scandium and cerium subgroup rare earths with the general formula RSc/sub 3/ (BO/sub 3/)/sub 4/ (R = Ce, Pr, Nd, Sm). It has been shown that these compounds have the structure of the carbonate mineral huntite. Their IR and luminescence spectra have been studied.