Materials Literature
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Corrosion behavior of mold-cast Mg alloy AZ91 is investigated in as-cast (F), homogenized (T4), and artificially-aged (T6) conditions in chloride media. Heat treatment influences mainly the distribution of intermetallic β-phase (Mg17Al12) in the alloy. Aging to T6 temper causes precipitation of the phase as a nearly c…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStabilization of a liquid-crystalline phase through noncovalent interaction with a polymer side chainTakashi Kato and Jean M. J. FrechetCite this: Macromolecules 1989, 22, 9, 3818–3819Publication Date (Print):September 1, 1989Publication History Published online1 May 2002Pub…
Abstract Synthesis, mesomorphism, orientation and photo‐initiated chain crosslinking of the liquid‐crystalline diacrylate 1,4‐phenylene bis{4‐[6‐(acryloyloxy)hexyloxy]benzoate} ( 1 ) are studied. Monomer 1 exhibits a broad nematic phase between 108 and 155°C and a monotropic smectic phase below 88°C. The monomer is un…
The phbC gene encoding the third enzyme of the poly-beta-hydroxybutyrate biosynthetic pathway, poly-beta-hydroxybutyrate polymerase, in Alcaligenes eutrophus H16 has been identified by the complementation of poly-beta-hydroxybutyrate negative mutants of A. eutrophus H16. These results demonstrate that the three enzyme…
The dynamics of laser-produced cavitation bubbles near a solid boundary and its dependence on the distance between bubble and wall are investigated experimentally. It is shown by means of high-speed photography with up to 1 million frames/s that jet and counterjet formation and the development of a ring vortex resulti…
Active transport across the vacuolar components of the eukaryotic endomembrane system is energized by a specific vacuolar H+-ATPase. The amino acid sequences of the 70- and 60-kDa subunits of the vacuolar H+-ATPase are approximately equal to 25% identical to the beta and alpha subunits, respectively, of the eubacteria…
A review is given of the experimental investigations of the magnetocaloric effect (MCE) in rare-earth magnetic materials of different classes: heavy rare-earth metals and their alloys, iron garnets, and intermetallic compounds. The results of measurements of the MCE near phase transitions are given for the vicinity of…
The gene coding for nitrite reductase of Pseudomonas aeruginosa has been cloned and its sequence determined. The coding region is 1707 bp long and contains information for a polypeptide chain of 568 amino acids. The sequence of the mature protein has been confirmed independently by extensive amino acid sequencing. The…
Crystals of hen egg white lysozyme soaked in 15% (v/v) dimethyl sulfoxide have been studied with single-crystal neutron diffraction to determine the effect of the solvent molecules on the protein configuration. A total of 9423 statistically significant Bragg reflections to a resolution of approximately 1.8 A were used…
The dynamics of ultra-thin wetting films has been studied experimentally under a controlled atmosphere using a dynamic ellipsometric technique. The spreading fluid was PDMS and the substrates were oxide covered silicon wafers. The situations of capillary rise up a vertical wall, and the spreading of 'nanoscopic' drops…
We report on measurements of the thermal conductivity ${\mathrm{\ensuremath{\kappa}}}_{\mathrm{T}}$ close to the Peierls transition temperature ${\mathrm{T}}_{\mathrm{P}}$ in ${\mathrm{K}}_{0.3}$${\mathrm{MoO}}_{3}$ and (${\mathrm{TaSe}}_{4}$${)}_{2}$I. In both cases there is an enhancement of ${\mathrm{\ensuremath{\k…
We report identical double fluorescence lifetimes of τ = 3·7 and 6·3 ns for the 0-0 fluorescences of each of the two tautomeric species of metal-free phthalocyanine (H2Pc) in a mixed solvent matrix of α-chloronaphthalene and n-octane at 4·2K. Such double lifetime feature has not been reported previously for this molec…
Abstract A series of novel photosensitive urethane oligomers was synthesized in which methacryloyl group was contained in the hard segment. The hard segment was prepared by reacting 4,4′‐diphenylmethane diisocyanate with glycerine mono methacrylate, which was successively reacted with three kinds of glycols involving…
Photoluminescence (PL) bands at 4.1 eV with decay time τ < 20 ns and at 3.0 eV with τ = 78 μs are excited in the oxygen defieiency-related optical absorption band at 5.06 eV. These PL bands are closely similar to the PL bands in Ge-doped glassy SiO2. They are attributed to the transitions from 1B1 and 3B1 excited stat…
Optical experiments on free-standing liquid crystal films which address the issues of structural ordering, fluctuations in two dimensions and enhanced surface ordering will be reviewed. Also, results on a novel electrohydrodynamic mode will be presented.
By appropriate variation of starting composition we demonstrate that melt-spun materials comprised primarily of Nd2(CoxFe1−x)14B and having optimum energy products can be prepared. Twelve cobalt concentrations spanning the entire cobalt substitution range have been investigated. We report ambient as well as elevated t…
We report picosecond photoinduced bleaching (PB) of the exciton absorption of the emeraldine base form of polyaniline. The temperature- (T-) independent dispersive decay, \ensuremath{\sim}${t}^{\mathrm{\ensuremath{-}}0.11}$, observed in this study differs markedly from the dynamics of earlier studied semiconductors. I…
A Fabry–Perot interferometer system was used to measure the free-surface velocity of α-alumina powder compact. In situ pressure profile measurements using a pair of manganin gauges were also carried out to clarify the compaction process during compression and stress release. The Fabry–Perot system indicates that the r…
Diffusion coefficients of hydrogen have been measured in disordered ${\mathrm{Ti}}_{1\mathrm{\ensuremath{-}}\mathrm{y}}$${\mathrm{V}}_{\mathrm{y}}$ alloys, as a function of temperature, hydrogen concentration, and alloy composition. Diffusion and electron microprobe analysis data indicate the existence of short-range…
Precise results of first-principles electronic-structure calculations of the structural and electronic properties of the binary compound LiAl are presented for the bcc-based B32 and B2 crystal structures, the fcc-based L${1}_{0}$ and the simple-cubic-based B1 structures as obtained with the full-potential linearized a…