Materials Literature
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Herein, we report a study on magnetic and optical properties of hexagonal (GaMn)N nanocrystalline powders obtained by two methods: aerosol-assisted vapour phase synthesis and anaerobic imide route. Measurements of the magnetization as a function of temperature and magnetic field for the powders show a typical paramagn…
In this chapter we discuss carbonylation reactions in which carbon monoxide (CO, Box 1) is incorporated into organic molecules. CO is one of the major building blocks of the organic commodity chemicals industry today, and is of increasing importance in fine chemicals too (Chapter 1). It can readily ...
HgTe nanowires nucleated by Au particles have been grown on Si and GaAs substrates by molecular beam epitaxy. The wires are polycrystalline. They evolve from crooked to straight during growth and have rounded to rectangular cross-sections. The widths are in the range 20–500 nm, with lengths up to 4 μm. The height of t…
A model is developed for the voltammetric response due to surface charge injection at a single point on the surface of a sphere on whose surface the electroactive material is confined. Accordingly, charge diffusion is constrained to the spherical surface and thus mimicks the voltammetric response of immobilised microp…
We investigate theoretically the elliptical shapes of soft colloids in freely standing smectic- C films, that have been reported recently. The colloids favor parallel alignment of the liquid crystal molecules at their surfaces and, for sufficiently strong anchoring, will generate a pair of defects at the poles of the…
1,4-Dicyanotetrafluorobenzene (DCTB) was polycondensed with various diphenols in DMF or DMSO using K 2 CO 3 as catalyst and HF acceptor. At concentrations of 0.1 or 0.2 mol/L for DCTB, gels were obtained with 1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, with 1,3-bis[(4-hydroxyphenyl)-2-propyl]benzene and with α,ω-bis…
In this paper, we demonstrate the effect of dc substrate bias on high-rate deposition of microcrystalline silicon (μc-Si) films by using a high-density microwave plasma source. Film depositions are performed at a high silane concentration of 67% (deposition rate of ∼ 60 Å s −1 ) with a low substrate temperature of 250…
Abstract Ceria–zirconia mixed oxide was successfully synthesized via the sol–gel process at ambient temperature, followed by calcination at 500, 700 and 900 °C. The synthesis parameters, such as alkoxide concentration, aging time and heating temperature, were studied to obtain the most uniform and remarkably high‐surf…
The relaxation and localization times of excited electrons in CdS/CdSe/CdS colloidal quantum wells were measured using subpicosecond spectroscopy. HRTEM analysis and steady-state PL demonstrate a narrow size distribution of 5-6 nm epitaxial crystallites. By monitoring the rise time of the stimulated emission as a func…
Introduction Particle monolayers are formed when small colloidal solid particles adsorb at liquid–vapour or liquid–liquid interfaces. Typical examples are latex monolayers at the air–aqueous salt solution and oil–water interfaces. The interaction between particles within the monolayer is dependent on both the properti…
Electrochemical etching may be used to form high aspect-ratio pores and pillars in silicon. Starting from lithographically patterned surfaces, regular arrays of macro pores or pillars can be fabricated. The pitch and pillar/pore size must then scale with the depletion width, in turn set by the material resistivity. We…
The electronic structure of $A$-type antiferromagnetic insulator $\mathrm{La}\mathrm{Mn}{\mathrm{O}}_{3}$ is investigated by the GW approximation. The band gap and spectrum are in a good agreement with experimental observation. The lifetime of electrons in conduction bands is much shorter than that of holes in valence…
Trading places: Bifunctional thiol ligands were immobilized onto positively charged silica gel and onto Rink resin through electrostatic interactions. The image shows the place-exchange reaction between the alkanethiolate-protected gold nanoparticles and the polymer-bound bifunctional thiol ligands; monocarboxyl gold…
Abstract Evaluation methods of the CaCO 3 scaling risk are still far from being well understood and in many cases lack accuracy. Most of the saturation indices and models used so far for predicting scaling are based on the thermodynamic data of calcite, which is considered to be the most stable form of the different c…
Introduction Many food colloids are stabilized, at least in part, by the presence of particulate material that accumulates at oil–water or air–water interfaces. As applied to emulsion droplets, this type of stabilization mechanism is commonly referred to as Pickering stabilization. Some examples of particles involved…
Introduction The antifoam effect Foams appear as an integral part of various technological applications, such as ore and mineral flotation, tertiary oil recovery, production of porous insulating materials, fire fighting and many others. Foams are also encountered in certain types of consumer products, e.g. the mousses…
A new strategy has been successfully designed to synthesize curved ammonium copper molybdate [(NH(4))(2)Cu(MoO(4))(2)] nanoflakes on a copper surface by employing a novel solution-phase approach at room temperature. This method consists of a liquid-solid reaction between Na(2)MoO(4) solution and the copper substrate i…
A clear understanding of the pathological mechanism of amyloid beta peptide (Abeta) 1-42, a currently unexplained process, would be of great significance for the discovery of novel drug targets for Alzheimer's disease (AD) therapy. To date, though, the elucidation of these Abeta1-42 dynamic events has been a difficult…
Time-resolved in situ video monitoring and ultraviolet-visible spectroscopy in combination with X-ray absorption near-edge spectroscopy (XANES) have been used for the first time in a combined manner to study the effect of synchrotron radiation on a series of homogeneous aqueous copper solutions in a microreactor. This…
Enzymatic systems that exploit pericyclic reaction mechanisms are rare. A recent addition to this class is the enzyme PchB, an 11.4-kDa isochorismate pyruvate lyase from Pseudomonas aeruginosa. The apo and pyruvate-bound structures of PchB reveal that the enzyme is a structural homologue of chorismate mutases in the A…