Sensitive solid-state optical sensible materials for photothermal determination of trace metals

Methods of photothermal (thermal-lens) determination of iron and mercury on the basis of solid polymer matrices with immobilized reagents are developed. These methods combine selective and efficient preconcentration of trace elements to be analyzed on a transparent polymer matrix, the sensitivity of determination with the reliable and traceable photometric procedures and highly sensitive thermal-lens detection (enhanced in polymers compared to solutions). The advantage of this approach is in the use of sensitive organic reagents previously developed for spectrophotometry. In this study, transparent polymethacrylate matrices modified with copper dithizonate and 1,10-phenanthroline were applied to the determination of mercury(II) and iron(II), respectively.     

Sorption-spectrophotometric determination of iron(II, III) with the use of organic reagents immobilized in a polymethacrylate matrix

The interaction of iron(II) with 2,2′-dipyridyl and 1,10-phenanthroline immobilized in a polymethacrylate matrix was studied. The optimum conditions of the complexation of iron(II) with the immobilized reagents and the chemical analytical properties of the complexes in the polymethacrylate matrix were determined. A sorption-spectrophotometric procedure was developed for the determination of iron(II) and the total of iron(II, III) after the reduction of iron(III) by ascorbic acid. The procedure with 2,2′-dipyridyl was used for the analysis of samples of tap, well, and mineral water and a solution of glucose.     

Luminescence and lasing properties of SOCl2-GaCl3-Nd3+ inorganic laser liquids

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 50, No. 4, pp. 609–613, April, 1989.     

Redox and acid-base properties of 2,6-dichlorophenolindophenol immobilized on a polymethacrylate matrix

The effect of the immobilization of 2,6-dichlorophenolindophenol (DCIP) on a polymethacrylate matrix on its redox and acid-base properties was studied. The ionization constant and formal redox potentials of the immobilized DCIP were determined by solid-phase spectrophotometry. It was shown that the acidity constant and the formal potentials of DCIP decreased upon the immobilization in the polymethacrylate matrix. The results of studying the interaction of ascorbic acid with immobilized DCIP are presented.     

Environmental State of Water in the Blagopoluchiya Bay of Solovetskii Island According to Hydrochemical and Hydrobiological Parameters

The results of hydrochemical and hydrobiological studies performed in October 2009, July 2010, and July 2016 in the Blagopoluchiya Bay of Solovetsky Island are given. The concentrations of petroleum hydrocarbons, phenols, oxygen, nutrients, and chlorophyll a, BOD₅, and qualitative and quantitative compositions of phytoplankton have been determined. The integrated pollution and eutrophication indices have been calculated, and the up-to-date water quality in the Blagopoluchiya Bay has been assessed; increased level of seawater pollution has been revealed. The obtained results are important from both scientific and practical viewpoints with respect to environmental safety of the community facilities in the study region.

     

Mechanisms of fracture of the free surface of shock-compressed metals

The mechanisms of the ejection of aluminum and copper microparticles from the free surfaces of these metals have been studied under conditions of the escape of a moderate-intensity shock wave from a sample. The free surfaces of samples contained 0.7–0.9 mm deep artificial wells and protrusions simulating (on a greater scale of 10: 1) the natural surface roughness retained upon mechanical processing. The pressure in a shock-wave pulse at the base of a protrusion was controlled within P = 5–20 GPa (i.e., below the melting region), and the variable duration of pressure pulses was 0.02, 0.2, and 1 μs. Analysis of the free surfaces of postloaded samples showed that, for certain loading and roughness parameters, the ejection of metal from vertices of protruding ridges or pyramids (as a result of the longitudinal fracture) was about ten times greater than the amount of metal ejected in the form of cumulative jets from wells. The amount of ejected metal and the size distribution of metal microparticles were quantitatively characterized using “soft collecting targets” and by measuring mass losses of samples upon fracture.     

Collisional depolarization of 2P states of alkalies on weak spin—orbital coupling

Depolarization, relaxation and intramultiplet mixing cross sections for Na^*(²P) in collision with He are calculated using the matching approximation; the distortion of relative motion of partners in the fields of ²Σ and ²Π terms are taken into account. The theory provides an interpretation of inelastic events which is consistent both with experimental data on cross sections and the general pattern of adiabatic potentials.