Materials Literature
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Intracellular polysaccharide fractions were isolated from calcifying B‐type cells of Emiliania huxleyi and separated by electrophoretic fractionation. In all fractions, the polysaccharide was immunologically related to the polysaccharide of (extracellular) B‐type coccoliths (CP‐B) and not to polysaccharides of A‐type…
The acoustic wave field generated in front of a submerged fiber tip by short laser pulses is theoretically and experimentally studied by fast imaging and optical pressure measurements. It is shown that the finite size of the fiber causes strong tensile stress leading to cavitation. Depending on the absorption coeffici…
▪ Abstract Basic scientific and technological advances on ferroelectric thin films and heterostructures are discussed in relation to the work on nonvolatile ferroelectric random access memories (NVFRAMs) performed by different groups during the last seven years. A reasonable understanding of the synthesis and microstr…
We studied mixed-layer illite-smectite (I/S) (<1 or 0.5 μm size fractions) in 28 diagenetic bentonite samples, Pliocene to Ordovician in age, from different locations in North America and Europe to investigate the smectite-to-illite transformation mechanism. XRD- measured illite contents ranged from 3 to 100%, and…
Ozone (O 3 ) adsorption on CeO 2 pretreated under different conditions and characterized by low-temperature CO adsorption was studied by Fourier transform infrared (FTIR) spectroscopy at 77−300 K. Preliminary exposure to CO 2, pyridine, acetonitrile, or methanol at 293 K or to CO at 77 K, as well as adsorption of 18 O…
This paper focused on the effects of various phases of SiO 2 additives on the γ‐Al 2 O 3 ‐to‐α‐Al 2 O 3 phase transition. In the differential thermal analysis, the exothermic peak temperature that corresponded to the theta‐to‐α phase transition was elevated by adding amorphous SiO 2 , such as fumed silica and silica g…
Model multigraft copolymers of butadiene (Bd) and styrene (St) with randomly placed trifunctional, poly(Bd- g -St), and tetrafunctional branch points, poly(Bd- g -St 2 ), were synthesized by hydrosilylation of polybutadiene (∼92 wt % 1,4) with HSiMe 2 Cl and HSiMeCl 2, respectively, followed by reaction of the resulta…
The kinetics of decomposition of thermotropic liquid crystalline poly(p-oxybenzoate-co-ethylene terephthalate) (poly(B-co-E), BE polymer) with different monomer ratios in both nitrogen and air were studied by dynamic thermogravimetry (TG) from ambient temperature to 800°C. The kinetic parameters, including the activat…
Polystyrene and polyethyleneterephthalate surfaces were exposed to helium, oxygen/helium and nitrogen/hydrogen plasmas singly and in combination. The treated surfaces were evaluated by water contact-angle measurements and by x-ray photoelectron spectroscopy. It was found that the oxygen and nitrogen tend to graft to c…
SmI 2 (THF) 5 acted as a reducing agent in the reaction with phenylenebis(3,5-Bu t 4 salicylidene)iminatosodium, (3,5-Bu t 4 salophen)Na 2 (THF) 2, to yield a dimeric compound [Sm 2 (SB−SB)(THF) 3 ]·2toluene ( 2 ) [SB−SB = C−C bonded 3,5-Bu t 4 salophen dimer] arising from the reductive C−C coupling of two imine funct…
Abstract The difference in the glass transition temperatures, T g , of the iso‐ and syndiotactic forms of PMMA has been investigated through molecular dynamics simulations of short duration (110 ps) using an accurate force field, pcff. To correlate with the Gibbs‐DiMarzio theory, which specifies that conformational en…
The field-induced superconductivity-destroying quantum transition in amorphous indium oxide films are investigated at low temperatures down to 30 mK. It is found that, on the high-field side of the transition, the magnetoresistance reaches a maximum and the phase can be insulating as well as metallic. With further inc…
Xenotime‐type RPO 4 (R = Y, Er, Yb, or Lu) powder was dry‐pressed into disks and bars. The disks and bars could be sintered to a relative density of greaterthan equal to98% in air without cracking at 1300° (R = Yb or Lu) or 1500°C (R = Y or Er), depending on the grain size. The linear thermal expansion coefficient (at…
Ultrafine crystalline TiO 2 powders were prepared by just heating and stirring aqueous TiOCl 2 solution with a Ti +4 concentration of 0.5 mol/ l at room temperature to 100°C under one atmosphere. The crystallinity, the phase transformation and the particle shape of ultrafine TiO 2 powders obtained by this simple preci…
All articles of this category functionalized triphenylene - hexakis(pentyloxy)triphenylene - selective ether cleavage - discotic liquid crystals
For iron-rich compositions, reactions among titanite, clinopyroxene, olivine, quartz, magnetite, and ilmenite can constrain the conditions under which common rocks form. Phase equilibrium experiments in the system CaO-FeO-Fe 2 O 3 -TiO 2 -SiO 2 constrain two of these reactions: clinopyroxene + ilmenite = titanite + ol…
Thermogravimetric analysis was used to determine the synthesis conditions for obtaining samples of the Ba-substituted ${\mathrm{LaMnO}}_{3}$ with stoichiometric oxygen content. Single-phase and vacancy-free samples of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ba}}_{x}{\mathrm{MnO}}_{3}$ have been prepared for $x=0.12-…
Abstract Short term flexural creep tests were conducted to investigate the creep behavior of wood‐fiber polypropylene composites. Three experimental parameters were selected: the addition of a wetting agent, temperature, and wood‐fiber concentration. All creep curves are presented in terms of relative creep as a perce…
This work reports the synthesis and characterization of diamantane-based polyimides obtained from 1,6-bis[4-(4-aminophenoxy)phenyl]diamantane and various aromatic tetracarboxylic dianhydrides. This novel polyimide exhibits a low dielectric constant (2.56−2.78), low moisture absorption (<0.292%), good solubility, and h…
Enzymatic ring-opening polymerization of medium-size lactones, ϵ-caprolactone (ϵ-CL) and δ-valerolactone (δ-VL), was performed by using a lipase as a catalyst. For the polymerization of ϵ-CL in bulk, a lipase derived from Pseudomonas fluorescens (lipase PF) showed the highest catalytic activity among the powdery lipas…