Calibration model of simultaneous multielement atomic-emission analysis using analytical line groups of each determined element

A calibration model of multielement methods for simultaneous determination of micro- and macro-concentrations of elements by computing the arc atomic-emission spectra has been developed. A calibration procedure for the analytical line group of the elements to be determined is offered. It allows the lower and upper limits of the concentration range for each line of the determined element to be calculated by means of the least-square method (LSM) and the Weibull distribution law is used to extend the concentration region. The calibration model was successfully tested for different arc optical emission spectroscopy (OES) methods. Received: 17 June 1997 / Revised: 3 November 1997 / Accepted: 7 November 1997     

METHODS TO DETERMINE CRYSTAL LATTICE PARAMETERS OF OPAL-LIKE STRUCTURES

Journal of Structural Chemistry - Series of high-quality spherical poly(methyl methacrylate) particles with a polydispersity less than 5% are prepared by chain-growth emulsifier-free controlled...     

Study of structural changes in an ion-irradiated YBa<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>7 − <Emphasis Type="Italic">x</Emphasis></Subscript> film using scanning tunneling microscopy

The effect of He ⁺⁺ ion irradiation on the structure of the superconducting epitaxial YBa₂Cu₃O_{7 ? x} film was studied using scanning tunneling microscopy. Cluster-like surface damages several tens of nanometers in size, as well as crystallite blurring were detected in the irradiation region. We observed a noticeable profile irregularity compared to the profile of the unirradiated sample region.     

Interrelation of the critical magnetic field H c2 and the residual resistivity for the two-band superconductor MgB2

An expression that describes the upper critical magnetic field H _c2 and generalizes the Gor’kov relation has been derived for the two-band two-gap superconductor MgB₂. The expression relates the upper critical magnetic field H _c2 to the residual resistivity and the parameters of the band structure and holds in the range from the clean limit to the dirty limit. The ratios of the relaxation times τ_π/τ_σ and the mean free paths of π- and σ-band electrons for MgB₂ samples with a low defect level and Mg(B_{1 ? x} C _x )₂ samples with a partial substitution of carbon for boron are determined from experimental data.     

Structure of the Products of Stimulated Carbonization of Aromatic Hydrocarbons

This paper deals with X-ray photoelectron and electron microscopy studies of the structure of carbon–metal-containing micro- and nanotubulenes. Ab initio quantum-chemical calculations were performed to analyze the possibility and mechanism of tubulene formation.     

Features of the electronic structure of cerium-based systems

Ce-based systems were studied by means of x-ray photoelectron spectroscopy. The density of states was calculated by the TB-LMTO-ASA and APW+LO band methods. A correlation was found between 4f level localization and x-ray photoelectron spectra with characteristics of the heavy fermion state. It was shown that a high value of interatomic interaction is characteristic of Ce-based systems with heavy fermions under normal conditions.     

Magnetophoresis of Microparticles in a Magnetic Fluid

Russian Physics Journal - An experimental setup is developed for studying magnetophoresis in a layer of a magnetic fluid several millimeters thick by the method of light transmission and...     

X-ray photoelectron investigation of nanostructures in modified cast irons and steels

A comparative study of industrial samples of classic cast iron, stainless steel, and nanomodified samples was performed. It was shown that the high strength of the obtained materials could be explained by the formation of strong hybridized 3d(Fe) and 3p(Al) bonds, and by the presence of C-C complexes with diamond-like sp ³ hybridization of electrons.