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The vitality structure of forest stands and the annual radial increment of Scots pine trees of different vital state categories growing in the northern taiga middle-aged lichen pine forests and woodlands of the Kola Peninsula have been studied. This study has shown a prevalence (60–75%) of weakened and strongly weakened trees in the Scots pine forests and woodlands; the fraction of healthy trees does not exceed 15–20% (30% in terms of the stand volume). In the age range of 30–85 years, the radial growth of Scots pine trees in the communities studied decreases 1.5- to 3.5-fold, and the annual basal area increases 1.5- to 5-fold. Differentiation of trees of differing vitality in relation to the radial increment is clearly manifested starting from 50 years after the fire. The ratio between the annual basal areas of healthy, weakened, strongly weakened, and dying trees in pine forests and woodlands is 8 : 5 : 2.5 : 1 and 11 : 5.5 : 3.5 : 1, respectively. The difference between the resource potentials of pine woodlands and forests is 1 : 1.6 and is manifested at the level of communities, but not at the level of individuals.

Technical carbon CH210 was processed by chemical reduction of the diazo derivative of anthraquinone for surface modification. The presence of anthraquinone groups on the carbon surface was confirmed by attenuated total internal reflection (ATR) IR spectroscopy. Carbon with the anthraquinone-modified surface was deposited on a glassy carbon support using a polymer binder. The behavior of the thus obtained catalyst in oxygen electroreduction in an alkaline medium was studied by the rotating disk electrode method. The kinetic characteristics of the reaction were determined: half-wave potential, limiting current, number of electrons, Tafel slope, exchange current, and charge transfer coefficient. Hydrogen peroxide is formed on the surface of the carbon–polymer composite at higher positive potentials than on technical carbon and glassy carbon electrodes. Therefore, the proposed material can be used as an effective electrocatalyst for this reaction.

Cast composite material based on Cr2AlC MAX phase has been prepared by metallothermic self-propagating high-temperature synthesis (SHS) from a mixture of powders of chromium oxide, aluminum, and carbon. The experiments have been performed using an SHS reactor with a volume V of 3 L under an excess inert gas (Ar) pressure (P = 5 MPa). The prepared material has been studied by X-ray diffraction analysis, scanning electron microscopy, and local microstructural analysis. The quantitative analysis has been performed by the Rietveld method. The electrical resistivity was measured in the 100–1300 K temperature range. The resulting material is an electrical conductor with metallic conductivity in the 100–1300 K temperature range, and has the electrical resistivity of the same order as the samples containing 100% Cr2AlC.

Changes in characteristics of the upper soil horizons in dark coniferous forests in the course of their postfire restoration were assessed. The studies were carried out in the northern taiga forests exposed to fire 8 to 400 years ago in the Kola Peninsula and in the middle taiga forests burned 70 and more than 500 years ago in the northern Cis-Ural region (Pechoro-Ilychskii State Biospheric Reserve). Samples from 23 soil pits on 20 test plots were analyzed. The actual acidity, loss on ignition, contents of exchangeable K, Ca, and Mg and mobile Mn, Fe, and Zn were determined. Two boundaries (~80 and 160–200 years after fire) and three main periods in the postfire dynamics of the upper soil horizons properties were established. The ash and Fe content in the litter was found to decreases about 80 years after the fire. In 160–200 years after fire, the thickness of the forest litter is restored and stabilized at the level of about 9.7 (8.3–10.4) cm; the pH value and the Ca, K, and Mn concentrations in the litter become lower. Thus, it can be concluded that the properties of soils under dark coniferous forests of the European North considerably change in the course of postfire successions.

The specific energy parameters of nanostructured electrode materials of electrochemical capacitors obtained by the method of multistage calendering are studied in this work. The dependence of electrical conductivity; the specific capacity of an electrical double layer of electrodes; and the internal resistance of electrochemical capacitors on the nature, quantity, and spatial localization (in the volume of the active layer and/or at the active layer–current collector interface) of conductive dopants (carbon black and grown in vacuum carbon fibers) are examined.

The redox sorption of molecular oxygen from water by a thin granular layer of a copper-ion exchanger nanocomposite in the currentless mode and under cathodic polarization is studied. The speed of propagation of the boundaries of the chemical reaction of stepwise oxidation of copper nanoparticles under the conditions of polarization slows considerably. At the same time, the amount of electrochemically regenerated copper from the resulting oxides that is capable of interacting with oxygen again grows. The stationarity of the redox sorption of oxygen is due to the equality of the rates of oxidation and reduction of the metallic component of the composite.

The thermodynamic characteristics of adsorption (TCA) of aniline, cyclohexylamine, and some of their derivatives on surfaces of graphitized thermal carbon black (GTC) are experimentally determined under conditions of gas-adsorption chromatography. It is concluded that the TCA values for the studied compounds depend to a large extent on the features of the geometrical and electronic structure of molecules in the gas phase. The effect of the sp3-sp2-rehybridization of nitrogen atoms upon moving from molecules of unsubstituted aniline to N-methyl- and N,N-dimethylanilines are determined, along with the ortho-effects in 2-methyland 2,6-dimethylanilines on the TCA values. It is shown that the above intramolecular effects result in nonadditive contributions to the energy of adsorption of the NH2-group in the a number of the studied compounds. Values of the thermal component of adsorption entropy are calculated, allowing conclusions on the physical state of the molecules of the studied compounds in the field of GTC adsorption forces. The mobility of adsorbate molecules is estimated using models of delocalized and localized adsorption. It is shown that in the series of ortho-meta-para-substituted anilines, the para-isomer is characterized by the highest values of retention on GTC, while the relative order of ortho- and meta-isomer elution is determined by the Van der Waals sizes of substituents in aromatic rings. A conclusion is reached on the high structural selectivity of a GTC surface in respect to positional isomers in the series of studied aniline derivatives.

We have studied the redox sorption of oxygen from flowing distilled water in a multistage sorptionmembrane cell with a metal (Cu)–sulfo cation exchanger (KU-23 in the H+ form) granular nanocomposite in the cathode compartment and a sulfo cation exchanger (KU-23 in the H+ form) in the anode compartments separated by a cation-exchange membrane (MC-40 in the H+ form). It is shown that the redox sorption of oxygen on the granular nanocomposite bed polarized with a current which is less than the limiting external diffusion one is complicated by internal steps (oxygen diffusion in the polymer matrix pores and the chemical oxidation of metal nanoparticles) and proceeds with a mixed diffusion-kinetic control. In the mode of limiting diffusion current polarization, the contribution of internal stages decreases and the process becomes steady due to the transition into the external diffusion region. A theoretical calculation shows that the process performed in series-connected multistage cells with polarization of each stage in the mode of limiting external diffusion current allows obtaining water with a dissolved oxygen content of

The kinetics of the electroreduction of oxygen in the diffusion mode on single granules of nanocomposites consisting of dispersed particles of the metal (Au, Cu) of the nanometer size and macroporous sulfonic cation-exchanger matrix KU-23 is studied. No noticeable effect of the factors of size of the metal component and ion exchange over the matrix on the external diffusion current of oxygen reduction is observed. The drop in current observed in a number of cases is due to a transition to the mixed external and internal kinetics as a result of the macroporous structure of the matrix and the chemical activity of nanoparticles of the metal component.

The relationships between different manifestations of solar and geomagnetic activity and the structural peculiarities of the dynamics of the pole wobble and irregularities in the Earth’s rotation are studied using singular spectrum analysis. There are two close major peaks and several lower ones in the same frequency range (1.1–1.3 years) in the Chandler wobble (CW) spectrum. Components in the geomagnetic activity were distinguished in the same frequency band (by the Dst and Ap indices). Six- to seven-year oscillations in the Earth’s rotation rate with a complex dynamics of amplitude variations are shown in variations in geomagnetic activity. It is revealed that secular (decade) variations in the Earth’s rotation rate on average repeat global variations in the secular trend of the Earth’s geomagnetic field with a delay of eight years during the whole observation period.

The VMEbased data acquisition system designed for physics experiments involving measure� ments of several hundreds of parameters is described. The equipment has been tested in the experiments with the 6 He, 8 He, 18 Ne, and 27 S beams at the ACCULINNA fragment separator (http://aculina.jinr.ru/) in the energy range of 20-35 MeV/nucleon. The system is composed of the RIO�3 processor module, which is used to read the VME bus, communicate with the CAMAC and FASTBUS crates, and transmit data to the per� sonal computer; the TRIVA�5 master trigger module; st andard analogtodigital, chargetodigital, and timetodigital converters from CAEN (V785, V792 , and V775 models); and related software. This data acquisition system is faster (by a factor of 10) than a CAMACbased system and is capable of operating with new types of electronic modules, e.g., with digitizers.

The redox sorption of molecular oxygen from a flow of deionized water onto a cathode-polarized granular layer of nanocomposite copper-ion exchanger is considered. A mathematical description of it in terms of external diffusion is given. In contrast to better-known approaches, conditions are created that are as close as possible to the limiting diffusion current; this effect can be achieved by dividing the granular layer into shallow layers, each of which is then polarized with a near-limiting current. This allows water to be obtained with a particular value of deoxygenation close to the theoretically calculated value in stationary sorption membrane electrolyzers equipped with a unit containing a nanocomposite copper-ion exchanger. It is established that the lower deoxygenation value relative to the one calculated from the limiting current is associated with the additional reduction of oxygen with copper nanoparticles.

The kinetics of the reduction of oxygen on a granular copper-containing electron-ion exchanger, or a nanocomposite consisting of an ion-exchanging resin matrix and a nanodispersed copper bulk distributed in it, used for the deep removal of oxygen from water and gases, is investigated. It is established that reduction of oxygen with the cathodically polarized nanocomposite proceeds in two stages: external diffusion and internal diffusion. It is shown that the external diffusion transfer of oxygen is maintained by the electric current of the cathodic direction. Its contribution is prevalent under conditions of the localization of copper nanoparticles on a grain’s surface. It is established that the limiting current corresponds to the reduction rate of oxygen. It is noted that during the bulk distribution of copper nanoparticles in the grain pores, the contribution of the stage of the internal diffusion transfer of oxygen increases. It is shown that oxygen reduction rate exceeds the limiting external-diffusion current. The joint occurrence of both stages ensures a generally high oxygen reduction rate.

The formation of copper nanoparticles in a KU-23 15/100 sulfocation-exchanger was studied. It was demonstrated that the formation of copper as assemblies from nanoparticles with sizes of 3 to 10 nm during chemical synthesis is determined by the nature of the polymer and does not depend on the amount of metal precipitated. The percolation threshold of electron conductivity, which determines the formation of electrochemical activity of nanocomposites, was discovered. It was determined that the electroreduction of molecular oxygen takes place on the surface and in the subsurface zone of a nanocomposite grain, the size of which is determined by the local concentration of metal particles in the ion-exchanger phase.

The optical absorption and nuclear magnetic resonance spectra of Li4 − xCr3xTi5 − 2xO12 (x = 0, 0.01, 0.02, 0.04) solid solutions have been investigated. It has been found that, in the Li4Ti5O12 spinel, lithium ions migrate from tetrahedral to octahedral positions with increasing temperature. Doping of chromium to the spinel favors an increase in the fraction of tetrahedrally coordinated lithium and hinders diffusion.

The so-called Markowitz wobble (MW) is a quasi-harmonic variation of the mean pole of the Earth with a period of about 30 years and an amplitude of 0.02''-0.03''. In turn, the North Atlantic Oscillation (NAO), which is characterized by large-scale phenomena in the system of atmosphere-ocean processes in this region, shows variations of some meteorological parameters in a wide frequency range. Synchronous oscillations of the pole (MW) and the NAO indices are revealed in the present study. The possibility of geophysical excitation of MW oscillations by variations of pressure fields in the North Atlantic is investigated as well.

The possibility of using single-sided photon injection to reconstruct a tested object structure on the basis of the intensity of backscattered noncollimated radiation is considered. The reconstruction algorithm is based on statistical simulation of the interaction between radiation and a homogenous object, whose geornetry is adequate for that or the tested object. The results of reconstruction are discussed.

The existence region of the ternary solid solution in the Bi-Sb-As system is studied using DTA, X-ray powder diffraction, and thermodynamic calculations. The alloys of this system have positive nonideality, which is mainly due to the elastic component of the enthalpy of mixing. The nonideality increases as the antimony concentration in the sample decreases, and finally brings about the instability and decay of the solid solution. It is shown experimentally that complete miscibility is observed at high antimony concentrations, when the antimony atom fraction is higher than or equal to 0.75–0.80.

To investigate 5H resonance states with a better instrumental resolution, we utilized the two-neutron transfer reaction 3H(t, p)5H accomplished with the use of a cryogenic liquid-tritium target and 57.5-MeV triton beam. As a result of this study, a valuable fraction of protons detected at θlab = 18°-32° in ptn coincidence events was attributed to the states of the 5H nucleus. Two resonance states situated at 1.8 plusmn; 0.1 and 2.7 ± 0.1 MeV above the t + n + n decay threshold were obtained in the missing mass energy spectrum of the 5H nucleus. The peak located close to E5H = 1.8 MeV was clearly seen in the H spectrum obtained from the energy distributions of 3H nuclei emitted in the reaction 2H(6He, 5H)3He at θ lab = 17°-32°. The width (Γobs ≤ 0.5 MeV) obtained for the two 5H resonance states is surprisingly small. A state of 4H with Eres = 3.3 MeV and γ2 = 2.3 MeV was obtained in the reaction 2H(t, p)4H from the spectra of protons leaving the target at θlab = 18°-32° and detected in coincidence with neutrons emitted in the decay of 4H nuclei. © 2003 MAIK "Nauka/Interperiodica".

Within the past twelve years, the recoil separator VASSILISSA has been used for the investigations of evaporation residues produced in heavy-ion-induced complete fusion reactions. In the course of the experimental work, fourteen new isotopes have been identified by the parent-daughter correlations in the region of elements with 92≤Z≤94. The study of the decay properties and formation cross sections of the isotopes of elements 110, 112, and 114 was performed using high-intensity 48Ca beams and 232Th, 238U, and 242Pu targets. At the beam energies corresponding to the calculated cross-section maxima of the 3n evaporation channels, the isotopes 277110, 283112, and 287114 were produced and identified. For further experiments aimed at the synthesis of the superheavy element isotopes (Z≥110) with the use of intensive 48Ca extracted beams, improvements in the ion optical system of the separator and the focal plane detector system have been made.

The neutron-transfer reaction d(6He, p)7He is investigated. The data obtained show that, in the range between 1 and 7 MeV above its ground-state resonance, 7He does not have well-pronounced narrow excited states with a single-particle structure. A resonance state of 5H with an energy of 2 MeV above the n+n+3H decay threshold is obtained for the first time by making use of the reaction p(6He, 2He)5H.