Nano- and microparticles of iron with a modified surface and prospects for their application. Part I: Copper-coated iron particles

The catalytic properties of metal copper in chemical reactions between ferrite-garnet materials and orthophosphoric acid are described. It was shown that the reactions occur more efficiently provided copper is used in the form of shells on nano- and microparticles of iron and stirring of the etching agent is performed by the magnetic fields. The formation of the metal copper on iron particles is carried out using a chemical method owing to the reaction between the iron particles and the water solution of blue vitriol and sulphuric acid. The highest efficiency of stirring is registered using a magnetic field with a variable direction of the magnetic field gradient.     

Formation, retention, and discharge of products of atmospheric corrosion of metals. 4. Model: Corrosion-discharge of products

An empirical mathematical model K = K ₀ + km _los (relating atmospheric corrosion to the weight loss of its products) for incubation + transient and steady-state stages of the process, is considered. To develop the model, we used the results of long-term (from 3 month to 1–17 years) field tests of metals according to the Russian, International ISOCORRAG, and Russia-Vietnam-Cuba programs. The K ₀ and k factors in the model were determined according to the corrosion of Ct3, copper, brass, zinc, aluminum, Δ16 alloy, and AMц alloy in the zones of cold, moderate, subtropical, and tropical climates. The model quantitatively relates the corrosion losses of a metal to those of the products discharged to the environment. It may be useful when it is necessary to estimating the amount of detrimental metals, e.g., unprotected copper and zinc dispersed to the environment, but there is no data on the weight of products that had been retained by the metal in the air. Original Russian Text ? Yu.M. Panchenko, P.V. Strekalov, T.V. Nikulina, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 2, pp. 167–191.     

Interaction of slow electrons with surface: Empty electronic states and inelastic scattering effects

The fine structure of experimental true secondary-electron emission spectra along the normal to a clean W(1 1 0) surface, target (or total) current spectra, and low-energy-electron-transmission spectra along the normal to a clean 2H-MoS₂(0 0 0 1) surface are interpreted theoretically. It is shown that the fine structure of these spectra is mainly due to the electronic structure of unoccupied high-level electronic states (above the vacuum level), which become occupied by electrons entering the solid. In addition, a comparison to existing theoretical and experimental data is given.     

Effect of dose and temperature parameters of neutron irradiation to maximum damaging dose of 77 dpa on characteristics of porosity formed in steel 0.07C-16Cr-19Ni-2Mo-2Mn-Ti-Si-V-P-B

The microstructure of samples of cladding tubes made of steel 0.07C-16Cr-19Ni-2Mo-2Mn-Ti-Si-V-P-B (EK164) irradiated to different damaging doses (up to 77 dpa) in the BN-600 reactor at temperatures from 440 to 600°C has been investigated. Characteristics of radiation porosity formed during irradiation in different temperature intervals have been determined. The dependences of the porosity characteristics on the rate of generation of atomic displacements and temperature of neutron irradiation have been established.     

Routes to polymer-based photonics

The advances in polymer materials and technologies for telecom applications are reported. The polymers include new highly halogenated acrylates, which possess absorption losses less than 0.25 dB/cm and refractive indices ranging from 1.3 to 1.5 in the 1.5 μm wavelength region. The halogenated liquid monomers are highly intermixable, photocurable under UV exposure and exhibit high contrast in polymerization. The polymer technologies developed at the Institute on Laser and Information Technologies of the Russian Academy of Sciences (ILIT RAS) include:

IRS study of ethylene polymerization catalyst SiO2/MAO/zirconocene

Summary Lewis acidic sites (LAS) of silica, modified with TMA and MAO samples differed by TMA content, have been characterized by IR spectroscopy (CO adsorption as probe molecule at 77 K). Two types of LAS were found on the surface of silica modified with MAO and TMA: M LAS of moderate strength (ν_CO= 2204−2212 cm⁻¹) and weak W LAS (ν_CO= 2194 cm⁻¹). The concentration of these acidic sites has been estimated. It was shown by IRS study Cp₂ZrMe₂ interacts both with W LAS and M LAS. Correlation between the amount of M LAS and the activity of ethylene polymerization has been found. Received: 13 October 1998/Revised version: 10 June 1999/Accepted: 10 June 1999