Materials Literature
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A well characterized homogeneous ceramic sample of ${\mathrm{La}}_{0.7}{\mathrm{Ca}}_{0.3}{\mathrm{M}\mathrm{n}(}^{57}{\mathrm{C}\mathrm{o})\mathrm{O}}_{3}$ shows two ferromagnetic phases below ${T}_{c}$ in contrast to the 20% Ca compound where only one is observed. One of the phases exhibits stronger exchange interac…
Using Monte Carlo simulations we study the dynamics of three-dimensional Ising models with nearest-, next-nearest-, and four-spin (plaquette) interactions. During coarsening, such models develop growing energy barriers, which leads to very slow dynamics at low temperature. As already reported, the model with only the…
Abstract Analytical electron microscopy of representative smectites from soils and sediments revealed that K was present in significant proportions. It was the major interlayer cation in soils from pelitic rocks, continental and marine sediments, independent of their diagenetic grade. Sodium was predominant only in so…
The effect of Cu substitution for Mn in layered manganese oxides ${\mathrm{La}}_{1.4}{\mathrm{Sr}}_{1.6}{\mathrm{Mn}}_{2\ensuremath{-}x}{\mathrm{Cu}}_{x}{\mathrm{O}}_{7}$ on magnetic and transport properties has been investigated. It is interesting that the undoped samples undergo complex transitions with lowing tempe…
After a few hundred years in a geologic repository, α-emissions will dominate the radiation field in and around spent nuclear fuel. In the event of a failure of the spent fuel container, the dissolution of the uranium dioxide matrix in contact with groundwater could be enhanced by α-radiolysis, which could create oxid…
We report on the growth of 99,9 % enriched 28Si, dislocation free monocrystals (111- and 100-orientated) with nearly 10 g weight and less than 1015 foreign atoms/cm3.
A redox-active alternating π-conjugated copolymer of ferrocene with dithiafulvene was synthesized by cycloaddition polymerization of aldothioketene derived from 1,1‘-bis(trimethylsilylethynyl)ferrocene ( 1 ). The obtained polymer ( 2 ) was soluble in common organic solvents such as THF, CH 2 Cl 2, CHCl 3, DMF, and DMS…
Silicon (Si)-doped diamond-like carbon (DLC) was prepared on Si(100) and polymethyl metha_crylate (PMMA) substrates using a C2H2–SiH4–Ar plasma immersion ion processing (PIIP) method. The chemical composition of the films was varied by adjusting the reactive gas-flow ratio of SiH4 to C2H2 during PIIP depositions. The…
Abstract A new prominent gelator 1, Nε-lauroyl-Nα-stearylaminocarbonyl-l-lysine ethyl ester was effortlessly prepared by esterification of Nε-lauroyl-l-lysine and addition of n-octadecyl isocyanate in a total yield of 89%. Gelator 1 was capable of gelling up a wide variety of organic fluids. A comparison of the gelati…
Theoretical analysis and extensive numerical simulations are performed on the system of a spherical absorber illuminated by a pulsed laser. Both bubble formation and shock wave generation are investigated. We find that a strong shock front forms just outside the absorber and attenuates quickly into an acoustic wave as…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPredictions and Assignments of NMR Spectra for Strongly Paramagnetic Supramolecular Lanthanide Complexes: The Effect of the "Gadolinium Break"Stéphane Rigault and Claude PiguetView Author Information Department of Inorganic, Analytical and Applied Chemistry University…
To obtain powder with a composition of 3 mol% Y 2 O 3 –97 mol% ZrO 2 , a process of Y‐Zr oxalate powder production has been optimized, to produce an oxalate with minimal particle size. The methodology of the nonisothermal decomposition of Y‐Zr oxalate has been explained. Characteristics of the nonisothermal decomposit…
Accurate quantitative X‐ray diffraction analysis of SiC‐based ceramics is difficult because of the significant overlap of the Bragg reflections from the different SiC polytypes. In this regard, the Rietveld method is a powerful tool for the accurate and precise analysis of the phase/polytype compositions in these mate…
Hydrogenated carbon nitride films were deposited by reactive dc magnetron sputtering in mixed Ar/N2/H2 discharges at temperatures of 100 and 350 °C. The total pressure was kept constant at 0.33 Pa and the gas mixtures were varied in order to study the effect of the hydrogen on the resulting film structure and properti…
Brain extraction of (18)F-labeled 2-fluoro-2-deoxy-D-glucose (FDG) was significantly higher in pentylene tetrazole (PTZ)-treated rats (32 +/- 4%) than controls (25 +/- 4%). The FDG permeability-surface area product (PS) was also significantly higher with PTZ treatment (0.36 +/- 0.05 ml. min(-1). g(-1)) than in control…
The effects of the molecular mass of B-site ions of Pb(B ′ B ′′ )O 3 –PbTiO 3 (B ′ =Mg, Zn, Ni, Sc, In and Yb; B ′′ =Nb and Ta) and Pb(B, Ti)O 3 (B=Zr, Hf and Sn) piezoelectric materials on the electromechanical coupling factors were investigated. The relationship between the electromechanical coupling factor k p near…
Polycrystalline In2O3:Sn (ITO) films have been prepared by reactive radio frequency diode sputtering of an oxidic target using various oxygen/argon mixtures. They mostly contain more oxygen than the ideal crystal. When deposited at low pressure, the crystals have an expanded lattice (up to 3.5%) and, for small oxygen…
We report low temperature specific heat measurements of ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ $(0.3<~x<~0.5)$ and ${\mathrm{La}}_{0.5}{\mathrm{Ca}}_{0.5}{\mathrm{MnO}}_{3}$ with and without applied magnetic field. An excess specific heat, ${C}^{\ensuremath{'}}(T),$ of nonmagnetic…
Dielectric beta relaxation in a pyridine-toluene solution is studied close to the glass transition. Loss peak frequency and maximum loss both exhibit thermal hysteresis. An annealing-state-independent parameter involving loss and loss peak frequency is identified. This parameter has a simple Arrhenius temperature depe…
Most bacterial proteins are stable, with half-lives considerably longer than the generation time. In Escherichia coli, the few exceptions are unstable regulatory proteins. The results presented here indicate that the first enzyme in methionine biosynthesis - homoserine trans-succinylase (HTS) - is unstable and subject…