Materials Literature
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SmFe 2 crystals were grown by the self-flux method using Sm as a flux, and the crystallographic and magnetic properties of the crystal were studied for the first time. SmFe 2 crystallizes in a cubic MgCu 2 -type structure (space group of Fd3m ) with lattice constants of a =0.7425 nm. Saturation magnetization M S at 5…
By taking into account the effects of domain structures and X-ray absorption, the superstructure of PbZrO 3 , lead zirconate, has been determined at room temperature. The space group is Pbam with a unit cell of a = 5.8884 (19), b = 11.771 (4) and c = 8.226 (3) Å, with Z = 8. The intensity data were collected using sho…
It has been demonstrated that Fourier transform infrared (FT-IR) microspectroscopy can be used to study different types of spherulites of poly(vinylidene fluoride) formed by different crystal modifications. Because of selective IR bands of the α and the γ modification, respectively, it is possible to map the crystalli…
The hydrolysis behaviour of lactic acid based poly(ester-urethane)s has been studied in a buffer solution of pH 7·00 at 37 and 55°C. Samples were prepared using a straight two step lactic acid polymerization process. The lactic acid was first polymerized by condensation with a low molecular weight by hydroxyl terminat…
Abstract The microtextural changes in the kaolinization of primary phyllosilicates including biotite, sericite, clinochlore and muscovite were investigated by scanning electron microscopy (SEM) and microchemical analysis of thin sections of weathered anorthosite. Kaolinization began at grain edges and propagated towar…
L'inhibition de la corrosion de l'alliage Cu-Zn (70/30) en milieu H2SO4 0.1 M par des composés organiques de type “tétrazole" a été étudiée en utilisant les méthodes gravimétrique et électrochimique. Les résultats obtenus montrent que le 1-phényl-5-mercapto-1,2,3,4-tétrazole (PMT) est le meilleur inhibiteur de la séri…
The process of phase separation for quenched, three-dimensional binary alloy systems with coupled elastic fields was investigated with Langevin simulations. The elastic effects are the result of a dilational misfit introduced via inhomogeneities in the elastic constants of the system. A selection criterion for the sha…
Modified sol‐gel processes have been developed for the preparation of lead zirconate titanate (PZT) (52/48) powders. These processes use different starting sources to introduce the titanium and zirconium components, namely tetraethyl orthotitanate, titanium isopropoxide, or titanium diisopropoxide bis(2,4‐pentanediona…
Grafting of polyethylene glycol chains onto cellulosic membrane can be expected to reduce the interaction between blood (plasma protein and cells) and the membrane surface. Alkylether carboxylic acid (PEG acid) grafted high flux cellulosic membranes for hemodialysis, in which the polyethylene glycol chain bears an alk…
The influence of water, formamide, and n -dodecane on the liquid crystalline properties of several rodlike 4,4‘‘-bis(decyloxy)- p -terphenyl derivatives incorporating nonionic hydrophilic groups in a central position was investigated by polarizing microscopy and X-ray scattering. Up to three different rectangular colu…
In colossal magnetoresistance materials, ferromagnetic double exchange presumably coexists with a direct nearest-neighbor antiferromagnetic interaction. We construct a single-site mean-field theory that explicitly takes into account the different nature of carrier-mediated ferromagnetism vs Heisenberg-like superexchan…
Principles of solid-state structure and bonding that relate metal-halide and metal-chalcogenide materials are described through a comparison of binary AX n salts. Structural variation is rationalized by a comparison of the size and charge of the respective ions, the d-electron count of the cations, and the type of A−X…
This paper studies the dye-sensitized photooxidation of tyrosine (tyr) and tyr di- and tripeptides (tyr-tyr and tyr-tyr-tyr) mediated by singlet molecular oxygen (O2[1 delta g]) in alkaline media. Photooxidation quantum efficiencies (phi r) were obtained by determining the overall and reactive rate constants of intera…
Ring-opening reactions of 1,3-dioxepan-2-one (1) and 1,3-dioxan-2-one (2) with several alcohols were examined. The reactions proceeded without trifluoroacetic acid (TFA) in low conversions, while they proceeded smoothly with TFA to afford the ring-opened adducts and oligomers. Ring-opening polymerizations of 1 and 2 w…
Identification of the metal-containing products of reactions of the neutral transition metal atom Zr(4d 2 5s 2, 3 F) with ethylene and propylene is accomplished using one-photon ionization at 157 nm and time-of-flight mass spectrometry. The reactions proceed in a fast flow reactor at 298 K with He/N 2 buffer gas at 0.…
Double emulsions are emulsion-within-emulsion systems with promising applications. Attempts have been made to find new amphiphiles to improve their thermodynamic stability and to control the release of active matter or markers from double emulsions. The present review summarizes our efforts to study the mechanisms of…
The effect of a near-bottom transport scheme on the sensitivity of the thermohaline circulation is analyzed in a coupled model. In this model with idealized geometry of the Atlantic, it is shown that in the presence of a northern source of deep water, an accurate representation of the overflow process has a stabilizin…
The Escherichia coli surE gene is co-transcribed with pcm, encoding the L-isoaspartyl protein repair methyltransferase, and is highly conserved among both the Eubacteria and the Archaea; however, no biochemical function has yet been identified for this gene. Isoaspartyl accumulation during stationary phase was much hi…
During the wet oxidation of contaminated wastewaters, the destruction of low molecular weight carboxylic acid intermediates such as acetic, glyoxalic, and oxalic acids is often the rate-controlling step. Oxidation of acetic acid, a very recalcitrant intermediate, requires compelling treatment severity. Heterogeneous c…
Lithium silicophosphate glasses have been prepared by a sol−gel route over a wide range of compositions. Their structural and electrical properties have been investigated. Infrared spectroscopic studies show the presence of hydroxyl groups attached to Si and P. MAS NMR investigations provide evidence for the presence…