— We have experimentally demonstrated continuity of hypoeutectoid and pearlite ferrites in aggregates in the microstructure of low-carbon, low-alloy ferrite–pearlite steel. Such ferrite aggregates of various origins have been repeatedly observed along with hypoeutectoid ferrite and pearlite grains. We propose that aggregates of hypoeutectoid and pearlite ferrites should be regarded as a characteristic microstructural feature and this should be taken into account in microstructural characterization.

Due to their unique physical and chemical properties, monodisperse titanium oxide microspheres can be used in dye-sensitized solar cells, as cosmetic pigments, and for other applications. However, the synthesis of microspheres with narrow size distribution, desired phase composition, and porosity is still a challenge. In this work, spherical titania particles with controllable size, crystallinity, and pore size were obtained by Ti(OnBu)4 hydrolysis in ethanol. The influence of NaOH addition on the particles' size and morphology was investigated for the first time. Particle diameter can be tailored from 300 nm to 1.5 μm by changing water and NaOH concentrations. Particle size was analyzed by the statistical processing of scanning electron microscopy (SEM) images and differential centrifugal sedimentation (DCS) measurements. Optical properties of the microspheres were studied by diffuse reflectance UV-Vis spectroscopy. Thermal and hydrothermal treatment allowed transforming amorphous phase in as-prepared particles into nanocrystalline anatase and/or rutile. Transmission electron microscopy (TEM) study of the lamellae, cut out from spherical particles using focused ion beam (FIB), revealed that as-synthesized microspheres are non-hollow, homogeneous, and crystallize throughout the whole volume of the particle. The spherical particles possess photoprotective properties; the highest sun protection factor (SPF) was observed for amorphous microspheres.

Using high-temperature X-ray diffraction, differential scanning calorimetry, and electron microscopy, we have studied the formation of yttrium aluminates and Nd:YAG (YAG) activated garnet nanoparticles during the thermal decomposition of a poorly crystallized carbonate precursor prepared in the NH4Al(OH)2CO3–(Y,Nd)(ОН)CO3 nanosystem and the development of the morphological structure of powders during heating to a temperature of 1350°C. The results demonstrate that heat treatment in the temperature range 850–950°C leads to the formation of metastable nonstoichiometric YAlO3 with a garnet-like structure, which reacts with Al2O3 at a temperature of 1000°C to form YAG. The cubic cell parameter a and X-ray density of YAG crystals with the composition Y2.97Nd0.03Al5O12 synthesized at 1200°C are 1.2009 nm and 4.565 g/cm3, respectively, and the average particle size is 108 nm. Using carbonate route, we prepared transparent Nd:YAG ceramics with a relative density of 99.7%, X-ray density of 4.562 g/cm3, and crystallite size in the range 1–7 μm.

Titania microspheres with narrow size distribution and diameters of about 1 mu m were prepared and subsequently functionalized using surface-initiated atom transfer radical polymerization (ATRP) of N-isopropylacrylamide. The ATRP initiator was immobilized on the particle surface via acylation of surface hydroxyl groups with -bromoisobutyryl bromide. Subsequently, an established ATRP reaction system was used for the preparation of titania surface-grafted poly(N-isopropylacrylamide) (PNiPAAm). Characterization was performed with electron microscopies, X-ray diffraction, infrared spectroscopy and dynamic light scattering. It was found that the particle size in aqueous dispersions changed reversibly with temperature as expected for a shell of PNiPAAm, a polymer with a lower critical solution temperature at 32 degrees C. This confirmed the successful preparation of functional, stimuli-responsive TiO2 microparticles via a straightforward controlled surface-initiated polymerization method.

The collective acceleration of xenon ions in a plasma-anode vircator is studied. It is shown that the energy of accelerated ions may reach 900 MeV. The image of a bremsstrahlung source on the target suggests effective transport of relativistic electrons in the drift channel.

The emissivity of membrane structures based on silicon carbide of the 6H polytype has been experimentally investigated at high temperatures. The dependence of the monochromatic emissivity of the SiC membranes on their thickness has been obtained. (c) 2007 Optical Society of America.

The effect of oxidizing annealing on the phase composition, microstructure, and magnetic properties of solid solutions based on Pb-containing strontium M hexaferrite is studied. The solid solutions prepared by different methods (ceramic route and glycol-citrate sol-gel process) are shown to differ in composition. Oxidizing annealing (air, 500–700°C) of single-phase materials leads to the formation of nanometer-sized (10–20 nm) equiaxed precipitates on some of the faces of the (initially smooth) hexaferrite grains. In some cases, such precipitates form chains running over the entire surface of the hexaferrite grain. Some of the annealed solid solutions contain a second phase, which has not been identified. Annealing slightly increases the coercive force of the solid solutions (by 2 to 25%, depending on their composition), which may be due to oxidation-induced second-phase precipitation or phase segregation of the solid solution within the hexaferrite grains.

An inverse-pinch plasma opening switch (POS) of a new type has been studied, which is capable of switching a 300–400 kA current at a rise time of ∼1 μs and a current fall rate of 8 × 1012 A/s. The POS can operate at both negative and positive polarity of the central electrode.